Bio Mock Review

use of Cairns' technique

-Cairns used it to identify that prokaryotes have circular DNA that is very condensed (1,100micrometers in 2 micrometers wide e. coli cell) -used by others to investigate eukaryotic chromosomes and determine they are linear and much longer

prophase 1

-DNA condenses into chromosomes becoming visible -nuclear membrane starts to breaks down -spindle fibers start to form from the centrioles that migrate to opposite poles of the cell -homologues pair up forming bivalents -crossing over occurs

n

# of chromosomes in haploid cell of certain species 2n = diploid

DNA vs RNA

# of strands: RNA = 1, DNA = 2 Nitrogen bases: RNA = Uracil, DNA = thymine pentose sugar: RNA = ribose, DNA = deoxyribose Length: RNA = short (1 gene), DNA = long (100s-1000s of genes) Purpose: RNA = protein synthesis and gene expression DNA = store, copy, transmit genetic info + reproduction

action spectrum

% of light of a certain wavelength that is used in photosynthesis showing range of light within which photosynthesis takes place peaks at red and blue some green bc although chlorophyll doesn't absorb it, accessory photosynthetic pigments do

details of stomata opening + closing

- certain wavelength of light (blue light) activates potassium pump causing high potassium concentration inside the guard cells (triggered by light so occurs during the day when photosynthesis rates peak) -water enters the guard cells by osmosis due to the high solute concentration -osmosis into the cell increases the turgor pressure (water pushing against the cell wall) causing the cells to bulge which opens the stomata -hormone abscisic acid causes potassium ions to diffuse out of the cell causing water to leave too so guard cells become flaccid again, closing the stomata

cons of GMO crops

- herbicide or pesticide resistance may spread to natural populations causing invasive plant species - pests may become resistant to pesticides -may kill/harm other organisms unintentionally e.g. monarch butterflies and bt corn -reduced biodiversity

eukaryotic cells

- larger + complex structure - membrane-bound organelles + nucleus (compartmentalization) - DNA in nucleus = linear DNA strands wrapped around histone proteins -Plantae (cellulose), Animalia (no cell wall), Fungi (chitin), and Protista (depends) drawing: plasma membrane, cell wall (plant only), cytoplasm, 80S ribosomes, nucleus, mitochondria, other organelles

causes of infertile couples

- low sperm count - impotence / ED - blocked fallopian tubes - abnormal female ovulation

auxin in positive phototropism

- phototropins (pigments) detect intensity of blue light triggering active transport of auxin in the stem -auxin is redistributed from the light to the dark side through auxin efflux pumps that move it from cytoplasm to cell wall -concentration of auxin in intercellular space is increased, it binds to proton to balance its negative charge so can now diffuse along concentration gradient into adjacent cells to the dark side -in new cell it releases the proton so becomes trapped again by negative charge -auxin binds to receptor on nucleus causing transcription of specific genes that activates a proton pump -protons pumped into the cell wall cause a drop in pH (acidification) which breaks H-bonds in cellulose allowing the wall to elongate

evidence proving Dawson-Danielli model wrong

- proteins = amphipathic so wouldn't form layer on the surface bc hydrophobic parts need to be transmembrane - antibody tagging reveals that proteins are mobile within the membrane/membrane fluidity - freeze factoring splits phospholipid layer proving membranes have transmembrane proteins (not just on outer surface)

metaphase 2

- sister chromatids line up at the equator by random orientation -spindle fibers extend and attach to chromosomes at the centromere

small pox vaccine

-1796 : first disease for which human vaccine was tested: Edward Jenner deliberately infected 8 year old child w/ cowpox (less virulent pathogen) to make him immune to smallpox virus (deadly) which has similar antibodies -unethical bc no informed consent since no knowledge of possible risks (i.e. harmful side-effects) -1960s-70s: first human infectious disease that was eradicated by vaccination due to WHO worldwide vaccination program -last case of the disease ever in 1977

DNA molecule structure

-2 antiparallel DNA strands (one in the 5' to 3' and one in the 3' to 5' direction) forming double helix held together by hydrogen bonds b/w the complementary base pairs in the center -pentose-phosphate backbone on the outside held together by phosphodiester (covalent) bonds

jet lag and melatonin

when the period of light/darkness is altered or irregular the production of melatonin is irregular so the natural rhythm is altered - caused by : jet lag, poor sleeping schedule, night shifts, etc. can be treated by orally consuming melatonin at the time when sleep should be induced

continuous variation

when there are several possible intermediate phenotypes due to multiple genes affecting a trait which creates a bell-shaped distribution curve of the phenotypes due to the smooth transition b/w groups e.g height

when + where does DNA replication occur

when: in S phase of cell cycle b/w G1 and G2 where: eukaryotes = inside the nucleus (linear DNA = multiple replication bubbles) prokaryotes = in cytoplasm (circular DNA = 1 replication bubble so slower)

factors that affect transpiration rate

wind speed, humidity, temperature

meiosis drawing

with annotations

plant adaptations for water conservation in deserts

xerophytes: ex. cacti -thick waxy cuticle -CAM physiology = open stomata at night bc less hot so less evaporation - small leaves or spines to reduce SA. -roll up leaves -hairs on leaves to maintain humidity near stomata -few stomata + in pits to maintain high humidity outside stomata so that water won't diffuse out -vertical stems so only do photosynthesis early or late in the day when temp. is lower so less H2O evaporates

movement of water from roots to leaves

xylem tubes transport water and minerals from roots to leaves through cohesion/adhesion tension: -water in xylem tubes forms continuous water column countering gravity as they adhere to cellulose in the xylem walls and cohere to each other -during transpiration water moves out of high concentration/humid leaves to low concentration/low humidity air out of the leaf - the departing water molecules pull up the entire water column due to cohesion b/w all the molecules (tension force) from leaves to roots -water is pulled from roots to xylem and from xylem to leaves forming a continuous flow/water column

xylem vs phloem

xylem: -dead cells -one way -hollow + no end walls b/w cells = continuous tube -lignified walls = support plant phloem: -alive cells -bi-directional -sieve plates b/w cells = not continuous tube -no plant support

autotrophs

-Organisms that synthesize their own food/carbon compounds they need to live using CO2, water, and inorganic nutrients from the abiotic environment -obtain energy from the sun or chemicals and convert it to chemical energy stored in bonds also called producers bc the compounds they create + the organisms themselves are consumed by heterotrophs for nutrition ex. plants, algae, extremophile bacteria

Sex-linked allele formatting

-Write X or Y to define chromosomes+sex -Write capital or lowercase letter for the gene as a superscript -if gene isn't on the Y chromosome then just write Y with no superscript Ex: XA vs. Xa vs Y

other factors influencing global temperature (don't rly need to know)

-aerosols blocking sunlight (ex. volcanoes or wildfires) -quantity of radiation from the sun -ocean current oscillations -Earth's orbit and inclination

cell theory

-all organisms are composed of one or more cells -cells are the smallest unit of life -all cells form from pre-existing cells

measuring phloem transport rates experiment

-aphids are insects w/ stylets to pierce sieve tubes and feed on sap -the aphid is cut off leaving just the narrow tube from which sap continues to emerge -supplying radioactive CO2 (only possible when these became available in 1940s) to the leaf forms radioactive sucrose whose progress can be tracked in the phloem over time to calculate the transport rate

challenges to species definition

-asexually reproducing organisms don't "interbreed" -populations that could interbreed but are reproductively isolated so don't actually breed -infertile individuals -hybrids

transfer RNA structure

-base pairing + H-bonds in 4 diff. places within the same single strand causes it to bend into 3 loops forming 3D structure -on 3' end an amino acid is bonded -center loop contains a series of 3 bases pairs (anticodon) that corresponds to the amino acid attached to the molecule

metaphase 1

-bivalents line up at the cell's equator by random orientation -spindle fibers extend from the centrioles at opposite poles of the cell and attach to centromeres of each chromosome

carbon sinks in the cycle

-carbon compounds in producers -carbon compounds in consumers -carbon compounds in decomposers -carbon dioxide in the atmosphere and water -fossil fuels (coal, peat, oil, gas) -limestone

DNA purpose

-carries genetic code for storage, copying (self-replication), and transmittance (makes RNA for protein synthesis)

plant hormones

-chemical messengers in plants that control various functions/trigger responses by binding to target cells -produced in small amounts and various locations -have varying effects depending on part of plant -move through phloem and cell to cell (don't stay close to source) ex. auxin promotes growth in the shoot apical meristem, in seeds, fruits, flowers, etc. by changing the pattern of gene expression

gene expression and the environment

-chemical signals moderate protein levels so control gene expression through transcription factors and regulator proteins according to environmental conditions examples: -hydrangea flowers change colors based on pH of soil -humans produce skin pigment melanin depending on sun exposure -certain species can change genders

telophase 2

-chromosomes untangle into chromatin -nuclear membrane starts to reform -spindle fibers break down -cytokinesis occurs splitting the 2 haploid daughter cells into 4 genetically different haploid daughter cells

phloem on micrograph

-companion cells are smaller and darker -sieve tubes have visible plate separating the cells

hydrostatic pressure gradients in phloem

-companion cells load solutes into sieve tubes at the source increasing the concentration which causes osmosis of water into the cells from the xylem -water is incompressible so high water concentration causes hydrostatic pressure to push the sap/solutes up or down the tubes to the sink following pressure gradient -at sink solutes are unloaded so water leaves (back into xylem) by osmosis reducing the hydrostatic pressure

experiment for seed germination factors

-control group w/ seeds that have all necessary factors -experimental group given all factors except for one so if they germinate the eliminated factor must not be essential

Pasteur's experiment

-control: broth in unsterilized flasks grows microorganisms -experiment: sterilized nutritious broth to kill all microorganisms present + placed broth in flasks sealed completely = no growth opened to air/contaminants = growth conclusion: bacterial growth occurs due to external contaminants not spontaneous growth

genetic variation in sexual reproduction

-crossing over -random orientation -fusion of gametes

use of karyograms

-deducing the sex of an individual based on sex chromosomes: XX = female, XY = male -diagnosing conditions caused by chromosome abnormalities = extra or missing chromosome in a pair e.g. down syndrome = 3 copies of chromosome 21 (see image)

repolarization

-depolarization / potential reversal opens potassium channels allowing them to passively diffuse out of the cell along gradient -movement of positive charge out makes inside negative relative to the outside (-80mV) so potential is re-established/repolarized -concentration gradient of resting potential still needs to be re-established

osmoregulation in loop of Henle

-descends into medulla -descending part is permeable to water and impermeable to ions so some water enters medulla through osmosis -ascending part is permeable to ions and impermeable to water so ions pumped into medulla by active transport creating high concentration / hypertonic medulla relative to hypotonic filtrate in the distal convoluted tube -animals that need to reabsorb more water have longer loop of Henle to establish greater solute gradient b/w filtrate and medulla

William Harvey (17th century)

-disproves Aristotle's theory that males produce a seed that forms an egg when it mixes w/ menstrual blood -deer are seasonal breeders (only sexually active in fall) so he slaughtered and dissected female deers after the mating season and found that nothing grew until 2 months after the season -concludes offspring aren't result of mating but also disproves spontaneous generation - was limited by the fact that gametes and fertilization and embryos are too small to see w/o a microscope that wasn't invented at the time

sex determination

-during fertilization a male and female gamete fuse together forming a zygote with half its chromosomes from each parent - 100% of female gametes contain an X chromosome but 50% of male gametes contain a Y chromosome so the male gamete determines the sex of the zygote -embryonic gonads (tissue) form that can either develop into testes or ovaries - if the fetus contains a Y chromosome, the SRY gene on it causes the embryonic gonads to form testes that secrete testosterone resulting in primary sex characteristics -if the fetus doesn't contain a Y chromosome the SRY gene isn't present so the embryonic gonads develop into ovaries, estrogen levels go up resulting in primary sex characteristics, and pre-natal development occurs (oogenesis)

internal fertilization

-egg and sperm come together inside the fallopian tubes - much higher success rate so less gametes produced - requires intercourse - results in the egg being laid or growing inside the female - more parental care of the offspring -done by: birds, reptiles, mammals

external fertilization

-egg and sperm come together outside the body --> female lays eggs and males spray sperm over the eggs -many gametes produced bc many will die -no parental care of offspring --> even more die -done by: amphibians, fish, etc

skeletal muscle cells/fibers

-elongated shape -multiple nuclei - plasma membrane = sarcolemma that has tunnel extensions penetrating into cells (T tubules) - cytoplasm = sarcoplasm - glycogen storing organelles for glucose/energy reserve - myoglobin molecules store O2 for aerobic respiration -myofibrils = several cylindrical structures running parallel to each other, made of repeating sarcomeres forming dark and light band pattern (striated muscle) -sarcoplasmic reticulum = specialized ER surrounding myofibrils -many mitochondria b/w myofibrils for ATP

effect of humidity on transpiration rate

-enclose shoot in plastic bag and increase relative humidity of outside air using mist sprayer -use an electronic hygrometer to measure the relative humidity -water diffuses out of leaf when low humidity outside bc goes along concentration gradient

arguments to support that human activities cause climate change

-evidence of temp. rise since industrial revolution -predictions of extreme weather, record temps, receding ice are being confirmed -general contentious w/in scientific community - aerosols produced by human activities may diffuse light which can cancel out some predicted warming -the speed and magnitude of CO2 and temp. rises are unprecedented so historical fluctuations aren't comparable -the sun being in an high-energy output phase has a minor effect on temp.

selective reabsorption

-filtrate from Bowman's capsule enters proximal convoluted tube -contains substances that the body needs so must be reabsorbed into peritubular capillary bed that surrounds tubes -tubes lined with 1 cell thick layer w/ microvilli to maximize SA for absorption -100% of glucose reabsorbed first through facilitated diffusion then active transport when gradient lost -80% of salt ions actively transported by pumps -water moves by osmosis following ion concentration gradient (hypo to hypertonic)

water re-absorption

-filtrate that enters differentially permeable collecting duct from distal convoluted tubule is very dilute so some of the water needs to be reabsorbed to reduce loss -antidiuretic hormone (ADH) is produced in pituitary glands and target collecting ducts to make them permeable to water allowing some water to move into hypertonic medulla by osmosis to be reabsorbed into the blood stream making urine less dilute -if ADH not present then collecting ducts are impermeable to water so it is eliminated in very dilute urine -amount of water lost depends on: perspiration rate, volume ingested, ventilation, diet, exercise, etc.

deciphering a locus

-first # = which chromosome gene is on -letter = short arm (p=petite) or long arm (q) -last numbers = section, subsection, sub-subsection (sections increase from the centromere on both arms)

types of ribosomes

-free ribosomes in cytoplasm produce proteins for use w/in the cell -ER bound ribosomes produce proteins to be secreted from the cell or used in lysosomes

fungal hyphae action in roots

-fungi grow around and into root cells -decompose nutrients returning minerals to the soil or into the cells for the plant to use

production of human insulin in bacteria

-gene that codes for insulin protein is transferred from humans to E. coli bacterium and other organisms to produce insulin for diabetic patients -due to the universality of the genetic code codons code for the same amino acids in all species and hence E. coli are able to produce the exact same amino acid sequence as human insulin from the transferred gene

Purpose of micropropagation

-growing new varieties in bulk -virus-free strains of existing varieties -growing rare plants for market or endangered species (ex. orchids)

therapeutic cloning applications

-growing skin for severe burns - growing heart muscle or new kidneys for failing organs - growing pancreatic cells that produce insulin for diabetic patients

penis

-has erectile tissue that becomes hard and enlarged due to blood engorgement allowing vaginal penetration and ejaculation of sperm near the cervix -also the urinary elimination organ

properties of phospholipid bilayer

-held together by weak hydrophobic interactions b/w hydrocarbons= fluid + flexible -hydrophilic + phobic layers make it selectively permeable (restrict passage of many substances) -phospholipids can move within membrane allowing for endo and exocytosis of waste and nutrients

uric acid

-highly energy intensive -insoluble + non-toxic so doesn't require water to excrete (excreted as thick paste/bird poop) -used by birds and insects or arid animals bc less water needed so have smaller body mass to be able to fly and non-toxic so can be stored in self-contained eggs before hatching

Human Genome Project use

-identify loci for genetic diseases = improve diagnosis -genetic engineering to produce drugs from beneficial genes -assess risk of carcinogens in causing cancer -studying evolution and migration through alleles/mutations -forensic identification + paternity/maternity test

active transport of ions into roots

-if ion concentration in root is greater then cannot diffuse along gradient -also ions cannot pass cell membrane due to charge -ion specific transport proteins pump/carry ions into the cell using ATP (ex. potassium channels) -very hypertonic root so high amounts of water absorbed by osmosis

auxin in negative phototropism/gravitropism

-in roots dense organelles called statholiths accumulate at the bottom of the cell indicating direction of gravity -auxin moves to the bottom of cells and inhibits cell growth (opposite of in shoots) -top part of cells continue growing so root bends downward away from light/in direction of gravity

Malpighian tubules

-insects have an open circulatory system so hemolymph (blood) isn't contained in vessels but in large cavities that organs bathe in -malpighian tubules: closed distal end extends into hemolymph cavities and open proximal end empties into the gut -molecules such as salt ions, uric acid and water are absorbed into the distal end of the tubules -useful substances are transported back into the blood cavity but waste such as uric acid moves to proximal end and is emptied into the gut where it is excreted along w/ feces

photoperiodism

-length of night determines when flowers bloom to ensure proper pollinators are available: long vs short day plants -phytochromes are leaf pigments that exist as active (Pfr) or inactive (Pr) -Pr is activated into Pfr when it absorbs red light (660nm) during the day -Pfr turns back into Pr when it absorbs far red light (730 nm) or in darkness -levels of Pfr rise quickly during the day but conversion back to Pr takes a lot longer at night w/o sun energy -so plants can tell how long nights are by the amount of Pfr that's converted back to Pr (long nights = high Pr levels, short nights = high Pfr levels)

transpiration

-loss of water vapor from plants through stomata in the leaves -results from gas exchange of photosynthesis reactants (CO2) and products (O2)

use of anaerobic respiration

-low oxygen environments or supply (swamps) -quick energy burst during exercise

small intestine layers

-lumen -epithelium (1 cell thick inner lining) -mucosa forms villi -submucosa -circular muscles (perpendicular) -longitudinal muscles (parallel)

ribosome structure

-made of proteins and ribosomal RNA that form a large and a small sub-unit -small subunit has binding site for mRNA -large subunit has 3 binding sites (A,P,E) for tRNA -polypeptide channel for growing chain to pass through in the large subunit free floating or attached to ER

phloem structure

-made sieve tubes and companion cells that are alive -sieve tubes: connected cells w/ no organelles but don't form continuous tube bc perforated sieve plates separate cells but allow for fluid to pass b/w them -companion cells: support sieve tubes and load/unload products into tube

advantages of lactose-free milk

-may be consumed by lactose intolerance ppl -glucose+galactose doesn't crystallize during ice cream production so smoother texture -bacteria ferment glucose+galactose faster so yoghurt and cheese made faster -glucose+galactose are sweeter than lactose so need to add less sweetener

xylem water transport models

-moves up cellulose filter paper bc adheres to cellulose so pulled up through pores -capillary tubes: water moves up bc adheres to glass -porous pot: water evaporates from pot surface causing water to rise through the tube from the bottom

plant + pollinator relationship

-mutualistic relationship bc animals (insects, hummingbirds, bats) get food in the form of nectar on the stigma or pollen, while plants have their pollen (male gamete) dispersed to other flowers -most plant species have a specific pollinator species to ensure that the it transfers pollen to flowers of the same species and not other species -makes it essential to protect entire ecosystems not just individual species

energy loss through other mechanisms

-not all of an organism is swallowed -not all swallowed parts can be digested (ex. cellulose, hair, bones, seeds) -organisms die w/o being eaten -biomass lost as waste products of metabolism (CO2 from cell respiration, urea)

drawing a DNA molecule checklist

-nucleotide -phosphate group -pentose sugar -nitrogen base -phosphodiester bonds -pentose-phosphate backbone -hydrogen bonds -antiparallel (5' and 3' ends on each strand)

comparing gene counts

-number of genes is characteristic of a species -basic organisms may have larger genomes than complex ones -total # of genes for humans isn't yet known precisely but around 23,000 -bacteria have fewer genes than eukaryotic cells

hybrids

-offspring produced by breeding of 2 different species -are infertile so only 1 generation = challenge for population to survive -parents don't have matching # of chromosomes so the offspring is infertile examples: liger, mule, zorse

prokaryotic cells

-oldest cells -small + simple structure + unicellular -no compartmentalization (no nucleus or organelles) - naked circular chromosome + DNA plasmids -divide through binary fission -archaebacteria + eubacteria drawing: cell wall, pili and flagella, plasma membrane, cytoplasm, 70S ribosomes, nucleoid of naked DNA (no membrane or proteins attached)

detecting linked inheritance

-only get offspring that are identical to the parents -get very very few recombinant offspring with new combinations of traits (not parental ones due to crossing over) -get any ratio besides Mendelian ones - sex-linked (only males or females affected)

conditions for germination

-oxygen for aerobic respiration - water for metabolic activation - temp. for optimal enzyme function - soil pH for optimal enzyme function

DNA profiling uses

-paternity testing to identify parent of a child -forensics to match crime scene DNA to a suspect - ecology to compare different species and identify evolutionary or migrational relationships/patterns

carbon fluxes in the cycle

-photosynthesis (-120gt): atm+water to producers -feeding: producers to consumers, consumers to consumers -cell respiration (+119.6gt): producers, consumers, decomposers to atm or water -death/excretion: consumers+producers to decomposers -incomplete decomposition and fossilization: producers +consumers to fossil fuels and limestone -combustion (+8 gt): fossil fuels and producers to atm. -dissolving: atm CO2 uptake into or loss from water (+/- 90 gt), limestone into atm by acid rain -methanogenesis + methane oxidation: decomposers to atm, atm to atm

roles of auxin

-phototropism: shoot and root elongation + movement -primary growth through cell division and elongation -promotes apical dominance = no lateral buds so vertical elongation other : -regulates fruit development -promotes vascular differentiation

manipulating flowering

-plants can be triggered to flower by using artificial light or blinds in order to fake a long or short period of darkness, interrupt or induce critical darkness length -critical length of uninterrupted darkness triggers flowering in short day plants (ex. chrysanthemums=15 hrs): if long night interrupted by flash of light then won't flower bc darkness isn't continuous -in long day plants: if darkness period is interrupted w/ flash of light then will bloom bc thinks the night was short

PCR

-polymerase chain reaction is used to artificially make millions of copies of a desired gene (short DNA segments only) for gene technology, gene transfer, and forensic analysis -uses DNA polymerase from Thermus aquaticus bacterium (Taq) which lives in hot springs and hence whose enzymes are active at very high temperatures -artificial replication occurs in eppendorf tubes at high temperatures to speed up the reaction -doubles the quantity of copies every cycle

skeleton

-provide support -points for muscle attachment: one end of bone is anchorage that doesn't move, when muscles contract the opposite end of the bone moves along with surrounding tissue acting as lever bc changes size and direction of force exerted by muscles exoskeleton in arthropods (insects) - on the outside + made of chitin endoskeleton in vertebrates -inside made of bones

roles of shoot apex

-rapid mitosis and differentiation for leaf and flower growth -produces auxin for phototropism and primary growth (cell elongation) -contains pigments that detect light for phototropism (phototropins)

blood typing

-red blood cells aren't nucleated so don't have MHC genes / self-markers found on all body cells meaning they can be transfused b/w individuals do have some antigenic markers: -rhesus type (rH protein): if present = + , if not present = - blood type -ABO type (A and B proteins): if A present = A type, B present = B type, A and B present = AB type, neither present = O type individuals create antibodies against the A or B protein depending on which blood type they have making blood transfusions difficult: -A produce B antibodies -B produce A antibodies -AB produce no antibodies = universal recipient -O produce both antibodies = universal donor

therapeutic use of stem cells

-regenerating tissues (burn victims) -replace malfunctioning or damaged cells lost by degenerative conditions (Stargardt's, Parkinson's, Diabetes, leukemia) -grow replacement organs

pros of GMO crops

-remove undesirable trait - introduce herbicide or insecticide resistance -resistance to viruses -drought, saline, or cold tolerance - increased vitamin content -reduced allergens -pest resistant so you don't need to use as much pesticides

untreated diabetes symptoms

-retina damage - kidney failure - nerve damage - cardiovascular disease - poor wound healing

water uptake into roots

-roots are branched and have root hairs (small volume large SA) to maximize surface area for water and mineral intake -mineral ion concentration in the roots is made higher (hypertonic) than in the soil causing water to enter roots by osmosis -ion concentration increased through active transport/protein pumps, facilitated diffusion, or fungal hyphae action (decompose nutrients into cells and soil)

shoot apical meristem structure

-shoot apex -new leaves -axillary buds

# of chromosomes exceptions

-some individuals can be born w/ fewer or extra chromosomes -some cells don't contain a nucleus so don't contain chromosomes e.g. red blood cells are produced by bone marrow so don't need to undergo mitosis so don't need chromosomes/nuclei -possible for chromosomes to split or fuse during evolution of species but this is very rare

anaphase 2

-spindle fibers contract splitting the sister chromatids into 2 individual chromosomes by splitting the centromere and pulling them to opposite poles of the cell + separating alleles/genotypes -due to random orientation, any combination of allele could be pulled to either side randomly

transpiration mechanisms

-spongy mesophyll at bottom of leaf has air spaces for gas exchange -water evaporates from the humid cell walls of mesophyll cells to the air spaces and hence try to diffuse out of the leaf due to the high humidity of the air spaces relative to the air outside the leaf -presence of waxy cuticle outside the leaf blocks water loss and gas exchange so need stomata to exit -guard cells absorb water which increases their turgor pressure causing them to bulge apart and open the stomata through which gases enter/exit and water vapor in the air space is released

natural plant clones

-strawberry plants can send out horizontal structures called runners that grow into identical plants a short distance away from the parent -potatoes are structures called tubers that can be planted to grow into clones of the parent plant -plants can also asexually produce bulbs that grow into clones lack of genetic diversity poses a risk bc 1 unfavorable environmental condition could wipe out the entire cloned population

activating tRNA

-tRNAs have variable 3D features and chemical properties due to different nucleotide sequences allowing tRNA activating enzymes to identify them - 20 diff. activating enzymes (1 per amino acid) binds correct amino acid to tRNA w/ corresponding anticodon activating the tRNA - active site is specific to tRNA and amino acid

telophase 1

-the spindle fibers disintegrate -the chromosomes uncoil into chromatin -the nuclear membrane starts to reform around each haploid daughter nuclei (contain 1/2 of a homologue pair so haploid but each chromosome still contains 2 sister chromatids so don't need DNA replication) -inter-cytokinesis occurs forming 2 intermediate daughter cells as cytoplasm splits

Hershey and Chase Experiment

-the structure of bacteriophage virus (T2) is viral DNA inside a protein coat: DNA contains phosphorus, protein coat contains sulfur 1) they cultured 2 strains of T2 one w/ DNA labelled w/ P-32 and one w/ protein coat labelled w/ S-35 (radioactive isotopes) 2) both strains are allowed to infect E. coli bacterium 3) mixture is agitated and centrifuged at high speed forming solid bacterial pellet in liquid supernatant then locate radioactivity using Geiger counter results: - in P-32 strain: 65% of radioactivity in the pellet - in S-35 strain: 20% of radioactivity in the pellet analysis: - virus injects its DNA into the bacterium which starts producing viral proteins so DNA must be genetic material - agitating mixture causes most protein coats to detach from surface of bacteria after DNA injection but some remain attached hence the small % of radioactivity in the pellet in the S-35 strain

villi structure

-thin 1 cell thick layer of epithelial cells w/ microvilli to increase SA even more and minimize diffusion distance -lacteal (type of lymph vessel) for large monomers -capillary bed for small monomers

structure of xylem vessels

-tracheids and vessel elements = form hollow continuous tube + dead cells -tracheids = taper at the ends and connect forming continuous column, pits allow for water to move b/w cells laterally -vessels = thick lignified (woody/strong to resist inward collapse and support plant) walls with perforated ends allowing water to move between them forming continuous vertical column

function of phloem

-transport organic materials (sugars and amino acids/hormones) from source to sink in both directions -materials are dissolved in viscous substance called sap

Reasons for the Davson-Danielli Model

-under electron microscopes w/ low resolution: dark layers of phosphate groups misidentified as protein layers other: - chemical analysis shows phospholipids + proteins - enough phospholipids to form area 2x as large as area of membrane so must have bilayer -membranes = selectively permeable + very thin so protein layer must act as barrier

effect of temperature on transpiration rate

-use a heat lamp to vary temp. and an infrared thermometer to measure leaf temp -as heat rises, more water evaporates from mesophyll cells so transpiration rate rises (measured using potometer) -in high temps stomata may close

effect of wind speed on transpiration rate

-use electric fan to generate air and measure velocity by changing rotation rate -use an anemometer to measure the speed of the moving air -low wind = humidity builds up so transpiration rate drops -high wind = reduce humidity so transpiration rate increases -at high wind speed stomata may close

ultrafiltration

-wide afferent arteriole branches off renal artery and feeds unfiltered blood into capillary bed called glomerulus located in Bowman's Capsule -blood edits glomerulus through efferent arteriole which has a narrower diameter than afferent creating high blood pressure (volume in > volume out) -high BP opens fenestrations (slits) in glomerulus walls allowing small molecules to filter into Bowman's capsule forming filtrate: blood cells and proteins too large water, glucose, salt ions (Cl-, K+, Na+), and N waste pass

identifying xylem + phloem from cross section micrograph (top view)

-xylem are big circles/open (hollow) vessels on the inside -phloem is small circles on the outside near epidermis in monocotyledons roots = form circles in dicotyledons roots = xylem forms an x at the center surrounded by phloem in monocotyledons stem = vascular tissues are scattered in dicotyledons stem = circle around the center of stem

immune response steps

1 - Immediate inflammatory response = innate / non-specific 2 - adaptive / specific = humoral (B cell activation) or cell-mediated (Cytotoxic T cells) 3 - memory cells / secondary response

stages of fertilization

1) Capacitation 2) Binding 3) Acrosome Rxn 4) Fusion 5) cortical rxn

DNA sequencing

1) DNA fragments copied through PCR 2) DNA is denatured into single strands by heating 3) DNA copies placed in 4 different test tubes containing primers, DNA polymerases and nucleotides for replication 4) each tube contains dideoxynucleotide for each base type (A,T, C, G) derived from dideoxyribonucleic acid which prevents any further nucleotides from being added to new strand once its added and therefore creates different lengths fragments 5) each tube is placed into a lane on electrophoresis gel labelled by which base dideoxynucleotide was added to it and electrophoresis is carried out 6) pattern of bands then used to determine sequence of base in the section

Gene transfer steps

1) DNA from donor is extracted by centrifuge and the gene of interest is cut out by restriction endonucleases and copied by PCR* 2) the vector is also isolated from the host and cut open using restriction enzymes * *if sticky ends don't form they can be added artificially 3) the gene of interest is binded to the vector DNA using complimentary base pairing of the sticky ends and enzyme DNA ligase to seal nicks which forms recombinant DNA 4) the vector is inserted into the host organism which starts producing the protein that the gene codes for 5) the host is placed in a bioreactor with ideal conditions to grow and replicate 6) the organisms are screened to isolate the ones in which the gene is successfully inserted 7) GMOs synthesize the desired protein/trait

DNA replication: Base-pairing

1) DNA polymerase III binds to RNA primers on leading and lagging strand on the leading strand: -binds to primer on the 3' end of the template strand and assembles free floating nucleotides into new strand using base pairing rules and parent strand as a template moving in 5' to 3' direction (on new strand being formed) towards helicase/replication fork located at the 5' end of the template strand on the lagging strand: -binds to a primer on 3' end of template strand near helicase and assembles free floating nucleotides into new strand using base pairing rules and parent strand as a template - moves in the 5' to 3' direction to the next primer away from helicase/replication fork forming several Okazaki fragments 2) polymerase 1 replaces RNA primers with DNA nucleotides but leaves a nick in sugar-phosphate backbone 3) ligase seals up nick by glueing together Okazaki fragments on lagging strand forming a single continuous strand 4) 2 new DNA molecules recoil into helix

DNA replication: unwinding

1) Enzyme DNA gyrase goes in front of helicase to relieve the tension that builds up due to supercoiling as strands are separated 2) Helicase enzyme unwinds double helix into 2 template strands by breaking hydrogen bonds b/w nitrogen bases opening replication bubble - various replication bubbles open along the molecule and move bi-directionally until they merge forming 2 separate molecules 3) single-stranded binding proteins attach to strands at the replication fork to keep replication bubble open for templates to be copied 4) DNA primase adds RNA primer (short RNA nucleotide sequence) which signals to DNA polymerase III where to attach -adds one primer on leading strand and multiple along lagging strand

follicular phase steps

1) FSH levels rise stimulating follicle development in the ovary (undergo meiosis 1 forming oocyte surrounded by 2 layers of follicle cells and follicular fluid) which stimulates estrogen secretion from the follicle ==> follicles compete and only the 1-2 that become dominant are released during ovulation 2) estrogen secretion increases FSH receptors in follicles causing an increased receptiveness to FSH which forms positive fb bc estrogen levels rise even more 3) estrogen causes thickening of endometrium (uterus lining) as it becomes highly vascular for implantation 4) when estrogen peaks it induces a blast of LH secretion and causes pituitary gland to stop producing FSH causing estrogen levels to decrease (negative fb)

menstrual cycle steps

1) Follicular Phase 2) Ovulation 3) Luteal phase 4) Menstruation

digestion process overview

1) Mouth: mechanical digestion (chewing) + chemical digestion (salivary glands secrete amylase to lubricate food and hydrolyze starch) 2) esophagus: peristalsis pushes food to stomach 3) stomach: mechanical churning, gastric glands secrete HCl to kill pathogens and protease enzymes to start protein digestion 4) small intestine: final digestion of all macromolecules + absorption of nutrients -liver secretes bile into the gallbladder that releases it through the same duct as pancreas. bile breaks apart lipids -pancreas secretes: amylase, lipase, endopeptidase -walls of small intestine secrete: nuclease, maltase, lactase, sucrase 5) large intestine: water gets reabsorbed, carbs further digested by symbiotic bacteria (no enzyme to digest cellulose), feces formation and storage 6) anus: releases feces

sliding filament theory

1) action potential reaches motor neuron at neuromuscular synapse sending acetylcholine that binds to receptors on sarcolemma of muscle cells transmitting the action potential to it 2) action potential movement through T tubules causes Ca ions to exit sarcoplasmic reticulum into sarcoplasm where it binds to troponin 3) troponin protein is binded to tropomyosin protein and when Ca binds to it, both filaments slide exposing binding sites for myosin on actin filaments (control muscle contraction) 4) myosin heads bind to sites on actin filaments forming cross-bridges then hydrolyze ATP into ADP + P group causing myosin head to change angles pulling binded actin fibers towards center of sarcomere 5) Z lines move towards each other so entire sarcomere shortens causing other sarcomeres to shorten contracting the whole muscle

implantation

1) blastocyst travels down the fallopian tubes and enters the uterus when it is 100 cells big on day 7 2) it sinks into the thickened uterine endometrium and villi from the trophoblast penetrate the lining to receive nutrients from the mother (beginning of placenta development) to keep growing into a fetus

drawing an energy pyramid

1) create scale by dividing largest value in order to create a length that fits w/in the designated box 2) calculate the length for the other energy values by dividing them by the scale 3) draw boxes starting at the bottom and in the middle then move up trophic levels making each box have the same height of 1-2 cm + are symmetrical 4) add pyramid title, include scale, and label trophic levels (producer, primary consumer, secondary, etc), can also label energy values per box

Meselson and Stahl Experiment

1) culture E. coli bacteria in medium w/ heavy N15 isotope so it becomes part of their DNA bases 2) transfer them to a less dense N14 medium 3) centrifuge DNA cultures from different generations of bacteria w/ Caesium ions creating a density gradient for the DNA molecules: DNA appears as dark bands results: -after one generation: the DNA band is in b/w N14 and N15 -after 2 generations: one band is in the middle and one is at N14 -in the following generations: the N14 band gets darker conclusion: DNA replication is semi-conservative bc intermediate band forms after one generation containing one heavy parent strand and a newly made lighter strand, since only 2 N15 parent strands exist the following generations become purely N14

gas exchange

1) deoxygenated blood from the pulmonary artery (right ventricle) enters capillary bed surrounding alveoli while oxygen rich air fills alveoli air space 2) concentration gradient causes CO2 to diffuse out into the air space while O2 dissolves in surfactant and diffuses into the bloodstream (cross 2 cells only: alveoli wall cell + capillary wall cell) 3) re-oxygenated blood leaves capillary bed into pulmonary veins to left atria + CO2 rich air is exhaled out of the lungs 5) lungs inhale O2 rich air so the process repeats

oil and gas formation

1) during the carboniferous era (past geological era), places that are dry today were underwater: the remains of marine organisms accumulated on the ocean floor where conditions were anaerobic so only partial decomposition occurred 2) sediment and silt accumulated on top of partially decomposed matter causing pressure and heat as organic matter moved deeper underground 3) over millions of years, these compressed hydrocarbons formed natural gas and oil which gets trapped in porous rocks forming deposits (trapped bc non-porous rocks above prevent them from rising) 4) the movement of tectonic plates can cause rocks to bend into domes forming pockets where oil and gas accumulate into a reservoir natural gas (mostly CH4) and crude oil are extracted and combusted as energy source

formation of blastocyst

1) fusion of the sperm with the egg triggers the egg to undergo meiosis 2 2) 2 haploid nuclei merge so cell becomes a diploid zygote 3) zygote undergoes mitosis repeatedly as it travels down the fallopian tubes forming a hollow ball of cells w/ an inner mass of cells (embryo) called a blastocyst egg has to be large to hold all the nutrients needed for the egg to divide during this phase

Cairns' technique

1) grow e. coli bacteria with thymidine (thymine nucleotide containing radioactive hydrogen isotope "tritium" = H3) to label the DNA for 2 generations 2) lyse open the cells using lysosome enzyme (digests cell wall) to let DNA spill out on a membrane 3) autoradiography: coat membrane w/ radioactive film and soak in a photographic emulsion (liquid) for 2 months in the dark to develop it 4) radioactive isotopes decay and radiation energy reacts w/ film to form dark dots indicating the DNA strand 5) observe film using an electron microscope to see cell structure and dots where each atom decayed

humoral immunity

1) helper T cells have antibody-like membrane proteins to receive antigen from phagocyte during presentation activating it 2) helper T cell takes antigen to specific B cell with corresponding antibody to activate it (bind to antibody on its surface) 3) B-cell grows and divides (clone) quickly into plasma and memory cells -plasma cells produce and release specific antibodies that bind to antigens = tag + clump together pathogens for destruction (agglutination), block viral binding sites until destroyed -memory cells stay in blood stream in case of secondary infection = react faster + produce more antibodies to reduce symptoms

cell-mediated immunity

1) helper T cells receive antigen from phagocyte during presentation 2) helper T cells activate cytotoxic T-cells which divide into cytotoxic T cells and memory T cells 3) cytotoxic T cells bind to infected body cells and destroy them (prompt apoptosis or puncture cell membrane) -suppressor T cells keep cytotoxic cells in check to prevent autoimmune diseases/cytokine storm 4) memory T cells stay in blood for quick response upon secondary infection

peat formation

1) in bogs and swamps the soil is waterlogged and acidic so no decomposers survive bc of pH and anaerobic conditions (water pushes air out from b/w soil particles) 2) energy rich partially decomposed plant matter accumulates forming peat deposits over time that are high in hydrocarbons peat can be dried and burned as a fossil fuel

hybridoma cell creation

1) inject mouse w/ targeted antigen to stimulate immune response: plasma cells clone + produce specific targeted antibodies 2) harvest short-lived plasma cells from animal's spleen + cancerous myeloma cells from culture 3) mix plasma and myeloma cells in the same culture so they fuse into hybridoma cells that are antibody producing + grow and divide endlessly 4) separate + culture hybridoma cells individually in medium where non-hybrids don't survive to screen for impurities 5) keep culturing them and harvesting their antibodies which target only 1 specific antigen

path of air

1) into nose or mouth 2) down trachea 3) enters lungs through left and right primary bronchi 4) go down increasingly smaller bronchioles 5) at the end of bronchioles reach cluster of alveoli air sacs

coal formation

1) layers of peat and sediment accumulate over lower peat layers (partially decomposed plant matter) pushing them further and further underground (closer to warm center of Earth) 2) pressure and heat removes moisture from the peat and causes a chemical reactions that turns peat into coal (fossilization/lithification) coal is extracted and combusted as source of energy

limestone formation

1) marine organisms (mollusks and corals) absorb calcium ions and carbonate ions from the water to produce calcium carbonate for their shells and exoskeletons Ca+2 + CO3- --> CaCO3 (calcium carbonate) 2) when animals die their CaCO3 remains accumulate at the bottom of the ocean and undergo fossilization/lithification w/ sediment forming limestone rock 3) this process sequesters/locks up large amounts of carbon for extended period carbon is released from limestone as CO2 when it's used to make cement and it's released as HCO3 when it reacts w/ acid rain

measuring length of sarcomeres

1) measure distance b/w start of 10 dark bands on micrographs in millimeters 2) divide by 10 to find length of 1 dark band 3) multiply by 1000 to convert to micrometers 4) divide by magnification of microscope to find actual size can also use eyepiece w/ a scale but no units on it that is calibrated w/ units using stage micrometer slide depending on magnification level

using STR for DNA profiling

1) obtain DNA sample 2) use PCR to copy STRs from various loci (11-13 loci) 3) separate STR copies by gel electrophoresis bc of the diff # of repeats at each loci b/w individuals, the banding pattern formed will be different for everyone so it can be used to identify ppl or who they are related to by comparing band patterns

immediate inflammatory response

1) pathogen enters the body through cut or opening triggering second line of defense = non-specific and innate response 2) pathogen triggers white blood cells (basophil/mast cells) to release histamine granules (degranulate) dilating capillaries to increase blood flow + fluids in infected area -blood = carries heat to speed up response/ rxns - fluids = phagocytes to engulf pathogen (pus) -effect: area is red, inflamed, painful, warm -overall body fever caused by other chemicals 3) phagocytes engulf pathogens and partially digest them then present their antigens on their cell membrane to help T cells = antigen presentation

respirometer lab

1) place organism inside a sealed container attached to a pipette and containing an alkali that absorbs the CO2 produced by respiration (change in volume due to oxygen consumption as precipitate forms) 2)submerge respirometer in water to maintain constant temperature in order to avoid volume changes 3) as respiration occurs, the volume of air inside the container will decrease bc CO2 converted into a solid/precipitate so water pressure will push water into the pipette 4) the volume of water in the pipette matches the volume of oxygen consumed by the organism

Calvin's experiment

1) places algae (chlorella) in a round container with nutrient solution 2)places container in front of bright light and has tube of CO2 entering from the top, uses radioactive isomer Carbon 14 to track their progress in the cells 3) releases samples from the container at different intervals and kills the cells using methanol to capture the different stages of photosynthesis 4) uses paper chromatography in 2 directions (by flipping paper 90º and using 2 solvents) to spread the samples into their component chemicals by size 5) places photosensitive film (that's affected by radiation of C-14) over chromatography paper to identify the location of these atoms at different stages of the process 6) deduces that CO2 undergoes multiple transformation and forms different intermediate compounds before becoming glucose, takes 10 years to identify the name and composition of each one

birth

1) progesterone levels drop to allow for uterine contractions, high estrogen levels cause an increase in oxytocin receptors in the uterine muscles 2) oxytocin is released from the pituitary gland which cause the uterus to contract when they bind to the receptors 3) uterine contractions stimulates more oxytocin release forming a positive feedback loop that intensifies contractions 4) the cervix relaxes/dilates 5) amniotic sac bursts and releases amniotic fluid 6) after hours of increasing contractions the baby is pushed through the cervix and vagina 7) umbilical cord is cut and the placenta is expelled from the uterus

Translation: translocation

1) ribosome moves down 3 bases along mRNA towards 3' end (5' to 3' direction) moving tRNA in P to E site and tRNA carrying the growing chain in A site to the P site 2) tRNA in E site detaches into cytoplasm to reload amino acid 3) tRNA w/ anticodon for next codon on mRNA binds to A site and growing polypeptide chain is transferred to it as peptide bond forms b/w amino acids in P and A site 4) ribosome moves down to next codon and cycle repeats

translation: initiation

1) small subunit binds to 5' end of mRNA and moves to start codon AUG 2) initiator tRNA carrying methionine w/ anticodon (UAC) matching start codon (AUG) binds to mRNA forming H-bonds b/w codons 3) large subunit combines w/ small subunit forming initiation complex where initiator tRNA is in P site

steps for chi-square test

1) state null and alternative hypothesis (null = no association or no significant difference) 2) enter observed values in contingency table (# of quadrats that the organism is found in not the # of organisms) 3) calculate expected values for each box by multiplying: (row total x column total) / grand total 4) calculate chi squared value 5) calculate degrees of freedom: (# of rows-1) x (# of columns-1) and find critical value for significance lvl of 0.05 (5%) 6) accept the null if chi-squared value is less than (<) critical value

Leptin Mice Experiment

1) strain of obese mice discovered in the 1950s that were found to have 2 recessive alleles (ob) for leptin hormone discovered in 1990s 2) they were injected w/ leptin which caused their body weight to drop dramatically in little time 3) obese humans were injected with leptin to see if it would control their body weight but it caused skin irritation and swelling + any weight lost was quickly regained findings: - shows that lack of leptin causes obesity - the hypothalamus cells in obese individuals become resistant to leptin therefore they won't respond to increased concentrations of leptin through injections - only some obese individuals have a mutation in leptin gene and are treated with leptin injections

experiment for photosynthesis limiting factors

1) submerge leaves in water and seal the container with a gas pipette 2) adjust one of the limiting factors: light = adjust the distance of a light source from leaves temperature = slowly heat the water CO2 concentration = boil and cool water to eliminate CO2 then add different amounts of NaHCO3 to increase CO2 concentration 3) measure the change in volume of the gas in the pipette showing how much oxygen is produced

transmitting impulse across 2 neurons

1) synaptic terminal buttons at the end of pre-synaptic neuron are swollen membranes w/ vesicles that contain neurotransmitter chemical 2) when the action potential reaches the terminal button the membrane depolarizes causing Ca ions to diffuse in 3) Ca ions bind to vesicles causing them to fuse with the cell membrane to secrete neurotransmitters into the synaptic cleft through exocytosis (uses ATP bc active transport) 4) neurotransmitters diffuse across the gap and bind on protein receptors on the dendrite membrane of post-synaptic cell opening transmitter-gated Na channels which activates depolarization/self-propagating action potential in post-synaptic neuron 5) neurotransmitters release from receptors and diffuse back across the gap while enzyme breaks them down into fragments that get repackaged inside the pre-synaptic terminal buttons

Translation: elongation

1) tRNA w/ anticodon matching next codon on mRNA strand binds to the A site and a peptide bond forms b/w the 2 amino acids 2) tRNA in P site is deacylated bc polypeptide chain transferred to A site tRNA

greenhouse effect (GHE)

1) the sun emits short wavelength radiation (UV and visible light) --> ozone in the atm. absorbs 25% of it (harmful UV radiation) but the rest reaches the Earth's surface 2) when short wavelength radiation hits the surface of Earth some of it is reflected back to space by albedo and some is absorbed and re-emitted as long wavelength infrared radiation (heat) = warms the surface 3) up to 85% of IR is absorbed by greenhouse gases (CO2 and H2O) in the atmosphere who reradiate it in all directions --> to space, in the atmosphere, back down to Earth's surface causing warming 4) some heat escapes but most heat is trapped in a cycle of reradiating even when there's no source of light to provide new IR/heat, keeping the temperature of the Earth's surface relatively constant

seed germination

1) water absorption in micropyle triggers gibberellin production 2) gibberellin triggers amylase production which breaks down starch stored in cotyledon into maltose either for energy or to make cellulose/cell walls 3)energy used to promote shoot and root growth 4) testa ruptures and radicle grows into ground to extract nutrients 5)cotyledon emerges as first leaves

Translation: Termination

1) when 1 of 3 stop codons is reached, protein called release factors binds to A site bc there is no tRNA w/ a corresponding anticodon 2) release factor causes polypeptide chain attached to tRNA in P site to release 3) tRNA in P site detaches, mRNA detaches from small subunit, large + small subunit separate

Punnett grid

1. Chose a letter to represent the gene of interest and use a capital letter to represent dominant alleles and a lowercase letter to represent recessive alleles 2.determine the parents' genotypes and draw a 3x3 grid placing the alleles of each parent in separate boxes in the headers 3. Combine the alleles in the each row and column to find the possible genotypes 4. Identify the chance of each phenotype formed from the genotype combinations

sexual life cycle

1. adults = diploid (2N) 2. meiosis produces haploid gametes (N) = sperm and eggs 3. fertilization of gametes (N) produces a diploid zygote (2N) 4. the zygote grows and develops into an adult through mitosis (2N) 5. cycle repeats

healthy BMI

18.5 to 24.5 is healthy

product of DNA replication

2 identical DNA molecules (same base pair sequence) that are semi-conservative (1 parent + 1 new strand) new molecules are also identical to original parent molecule

ovaries

2 organs that produce female sex hormones estrogen and progesterone + store eggs and help them mature into follicles + site of ovulation

testis

2 organs that produce sperm in seminiferous tubules + secrete male sex hormone testosterone

scrotum

2 sacs that hold and protect the testes outside the body to maintain them at lower temp. than body temp. for sperm production

energy storage in lipids

2x more energy stored in x grams of lipids than in x grams of carbs but takes longer to release (why you should exercise for more than 40 minutes to lose weight) so carbs are used as easy/quick access energy source. lipids take up less body mass for same amount of energy

5' and 3' end

5' end: phosphate group attached to C5 of pentose sugar, no other nucleotide bonded above it 3' end: no nucleotides attached below it so no phosphate group of another nucleotide bonded to the -OH of the C3 on the pentose sugar

Products of cellular respiration

6 CO2 6H2O 38 ATP max.

energy loss b/w trophic levels

90% of energy is lost from one trophic level to the next (heat loss + not all biomass passed on) so each level supports fewer # of organisms/less biomass bc less and less chemical energy available and more matter lost as waste (CO2 or remains decay) this limits the length of food chains to 4-6 organisms on avg.

rRNA binding sites

A = acceptor: holds tRNA w/ next amino acid to be added P= polypeptide: holds tRNA carrying growing polypeptide chain E = exit: holds tRNA who has lost its amino acid and is discharged into cytoplasm to reload

meiosis

A cell division that halves the number of chromosomes (reduction division) in the nuclei producing 4 genetically distinct haploid gametes (n) that can fuse with another gamete during fertilization to produce a zygote with the same number of chromosomes as other diploid somatic cells in the organism (2n) --> separates alleles to form new combinations during fertilization necessary for the process of sexual reproduction bc if gametes weren't haploid then each new generation would contain double the chromosomes of the previous when fusion of diploid cells would occur

polysome

A complex formed when multiple ribosomes are moving down the same mRNA and simultaneously translating it

malaria

A disease caused by mosquitoes implanting Plasmodium protist (parasite) in the blood. 5 different species around the world. development of the parasite is controlled by enzyme pathways. protozoa have become resistant to existing drugs so new ones are needed urgently

amphipathic

A molecule that has both a hydrophilic region and a hydrophobic region

mutation

A rare, random change in the base sequence of a gene due to an error of 1 or more base substitutions when replicating which may affect the protein coded for by a gene = forms allele mutations are a source of genetic variation and are necessary for evolution to occur -beneficial = increases chance of survival of the species so is passed on to the next generation --> an allele -detrimental = lowers species survival (causes death or disease) so isn't passed on -neutral = no effect on the species survival

gene

A segment of DNA that is heritable, influences a specific characteristic, and is expressed by the protein it codes for also called a unit of inheritance

heritable

A trait that is passed on from parent to offspring

important codons (don't need to know)

AUG = start codon or methionine UAA, UAG, and UGA = stop codons

albedo

Ability of a surface to reflect light: light surface has high albedo, dark surface has low albedo most of the short wavelength radiation that reaches the surface of Earth is reflected back into space not absorbed and transformed into IR

protein functions

Acronym: SHITS ME S tructure: collagen prevents tearing in skin and bones + spider silk catches prey and has high tensile strength H ormones: insulin travels in blood and binds to cell membranes so they absorb glucose which lowers blood glucose levels I mmunity: immunoglobins (antibodies) bind to specific pathogens T ransport: oxygen binds to hemoglobins on red blood cells to be transported throughout the blood stream S ensation: rhodopsin is a visual pigment that makes rod cells in retina light-sensitive M ovement: actin + myosin are fibrous proteins in muscles E nzymes: catalyze reactions ex. rubisco catalyzes carbon fixation in first step of photosynthesis

recessive allele

Allele that is less highly expressed bc it is masked by the dominant allele so is only expressed in a homozygous recessive organism written as a lowercase letter in the genotype

dominant allele

Allele that is most highly expressed bc it masks the recessive allele, affects the phenotype when at least 1 copy present written as a capital letter in the genotype

non-disjunction

An error during meiosis 1 or 2 where chromosomes are failed to be separated: -during anaphase 1 homologous chromosomes aren't pulled apart: all 4 gametes produced are affected --> 2 have an extra chromosomes (n+1) 2 have a missing chromosome (n-1) -during anaphase 2 sister chromatids aren't pulled apart: only 2 gametes are affected --> 1 has an extra copy, 1 has a missing copy, 2 are normal Effect on fertilization: -when a normal gamete and a gamete w/ an extra copy merge they form a trisomic zygote with 3 copies of a chromosome type/trisomy -when a normal gametes and a gamete w/ a missing copy merge they form a monosomic zygote w/ only 1 copy of a chromosome type

cohesion

Attraction b/w molecules of same substance. ex. hydrogen bonds b/w water molecules

Huntington's disease

Autosomal dominant genetic disease so only need 1 dominant copy of the allele to express it Symptoms start after 40 years of age:-severely debilitating nerve damage ex. Difficulty walking, speaking, holding objects -after a few years of symptoms = complete loss of muscle control -early death

ABO Blood types

Blood cells contain A or B antigens on their cell membrane that serve to identify the cell as "self" and not "foreign" There are 4 blood types: A = A antigens only B = B antigens only AB = A and B antigens O = no antigens Individuals contain antibodies for the type of antigen that they don't possess e.g. a Type A person has anti-B antibodies

double circulation

Body contains a double circulatory system so in 1 full circuit blood goes through heart twice: pulmonary (right side of heart) = pumps deoxygenated blood through pulmonary artery to the capillary beds in the lungs where it becomes oxygenated (drops of CO2, picks up O2), then enters left side of heart through pulmonary veins systemic (left side of heart) = oxygenated blood from lungs is pumped out of the heart through aorta to the capillary beds in organs and tissues of the body where it becomes deoxygenated (drops of O2, picks up CO2) and then returns to the heart through vena cava

endocrine gland locations

Brain: pineal, pituitary, and hypothalamus Throat: thyroid and thymus Abdomen: Pancreas Sex organs: ovaries and testes

structure of deoxyribose

C5H10O4

structure of ribose

C5H10O5

urea

CH4N2 -requires less energy than ammonia but more than uric acid -only toxic at abnormal levels so requires less constant water supply + animal can conserve some water -used by mammals + terrestrial organisms bc have kidneys to filter it out of blood and eliminate it in urine to regulate toxicity

most common elements

CHNOPS (in order of abundance in organisms) carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur

human activities that release GHGs

CO2 = combustion of fossil fuels for transport, heating homes, meat industry, deforestation + burning wood as fuel CH4 = fossil fuels, cattle from meat industry NOx = fossil fuel combustion, fertilizers, industry, car exhaust

most significant GHGs

CO2 = gas w/ highest atmospheric concentration water vapor (H2O)

role of autotrophs in Carbon cycle

CO2 in the atmosphere or dissolved in water diffuses into autotrophs who complete photosynthesis to sequester it into glucose/carbs which are then used to make further carbon compounds (lipids, amino acids, etc) by combining w/ other elements (ex. nitrogen) organic compounds are either used by the autotroph or consumed by heterotrophs as a source of chemical energy and nutrients autotrophs undergo cellular respiration in the absence of sunlight which returns CO2 to the atm.

role of cell respiration in carbon cycle

CO2 is a waste product of cell respiration in autotrophs and heterotrophs (including decomposers) so it diffuses back into the atmosphere or water

comparing # of diploid chromosomes of species

Canis familiaris (dog) = 78 Pan troglodytes (chimpanzee) = 48 Homo sapiens (human) = 46 Oryza sativa (rice) = 24 Parascaris equorum (horse threadworm) = 2

Sickle cell anemia: Disease

Cell shape: Single base substitution creates a differently shaped hemoglobin which makes the whole cell curved rather than a hollow centered disc Issues: -hemoglobin has different properties which makes it carry O2 less efficiently -hemoglobin crystalizes making the cell less flexible which combined w/ its shape, makes them get stuck and accumulate in capillaries which slows or blocks blood flow = painful Symptoms: weakness, fatigue, shortness of breath, anemia (low healthy RBC lvls), paleness

anabolism

Chemical reaction that builds up larger molecule using enzyme (simple to complex). Forms bonds so absorbs energy = endergonic/cold. Condensation reactions= produce water molecule: ex. -monomer to polymer -photosynthesis makes glucose -protein synthesis -DNA synthesis -complex carbohydrates for energy storage (cellulose, starch, glycogen)

Chernobyl

Chernobyl, Ukraine 1986: explosion in the nuclear reactor of a nuclear power plant releases radioactive isotopes of caesium and iodine all over Europe Effects: -increased rates of leukemia in plant workers -increased iodine concentration in the environment pollutes drinking water and milk resulting in elevated thyroid cancer cases -radioactive caesium bioaccumulation in fish and lamb

RNA purpose

Copies genetic code/gene on DNA strand to carry it out of the nucleus in order to synthesize proteins in the cytoplasm

Monohybrid cross

Crossing the alleles of 2 parents to determine all the possible allele combinations for their potential offspring for one gene only (in a Punnett grid)

dogma theory

DNA directs the function of a cell by determining what proteins it creates through the genetic code: DNA to RNA to proteins

effect of specific gene expression

DNA is transcribed into mRNA which is then used to determine the order of amino acids in protein synthesis so gene expression determines what proteins are made/what function an organism is going to carry out

S phase

DNA replication occurs

eukaryotic chromosomes

During mitosis/meiosis DNA strands of eukaryotic cells supercoil around histone proteins into multiple linear chromosomes that are contained in the nucleus. These help organize genes/genetic info to be past on to next generation (when not replicating = chromatin) Since eukaryotic cells are produced through the fusion of parent haploid gametes, chromosomes come in pairs: a set of paternal genes and a set of maternal genes = 2 copies of each gene (diploid) -this means all eukaryotic cells have 2+ chromosomes (some exceptions: male wasps, bees, and ants have 1 chromosome only) -all chromosome pairs in the same set carry different genes -the same # chromosome carries the same genes at the same loci for all individuals of the same species Not capable of having plasmids

restriction enzymes

Endonucleases that scan a DNA molecule for a specific base sequence (4-6 bases) called a recognition site at which point they attach to the molecule and cut the bonds in the sugar-phosphate backbone which is called enzyme digestion cut can be blunt or have sticky ends

Mendel's Law of Segregation

Every gene is defined by a pair of 2 alleles that are separated randomly into haploid gametes (only 1 allele of each gene) during meiosis during fertilization, 2 gametes fuse so 2 random alleles come together for each gene to form a new combination genotypes for every gene resulting in genetic variation (alleles could be the same or different)

order of hormones peeking in menstruation

FELP = FSH, estrogen, LH, progesterone

Mutagens

Factors that increase the natural mutation rate of genetic material if high-concentration or long exposure, increasing the risk of genetic diseases such as cancer by modifying the genetic code Ex. high energy radiation and mutagenic/carcinogenic chemicals e.g. benzene

Florey and Chain's Experiment

Flemming discovers penicillin, Florey + Chain formulate it into an antibiotic (1930s): 1) infect 8 mice w/ deadly pneumonia bacteria 2) treat 4 mice with penicillin, leave 4 untreated (control) 3) all treated mice recover, all untreated mice die method problems: -small sample size = can't determine statistical significance -go straight into testing on sick humans = unsafe (should test in small quantities on healthy humans first), would not be approved today

FSH

Follicle stimulating hormone gland: pituitary gland in the brain effects: -stimulates follicle development (meiosis 1) into a mature follicle in the ovaries, follicles compete for dominance/fastest maturation -positive fb loop of estrogen

G1 phase

Function: Growth, protein production, organelle duplication, nutrients/respiration Checkpoint: Cell size, nutrients, growth factors, DNA damage G0: cells that lose ability to divide remain in this phase eternally

G2 phase

Function: prepare for mitosis = growing + protein production + organelle creation Checkpoints: Cell size, DNA damage during replication

reduction

GER = gain e- reduction gain e- gain H lose O

Bt Corn

GMO crop made by transferring a gene from the soil bacterium Bacillus thuringiensis into corn plants gene codes for insecticidal protein that kills the larvae of crop eating pests making the corn resistant to pests

proto-oncogenes

Genes that code for proteins to move through the cell cycle / cell division

species

Group of similar organisms that can interbreed and make fertile offspring -similar physiological and morphological characteristics -common gene pool / phylogeny -genetically distinct from other species -used as the basic unit of classification of organisms

Mendel's experiments

He deduced the principles of inheritance by artificially cross-pollinating thousands of purebred pea plants that had opposing physical characteristics (ex. yellow vs green peas, wrinkled vs round, tall vs short) P = parental generation of purebred plants First filial generation (F1) = offspring of the P generation: - all had the same trait as one of the 2 parents bc all are heterozygous Second filial generation (F2) = offspring formed from the self-fertilization of the F1 generation - had both the traits of the P generation in a 3:1 ratio bc 25% are homozygous dominant, 50% are heterozygous and 25% are homozygous recessive

discovery of DNA structure

Hershey + Chase: confirm that genetic material carried in DNA not in proteins (T2 bacteriophage virus experiment) Chargaff: confirms A to T and C to G ratio is constant Rosalind Franklin + Maurice Wilkins: use x-ray diffraction to confirm double helical structure w/ constant diameter Watson + Crick: combine all info above and use cardboard cut outs of nucleotides and bases to assemble antiparallel double helix structure w/ bases in the center maintained by h-bonds. base pairing suggests semi-conservative replication mechanism

consumers

Heterotrophic organisms that obtain organic compounds by ingesting other living organisms and their products to be digested and absorbed inside their digestive system ex. mammals, fish, birds

Effect of radiation on DNA

High energy radiation that hits a DNA molecule can knock base pairs out of place hence changing the genetic code E.g. Hiroshima and Chernobyl

homologous chromosomes

Homologous chromosome pairs in diploid cells = 2 chromosomes of the same type (1 maternal, 1 paternal) that carry the same genes at the same loci (same sequence) but may differ in the alleles of each gene recognizable by: -same size -same structure -same banding pattern -same centromere position

HIV

Human Immunodeficiency Virus -infection + destruction of lymphocytes (antibody producing cells) eventually causes infected person to lose specific immunity after years = AIDS -AIDS = Acquired immune deficiency syndrome -person w/ AIDS dies from secondary infection treatment: -no cure but may use antiretroviral drugs to slow onset of AIDS

Genotype for phenotype A blood

IAIA or IAi

Genotype for phenotype AB blood

IAIB

Genotype for phenotype B blood

IBIB IBi

Morgan's Experiment

In the 20th Century he crossed fruit flies from the Drosophila genus and obtained results that didn't support Mendel's law of Independent assortment: he crossed flies until he produced a recessive white-eyed male mutation 1) he crossed a white male with a red female and got that 100% of the offspring were red eyed 2) when he crossed a white female with a red male 100% of males were white and 100% of females were red didn't get the expected 3:1 Mendelian phenotype ratio and observed that the inheritance pattern is diff in males and females

IVF

In-vitro fertilization: 1) down regulation: inhale drugs to interrupt FSH and LH secretion to interrupt menstrual cycle to time ovulation with harvesting 2) superovulation: synthetic FSH is injected (more than in usual cycle) to overstimulate follicle development in the ovaries resulting in multiple mature/dominant follicles (up to 20) 3) male provides a semen sample that is processed for the healthiest sperms 4) mature egg cells are harvested from the ovary using a lacroscopy 5) fertilization: egg and sperms are mixed in a dish and incubated for up to 2 days before being checked for fertilization 6) implantation: women is given progesterone to maintain thickened endometrium + up to 3 embryos are transferred to the uterus to increase likelihood that one will implant and start normal pregnancy

Sex-linked inheritance

Inherited traits whose genes are on the sex chromosomes (X and Y) and hence tend to affect one sex more than the other (usually X chromosome genes), e.g. red-green color blindness and hemophilia Since the Y chromosome is shorter than the X, males have some genes on the extremities of the longer X chromosome that don't have a paired allele in the Y chromosome Therefore conditions with genes on the X chromosome affect males more bc females carry 2 copies and hence can be just carriers of a recessive allele (e.g. XAXa) whereas men only have 1 copy so express the trait even if they only have 1 recessive allele (XaY)

Human Genome Project

International science collaboration effort that began in 1990 and was complete in 2003 with the goal of sequencing the entire human genome/the order of all 3 billion base pairs and the location of 23,000 genes in the 23 human chromosomes and publishing it publicly on a database side effects: -improves data analysis tools and technology -ethical, legal, and social issues (e.g. DNA ownership + consent, privacy, patenting, etc.)

functions of membrane proteins

Junctions - connect 2 cells together in tissues Enzymes - catalyze chemical reactions, sequence = metabolic pathway Transport - passageways for passive or pumps for active transport Recognition - markers for cellular identification (glycoproteins) Anchorage - attachment points for cytoskeleton and extracellular matrix Transduction - receptors for hormones which relays message to the outside

oxidation

LEO = lose e- oxidation lose e- lose H gain O

functions of life in paramecium

Metabolism: enzymes catalyze chemical reactions in the cytoplasm + Diffusion of gases + large surface area to volume ratio Reproduction: binary fission or mitosis (asexual) + share genes though conjugation Sensitivity: Surface sensitive to chemicals and touch Homeostasis: contractile vacuoles fill up with and expel water to keep within tolerable limits Excretion: diffuse waste out of cell membrane Nutrition: cilia push food into oral groove + food vacuoles digest food + Cellular Respiration (mitochondria) Growth: increase in size w/ food consumption movement: Cilia propels the organisms (like ores of a boat)

meiosis vs mitosis

Mitosis = forms 2 genetically identical diploid (2N) nuclei Meiosis = 4 genetically distinct haploid (N) nuclei Mitosis = one division Meiosis = 2 divisions Crossing over occurs during meiosis producing greater genetic diversity as new combination of alleles are formed Random orientation allows for even more genetic diversity during meiosis --> in mitosis all the chromatids are identical so it doesn't matter what way they orient In mitosis homologues don't pair up so aren't separated In meiosis homologues line up in pairs (bivalents) at the equator so are separated mitosis produces somatic/body cells for growth, development and healing meiosis produces gametes/sex cells with genetic diversity for sexual reproduction

ammonia

NH3 -requires little energy to create -very toxic so need lots of water to dilute and excrete rapidly -used by fish and amphibians bc have unlimited water supply

correcting errors/mutations (not actually required)

Nuclease cuts out incorrect nucleotides Polymerase matches the correct nucleotide Ligase glues the new nucleotide into place mutations are extremely rare, 1 in 1 billion nucleotides

law of independent assortment

One of Mendel's laws: the segregation of alleles for one gene occurs independently to that of any other gene unless they are on the same chromosome/linked

PCR

Polymerase Chain Rxn: technique used to make amplify the number of copies of DNA in vitro for analysis Cycle: 1) heat DNA to 95ºC to separate the 2 strands 2) cool to 53ºC to allow primers to bind to the strands next to the sequence to be copied 3) raise to 73ºC to encourage Taq DNA polymerase (from bacteria in hot-springs) to replicate both strands starting at the primer creating double-stranded copy of original DNA using nucleotides 4) cycle starts again

Reproductive Isolation

Populations of the same species are separated from each other so don't interbreed although they could. May lead to speciation as new allele frequency evolves creating different traits. separated physically: by abiotic barriers ex. water, mountains, etc. separated sexually: -if two groups of migrating birds arrive at mating grounds at different times and start nesting before other groups arrive - if a population develops a new allele ex. a new mating call

estrogen lvls throughout lifetime

Pre-natal: produced by developing ovaries causing female reproductive organ development (fallopian tubes, uterus, vagina) = primary sex characteristics Puberty: estrogen levels increase causing secondary sex characteristics - menstrual cycle starts - breast enlargement - pubic hair Pregnancy: inhibit menstruation and ovulation

testosterone

Pre-natal: steroid hormone produced by the developing testes causing development of male genitalia (penis, sperm duct, prostate gland) = primary sex characteristics Puberty: levels increase causing male secondary sex characteristics -sperm production from puberty onwards - facial, chest, armpit, pubic hair -penis enlargement -voice deepening from larynx enlargement

obtaining fetal cells for karyograming

Prenatal testing of the karyotype of an unborn fetus is done for mothers at higher risk of genetic abnormality (ex. trisomy): - amniocentesis: puncture the mother's abdomen and womb w/ a hypodermic needle to collect amniotic fluid that contains fetal cells -chorionic villus sampling: obtain fetal cells from the villi of the placenta that project into the uterus wall, called the chorionic villi, use hypodermic needle inserted through the abdomen and uterus wall both have small miscarriage risk and very small risk of infection for the mother or fetus

prokaryotic chromosomes

Prokaryotic cells contain a single circular DNA strand that is densely coiled in the nucleoid region -contains no proteins = naked (some archaeans contain histones) -only 1 bc reproduce through binary fission so only 1 parent/1 set of genes Some may also contain small DNA loops in their cytoplasm which aren't attached to the chromosome = plasmids

Mendel's Law of Dominance

Recessive alleles will be masked by dominant alleles

diastole

Relaxation of the heart

Hemophilia

Sex-linked genetic disease that prevents blood from clotting properly making sufferers at risk of bleeding out from minor injuries such as bruises, cuts, and internal bleeding Males are at higher risk bc the Y chromosome doesn't contain an allele for the gene

Red-green color blindness

Sex-linked genetic disease that results in the inability to distinguish b/w colors making red and green look the same Males are at higher risk bc the Y chromosome doesn't contain an allele for the gene

okazaki fragment

Small fragments of DNA produced on the lagging strand during DNA replication, joined later by DNA ligase to form a complete strand

Questioning the cell theory

Striated muscle cells: fuse together to form long fibers resulting in multiple nuclei surrounded by a continuous membrane challenging that cells are autonomous units Aseptate fungal hyphae: hyphae structures in fungi may or may not be separated into cells by internal wall (septa) so can have continuous cytoplasm + multiple nuclei meaning not all organisms are made of discrete cells Giant Algae: unicellular algae species that may grow to large size challenging that large organisms are always multicellular

comparing genome size of species in millions of bp

T2 phage (virus) = 180,000 Escherichia coli (bacteria) = 5 million Drosophila melanogaster (fruit fly) = 130 million Homo sapiens (humans) = 3.2 billion Paris japonica (canopy plant) = 150 billion

S phase

The phase of interphase when the entire DNA sequence of a cell is replicated forming a second copy Occurs before mitosis and meiosis so results in 2 sister chromatids (2 copies of the chromosome) attached at the centromere forming a single chromosome in prophase

Endosymbiotic Theory

Theory of how eukaryotic cells evolved from prokaryotic cells. 1) larger cell takes in smaller prokaryotic cell through phagocytosis so smaller cell inside vesicle in cytoplasm (double membrane) 2) smaller cell isn't digested bc performs useful functions for larger cell 3) engulfed cell loses independence becoming organelle Mitochondria: take in aerobic cell which provides the host cell w/ ATP energy resulting in heterotrophic eukaryotes Chloroplasts: take in photosynthetic cell supplying host cell w/ organic compounds resulting photosynthetic eukaryotes

Blood type alleles

There are 3 alleles for the blood type gene: IA, IB, and i which result in the 4 phenotypes IA is the dominant allele for the type A antigen IB is the dominant allele for the type B antigen i is the recessive allele for no antigens IA and IB are codominant so they are both expressed in the phenotype if they are found in the same genotype, neither is one is masked by the other

Test cross

To determine if the unknown genotype of an organism with a dominant phenotype is heterozygous (Aa) or homozygous dominant (AA) you cross it with a homozygous recessive organism -If the offspring all have dominant phenotypes, the unknown individual is homozygous dominant -If some of the offspring have a recessive phenotype, the unknown individual is heterozygous

Hiroshima

US detonated an atomic bomb over the city of Hiroshima, Japan in 1945 which killed 90,000-166,000 ppl directly or within a few months The bomb released huge amounts of radioactive isotopes into the environment which exposed thousands of ppl to dangerously high levels of radiation The long term effect has been an increase in the # of deaths due to cancer e.g. leukemia → greater dose of radiation = greater cancer death rate

co-dominant alleles

When there are multiple dominant alleles for a gene so they have a joint effect on the phenotype when they are found together in the genotype ex. blood cell antigen genes IA and IB: when both present, both are expressed resulting in AB blood

sex determination

X and Y chromosome pair determine the sex of an individual (XX = female, XY=male) -X is larger than Y so contains more gender specific genes making the pair non-homologous -SRY gene on Y chromosome is male determining -during meiosis chromosome pairs are split so: female gametes contain only 1 X chromosome each, whereas half of male gametes contain 1 X and other half contain 1 Y (50% chance of either gender during fertilization)\ -23rd pair in humans

Wilkins and Franklin

X-ray diffraction: -passing X-rays through material causes some of the waves to get scattered / diffracted instead of going through -X-ray detector can be placed near the sample to collect the pattern of scattered rays on X-ray film Maurice Wilkins (1950): produces array of DNA molecules that are orderly enough (not crystalized) to create a diffraction pattern Rosalind Franklin: develops high resolution x-ray detector to produce clear images of diffraction pattern of DNA results: -double helix shape -constant diameter

antibody

Y-shaped protein produced by lymphocytes that has unique binding sites / amino acid sequence at each end of the fork to attach to unique antigens on specific pathogen -mark pathogens for destruction / more recognizable for phagocytes - clump them together for better identification and engulfing by phagocytes = agglutination - block functions until destroyed (i.e. binding proteins in viruses or neutralize toxins released) -burst pathogenic cell by rupturing membrane

sarcomere structure

Z lines actin filaments (thin) myosin filaments w/ heads (thick) light + dark bands

menstrual cycle

a 28 day cycle of hormones that starts at puberty and ends during menopause which controls the release of an oocyte from the ovary during ovulation so that it aligns with the thickening of the uterus lining for implantation if the egg is fertilized controlled by positive and negative feedback loops hormones: FSH, LH, estrogen, progesterone

recombinant DNA

a DNA molecule produced by combining DNA from different sources (i.e two different organisms from different species)

mutagen

a chemical or physical agent causing genetic mutations in cells

cancer development

a combination of mutations in tumor-suppressant and oncogenes causes uncontrolled cell division resulting in an abnormal mass of cells called a tumor. if cells keep mutating then the mass may turn into a malignant tumor

ecosystem

a community interacting with each other and the abiotic factors (non-living) in its environment (ex. air, water, soil, temperature)

dihybrid cross

a cross b/w parents that studies 2 genes that affect 2 different traits at once producing 16 total genotypic outcomes

community

a group of populations of different species living and interacting together in the same area interactions: -trophic relationship = feeding on another -provide vital substances (ex. fungi in plant roots that decompose nitrogen compounds and return it to soil or into the roots directly) -protect (ex. ants protect aphids) -habitat on another organism (ex. parasites)

electron tomography

a method used to generate 3D image of an active mitochondrion

competitive inhibition

a molecule w/ a similar structure to a substrate which takes its place in the active site reducing the substrate's ability to bind to the enzyme to be transformed. reduces reaction rate slightly . may be reversible or irreversible. overcome if substrate concentration increases bc substrates beat inhibitors when binding to active site

carcinogen

a mutagen that causes genetic mutations leading to uncontrolled cell division/cancer

carrier

a person with a heterozygous genotype who doesn't express a recessive trait in their phenotype but could pass it on to their offspring

complementary base pairs

a purine pairs w a pyrimidine so base pairs are equal in length: G-C (3 hydrogen bonds b/w them) A-T (U) (2 hydrogen bonds b/w them)

metabolic pathways

a sequence of enzymes clustered together usually in cell membranes that catalyze reactions in chains or cycles or a combination of both producing a final product with intermediate compounds in b/w. arrows represent enzymes, squares represent substrates

promoter

a short base sequence close to the start of a gene that indicates to RNA polymerase where to bind to start transcription (determines antisense strand), isn't copied itself example of non-coding region w/ a purpose

enzymes

a type of globular protein that catalyzes chemical reactions in the body regulating when they occur/metabolic rate: lowers activation energy w/o being consumed or altered each enzyme is specific to only 1 reaction/substrate enzymes can be reused until denatured

alleles

a variant form of a gene due to a difference of 1 or more nucleotide bases (mutation) that may result in different version of the trait that the gene codes for if the new codon formed codes for a different amino acid than the original which changes the protein structure and function alleles occupy the same locus bc are the same gene some alleles are more common in certain geographical populations so can be used to analyze migration and interbreeding patterns

trisomy

a zygote with 3 copies of a chromosome ex. down syndrome is a trisomy of chromosome 21

carbon as building block of life

able to form 4 covalent bonds = stable+diverse compounds able to form single, double, and triple bonds so versatile to various shapes+compounds

response/sensitivity

able to react to internal or external stimulus/change in the environment be it biotic or abiotic

excretion

able to remove waste produced by chemical reactions from body/cell as it may become toxic

light absorbed by chlorophyll

absorbs red and blue most effectively and reflects green

pH in living things

acids used in digestive system extreme pH: -denatures proteins -decreases bloods ability to exchange oxygen

interphase

active growth phase of cell life cycle: g1, s, g2 phases

use of energy in a cell

active transport anabolic reactions (DNA/RNA + protein synthesis) movement (muscles, vesicles, chromosomes)

loading + unloading of sieve tubes

active transport: -proton pump pumps H+ out of the cell forming gradient -co-transporter protein simultaneously moves sucrose and protons into the cell -occurs directly in sieve tubes or in companion cells to speed it up (move from companion to sieve through plasmodesmata = cytoplasmic connections)

protein pumps

active transport: move substances across membranes using energy + specific to particular substances only ex. sodium-potassium pump

active vs passive immunity

active: A form of acquired immunity in which the body produces its own antibodies against disease-causing antigens passive: An individual does not produce his or her own antibodies, but rather receives them directly from another source, such as mother to infant through breast milk

DNA methylation

adding a methyl group (CH3) to cytosines w/ a guanine on their 3' end tightens supercoiling inhibiting transcription enzymes from reaching the genes and hence silencing it -methylation patterns are inherited by daughter cells -environmental factors (diet, pathogens, carcinogens, etc.) affect methylation patterns and hence gene expression -in humans methylation levels peak at birth and decrease over lifetime expressing more genes ex. identical twins are born w/ same methylation pattern but as they grow methylation decreases causing differences in gene expression influenced by environmental factors causing them to become less similar as they get older

phosphorylation

adding a phosphate group (usually from ATP) to make a molecule less stable allowing it to react better glucose is phosphorylized in glycolysis allowing it to split into G3Ps due to instability

DNA acetylation

adding an acetyl group to N-terminal tails of histone proteins making them less positively charged loosening supercoiling allowing transcription enzymes to reach gene, promotes gene expression

substrate concentration and enzyme activity

adding substrates increases reaction rate bc more enzyme-substrate collisions occur. enzymes have a maximum work speed/rate so past a certain substrate concentration (point of saturation), all enzymes are occupied and cannot alter additional substrates any faster = reaction rate plateaus

DNA nitrogenous bases

adenine, cytosine, guanine, thymine

RNA nitrogenous bases

adenine, cytosine, guanine, uracil

ATP

adenosine triphosphate

ATP

adenosine triphosphate (don't need to know) nucleic acid used as energy "currency" and immediate energy source for the cell: -stores potential chemical energy in its bonds w/ 3 phosphate groups that can be released very quickly/hydrolyzed due to instability/short life time of molecule in the cell

methane in the atmosphere

after 12 years in the atm., methane naturally oxidizes into carbon dioxide and water: CH4 + O2 --> CO2 + H2O this is the reason why there is little methane in the atm. methane can also be combusted into CO2 and H2O by humans as the fossil fuel "natural gas"

decreasing HR

after exercise/during sleep: CO2 levels decrease in blood so medulla sends out signal down Vargus nerve to the SAN which slows down impulses/HR to normal speed

ovulation phase steps

after follicular phase: 5) LH levels peak suddenly causing oocytes to complete meiosis 1 so the follicle burst open releasing the oocyte into the fallopian tubes

Menstruation steps

after luteal phase: 7) if no embryo implants then estrogen and progesterone levels fall bc the corpus luteum degenerates allowing FSH levels to rise again resulting in break down of the thickened endometrium which exits body through the vagina 8) cycle starts again

Luteal phase steps

after ovulation: 6) LH causes ruptured follicle wall to form corpus luteum which secretes progesterone and estrogen resulting in inhibition (negative fb) of FSH and LH to avoid follicle growth and ovulation + maintains thickened endometrium

refractory period

after repolarization concentration gradient needs to be re-established before next impulse/action potential can fire -sodium potassium (Na/K) pump actively transports 3 Na ions out and 2 K ions in using ATP and going against concentration gradient -re-establishes resting potential of -70mV (polarized bc negative inside, positive outside) -re-establishes concentration gradient for passive diffusion of ions during de and repolarization

splicing

after transcription in eukaryotic cells: pre-mRNA strand contains exons (coding sections) interrupted by introns (non-coding sections) that must be cut out before translation occurs 1) Spliceosomes (nuclear RNAs + proteins) remove introns and rearrange exons allowing for multiple proteins to be made from a single gene to increase diversity 2) mature DNA now contains a cap at 5' end and a poly-A-tail at 3' end to protect the mRNA from degradation by restriction enzymes in cytoplasm + signal that mRNA is ready for translation : -cap = modified guanine nucleotide w/ 3 phosphate groups -poly-A-tail = sequence of adenine base nucleotides

vectors

agent used to carry the gene of interest into another cell can be a bacterial plasmid, modified virus, yeast, or artificial chromosomes

air monitoring of GHGs

air monitoring stations around the world measure atmospheric CO2, CH4, and NOx concentrations trends: -annual fluctuation of CO2 bc excessive photosynthesis globally during spring and summer of northern hemisphere when most plants are active -rising trend of CO2 due to human activities since industrial revolution (1750s)

metabolism

all chemical reactions (anabolic or catabolic) catalyzed by enzymes in an organism (chains or cycles)

paternity testing details

all of the bands of a child need to be accounted for in the bands of their 2 parents a.k.a. half of a child's bands correspond to the mother's bands, the other half of the child's bands correspond to the father's bands

metabolism

all the chemical reactions in an organism (ex. photosynthesis, cellular respiration, chemosynthesis)

autosomal chromosomes/autosomes

all the chromosomes that aren't sex chromosomes 1-22 in humans

tumor

an abnormal mass of cells in healthy tissue caused by uncontrolled cell division benign: cannot spread + not harmful malignant: able to spread through metastasis + harmful

allergies

an antigen on a harmless/non-pathogenic substance (allergen) is encountered by leucocytes (basophils/mast cell) with corresponding antibodies causing over-activation and excess release of histamine (degranulate) triggering an inflammatory response at the sight of infection symptoms: -local swelling + redness -congestion as air ways swell (asthma and anaphylaxis) -rashes / itchyness common allergens: pollen, foods, bee venom anti-histamines drugs used to block histamines and reduce response

quadrat sampling

an area of known size is divided into a grid then a square or rectangular frame of known size (a quadrat) is placed at random coordinates of the grid to isolate a sample and determine the abundance and distribution of organisms in an area/ecosystem by counting organisms present or absent can also place quadrats at random intervals along a transect line that separates 2 ecosystems in order to see if biotic or abiotic factors that change along the transect affect the distribution of organisms

Mesocosm

an experimental tool consisting of an enclosed, self sustaining, small scale model of an ecosystem under controlled conditions in order to study a natural environment

Malaria

an infectious disease caused by the parasite Plasmodium which is transmitted to the blood by female Anopheles mosquitoes the parasite attacks red blood cells causing fever, chills, and sometimes death

phenotype

an organisms's physical expression of the alleles of a gene as a characteristic/trait ex. yellow vs green peas

fermentation

another name for anaerobic respiration which results in various bi-products: yeast (unicellular microorganism): alcoholic fermentation produces ethanol and CO2 which are used in baking and wine/beer production humans: used as quick burst of energy during intense exercise bc faster and independent of oxygen availability but lactic acid fermentation lowers blood pH causing proteins to denature so can only be used for short time period (2 min)

muscles in insect leg

antagonistic muscle pair inside the femur attached to opposite ends of the tibia by tendons flexor muscle extensor muscle

Mendelian phenotypic ratios for dihybrid cross

any of these indicates that genes are unlinked: AaBb x AaBb: 9:3:3:1 AaBb x aabb: 1:1:1:1 AABB x aabb: 1:0:0:0

Respirometer

apparatus for the measurement of respiratory gaseous exchange.

Solvent properties of water in living things

aqueous solutions hold organic molecules. they interact and are transported. water = medium for metabolic reactions ex. blood is mostly water and transports the materials dissolved in its plasma. -carbs (glucose), proteins (amino acids), gases, vitamins, minerals = polar so dissolve in water -lipids (cholesterol + fats) = non-polar so transported as lipoproteins = small droplets of fat coated in phospholipids and proteins -oxygen = non-polar so carried by hemoglobin on red blood cells -sodium chloride (NaCl) = dissolves into ions Na+ and Cl-

chromosomes during cell replication

at the beginning of cell division (meiosis or mitosis) each chromosome has been replicated during interphase forming a single chromosome made up of 2 identical sister chromatids connected at the centromere (X shape) during anaphase (2 for meiosis) sister chromatids are pulled apart: when the centromere splits they are now 2 individual chromosomes instead of 1 (count chromosomes by # of centromeres)

coronary artery disease

atherosclerosis: plaque deposit (low density lipids and cholesterol build up) in b/w tunica media and endothelium/lining of the artery makes it hard/rough (minerals deposit) and bulge inwards decreasing lumen diameter occlusion: narrowed lumen impedes blood flow so heart beat increases to maintain circulation = hypertension + chest pain (angia) thrombosis: plaque ruptures causing coagulation cascade / blood clot formation which further blocks blood flow -in coronary artery = restricts blood flow to the heart causing defibrillation (some parts stop, other irregular) or heart attack (full stop) -in cerebral artery = stroke

carbon cycle diagram

atmosphere/hydrosphere: cell respiration, breakdown by acid, combustion carbon compounds in producers: photosynthesis and cell respiration carbon compounds in consumers: feeding carbon compounds in decomposers: death and excretion carbon compounds in fossil fuels: partial decomposition and fossilization of consumers and producers limestone: fossilization of consumers

pressure changes in heart

atrial systole: -atria contract causing increase in pressure that pumps the rest of the blood through the AV valve into the ventricle -arterial pressure higher so semilunar valves closed ventricular systole: -atria relax + fill w/ blood from veins reducing pressure which closes the atrioventricular flaps to prevent back-flow -ventricles contract simultaneously causing rapid pressure increase above atrial pressure opening semilunar valves through which blood gets pumped into arteries -when ventricles empty/stop contracting pressure decreases so both chambers back in diastole (semilunar valves close + AV valves open) diastole: -both chambers relaxed so blood flows from atria into ventricles passively (atrioventricular valve stays open bc atria have slightly higher pressure) -semilunar valves closed

peripheral proteins

attached to surface of membrane or to integral protein + hydrophilic surface

hydrophylic

attracted to water = soluble/polar ex. carbs, salt, amino acids w/ polar R groups, nucleic acids

adhesion

attraction b/w different kinds of molecules due to hydrogen bonding b/w water and other polar molecules

cystic fibrosis

autosomal recessive genetic disease caused by a mutated allele of the CFTR gene for mucus regulation resulting in excessive mucus production causing respiratory and digestive problems Mutated allele is only expressed in homozygous individuals affects 1 in 3000 babies born in the US

photosynthesis

autotrophs convert light energy into chemical energy trapped in the bonds of organic compounds using inorganic CO2 and H2O from their environment

nutrient cycling

autotrophs obtain inorganic nutrients from the abiotic environment in order to produce organic compounds (ex. minerals from soil, water, sunlight) when these chemicals are used by autotrophs to make organic compounds, they get locked up in their cells then passed on to heterotrophs through feeding when an organism dies, decomposers (detritivores and saprotrophs) break down their organic compounds into usable forms for themselves and other organisms hence returning the locked up substances to the abiotic environment for reuse ex. Carbon cycling, nitrogen cycling, phosphorus etc.

photosynthesis and the atmosphere

bacteria = first organisms to release O2 into the atmosphere 3.5 billion yrs ago, levels rise to 2% rising levels caused dissolved Fe in the ocean to precipitate into iron oxide which sank forming banded iron formations on ocean bed as algae and land plants evolved, global photosynthesis rate rose causing atmospheric O2 levels to rise to 20% resulting in more aerobic organisms

leading and lagging strands

bc DNA strands are antiparallel and DNA polymerase III can only add nucleotides to 3' end of a primer in one direction (5' to 3' direction on new strand), one strand is copied continuously = leading strand and one strand is copied discontinuously in fragments = lagging strand

levels of sickle cell anemia

bc humans carry 2 copies of each gene there are diff. severity lvls for the disease: -if both copies are for disc shaped RBCs = can only produce discs and have high susceptibility to malaria -if one copy for disc and one copy for sickle shape = can produce both cell shapes (sickle cell trait) so have malarial resistance but no anemic symptoms, can pass it on to offspring -if both copies are for sickle shape = produce only sickle cells so suffer severe anemia which may be fatal but are highly resistant to malaria

vitalism

belief that living things are made of organic compounds produced using "vital force" inside them. organic molecules can't be made form inorganic molecules bc need vital force from living organism.

animal size and gestation period

bigger animals take longer to grow so have longer gestation periods animals that are more developed at birth have longer gestation periods

Neonicotinoid Insecticides

bind to acetylcholine receptor proteins blocking the transmission of nerve impulses b/w neurons or b/w neurons and receptors and effectors causing insect to be paralyzed and eventually die not broken down by any enzymes so receptors blocked permanently same effect as nicotine in humans

atria

blood collection chambers from veins on both sides of the heart w/ muscular + thin walls

changes to blood in kidneys

blood in renal vein compared to renal artery has: -less urea -less salt -less water bc lost in urine -same glucose (fully reabsorbed) -same proteins (don't enter convoluted tubules) -same blood cells (don't enter convoluted tubules)

spermatogenesis vs oogenesis

both: -go through growth, mitosis, and 2 meiosis divisions -form haploid gametes females: - starts pre-natally + are born w/ all their eggs (400,000 total) -only release eggs 1 a month through ovulation b/w puberty and menopause -uneven cytoplasm division: forms 1 very large gamete and 2 polar bodies males: -continuously produce millions of sperm starting from puberty -can release sperm daily through ejaculation -equal cytoplasm division: forms 4 same sized gametes with very little cytoplasm

central nervous system (CNS)

brain, spinal chord, neurons receive sensory info from receptors then process it to initiate a response if necessary

coronary arteries

branch off of aorta into capillaries in the muscular wall of the heart which bring oxygen rich blood for aerobic respiration to get energy for contractions

inspiration

breathing in = expand thoracic cavity to decrease air pressure - diaphragm contracts / flattens = larger cavity volume -external intercostal muscles (b/w ribs) contract pulling rib cage up and out

expiration

breathing out = contract thoracic cavity to increase air pressure -diaphragm relaxes = curves up reducing volume -internal intercostal muscles contract = pulling rib cage down and in -abdominal muscles contract = push diaphragm up even more

nerves

bundle of neurons forming long fibers that connect parts of the nervous system i.e. cranial, spinal, peripheral

setting up a mesocosm

can be open but ideally in a sealed glass container so no external matter enters but light and heat can still go through contains: -autotrophs to regenerate oxygen and make carbon compounds -decomposers to break down dead organic matter and recycle nutrients -heterotrophs (nonessential) but usually included, unethical to include large animals

artificial embryonic cloning

can separate the cells of a growing embryo (blastocyst)when they are still all stem cells and place them in the uterus of a female of that species to produce artificial identical twins, triplets, etc.

adhesion in living things

capillary action = water travels against gravity through veins in humans or through xylem tubes in plants water sticks to walls of tubes + to other water molecules (adhesion+cohesion)

compounds of life

carbohydrates lipids proteins nucleic acids

products of cellular respiration

carbon dioxide (waste), H2O, energy (ATP + heat)

drawing of saturated fatty acid

carboxyl group (COOH) + C-H chain (14-20 Cs)+ methyl (CH3)

types of digestive enzymes

carbs: amylase turns starch+glycogen into maltose (disaccharide) maltase turns maltose into glucose x2 (monosaccharides) lactase turns lactose into glucose + galactose sucrase turns sucrose into glucose + fructose glycogen digested, cellulose not digested proteins: endopeptidase turns polypeptides into amino acids lipids: lipase turns triglycerides into fatty acids and glycerol nucleic acids: nuclease turns DNA/RNA into nucleotides

scavengers

carnivores that consume dead organisms although they do not kill the prey themselves (ex. vultures)

functions of life

carried out by all living organisms (if unicellular then all occur in the single cell, smallest organisms capable of independent life): M -metabolism R - reproduction S -sensitivity H - homeostasis E - excretion N - Nutrition G -growth

role of kidneys

carry out osmoregulation to maintain homeostasis levels of water, solutes, and toxic waste

synovial joint structure

cartilage (blue): cushioning b/w bones to reduce friction joint capsule (red): seals joint + holds synovial fluid synovial fluid (black): acts as lubricant b/w cartilage to reduce friction further ligaments: tough chords connecting bones that prevent dislocation by preventing movement in some directions

elbow joint diagram

cartilage: smooth + tough tissue at ends of bones to reduce friction and absorb compression synovial fluid: lubricant joint capsule: seals joint joining bones and holding synovial fluid cavity tendons: attach muscle to bones ligaments: tough chords connecting bones to bones and reducing movement to prevent dislocation biceps muscle : contracts to flex/bend arm at elbow triceps muscle: contracts to extend arm humerus: anchorage for muscles radius: lever for biceps ulna: lever for triceps

type 1 diabetes

cause: early onset diabetes where the immune system attacks beta pancreatic cells (autoimmune disease) causing insufficient insulin production so blood glucose remains high = hyperglycemia treatment: -regular blood glucose level measurements -daily insulin injections before meals to regulate glucose levels when they spike

type 2 diabetes

cause: late onset diabetes where a high carb/high fat diet, lack of exercise, being overweight, or genetics results in insulin receptors on skeletal muscle and liver cells to stop responding to insulin (insulin resistance) causing the pancreas to eventually stop secreting it treatment: controlling diet and exercise to avoid spiking glucose levels

lung cancer

causes: smoking (tobacco +marijuana), air pollution/chemicals (asbestos, exhaust fumes, coal dust), infection, genetics = when carcinogens inhaled cause mutation in lung tissue cells forming tumor effect: -abnormal growth of cells takes over healthy tissue (bronchioles and alveoli) reducing lung function -bigger tumor = reduces function more -prone to metastasizing (spreading through blood to other parts of the body) due to high blood vessel density in lungs symptoms: -persistent coughing + coughing blood -wheezing + respiratory distress -chest pain -weight loss mortality: very high -lung tumors prone to metastasizing / spreading throughout body -lung function is vital so when impeded = major issue

Emphysema

causes: smoking (tobacco +marijuana), chemicals (asbestos) air pollution, infections, coal dust effect: -cilia = damaged to mucus builds up in lungs causing infections -toxins from smoke damage white blood cells fighting infections so release trypsin enzyme which digest elastic fibers in alveoli walls -alveoli degrade into large+irregular air sacs w/ thick walls and holes = smaller surface area for gas exchange -lungs lose elasticity for ventilation symptoms: -lack of oxygen in blood = exercise becomes difficult -elasticity loss = difficult to inhale / shortness of breath -phlegm chronic + progressive = no cure and gets worse over time so prevention is best solution

purpose of DNA replication

cell division reproduction growth + development healing

cell differentiation

cells express only specific genes in their genome in order to become a certain type of cell that carries out a specific function required for the well-being of the multicellular organism (specialized tissues). lose ability to become other types of cells.

respiration overview

cellular respiration: cells breakdown glucose into ATP molecules that store energy -faster and more productive w/ oxygen present (aerobic) -releases carbon dioxide molecules as a byproduct body constantly needs to replenish its oxygen levels and eliminate CO2 waste products which cycle through the blood stream gas exchange: occurs in lungs b/w alveoli and capillaries where dissolves gas molecules passively diffuse b/w the two tissues ventilation: lung movement to cycle fresh air in and out of lungs to maintain a favorable concentration gradient for passive diffusion in gas exchange

matrix

central cavity containing enzymes and proper pH for the link reaction and krebs cycle

polypeptides

chains of amino acids linked by peptide bonds. vary in length. 20 different types of amino acids may be arranged in any order forming infinite sequence possibilities/protein shapes and functions organisms consistently produce only a few useful sequences

discrete variation

characteristics that are determined by a single gene (monogenic) and hence have a discrete # of possible phenotypes (you have it or you don't, or discrete categories --> ABO blood types) represented as a bar char bc no transition b/w the groups, categorical phenotypes e.g. attached ear-lobes vs unattached earlobes or ABO blood types

catabolism

chemical reaction that breaks down large molecules using enzymes (complex to simple). Breaks bonds so releases energy = exergonic/hot hydrolysis reactions = consume water ex. -polymer to monomer -cellular respiration -polysaccharides for energy -triglycerides / fats for energy -polymer + water = several monomer

antibiotics

chemical that kills pathogenic bacteria by targeting structural + biochemical differences b/w prokaryotic and eukaryotic (bacteria vs human) cells: -block protein synthesis bc 70s vs 80s sized ribosomes -block cell wall creation (human cells have no cell wall)

smoking and cancer

chemicals in tobacco smoke are mutagenic and carcinogenic meaning that smoking puts you at risk of developing mutations that lead to cancer

membrane fluidity

cholesterol: high temp. = holds phospholipids in place to reduce fluidity and maintain selective permeability low temp. = prevents membrane crystallization by hindering close packing of phospholipids saturation: unsaturated fatty acid tails = kink in the tail reduces closeness of phospholipids

prophase

chromatin condenses into chromosomes (2 chromatids attached by a centromere) + nuclear membrane breaks down + microtubules start forming from centrioles

supercoiling

chromatin condenses into chromosomes by becoming shorter and fatter = visible / condensed to make it easier to move them across the cell during mitosis

down syndrome

chromosomal abnormality resulting from a non-disjunction of type 21 chromosomes forming a zygote with an extra chromosome 21 / 3 copies (also called trisomy 21) results in a delay in mental development

pedigree symbols

circle = female square = male shaded = affected half-shaded = carrier crossed out = dead generations labelled with roman numerals individuals per generation are numbered left to right

micropropagation

cloning plants through asexual reproduction/vegetative propagation: steps: -small piece of tissue taken from shoot apex is sterilized and placed in sterile growth media -sterile nutrient agar gel contains high auxin concentration to promote growth of tissue -transfer to new agar gel containing cytokinins to promote lateral bud growth and root -shoot grows/differentiation into all the parts of the plant

therapeutic cloning

cloning specific tissues or organs rather than an entire organism using totipotent stem cells that are extracted from a growing embryo (inner mass of blastocyst) totipotent means they can differentiate into any type of cell ethically controversial bc growing a human embryo for sole purpose of research rather than reproduction

somatic-cell nuclear transfer

cloning technique used to clone Dolly the sheep in 1997: 1) somatic cell collected from udder of adult donor and is grown w/ low nutrients for a few days to eliminate the differentiation pattern in its genes before removing its nucleus 2) extract an unfertilized ovum from a female and remove the nucleus as well 3) insert the donor nucleus into the ovum and administer an electric shock to get them to fuse 4) allow the artificially fertilized ovum to grow into an embryo before implanting it in a surrogate mother's uterus (3rd sheep) 5) embryo grows and is birthed naturally but the offspring is a genetic clone of the donor sheep

operons

cluster of genes under control of same promoter so their expression is controlled simultaneously: -promoter upstream sequence where RNA polymerase binds -operator segment to which repressor protein binds inhibiting RNA polymerase from transcribing -structural genes: set of genes that are collectively regulated by same control region

alveoli

cluster of microscopic air sacs at the end of the bronchioles that are surrounded by dense capillary bed. millions in each lung to provide large surface area for gas exchange structure: -thin wall: 1 cell wide to minimize diffusion distance (only through 2 cells) -moist inner surface

acetylcholine

common neurotransmitter found in cholinergic synapses broken down into acetyl groups and choline by acetylcholinesterase enzyme, choline gets reabsorbed pre-synaptic neuron

osmolarity

comparative measure of solute concentration in 2 solutions hypotonic- lower solute, higher water isotonic - solutions have same water and solute hypertonic- higher solute, lower water

DNA profiling

comparing the unique gel electrophoresis banding patterns of different DNA samples to see if they match -identical pattern = same individual -similar pattern = related individuals

organic

compound containing carbon and a carbon-hydrogen bond, synthesized by cell/organism

feeding

consumers ingest other organisms (producers, other consumers, products of either) to obtain energy from the bonds and nutrients from the components of ingested organic compounds through digestion and absorption causes energy and carbon to flow through an ecosystem through a chain

reproduction

contain genetic material + able to produce offspring. sexual = 2 parents + sex cells make genetically similar offspring w/ genetic variation asexual= 1 parent makes genetically identical offspring w/ little genetic variation

plasmids/DNA

contain their own bacterial DNA allowing them to replicated independently from the rest of the cell if more energy is required (endosymbiotic theory)

lysosome

contains digestive enzymes to break down food and cellular waste

sarcomere

contractile subunit of myofibrils in muscle cells = each repeating sarcomere shortens pulling on each other and shortening the entire muscle made of fibrous proteins: myosin = can't shorten bc thick continuous structure (dark) actin = thin (light) filaments move towards center shortening unit and pulling Z-lines towards each other

electron micrographs of contracting and relaxed muscles

contracting = light bands (actin) of sarcomeres narrow relaxed = light bands (actin) of sarcomere widen

systole

contraction of a heart chamber

ventilation mechanism

contraction of respiratory muscles changes the volume of the thoracic cavity and of passive lung tissue (can't contract on its own) -volume and pressure = inversely proportional -air moves from high to low pressure zones -muscles are antagonistic = only do work when contracting in one direction, so need pair to be able to move in 2 directions / do opposite of each other inspiration: to bring air into lungs the volume must expand to lower the pressure relative to atmospheric air pressure expiration: to get air out of lungs the volume must decrease to increase the pressure relative to atmospheric air pressure

osmoregulation

control of internal solute concentration in cells and body fluids of living organisms to regulate osmosis and maintain water balance completed in different ways in each organism

using a codon chart

convert DNA bases to mRNA bases to corresponding amino acid

annotated ovum diagram

corona radiata = follicular cells that provide nutrients for early development of fertilized egg zona pellucida = glycoprotein coat that prevents polyspermy and protects egg plasma membrane cytoplasm/yolk = contains nutrients and organelles for development of fertilized egg before implantation cortical granules = vesicles that harden zona pellucida to stop polyspermy nucleus = haploid DNA arrested in P2

analyzing evidence

correlation does not mean causation bc other factors have to be ruled out

nucleotide structure

covalent bonds hold together: phosphate group - circle pentose (5C) sugar - pentagon (ribose = RNA or deoxyribose = DNA) nitrogen base - rectangle w/ first letter in center (4 diff. types)

condensation reactions

creation of polymers by combining monomers (anabolic) + forms H2O molecule

non-competitive inhibition example

cyanide alters the shape of the enzyme cytochrome oxidase which is responsible for getting electrons to oxygen atoms in the electron transport chain. when inhibited = no aerobic respiration so cells must rely on anaerobic respiration which doesn't produce enough ATP for life = death

dehydration vs overhydration

dehydration: lack of water makes body fluids hypertonic so experience dark urine, thirst, headache, dryness, low BP, increased HR causes: excess heat, perspiration, drugs, diarrhea overhydration: excess water makes body fluids hypotonic causing confusion, drowsiness, delirium, blurred vision, muscles cramps causes: too much water consumption

neuron structure

dendrites cell body / soma nucleus axon synaptic terminal synaptic terminal buttons if myelinated: Schwann cells myelin sheath nodes of Ranvier

DNA

deoxyribose nucleic acid

gene mapping

determining the position of particular gene on a chromosome using its loci

pregnancy tests

developing embryos secrete HCG hormone found in the urine of a pregnant woman 1) pregnancy test is dipped in urine and if HCG present anti-HCG antibodies with blue dye attached bind to it 2) HCG + antibody complex reaches first membrane where monoclonal antibodies targetting HCG are present so if HCG present it detaches from the complex and binds to the membrane antibody creating line 3) empty anti-HCG antibody keeps moving up to the next membrane where monoclonal antibodies that target the first antibody are present. when it binds another line forms indicating test is over/working

carb polymer

di and polysaccharides formed by combining monosaccharides through condensation reactions that create water molecules resulting in glycosidic bond between C1 and C4 in the monomers. used for energy storage di = 2 monomers: maltose, sucrose, lactose poly= more than 2 monomers: cellulose, starch, glycogen

energy pyramid

diagram indicating energy flow/the amount of energy transmitted b/w trophic levels in kj/m^2/yr in a community energy decreases w/ each level due to energy loss to the environment

osmosis

diffusion of water molecules across a membrane from low (hypotonic) to high (hypertonic) solute concentrations creating water concentration gradient. tissues in medical procedures must be bathed in solution w/ same osmolarity as cytoplasm to prevent osmosis from occurring - tissue bursts or shrivels up

absorption mechanisms

diffusion: passive (no ATP + along con. gradient) for small non-polar molecules like fatty acids and monoglycerides facilitated diffusion: passive (no ATP + along con. gradient) for larger and more polar molecules such as fructose osmosis: passive diffusion of water active transport: through membrane proteins (uses ATP + goes against gradient) for large and polar molecules such as mineral ions, glucose, amino acids endocytosis: engulfing of droplets by plasma membrane forming vesicles surrounding the molecules such as triglycerides and cholesterol forming lipoproteins

placenta purpose

disc shaped structure that develops after 12 weeks of pregnancy -placental villi are embedded into the uterus wall so that the blood of the mother and the fetus flow close to each other for material exchange -fetus is connected to the placenta through the umbilical cord which contains 3 blood vessels placenta also releases progesterone and estrogen

pathogen

disease causing organism or virus that invades the body i.e. virus, bacteria, protozoa, worms, fungi

Parkinson's disease

disorder caused by death of dopamine-secreting cells in the brain which results in inability to control smooth + purposeful movements embryonic stem cells can be implanted to replace dead nerve cells and improve movement control

mitosis

division of nucleus into 2 genetically identical nuclei Prophase Metaphase Anaphase Telophase Checkpoints: Failure of spindle fibers to attach to chromosomes

purine bases

double rings: adenine and guanine

nucleus

double-membrane structure storing genetic material + inner region called nucleolus produces ribosomes + divides through mitosis

mitochondria

double-membrane structure w/ own DNA carrying out cellular respiration (use glucose to make ATP energy that the cell can use)

sustainability

due to nutrient cycling, ecosystems stay productive for a longtime maintaining community at steady numbers w/o running out of resources bc they are continuously reused so never run out the only thing that isn't recycled is energy so as long as they have a constant supply of sun, they are sustainable

crossing-over process in detail

during P1 of Meiosis: 1) synapsis occurs: the chromatids of homologous chromosomes become tightly paired up/come together in bivalents 2) non-sister chromatids are cut at the exact same locus and they swap sections of DNA but remain connected to each other at a the point of exchange which is called the chiasmata 3) the resulting chromatids have new combinations of alleles from the parents so are called recombinant DNA

energy loss through respiration

during cellular respiration and other metabolic reactions in organisms (ex. muscle contraction), some chemical energy is converted to heat energy organisms can't convert heat energy back into chemical energy and they can't use it so it is lost to the environment, for this reason ecosystems need a continuous source of energy bc it cannot be recycled like nutrients --> source is usually the sun organisms w/ greatest loss: warm-blooded (mammals) + unstationary although decomposers also respire and release heat

variation during fertilization

during fertilization, a new combination of alleles is formed by the fusion of the parent gametes into a single individual/zygote gametes are all genetically distinct and they meet and fuse completely randomly which promotes genetic variation as a random combination of alleles is produced

Mendel's Law of Independent Assortment

during meiosis, alleles separate independently from the alleles of other genes ex. for pea color and plant height: a gamete could have tall and yellow alleles or tall and green alleles since the direction of the separation of the alleles doesn't depend on the other

crossing over

during prophase 1: Sections of non-sister chromatids in the bivalents twist around each other and break off reattaching on the opposite chromatid forming recombinant DNA as genetic material is exchanged. Maternal and paternal chromosomes mix. point of genetic exchange is called the chiasmata -can have multiple chiasmata per chromosome -produces chromatids w/ a new set/combination of alleles for all the genes it contains making all 4 chromatids in a homologue genetically different -causes genetic diversity bc the exchange occurs at a random length of the chromosome so random allele combination is formed

resting potential

electric potential/charge difference (voltage) across neuron membrane when it isn't conducting an impulse but is ready to do so, -70mV - concentration gradient needed for action potential is established by active transport of sodium (Na) ions out of the cell and potassium (K) ions into the cell through Na/K pump in a 3:2 Na to K ratio -presence of negatively charged Cl ions in the neuron creates net negative charge inside relative to the outside bc 3 + removed for every 2 + added -ion channels closed -polarized: outside= positive, inside = negative

electron vs. light microscope

electron = much higher resolution so sharper images at greater magnification

NADH and FADH2 role

electron carrier molecules that transfer the energy released from REDOX reactions to the ETC in the cristae of mitochondria

purpose of redox in e- carriers

electrons can't move across membranes by themselves due to charge so carrier molecules experience redox to be able to move e- across membranes in reduced form

Inner membrane

embedded w/ ATP synthase and e- carrier molecules in ETC for oxidative phosphorylation

activation energy

energy required for a chemical reaction to occur: to break or form bonds. in living things, the activation energy cannot be room temp. or body temp. because then reactions would occur too often. use enzymes to regulate when the reactions occur/regulate metabolic rate

atrioventricular + semilunar valves

ensure blood circulation by preventing back-flow

chloroplast diagram

enveloppe (inner + outer membrane) stroma thylakoid (membrane, space) granum (stack) lamella (bw stacks) ribosomes (70s) lipid droplets starch grains

DNA Ligase

enzyme that joins DNA fragments together by making sugar-phosphate bonds b/w nucleotides forming the backbone

enzyme-substrate complex

enzymes have a specifically shaped region called the active site to which the substrate (reactant being altered) attaches. enzymes and substrates have chemical properties that complement each other (+ binds to -) allowing binding the shape of the active site is specific to the substrate it alters but it undergoes conformational changes to adjust to the substrate slightly like glove fitting a hand. so enzymes can only alter one specific reaction

chromosomes

eukaryotes: linear DNA strands wrapped around histone proteins during mitosis only. otherwise in a tangle of chromatin. in nucleus prokaryotes: 1 naked circular chromosome w/ some plasmids. in nucleoid region

nitrogenous waste

excess amino acids are deaminated (removal of amine group NH2) which is turned into 1 of 3 types of nitrogenous waste products depending on organism's evolutionary physiology and habitat -ammonia (NH3) -urea (CH4N2) -uric acid

molecular biology

explains life process in terms of chemicals and reactions

natural animal clones

extremely rare: -identical twins are clones that form when an embryo naturally splits in half and both masses of cells implant in the uterus forming 2 identical fetuses -inter vertebrate Hydra vulgaris is capable of growing buds that develop into new identical adults and break off

mutagens

factors that increase the rate of mutation hence increasing the risk of developing a genetic disease such as cancer: -high energy radiation: x-rays, UV light, gamma rays, and alpha particles from radioactive isotopes -chemicals: in tobacco, mustard gas in weapons, benzene solvent, pollution

food chain

feeding hierarchy/sequence showing the feeding relationship and direction of energy flow b/w species in an ecosystem -starts w/ producers then primary consumer, secondary c, tertiary c, etc. -arrows point in the direction of energy flow -3-5 organisms long

nephron structure

filter unit, millions per kidney: -afferent arteriole -glomerulus -efferent arteriole -peritubular capillary bed (surrounds convoluted tube) -Bowman's capsule -proximal convoluted tube -loop of Henle -distal convoluted tube -collecting duct

importance of oxygen

final electron acceptor that forms water molecule. if not present then ETC stops so NADH cannot be oxidized back into NAD+ and so link reaction + krebs cycle stop. glycolysis continues anaerobically but only forms small yield of 2ATP

urea

final nitrogenous excretion product of organisms found in urine which was synthesized artificially by German chemist falsifying the theory of vitalism bc it's organic but produced artificially without a vital force

capacitation

first step of fertilization: the acidity of the vagina erodes the cholesterol layer surrounding sperms making them more mobile, sperm feeds on the fructose in semen for energy, they follow chemical signals up the fallopian tubes to the egg

thylakoids

flattened discs containing pigments (chlorophyll A + B + accessory) space: small volume to maximize H+ gradient after few photons of light absorbed membrane: folded for large SA for light absorption photosystems (ETCs) in light reaction for chemiosmosis

villi

folds and projections in the mucosa of the small intestine to maximize the surface area of epithelium for max absorption of nutrients into lymph and blood vessels nutrients absorbed: vitamins, mineral ions, monosaccharides, amino acids, glycerol and fatty acids, nitrogen bases

cristae

folds in inner membrane to increase surface area to maximize number of ETCs occurring

role of enzymes in digestion

food particles must be hydrolyzed / broken down from polymers into monomers that can pass through cell membranes during absorption and then can be reassembled into useful macromolecules inside cells enzymes are added to food throughout digestion to catalyze hydrolysis reactions so they can occur at body temp. each enzyme targets 1 specific macromolecule

end product inhibition

form of negative feedback that prevents cells from wasting chemicals and energy: the end product of a chemical pathway binds to an allosteric site on the 1st enzyme in the sequence inhibiting it. this temporarily stops the pathway until the end product is used by the cell/concentrations are low again.

ribose

formula C5H10O5

alpha-d-glucose

formula: C6H1206 Carbon 1 OH direction: down bc alpha looks down on others

beta-d-glucose

formula: C6H1206 Carbon 1 OH direction: up bc beta looks up to leader

assembling free floating nucleotides in detail

free floating nucleotides contain 3 phosphate groups instead of 1 so are called DNA/RNA triosphosphate when they bind to a strand they release 2 phosphates providing energy for phosphodiester bond to form

ethics of stem cells

from adult tissue: no issues from umbilical cord: no issues bc parental consent + these cells may be used by baby later in life from embryo: harvesting kills embryo/technically murder + may need immunosuppressant drugs

blood vessel sequence

from heart into aorta to smaller branching arteries to arterioles (smallest arteries) arterioles to capillary beds to venules (smallest veins) from venules to larger veins to vena cava into the heart

Chemiosmosis

from inner membrane space to matrix: 1) energy released from ETC redox rxns is used to pump H+ into the inner membrane space creating a concentration gradient that allows the protons to diffuse back into the matrix by through ATP synthase transmembrane protein 2) as H+ diffuse they release electrochemical energy that is used for oxidative phosphorylation of ADP into 32 ATP

biofuels/biomass

fuels (ex. ethanol or methane) that are created by biological processes such as by microorganisms fermenting veggie oils, animal fats, soybeans, corn, animal dung, etc. renewable bc takes much less time to create than fossil fuels that take millions of years

arteries

function: carry oxygenated blood away from the heart from ventricles to body tissues (exceptions: pulmonary arteries are deoxygenated) pressure: very high lumen diameter: narrow to maintain high pressure w/ each pulsation of blood wall thickness: thick to resist pressure/prevent bursting, rubbery/smooth and elastic strong muscles + elastic fibers contract and relax to adjust lumen diameter and maintain high pressure for each pulse b/w pump cycles

veins

function: collect deoxygenated blood from capillaries/tissues + carry it to the heart atria pressure: low pressure + slow flow lumen diameter: wide to maintain low+slow pressure and flow / no resistance build up wall thickness: thin walls are pressed flat by skeletal muscles to move blood against gravity, no risk of bursting fewer muscles + elastic fibers bc not pulsatile and presence of valves to prevent back-flow

palisade mesophyll cells of leaf

function: complete photosynthesis as have high light absorption due to many chloroplasts + location in leaf organelles: lots of chloroplasts, other plant specific organelles

capillaries

function: connect veins and arteries, capillary bed = network of capillaries to carry blood through body tissues, permeable walls for material exchange pressure: low lumen diameter: extremely narrow (1 cell wide) to fit into small spaces wall thickness: 1 cell thick permeable layer w/ pores in b/w cells to allow for material exchange b/w body tissues and blood through diffusion, plasma + phagocytes able to leak out

exocrine glans of pancreas

function: secrete digestive enzymes directly through duct where they will be used (not through blood stream) organelles: many ribosomes and ERs to make proteins (digestive enzymes), many mitochondria to produce lots of ATP for protein synthesis

cis isomers

functional group are on the same side

R group

functional group of amino acid that has different properties (basic, acidic, polar, non-polar, ionic, sulfur) determining how amino acids in polypeptide chain interact in tertiary structure. determines the shape and function of the protein. there are 20 different common R groups synthesized by ribosomes in all organisms with some rare exceptions. evidence that all organisms share common ancestry / same genetic code

trans isomers

functional group on opposite sides

ethylene

gas that acts as hormone: -stimulates ageing -causes fruit ripening (not growth) -loss of leaves + death of flowers

greenhouse gases (GHGs)

gases in the atmosphere that are able to absorb and reradiate long-wave IR as part of the GHE their concentration affects global temperatures and climate patterns a gas's impact on GHE depends on: -ability to absorb long wavelength IR -concentration in the atmosphere

labelling the heart

general: septum right = left side on diagram: vena cava (superior and inferior) atrium atrioventricular valve ventricle semilunar valve pulmonary arteries left = right side on diagram: pulmonary veins left atrium atrioventricular valve left ventricle semilunar valve aorta

unlinked genes

genes located on different chromosomes that separate independently: - when bivalents align at the equator during metaphase 1, their orientation is random meaning the orientation of one bivalent doesn't affect the orientation of another bivalent - therefore when alleles are pulled apart during anaphase 1, the pole that one allele moves to has no effect on the pole that another allele on another chromosome moves to

sex-linked genes

genes that are located on the sex chromosomes (X or Y) and hence affect one sex more than the other e.g. red-green colorblindness, hemophilia

tumor-suppressant genes

genes to stop cells from dividing when unnecessary or damaged. if mutated then cell cycle is never stopped or slowed resulting in uncontrolled cell division of possibly mutated cells

linked genes

genes whose loci is on the same chromosome that tend to be inherited together (more likely the closer together they are) rather than following the law of independent assortment new allele combinations (not those of the parents) of the linked genes can only be formed through crossing over

Stargardt's disease

genetic disease causing vision loss due to malfunction of active transport in photoreceptor cells in the retina. embryonic stem cells can be implanted to replace damaged photoreceptor cells and improve vision

transgenic organism

genetically modified organism containing DNA from 2 different sources giving it a new trait

blood transfusions

giving person blood from another person but need to match ABO blood type otherwise antibodies will trigger immune response: -agglutination = obstructs blood vessels -cells lyse open/destroyed -coagulation = heart attack or stroke

pancreas

gland that secretes pancreatic juice into the duodenum (first section of small intestine) through pancreatic duct pancreatic juice: -lipase enzyme -amylase enzyme -endopeptidase enzyme -bicarbonate ions to neutralize stomach acid

leptin

gland: adipose tissue cells trigger: higher levels of body fat results in higher leptin concentrations in the bloodstream target cells: hypothalamus in the brain effect: suppresses appetite causing reduced food intake to regulate body weight

glucagon

gland: hormone produced by the alpha cells of the pancreas trigger: low blood glucose levels detected by pancreas target cells: skeletal muscle cells + liver cells effect: cause these cells to hydrolyze glycogen to release glucose into the blood stream making levels rise = negative feedback

insulin

gland: hormone produced by the beta cells of the pancreas trigger: high blood glucose levels detected by pancreas target cells: skeletal muscle cells + liver cells + basically all body cells effect: causes protein channels in the membrane of cells to open allowing glucose to enter from the blood stream (lowers blood glucose concentration) = negative feedback - in normal body cells it is used for cellular respiration - in liver and muscle cells excess glucose is converted into glycogen for storage bc it is insoluble so prevent issues with osmosis

melatonin

gland: pineal gland in the brain trigger: ganglion cells in the retina detect light or darkness sending impulse to hypothalamus that controls secretion of melatonin from the pineal gland - light = low melatonin -dark = high melatonin (peaks at 2-4 AM) -production declines with age causing irregular sleep patterns target cells: various effect: regulates the circadian rhythm which is the 24 hour cycle of physiological responses in the body (e.g. eat, sleep, hormone release, etc.)

endocrine system

glands that produce a variety of hormone and releases them into the blood stream for dispersion throughout the body to the targeted cells of each specific hormone

sucrose

glucose + fructose (table sugar from plants)

lactose

glucose + galactose (milk sugar)

maltose

glucose + glucose

issues w/ glucose as energy storage

glucose is soluble in water so presence in a cell causes osmosis (water to enter the cell) which makes it lyse open. polysaccharides like starch in plants and glycogen in animals are insoluble so don't cause osmosis in a cell so they are used to store glucose/energy. glucose is removed from the ends when needed.

starting materials of cellular respiration

glucose or other carbs and fats, protein if starving and oxygen

carbohydrate bonds

glycosidic bond between monosaccharides. B/w carbons 1 and 4, or 1 and 6 for branching. condensation reaction = produces water molecule

oscilloscope traces

graph of membrane potential changes during action potential measured by electrodes -resting potential=-70 mV -threshold = -50 mV - depolarization = +30 mV - repolarization +refractory period = -80 mV -resting potential = -70 mv

anticodon

group of 3 base pairs on tRNA molecule that are complements of codons on mRNA strand and correspond to a specific amino acid

codon

group of 3 nucleotides (triplet) on mRNA strand that are complementary base pairs to group of 3 nucleotides on tRNA (anticodon) which code for a specific amino acid 64 total combos 3 stop codons, 61 amino acid codons

clones

group of genetically identical organisms or groups of cells produced from a single parent

population

group of organisms of the same species that live together in the same place at the same time

Phototropism

growth of a plant shoot or root towards or away from light triggered by phototropins (pigments that absorb blue lightwaves) -roots = negative -shoots = positive bc cells on dark side elongate faster than cells on light side

tropism

growth or movement responses to directional stimuli ex. light, gravity, touch, chemical

hormones during pregancy

hCG: produced from embryo, rises at first to maintain progesterone and estrogen levels for a thickened endometrium estrogen: produced by ovaries and then placenta, rises gradually throughout pregnancy to stimulate uterine muscle growth and cause mammary glands to produce milk for breast feeding progesterone: produced by ovaries and then placenta, rises progressively throughout pregnancy to maintain the endometrium, reduce uterine contractions, and reduce mother's immune response

pili

hairs surrounding some bacteria used for attachment or conjugation

plant adaptations for water conservation in saline soil

halophytes: soil has high Na+ and Cl- concentrations so risk losing water from roots through osmosis - small leaves to reduce loss -few stomata + in pits - increase Na and Cl concentration in vacuole - have removable leaves to get rid of excess Na and Cl and reduce water demand - extensive root system w/ active transport to increase ion concentrations in root -water storage tissue = succulents

Morgan's Discoveries

he inferred that the sex-linked inheritance pattern he observed was due to the gene being located on the X chromosome other anomaly ratios (1:0:0:1) that weren't sex-linked but weren't Mendelian he deduced were from genes located on the same autosomal chromosome

heart beat

heart walls made of cardiac muscle cells capable of myogenic contractions = able to contract w/o command from the nervous system 1) specialized mass of muscle cells (cardiomyocytes) in right atrium called sinoatrial node (natural pacemaker) generates + propagates electric signal across atrial wall (b/w adjacent muscle cells) to the left atrium stimulating simultaneous atrial contraction 2) impulse reaches atrioventricular node in the center where it is delayed for 0.5 seconds then sent down Bundle of His to Purkinje fibers which propagate it in ventricle walls stimulating simultaneous ventricular contraction 3) when ventricles relax SAN sends out another impulse

denaturing due to temperature

heat breaks the hydrogen bonds that hold the tertiary and secondary structures in place. usually irreversible ex. heating egg makes egg white turn solid

annotated sperm diagram

helical mitochondria = energy for swimming acrosome = contains enzyme for fertilization haploid nucleus = contains DNA for fertilization flagellum = mobility

enzymes in catabolic reactions

help break molecules by twisting substrate to put strain on bonds

Saprotrophs

heterotrophic organisms that obtain nutrients by externally digesting dead organic matter (dead organisms, feces) secrete digestive enzymes to break down complex molecules (ex. cellulose, proteins) then absorb simple energy rich carbon compounds they need also called decomposers bc the materials that they don't ingest are returned to the environment for use by producers ex. bacteria and fungi

detritivores

heterotrophic organisms that obtain nutrients by internally digesting detritus (dead organic matter) from once-living organisms (ex. dead leaves, decomposing flesh, feces) ex. woodlice, earthworms, dung beetle

trophic levels

hierarchy of food chain indicating how many organisms energy has flowed through before reaching an organism level 1 = producers level 2 = primary consumers level 3 = secondary consumers level 4 = tertiary consumers etc.

thermal properties of water

high heat capacity = absorbs and gives off a lot of heat without changing temperatures high boiling point = requires lots of energy to break hydrogen bonds/to evaporate evaporation requires lots of heat

thermal properties of water in living things

high heat capacity = temperature stabilizer, carry heat around body (blood) high boiling point = liquid at room temp. so universal solvent and medium of metabolic reactions evaporation = perspiration lowers body temp. bc a lot of heat lost to make sweat evaporate + through breaking of hydrogen bonds

endometrium

highly vascular inner lining of the uterus that breaks down during menstrual bleeding

bladder

holds pee

uterus

hollow muscular structure where blastocyst implants and develops + endometrium (inner lining) thickens w/ blood vessels to nourish the growing embryo + muscles contract to push out child during birth

homologue

homologous chromosome pair

bivalents

homologous chromosomes that are paired up during meiosis

HRT

hormone replacement therapy = manipulation of the menstrual cycle to overstimulate egg production and time ovulation for IVF procedure

insulin

hormone secreted by the pancreas in humans that lowers blood glucose levels by synthesizing glycogen

use of databases to identify anti-malarial drugs

huge bioinformatics databases are used to scan thousands of chemicals that may fit the shape of the enzymes responsible for Plasmodium development in a host. these enzymes were also identified using a database of metabolic pathways. the potential inhibitors are then turned into drugs and tested for effectiveness.

effect of GHGs on global temp.

human activities release increasing amounts of GHGs (CO2, CH4, NOx) into the atmosphere since start of industrial revolution 200 yrs ago average global temperatures have also risen over the past 200 years by 0.8ºC the correlation suggests that greater GHG concentrations in the atmosphere due to human activities have enhanced the GHE so the atm retains more heat leading to global temperature rises and climate changes changes in concentrations of GHGs and global temp. aren't proportional bc other factors influence temperature causing fluctuations in global warming year to year

hCG

human chorionic gonadotropin hormone produced by embryo which causes corpus luteum to keep producing estrogen and testosterone to maintain a thickened endometrium for implantation, also stops period after 3 months the placenta is fully formed and secretes its own estrogen and progesterone detected by pregnancy tests in pee

combustion in the carbon cycle

hydrocarbon rich substances (biomass or fossil fuels) can be oxidized w/ atmospheric O2 when heated through combustion (by man = fossil fuels or nature = wildfires) which releases the chemical energy trapped in the bonds as heat (exergonic rxn) the products of the rxn are always CO2 and H2O which get released into the atm. --> humans increase natural atmospheric levels

fossil fuels

hydrocarbon rich, fossilized organic matter: peat, coal, oil, natural gas combustion = much faster than fossilization so are nonrenewable energy source

drawing of amino acid

hydrogen atom + amine group (NH2) + caboxylic acid (COOH) + R group attached to central C atom 20 different R group types determine how amino acids interact in tertiary structure

trans unsaturated fatty acids

hydrogen atoms added to double bonded carbons through hydrogenation (food processing). hydrogens attach to carbons on opposite sides causing straight molecule that is solid at room temp. (animal fats)

secondary structure of proteins

hydrogen bonds form b/w oxygen in carboxyl group and hydrogen in amino group in 2 nucleotides in polypeptide chain allowing for formation of stabilized structures called beta pleated sheets (if chain runs parallel to itself) and alpha helixes (if chain twists) both structures have the same dimension

Link Reaction

if oxygen available then pyruvates from glycolysis enter mitochondrial matrix: 1) 2 pyruvates are decarboxylated (release one CO2 each) forming two acetyl (2C) 2) both acetyl are oxidized and 2 NAD+ are reduced into 2 NADH 3) redox reaction provides energy for coenzyme A to attach to each acetyl forming 2 acetyl CoA products: 2 CO2 (waste) 2NADH 2Acetyl CoA

Genotype for phenotype O blood

ii

enzymes in industry

immobilized enzymes used as catalysts in industry -lactose free milk -fiber processing in textiles -pulping wood for paper -biofuels

myelin sheath

in advanced nervous systems axons are surrounded by evenly spaced Schwann cells which wrap around them several times forming cell membrane layers called myelin sheath spaces b/w Schwann cells are called nodes of Ranvier

methane production

in anaerobic conditions where organic matter isn't fully decomposed by aerobic decomposers (fungi and bacteria), methanogenic archaeans (bacteria) produce CH4 as a waste product when breaking down organic matter through anaerobic respiration the CH4 may be released into the atm. or may accumulate underground forming natural gas deposits over millions of yrs. occurs in swamps, bogs, landfills, digestive tract of mammals and termites, etc.

sodium-potassium pump

in axons of neurons: 1) protein binds to 3 intracellular sodium ions 2) ATP loses a phosphate becoming ADP causing protein to change shape which expels ions to exterior 3) 2 extracellular potassium ions bind to protein releasing the phosphate group 4) no more phosphate makes protein return to original shape expelling ions inside cell concentration gradient needed for nerve impulse transmission

Electron Transport Chain (ETC)

in cristae/inner membrane of mitochondria: 1) e- from the H atoms on NADH and FADH2 are transferred to e- carriers embedded in the membrane (FADH2 at later point in the chain) 2) e- are transferred from a carrier to the next through series of redox reactions that release energy, this energy is used to pump H+ from the matrix to the inner membrane forming a concentration gradient 3) oxygen acts as last e- acceptor and combines w/ 2 H+ from matrix to form water molecule that is released to maintain H+ gradient product: NAD+ FAD H2O

glycolysis

in cytoplasm: 1) phosphorylation: glucose is phosphorylated by adding 2P from 2ATP making it unstable 2)lysis: glucose splits into 2 G3Ps (3 carbons each) 3)REDOX: both G3Ps are oxidized (lose e-) which reduces 2NAD+ into 2NADH (gain e- form H), G3Ps add another inorganic phosphate each 4)substrate level phosphorylation: energy released from oxidation is used to convert 4ADP into 4ATP by adding 2 phosphates from each G3P which become 2 pyruvate (still 3C each) products: net yield of 2ATP (small but no O needed) 2 NADH 2 pyruvate

protein synthesis eukaryotes vs prokaryotes

in eukaryotes: after splicing mature mRNA strand leaves nucleus through nuclear pores into cytoplasm where tRNA and ribosomes are located in prokaryotes: transcription and translation both occur in the cytoplasm and there is no splicing so both processes can occur simultaneously

nucleosomes

in eukaryotic cells long DNA strands need to be packaged into microscopic molecules (chromosomes) that fit inside the nucleus: nucleosome: - 8 histone proteins forming core with DNA strand wrapped around it twice (histones are positively charged and DNA is negatively charged) -H1 histone binds the DNA to the core (safety pins it closed) -nucleosomes linked together by single linker DNA strand in b/w them (beads on a string) - N-terminals on histone proteins extend out and link up w/ N-terminals of adjacent nucleosomes pulling them closer together and allowing for supercoiling regulating transcription: -supercoiled DNA is unaccessible to replication and transcription enzymes -N-terminals can be modified and H1 histones are removed to loosen up supercoiled nucleosomes allowing for polymerase enzymes to complete replication or transcription -therefore nucleosomes help regulate which sections condense and de-condense during interphase

immobilized enzymes

in industry enzymes are attached to inert substances to make them easier to measure, add and remove, separate from products, reuse, expand optimal pH and temp. range = overall cheaper ex. attachment to alginate beads (trapped in gel)

photolysis

in light-dependent reaction: H2O molecule is separated into 2e- + 2H+ + 1/2 O2 using light energy e- used to replace those excited in step 1 H+ contribute to concentration gradient O2 released as waste product

fertilization

in sexual reproduction: the fusion of haploid gametes (n=23 for humans) forms a diploid cell called the zygote (2n=46 for humans) which contains a set of genes from each haploid forming homologous chromosomes with a new combination of alleles/new genotype the zygote then divides by mitosis to form more diploid somatic cells w/ the same # of chromosomes (2n)

energy in photosynthesis

in the light reaction, sunlight energy is converted into ATP and NADPH as chemical energy sources in the light-independent reaction where CO2 is assembled into glucose

oogenesis

in the ovaries, females are born w/ all their eggs (400,000) pre-natal/in fetus: 1) oogonia (2n) undergo mitosis to grow #s and prepare for meiosis by growing into a primary oocyte (2n) 2) primary oocyte rests in prophase 1 of meiosis, has layer of follicle cells around it Puberty: 3) a few primary oocytes each month complete meiosis 1 forming a secondary oocyte (n) that rests in P2 and a polar body - one large 2nd oocyte is formed bc the cytoplasm is divided unequally, a small polar body that contains half of the DNA but barely any cytoplasm is expelled and degenerates -the follicular cells around the 2nd oocyte start to develop into a mature follicle -the 1st polar body undergoes meiosis 2 and expels 2nd polar body 4) during ovulation, a 2nd oocyte (n) is released into the fallopian tubes, if it is fertilized it undergoes meiosis 2 briefly forming an ovum (n) and expelling a 3nd polar body before forming a zygote/embryo

spermatogenesis

in the seminiferous tubules of testes starting during puberty, moving from outer layer to inner lumen: 1) outer layer called germinal epithelium contains spermatogonia (2n) (stem cells) that undergo growth to prepare for 2 meiosis divisions (DNA replication, add cytoplasm) and mitosis to replenish their #s for an endless supply of sperm throughout a lifetime 2) when a spermatogonia cell grows it forms a primary spermatocyte (2n) which goes through meiosis 1 to form two haploid secondary spermatocytes (n) 3) the two secondary spermatocytes (n) undergo meiosis 2 forming 4 spermatids (n) that are genetically different but the same size, and immobile (no tails yet) 4) spermatids (n) attach to sertoli cells for nutrition while they differentiate into mature spermatozoa (n) with flagella for movement/swimming and enzymes for fertilization in their acrosome (head) 5) spermatozoa detach from the sertoli cells and enter the lumen at the center of the tubule to travel to the epididymis where they are stored for ejaculation

CO2 in water

in water CO2 from the atm. or CO2 created by cellular respiration of aquatic organisms dissolves: CO2 + H2O --> H2CO3 (carbonic acid) dissociation: H2CO3 --> H+ + HCO3- (hydrogen ions and bicarbonate ions) HCO3- --> H+ + CO3-2 (hydrogen ions and carbonate ions) hydrogen ions = increase acidity/decrease pH of water (acidification)

diabetes

inability to control blood glucose levels causing large fluctuations out of the normal limits (hyper/hypoglycemia) two types of the disease

lactose intolerance

inability to digest sugar lactose found in milk bc of low production of lactase enzyme in small intestine. undigested lactose enters colon/large intestine where bacteria feed on it causing gas/bloating, cramps, diarrhea, etc... most adults are lactose intolerant bc mammals only need milk as infants. exceptions in humans due to mutation

impact of CO2 on coral reefs

increased atmospheric concentrations of CO2 cause more CO2 to be dissolved in oceans in water, dissolved CO2 forms Carbonic acid which dissociates into hydrogen ions and bicarbonate ions causing acidification/pH drop from 8.25 to 8.14 = 30% acidification increased hydrogen ions combine w/ carbonate ions to form bicarbonate which reduces carbonate available for corals and mollusks to build new shells and exoskeletons out of Calcium carbonate acidification also dissolves CaCO3 in existing organisms and limestone which kills coral reefs that support diverse ecosystems

growth in plants

indeterminate bc can keep extending stems and roots or adding extra leaves, stems, flowers, etc. throughout lifetime animals = determinate growth bc have fixed number of parts that can develop

neurons

individual cell that transmits sensory and motor messages/info across the body at high speeds in the form of electrical impulses in the nervous system -unusually long cells (up to 1 meter) -transmit impulses through action potentials -work in one direction only (from dendrites to synaptic terminal)

recombinants

individuals that have a different trait combination than their parents for linked genes due to crossing over very small amounts per sample of individuals bc very rare

minerals

inorganic molecule used as building material obtained from food don't give energy directly

transcription

inside nucleus: 1) RNA polymerase identifies and binds to promoter on DNA strand to open a transcription bubble to be able to replicate the sense strand using the antisense strand as a template 2) RNA polymerase starts assembling RNA nucleotides using base pairing rules in 5' to 3' direction (uracil instead of thymine) into a single messenger RNA strand 3) terminator nucleotide sequence signals end of the gene causing RNA polymerase and new mRNA strand to detach from the DNA molecule causing bubble to close and DNA to recoil 4) splicing occurs in eukaryotic cells

ATP synthase

integral protein embedded in the inner membrane that diffuses protons into the matrix during chemiosmosis resulting in oxidative phosphorylation/ATP production

quarternary structure

interacton b/w R groups allows multiple polypeptide chains to fold into a single protein

vaccines

introduction of antigens/chemical parts or dead or weakened pathogens (disabled = can't cause disease) acting as first exposure by triggering primary immune response causing formation of B and T plasma and memory cells + antibodies w/o causing disease/symptoms memory cell persist in blood stream so upon reinfection by the actual pathogen body undergoes secondary response which is faster w/ more antibodies resulting in mild to no symptoms = long-term immunity -vaccine boosters: some vaccines need several doses throughout lifetime to maintain memory cell population -some vaccines may cause allergies or side effects in some ppl (i.e. immunocompromised ppl)

hemoglobin

iron-containing pigment protein in red blood cells that carries oxygen for delivery to cells and gives them their color made of 4 polypeptide chains (alpha 1,2 and beta 1,2) and iron (heme groups)

growth

irreversible increase in amount of living material (volume or mass) development: all the changes that take place throughout life of organism (ex. puberty)

synapses

junction b/w neuron and other neurons or neuron and receptor or effector cells where plasma membranes are separated by a fluid filled gap called synaptic cleft giving cell = pre-synaptic neuron, receiving cell = post-synaptic neuron if neuron to neuron: synaptic terminals on pre-synaptic cell align with dendrites on post-synaptic cells

types of joints

junctions b/w bones = joints -fixed=no movement -synovial = limited movements in certain directions depending on type of synovial joint (hinge joints, ball and socket joint)

gel electrophoresis

lab technique sued to separate DNA fragments or proteins by size and charge: 1) separate DNA into single strands and chop it up into various sized fragments using restriction enzymes (endonucleases) 2) place the fragments into little wells in an agarose gel 3) attach a negative electrode to the well side and a positive one on the other side to pass an electric current through the gel 4) DNA is negatively charged so it is attracted to the positive side 5) the gel acts as molecular sieve: the rate at which the fragments move to the opposite side depends on their size and charge --> more negative and smaller fragments will move faster 6) DNA is dyed with methyline blue to reveal the banding pattern created by staggering

difference in cancer cells

large number, little cytoplasm, multiple nuclei, irregular shape,

vacuole

large water filled sac that maintains cell turgidity in plant cells (pressure against cell wall)

aorta

largest artery through which blood exits the heart to be distributed by branch arteries to capillaries through the body

hydrophobic

less attracted to water = insoluble/non-polar ex. lipids, amino acids w/ non-polar R groups

crossing over for linked genes

linked genes only form new allele combinations if sections of DNA are swapped b/w non-sister chromatids during P1 which forms recombinant individuals

steroids

lipid based hormone w/ 4 fused carbon ring structure (4 pentagons/hexagons) ex. cholesterol, estrogen, testosterone

triglyceride

lipid made through 3 condensation reactions of 1 glycerol and 3 fatty acids. creates 3 ester bonds and water molecules. function: longterm energy storage ex. adipose fat in animals and oil in plants

phospholipid

lipid made through condensation reaction of 1 glycerol, 2 fatty acids, and a phosphate group. amphipathic bc phosphate = hydrophilic, fatty acids = hydrophobic function: main component of cell membranes

stroma

liquid w/ enzymes and pH for Calvin cycle including rubisco/RuBP carboxylase, naked DNA, 70s ribosomes, lipid droplets, starch grains for carb storage until exported

locus

location of a gene for a specific trait on a chromosome the gene for a certain trait is located at the same locus and on the same chromosome for all organisms of the same species

short tandem repeats

loci in a chromosome where 2-9 bases of non-coding DNA repeat many times, the # of repeats varies per individual (can be 10-100 total bases): -related individuals tend to have a very similar # of repeats -unrelated individuals are very unlikely to have the same repeats - identical twins have the exact same #

flagella

long tail-like structure that aids in cell movement (found in both eukaryotic and prokaryotic)

kidney transplant

long-term treatment for kidney failure: -person can live w/o a kidney so can donate one of them (family member usually) or from recently deceased body -blood and tissues types need to match b/w patient and donor to minimize rejection by patients immune system -donated kidney connected to renal vein, artery, and ureter -patient needs to be on immune-suppressant drugs for rest of their lives to prevent rejection

peristalsis in small intestine

longitudinal and circular muscles in the lining of the small intestine contract in waves above and at the food bolus to keep it moving towards large intestine and to mix it with enzymes involuntary contraction directed by autonomic nervous system (don't need to think about it)

antibiotic resistance

longterm use + overuse of antibiotics causes bacteria to evolve/obtain resistance gene making them unaffected by antibiotics, may be resistant to 1 or multiple, if gene spreads through population new resistant strain forms increasingly common so need to discover new antibiotics MRSA = Methicillin Resistant Staphylococcus aureus is a multi-resistant staph infection causing bacteria posing major health threat

chromatin

loosely coiled DNA strands

light intensity as limiting factor

low = rate of photolysis / O2 production limited bc less light absorbed, e- not replaced so overall glucose production slows

concentration of CO2 as limiting factor

low =rubisco not effective bc too little collision b/w it and CO2 ATP and high energy e- used slower than produced restricting photolysis so no O2

temperature as limiting factor

low temp = less movement and collisions so much slower high temp = enzymes are decreasingly effective and eventually denature , specifically rubisco enzyme that fixes carbons low consumption rate of ATP and high energy e- restricts photolysis so no oxygen produced

temperature and enzyme activity

low temp. = molecules move slowly so don't collide as often causing low reaction rate increasing temp.= higher temp. causes higher molecular motion so collide more so react more high temp. = enzyme denatures/loses shape and function so no more enzyme-substrate binding bc no active site so reaction rate decreases

LH

luteinizing hormone gland: pituitary gland in the brain effects: - causes the mature oocyte to burst out of the follicle and ovary during ovulation - causes formation of corpus luteum out of burst follicle

white blood cells/leukocyte types (don't need to know)

lymphocytes for specific immunity = B and T cells granulocytes: release histamine + are short lived attackers for localized inflammatory response = basophils/mast cells, neutrophils, etc. monocytes eliminate invaders through phagocytosis/endocytosis + perform antigen presentation = macrophages, become dendritic cells during antigen presentation

chlorophyll

main photosynthetic pigment in chloroplasts (thylakoids) of green plants

homeostasis

maintain a stable internal environment (pH, temperature, water, etc...)

homeostasis

maintenance of a stable internal environment within normal range of values for life functions to be possible e.g. blood glucose concentration, pH, blood CO2 concentration, body temp, H2O balance in tissues

declining male fertility

male sperm count is declining by 2% each year and by 50% in last 50 years due to environmental estrogen and progesterone levels rising from female oral contraceptive pills and plastics in food packaging that form pseudo-estrogen steroids

diffusion of ions into roots

mass flow: -ion concentration in soil is higher so mineral ions bind to soil particles and diffuse passively into the root through protein channels along gradient -ions dissolve in water so root becomes hypertonic compared to soil causing water to come in by osmosis -water carries more dissolved minerals when it enters

movement across membranes

materials move to create dynamic equilibrium = continuous movement of particles but no concentration change through diffusion, facilitated diffusion, osmosis and active transport

pH

measure of H+ ion concentration basic = pH 7-14 bc more OH- concentration neutral = pH 7 acid=pH 0-7 bc more H+ concentration

stages of meiosis

meiosis 1: Prophase 1, metaphase 1, anaphase 1, telophase 1 interkinesis but no DNA replication in between meiosis 2: Prophase 2, metaphase 2, anaphase 2, telophase 2

crossbreeding

members of different species breed producing infertile hybrids

interbreeding

members of the same species breed producing fertile offspring

root apical meristem

meristem cells located at the tip of roots that provide cells for elongation of roots throughout soil

cell respiration

metabolic pathway: controlled release (by enzymes) of energy from bonds in organic compounds that is trapped in the form of ATP molecules.

functions of life in Chlamydomonas

metabolism/respiration: enzymes catalyze chemical reactions in the cytoplasm + Diffusion of gases + Large surface area to volume ratio reproduction: binary fission (asexual) + nuclei can fuse (sexual) sensitivity/response: light sensitive "eyespot" = swims towards it homeostasis: contractile vacuoles fill up with and expel water to keep within tolerable limits excretion: diffuse waste out of cell membrane nutrition: Photosynthesis (chloroplasts) + Cellular Respiration (mitochondria) Growth: increase in size w/ food consumption movement: 2 flagella like tail to move through water towards light

less significant GHGs

methane = has a greater warming potential than CO2 but bc of short lifespan (12 yrs before oxidized vs 50-200 yrs for CO2) it is 200x less abundant than CO2 so has less of an impact/is less of a concern nitrogen oxides (NOx) = warming potential 100x CO2 but concentration 1000x less than CO2 = less of an impact + less of a concern

thermal properties of water vs methane

methane and water have similar molecular mass but methane is non-polar while water is polar and hence can form hydrogen bonds/stronger intermolecular forces heat capacity: hydrogen bonds restrict movement so more energy stored by vibrating particles = water has higher heat capacity boiling point/heat of vaporization: higher for water bc more energy needed to overcome hydrogen bonds melting point: higher for water bc hydrogen bonds lock molecules in place so need more heat to be overcome

carbon sink

method of storing carbon in ecosystems

Metaphase

microtubules attach to centromere region of chromosomes who line up in the middle

evidence of endosymbiotic theory

mitochondria + chloroplasts: -have their own naked+circular DNA (bacterial DNA) -have double membranes (og + vesicle) -reproduce independently through fission - 70s ribosomes

Golden Rice

modified rice grains to contain beta-carotene which is converted into Vitamin A in the body good for impoverished communities where vit A deficiency can cause blindness/vision issues

golgi apparatus

modifies proteins before they are used, stored or released from the cell in vesicles

polarity

molecule w/ uneven distribution of charge bc nucleus from one atom pulls more on the shared electron in a covalent bond (higher electronegativity)

enzyme-substrate collisions

molecules react when they collide with compatible reactants at high enough speeds/ with enough energy. more collisions = higher reaction rate substrates must collide with enzyme's active site to be catalyzed

enzyme inhibition

molecules that are either created to regulate reactions or come from foreign agents which reduce enzyme activity. reversible if the molecule and enzyme bind weakly, reversible if the molecule and enzyme bind covalently.

non-competitive inhibition

molecules that interact w enzyme at allosteric site causing it to change shape. active site no longer matches substrate so can bind but cannot be altered. significantly lowers reaction rate bc unaffected by substrate concentration since substrate cannot prevent inhibitor from binding may be reversible or irreversible. can also activate instead of inhibiting.

mono vs dicots

mono: -one cotyledon -parallel leaf veins -vascular tissue = complex arrangement -fibrous roots -flowers in multiples of 3 di: -2 cotyledon -netlike veins in leaf -ring shaped vascular bundle -taproot -flowers in multiples of 4-5

proteins

monomer: amino acid polymer: polypeptide chain or dipeptide function: S tructure (collagen+spider silk) H ormones (insulin) I mmunity (immunoglobins) T ransport (hemoglobins) S ensation (rhodopsin) M ovement (actin + myosin in muscles) E nzymes (rubisco)

carbohydrates

monomer: monosaccharides (glucose, ribose, galactose, fructose) polymer: di- (maltose, lactose, sucrose) and poly- (cellulose, starch, glycogen) saccharides function: mono +di = short term energy + source of carbon for other molecules, poly = energy storage + cell structure general formula (CH2O)n

lipids

monomer: none polymer: phospholipids, fats+oils (triglycerides), vitamin D, waxes, steroids (cholesterol) function: phospholipids = repel water/hydrophobic so component of cell membrane cholesterol = cell membrane fluidity triglycerides = longterm + more efficient but less accessible energy source, insulate + protect organs from shock

nucleic acids

monomer: nucleotides polymer: DNA + RNA + ATP

nucleic acids

monomer: nucleotides polymer: DNA + RNA, ATP/ADP function: reproduction + passing on genetic traits, DNA replication, protein synthesis

glucose

monosaccharide sugar used as main energy source and substrate in many metabolic reactions

carb monomer

monosaccharides (glucose, ribose, fructose, galactose) are source of energy

polyunsaturated fatty acids

more than one double bond b/w carbons resulting in several bends/kinks causing molecule to twist around itself. usually from plants + liquid at room temp. can add hydrogen to replace double bond

polyspermy

more than one sperm penetrates the egg during fertilization which kills the fetus

importance of sunlight

most ecosystems rely on sunlight as the main initial source of energy for producers which gets passed on through trophic levels, since energy is lost not recycled ecosystems need a continuous source of sunlight a few ecosystems live out of sunlight (ex. caves or the deep ocean)

zoonosis

most pathogens are species specific = can only infect one host/specieis zoonosis: disease that can be passed to humans from animals due to pathogens crossing species barriers (i.e. transmit b/w different species) -in viruses = due to mutation in membrane protein allowing binding to a new receptor on host cell in another species (caused by close contact b/w the two) -very rare -in bacteria and fungi = specific body temperature requirements so zoonosis is more common ex. HIV, swine and avian flu, COVID-19, ebola, rabies, tuberculosis

exocytosis

movement of material to the exterior of a cell: vesicles containing substances synthesized inside the cell fuses with the membrane so content is secreted from the cell requires fluid membrane

endocytosis

movement of material to the interior of a cell: macromolecules enclosed by a section of the membrane that then pinches off and enters cytoplasm requires fluid membrane

translocation

movement of organic materials (sugars=sucrose, amino acids, and hormones) from source to sink of plant through phloem

passive transport

movement of substance across a membrane where particles travel along concentration gradients (high to low), no energy required diffusion, facilitated diffusion, osmosis

active transport

movement of substances across a membrane where particles travel against concentration gradients using ATP energy. allows cells to have interior concentrations of substances different from exterior ones. endoytosis or exocytosis or channel/carrier proteins

emergent properties

multicellular: interaction of different types of cellular components allows the overall organism to obtain new functions that aren't part of the functions of the individual parts (the whole is more than the sum of its parts). ex. cells to tissues to organs to organ systems are all made of individual cells w/ inferior properties unicellular: individual cells each carry out all functions of life but in a group may interact to form more complex tasks

quaternary structure of proteins

multiple polypeptide chains combine forming a single protein maintained by the same bonds as tertiary structure: -disulfide bridges -hydrogen bonding -hydrophobic interactions (b/w non-polars) -ionic bonds (b/w acidic(-) and basic(+) amino acids) conjugated proteins: -contain a non-polypeptide structure called a prosthetic

adult stem cells

multipotent stem cells that maintain tissues + organs throughout life. less useful in medicine ethics: easier to harvest so no ethical issues

antagonistic muscle pairs

muscles only exert force when they contract so can only cause movement in one direction to produce opposite movement, another muscle is paired w/ it that contracts in the other direction

fallopian tubes

muscular ducts that egg is released into during ovulation + site of fertilization + leads zygote to the uterus for implantation

vagina

muscular tube leading from the external genitals to the cervix + accepts penis during intercourse

vas deferens

muscular tube that carries sperm from the epididymis to the urethra during ejaculation

oncogenes

mutated proto-oncogenes causing overstimulation of the cell cycle resulting in uncontrolled cell division

saltatory conduction

myelin sheath acts as insulator so no charge is leaked from the axon therefore on myelinated axons the action potential jumps from node to node -depolarization of one node causes depolarization of the next one (current/wave) advantages: -impulse travels faster bc skips most of the axon membrane -consumes less ATP bc only Na/K pumps located at the nodes are active

cis unsaturated fatty acid

naturally occuring: hydrogen atoms attached to carbons w/ double bonds are on the same side causing a bend which prevents molecules from being packed tightly. lowers melting point so liquid at room temp. (oil in plants)

action potential

nerve impulse is an action potential traveling across axon membrane: when threshold potential rises from -70mV to -50 mV: a rapid change in membrane potential occurs due to opening and closing of voltage gated ion channels causing depolarization and repolarization of the membrane forms self-propagating wave/local current bc depolarization of one area initiates it in the next raising membrane potential to threshold (-50mV) which opens ion channels

increasing HR

nerves: -medulla part of the brain has receptors which monitor blood pressure and CO2 levels (through pH) -if low oxygen and high CO2 levels in the blood (during exercise bc lots of cellular respiration) then medulla sends impulse down cardiac nerve to the sinoatrial node causing it to fire impulses faster speeding up HR hormones: - epipherine may be secreted into the blood by adrenal glands (above kidneys) causing HR and BP to increase during excitement, stress, exercise, anxiety to prepare for vigorous physical activity (needs O2 for aerobic respiration/energy) -also causes SAN to fire more frequently

peripheral nervous system (PNS)

network of neurons (nerves) carrying info to and from the central nervous system -from receptors to brain -from brain to effectors

optimum pH and temp. for most enzymes

neutral pH of 7 body temp. 37ºC

anaerobic respiration

no oxygen required faster but less productive (only 2-4ATPs) occurs in cytoplasm (glycolysis) glucose is only substrate other products: lactate in humans and CO2 and ethanol in yeast

2nd Line of Defense

non-specific immunity, innate: phagocytes (white blood cell) -squeeze out of capillaries + move to infected tissue -identify antigens on invader cell membrane -surround and engulf pathogens then digest through phagocytosis using enzymes from lysosomes -pus = large amount of phagocytes at infection site

origin of cells

not spontaneous generation. must form from pre-existing cells

telophase

nuclear membrane reforms + chromosomes uncoil into chromatin + spindle microtubules break down

diploid

nuclei that contain 2 copies of each chromosome/gene (1 from each parent) which form homologous pairs (except for sex chromosomes) 2n = 2 x the # of chromosomes in haploid cell of certain species somatic cells (all cells not part of reproduction) = contain 46 chromosomes in humans

haploid

nuclei that contain only 1 copy of each chromosome/gene bc they replicate through meiosis (1 parent) which halves the # of chromosomes of diploid cells n = # of chromosomes in haploid cell of certain species sex cells/gametes (sperm and egg cells contain 23 chromosomes in humans)

genetic code

nucleotides on the transcribed mRNA molecule form groups of 3 (triplets) called codons, there are 64 possible codon combinations, they originate from the nucleotide order on the DNA molecule each codon codes for 1 of the 20 amino acids found in proteins (some repeats so degenerate) and hence the codons on mRNA strands determine the sequence of amino acids assembled by it during translation (this codon to amino acid code is universal for all organisms) since the function of proteins depends on their shape which depends on the amino acids in their polypeptide chains, nitrogenous base sequences in DNA determine the function of cells through the proteins they produce

mitotic index

number of cells in mitosis / total number of cells used to predict speed of tumor growth for treatment

energy vs nutrient supply

nutrients: finite amount of nutrients so need to be released from dead organisms they're locked into through decomposition to return them to the environment for reuse = recycled energy: lost to environment along the food chain but continuous supply from the sun so doesn't need to be recycled bc will never run out (replenished), supply may vary if less sunlight due to particles blocking it

prophase 2

occurs in each daughter cell formed in the first division: -DNA recondenses into visible chromosomes w/ 2 sister chromatids -spindle fibers reform and centrioles move to opposite poles -nuclear membrane starts to break down again -NO CROSSING OVER

light dependent reaction

occurs in intermembrane space of thylakoids, photosystem 2 (680 nm) and photosystem 1 (700 nm) 1) photo activation: photon of light absorbed by a pigment in PSII part of the membrane and is transferred b/w accessory pigments until it reaches chlorophyll A where it excites an electron excited e- moves down carrier molecules in the thylakoid membrane/ETC progressively losing energy 2) photolysis: an H2O molecule is split using light energy forming 2e- + 2H+ + 1/2 O2. electrons created are used to replace the excited electron from stage 1, protons contribute to concentration gradient in inner membrane space, O released as waste product 3) photophosphorylation: energy released by e- in first ETC is used to pump H+ into inner membrane space creating gradient, protons diffuse through ATP synthase back into stroma causing photophosphorylation of ADP + Pi into ATP 4) another photon of light is absorbed by PSI and transferred by accessory pigments until it excites an e- in chlorophyll A then moves down 2nd ETC (e- from first ETC replaces e- in PSI) NADP is final acceptor that gets reduced to NADPH products: 12 NADPH and 18 ATP and oxygen

Kreb cycle

occurs in mitochondrial matrix: 1) acetyl lose the CoA and combine w/ 4C compound to form a 6C compound 2) REDOX: 6C compound is decarboxylated (releases CO2) and oxidized which reduces an NAD+ into NADH and forms 5C compound 3) REDOX 2: 5C compound is decarboxylated and oxidized again releasing another CO2 and reducing a 2nd NAD+ to NADH forming 4C compound 4) 4C undergoes further changes: reduction of a 3rd NAD+ into NADH reduction of FAD into FADH2, substrate-level phosphorylation of ADP + Pi into ATP then 4C restarts cycle occurs twice per glucose bc 2 acetyl CoA formed in link so products: 2 ATP 6NADH 2 FADH2 4 CO2 (waste)

light independent reaction / Calvin Cycle

occurs in stroma after the light independent reaction 1) carbon fixation: rubisco/carboxylase enzyme combines 6 CO2 w/ 6 ribulose biphosphates (5C) six times total forming 6 unstable 6C compounds (36 C total) that split into 12 glycerate 3-phosphates 2) REDOX: 12 NADPH and 12 ATP (from light reaction) oxidized to reduce 12 glycerate-3-phosphates (3C) into 12 triosephosphate (3C) then are recycled in light reaction 3) 2 TPs (6C total) turn into a carbon containing molecule (ex. glucose, complex carbs, lipids), 10 TPs (30C) modified using 6 ATP to regenerate 6 RuBPs (5C)

monounsaturated fatty acids

one double bond between carbon atoms creating bend / kink in molecule, less hydrogen. can add hydrogen to replace double bond

platelets

one large cell forms in bone marrow then breaks down into small + irregular cell fragments called platelets 8-10 day lifespan

gametes

one of two haploid reproductive cells, egg or sperm, whose union is necessary in sexual reproduction to produce a diploid zygote

non-coding DNA functions

operons: regulate gene-expression by promoting or repressing transcription of adjacent genes introns: w/in gene there are non-coding segments (coding segments = exons) that are removed from mRNA by splicing before translation telomeres: repetitive base sequence at ends of chromosomes that prevent parts of genes from being lost during replication tRNA and rRNA coding genes: to produce ribosome and transfer RNAs

pH and enzyme activity

optimal pH: high reaction rate out of optimal range: lower reaction rate bc presence of H+ ions in acids and OH- ions in bases interferes w/ enzyme-substrate binding at the active site and causes ionic R groups to attract to their environment not other R groups so protein may denature/change shape

vitamins

organic nutrients required for growth + metabolism obtained from food or stored don't give energy directly

heterozygous

organism that has 2 different alleles for a gene ex. Aa

homozygous

organism that has 2 of the same allele for a gene homozygous dominant = AA homozygous recessive = aa

evolution of different species

organisms of different species may have greatly similar DNA with only a few base substitution mutations that don't align, the accumulation of mutations in various genes separates organisms into different species

heterotrophs

organisms that are unable of synthesizing their own organic compounds so must obtain them by consuming other organisms (autotrophs or other heterotrophs) and their products (fruits, honey, eggs) internally digest the carbon compounds they consume (starch, proteins) in a digestive system in order to absorb them and use them (glucose, amino acids) can be herbivores, omnivores, carnivores, scavengers ex. fish, mammals, insects, zooplankton

Osmoconformers

organisms whose internal tissues are isosmotic and isotonic to surroundings so have same solute and water concentration as environment meaning water moves in and out freely so don't use energy limited to specific environments w/ stable water (i.e. mussels, jellyfish, crabs, squid)

Osmoregulators

organisms whose internal tissues have specific solute and water concentrations that may differ from environment concentration so have mechanisms that require energy to maintain concentrations most animals i.e. humans

chloroplast enveloppe

outer + inner membrane makes a compartment w/ enzymes for photosynthesis

diagram of mitochondrion

outer membrane inner membrane inter membrane space cristae ATP synthase matrix 70s ribosomes plasmids/naked DNA

fossilization

over millions of years, organic matter from past geological eras undergo lithification/turn into rocks such as coal and limestone when under heat and pressure

redox reactions

oxidation and reduction reactions that are the reverse of each other and occur in pairs/simultaneously throughout respiration to reduce electron carriers: one molecule is reduced, the other is oxidized allowing for the transfer of energy in the form of H atoms NAD+ into NADH FADH into FADH2 (gain H that contain e-)

polarity of water

oxygen is slightly negative bc attracts shared e- more (higher electronegativity), hydrogens are slightly positive. water has 2 poles (+ and -) = dipole

aerobic respiration

oxygen required to accept e- in ETC much more efficient (34-38 ATP) occurs in mitochondria reactants can be various carbs and lipids produces H2O and CO2

sex chromosomes

pair of chromosomes that determine the sex of an individual X and Y

source

part of plant where a compound is made (ex. photosynthesis occurs in leaves and stem, or from storage organ)

sink

part of plant where a compound is needed for use or storage but cannot be made (ex. growing roots and leaves or fruits/seeds)

facilitated diffusion

passive movement of large+polar molecules or ions across a membrane via aid of carrier or channel proteins

diffusion

passive movement of small+ non-polar molecules across a membrane along concentration gradients. only permeable to certain particles faster if: high temp, concentration or pressure, smaller molecules

mono vs polyclonal antibodies

pathogens have multiple antigen types so activate multiple B-cell types which produce multiple types of antibodies = unpure / polyclonal monoclonal = artificial production of pure antibodies / 1 type only which target only 1 antigen by hybridoma cells

competitive inhibition example

penicillin fills the active site of the enzyme transpeptidase preventing the binding of beta-lactam rings. inhibits cell wall synthesis in bacteria, killing them.

protein bonds

peptide bond between nitrogen in amine group and carbon from carboxylic acid of another amino acid forming polypeptides or dipeptides. condensation reaction=produces water molecule bc lose OH from carboxylic acid and H from amine

glycoprotein

peripheral protein w/ hydrocarbon chain attached used for cell-to-cell communication

Davson-Danielli model

phospholipid bilayer sandwiched in between 2 protein layers

structure of phospholipid bilayer

phospholipids are amphipathic: have a hydrophilic end (phosphate head) that points outward and a hydrophobic end (2 fatty acid tails / hydrocarbons) that points inward in the presence of water forming a bilayer. integral, peripheral, and glyco proteins embedded throughout. cholesterol embedded throughout

karyogram

photograph or diagram of all the homologous chromosome pairs in a cell arranged in order of decreasing length/size and ending w the sex chromosomes (visualization of karyotype) 1) stain cells to make chromosomes and their banding visible under light microscope 2) take photomicrograph of them during metaphase in mitosis when the chromosomes become visible 3) arrange the image of each homologous pair by decreasing length ending w/ the sex chromosomes (XX or XY)

nutrition

photosynthesis: use light, water and carbon to make glucose cellular respiration: use food to make ATP (usable energy) chemosynthesis: make ATP from inorganic compounds (ex. sulfur)

material exchange in the placenta

placental villi containing fetal blood vessels penetrate into the endometrium/uterus wall containing the mother's blood vessels for increased surface area and facilitation of material exchange materials from mother: glucose, O2, amino acids, vitamins, minerals, H2O, hormones, antibodies, some drugs materials from fetus (waste): urea, CO2, H2O, hormones (hCG)

abscisic acid

plant hormone that promotes stress responses: -closes stomata during drought -inhibits growth and development -causes seed dormancy -dormancy during winter -promotes death of leaves

cytokinins

plant hormone: -regulates cell division in roots and shoots -promotes secondary growth/regulates lateral bud growth -promotes nutrient movement into sink tissue -stimulates fruit development

gibberellin

plant hormone: -triggers germination in dormant seeds -causes stem elongation through cell division + elongation -promotes fruits

using stem cuttings for cloning

plant stem cuttings can be cut and grown in water or a solid medium to develop roots and grow into a clone of the plant that it was taken from

chloroplast

plants only: double-membrane structure w/ own DNA that uses water, light and carbon to produce food for the cell through photosynthesis

secondary immune response

plasma cells disappear after infection but small amount of memory cells persist in the blood stream and respond quicker + produce more antibodies if re-exposure to same pathogen occurs results in mild or no symptoms + much shorter infection as long as memory cells present = person is immune, some vaccines require several doses throughout life time to maintain memory cell levels

alveolar cells

pneumocytes = cells lining alveoli wall type 1 = site of gas exchange (permeable) -flat and thin = best SA:V ratio and shortest distance for diffusion -alveolar wall is made of single layer of these cells -occluding junctions prevent fluid leakage into air space -can't replicate if damaged type 2 = -cube shape = smaller surface area -produce and secrete surfactant granules = fluid that coats inner surface (stays moist) to dissolve oxygen (easier to diffuse) and reduce surface tension to prevent walls from sticking together when exhaling -able to replicate + differentiate into type 1 or 2 to replace damaged cells

absorption of glucose

polar so can't diffuse passively 1)Na/K pump in microvilli of epithelial cells pumps out Na into lumen of small intestine to increase concentration 2)Glucose and Na carried into villi simultaneously through co-transporter protein (active transport) -glucose moves against concentration gradient bc Na moves along concentration gradient 3) Glucose diffuses through channel protein from villus into capillary bed 4) glucose blood carried in blood vessels to liver where excess is converted into glycogen for storage

seed formation

pollen grain contains male gamete, ovules in ovary contain female gamete when they fuse they form a zygote/seed = fertilization

fertilization

pollen grain on the stigma germinates sending pollen tube down the style to the ovary male gamete goes down tube and fertilizes ovule that starts developing into a seed the ovary develops into a fruit containing the ovule/seed

environmental effects on polygenic inheritance

polygenic traits are genetically determined but they can also be influenced by environmental factors: - height depends on proper nutrition while growing - skin-tone depends on sun exposure

secondary structure of proteins

polypeptide chain forms alpha helix or beta pleated sheets maintained by hydrogen bonds

tertiary structure of proteins

polypeptide folds into 3D conformation due to interactions b/w R-groups of amino acids which determines its function: bonding: -disulfide bridges -hydrogen bonding -hydrophobic interactions (b/w non-polars) -ionic bonds (b/w acidic(-) and basic(+) amino acids) structure: -polar amino acids on the outside bc hydrophilic so want to interact w/ water -non-polar/hydrophobic amino acids in the center to avoid water contact

primary structure of protein

polypeptide: unbranched chain of amino acids bonded together by peptide bonds (covalent) sequence and # of amino acids is determined by the base sequence of the gene that codes for the polypeptide and determines next 3 levels of organization

making lactose free milk

pre-digest lactose molecules into glucose and galactose so they can be absorbed into the bloodstream by lactose intolerant ppl. - immobilize lactase enzyme extracted from microorganism into calcium alginate beads - pass normal milk through the beads so it can be digested - results in milk w/ glucose and galactose but no lactose

urine tests

presence of blood cells: infection or cancer presence of glucose: diabetes presence of proteins: HCG or insulin is normal, large proteins indicate disease presence of drugs: drug abuse (recreational or sports advantage)

William Harvey

previous blood flow theory = Galen Greek Philosopher -blood created in liver then pumped out by the heart and consumed in other organs Harvey's circulation discoveries (17th century): -unidirectional circulation w/ valves to prevent back-flow -blood not consumed it is pumped out of the heart through arteries then returns to the heart through veins -predicts fine vessels (capillaries) link arteries + veins but doesn't have microscopes to prove it

primary vs secondary xylem

primary grows during vertical stretch of plant stem secondary grows during widening of plant stem

carbon flux

process by which carbon is transferred from one sink to another estimates in gigatonnes per year bc can't measure actual values precisely

photosynthesis

process in plant cells and in other photosynthetic autotrophs (some bacteria, algae) used to capture energy from sunlight in the bonds of carbon compounds such as carbohydrates and lipids

progesterone

produced by the corpus luteum or placenta during pregnancy effects: - maintains thickened endometrium - inhibits LH and FSH (negative fb) - inhibits uterine muscle contractions throughout pregnancy

estrogen in the menstrual cycle

produced by the maturing follicle walls effects: -initially promotes ovary responsiveness to FSH to create positive fb loop of estrogen - causes endometrium to become highly vascular - eventually inhibits FSH and LH (negative fb)

karyotype

property of a cell described by the # and type of chromosomes present in its nucleus deduced from a karyogram

pros and cons of Bt Corn

pros: - higher crop yields bc less lost to pest damage - less land needed for crop production - less use of insecticide sprays which can harm humans and wildlife cons: - GMO corn pollen can spread to natural plant populations (cross-pollination) near the field which can kill the insects that feed on the wild plants e.g caterpillars of Monarch butterflies feed on milkweeds that grow near corn fields - pests can become resistant to Bt toxin

ribosomes

protein + RNA structure where translation occurs during polypeptide synthesis. 70s in prokaryote, 80s in eukaryote (bigger)

clotting factors

protein in blood plasma that activate blood clots heamophylia = disease w/ clotting factor deficiency so blood doesn't clot

fluid-mosaic model

proteins + cholesterol embedded within protein bilayer randomly creating diversity in function. membrane is fluid for function.

denaturing due to pH

proteins have optimal pH that they function at. when outside of optimal range bc increased presence of H+ and OH- ions prevent hydrogen bonding and causes ionic R groups to turn towards/away from environment instead of other R groups

Major Histocompatibility Complex (MHC)

proteins or glycoproteins that are unique to an organism which are coded for by genes on the 6th chromosome that are found on the cell membrane of all nucleated cells in an organism to identify them as "self" used by viruses to recognize and bind to host cells

historical CO2 and temp. changes

proxy data: in the antarctic, ice builds up over thousands of years so columns can be drilled out to analyze the gas bubbles and isotopes of hydrogen trapped in them which reveal changes in atmospheric CO2 concentrations and global temperatures over time results indicate that for the past 800,000 years there has been a correlation b/w CO2 concentrations and global warming vs cooling periods

enzymes in anabolic reactions

push substrates together to form bond b/w them

cell size/division

rate of metabolism depends on cell's volume. rate of material exchange depends on surface area. as a cell grows the SA:V ratio decreases (slow diffusion) bc volume increases faster than SA so in order for the cell to stay efficient/survive it must divide to increase the ratio. also divide if need to reproduce (survival of the species)

epididymis

receives sperm from testes and stores it for ejaculation

blood composition

red blood cells = erythrocytes white blood cells = leukocytes (i.e. lymphocytes, phagocytes, neutrophils) platelets = cell fragments plasma = liquid (mostly H2O) carrying other substances such as fatty acids + cholesterol, oxygen, glucose, CO2, hormones, clotting factors (protein), ions, thrombin and fibrin

centromere

region of the chromosome where sister chromatids are attached together becomes attached to the spindle fibers during anaphase so is split in 2

tandem repeats

regions in genome w/ repeating base sequences, # of repeats varies b/w individuals so used to identify ppl in DNA profiling

meristem

regions of undifferentiated cells that continue to divide and differentiate to form new tissues and organs throughout the lifetime of the plant, located at tip of shoots and roots when they divide one cell remains undifferentiated and one differentiates like stem cells in humans/animals

role of atmosphere

regulates the temperature on Earth's surface through the greenhouse effect to reduce large fluctuations when sunlight isn't present w/o atm. Earth's surface temp. would be -18ºC, w/ atm it is 14ºC

types of neurons

relay/inter : carry info b/w sensory and motor neurons in processing/decision making process sensory: transmit sensory info from receptors to the CNS for processing motor: transmit info from CNS to muscles or glands (effectors) to initiate a response

excretion

removal of potentially toxic waste products of metabolic pathways from the organism

kidney structure

renal artery - carries blood to kidney renal vein - carries blood away from kidney renal pelvis - collects urine ureter - drains urine into urinary bladder medulla -tissue surrounding renal pelvis that creates urine cortex - tissue surrounding medulla that also participates in urine production

RNA

ribonucleic acid

cell wall

rigid layer outside cell membrane present in plants and some protists (cellulose) + fungi (chitin) + not in animal cells used for structural support

cervix

ring shaped muscle that separates the vagina and the uterus to control when sperm enter and baby exits

risk of non-disjunction

risk increases with age of pregnant mother for older mothers (35+), karyograming is used to see if the baby has a trisomy or other genetic defect

saturated vs. unsaturated fatty acids

saturated: single carbon bond so more hydrogen atoms. straight tails unsaturated: double carbon bond so less hydrogen atoms. results in kink (bend) in the tail

tertiary structure of proteins

secondary structure folds into a unique globular 3D shape which determines the function of the protein. held together by interactions between R groups therefore sequence of amino acids determines 3D structure and function hydrogen bond = H and FON ionic bond = charged R groups disulfide bridge = b/w 2 sulfur atoms hydrophobic interaction = clustered on inside of structure

seminal vesicles

secrete a fructose-rich fluid into the ejaculatory duct as food for the sperm during ejaculation

prostate gland

secretes an alkaline fluid to protect sperm from the acidity of the vagina + to help them swim

plasma membrane

selectively permeable layer that controls what substances enter and exit the cell

outer membrane

separates mitochondria from cytoplasm and forms compartment for aerobic respiration (ETC and chemiosmosis)

hydrolysis reaction

separation of polymers into monomers (catabolic) +consumes H20 molecule (lyses water apart into H+ and OH-)

genes and proteins

sequence of amino acids in polypeptide chain is coded for by genes. 3 nucleotides in a gene form codon which match anticodon on a single amino acid. synthesized at ribosome. therefore genes determine the shape and function that a polypeptide chain assumes. differentiation means cells only express genes/proteins necessary for their function in organisms.

primary structure of proteins

sequence of amino acids linked by peptide bonds forming polypeptide chain. not affected by denaturing. coded for by genes. R group sequence determines 3D structure

single DNA/RNA strand structure

sequence of nucleotides held together by phosphodiester (covalent) bonds b/w phosphate group of bottom nucleotide and 3rd carbon of top nucleotide forming pentose-phosphate backbone

terminator

sequence of nucleotides that cause RNA polymerase and new mRNA strand to detach from DNA when transcribed example of non-coding region w/ a purpose

cell respiration

series of chemical reactions by which organisms release the chemical energy trapped in the bonds of organic compounds in order to convert it to useful energy that is stored in ATP energy carriers then used to carry out functions/activities (ex. muscle contractions or active transport)

proteome

set of all the proteins produced by cell, tissue, or organism (genome = all its genes). varies bc different cells make different proteins depending on function and time/genes expressed. unique to each individual bc small difference in amino acid sequence + activities so proteins may be separated by gel electrophoresis to identify an organism

flower

sexual organ of angiosperms (flowering plants) that can be hermaphroditic (male and female) or one gender only, develop from shoot apex

absorption spectrum

shows % absorption of different sized wavelengths of light by a pigment

food web

shows the network of feeding relationships b/w organisms in a community

Sickle Cell Anemia and Malaria

sickle shaped cells contain less potassium than normal cells which causes the Plasmodium parasite to die giving the carrier resistance to malaria

hormones

signaling molecules produced by en endocrine gland in one part of the body that travel through the blood stream to a different part where they induce a change they have specific target cells/tissues/organs that they can influence

climate change

significant changes in the Earth's climate: weather patterns, oceans, ice and snow, and ecosystems

Sickle cell anemia: Mutation

single base substitution mutation in the HBB gene (beta polypeptide of hemoglobin) of red blood cells which may be passed on to offspring but is autosomal recessive so need 2 copies of mutated gene for it to show (W. Africa + Mediterranean): -in a healthy cell the 6th codon is GAG which transcribes to the mRNA codon GAG which codes for the amino acid "glutamic acid" -in a mutated cell the second base of the 6th codon is changed to GTG which transcribes to the mRNA codon GUG which codes for the amino acid "valine" change of 1 base changes an amino acid in the polypeptide change which changes the structure and function of the hemoglobin protein which causes the disease sickle cell anemia

saturated fatty acids

single bonds between carbon atoms so saturated with hydrogen atoms resulting in straight molecule. solid at room temp. ex. bacon, butter, meat fat

Pyrimidine bases

single ring : cytosine and uracil/thymine

ribosomes

sized 70s like bacteria (endosymbiotic theory), used in protein synthesis

lamella

skeleton of chloroplast, keep grana at safe distance to avoid shading

primary defence

skin + mucous membranes act as physical barrier preventing pathogen entry into the body skin: -epidermis = out layer of tough dead cells -sebaceous glands = release fatty and lactic acid to prevent bacterial growth mucous membranes: -entry points that aren't covered by skin have cells that secrete sticky mucous (moist) to trap pathogens -lysozyme enzyme kills them -cilia also trap pathogens and move them out -located: nose, trachea, vagina, urethra

inter membrane space

small volume allows for accumulation of protons during ETC for chemiosmosis to occur

plasmids

small, independently replicating extra DNA loops found in the cytoplasm (not attached to main chromosome) of some prokaryotic cells which control unusual survival functions (not normal life functions) e.g. antibiotic resistance -may be exchanged b/w organisms through conjugation -used in genetic engineering

coronary artery disease risk factors

smoking diabetes (high blood sugar) hypertension chronic stress genetic factors diet / exercise (high cholesterol or mineral)

3rd line of defense

specific immunity, adaptive: 1) lymphocytes (B and T cells) display their unique antibody on the surface of their cell so when the targeted antigen binds to it (from pathogen directly or phagocyte presentation) a specific immune response is triggered 2) specific lymphocyte activated = clones itself (rapid mitosis) into plasma/cytotoxic and memory cells 3) plasma cells release large amounts of specific antibodies that circulate through the bloodstream tagging/marking pathogens 4) tagged pathogens: easier to identify by phagocytes, clump together so easier to engulf, are inhibited until destruction (i.e. binding site of viruses), cell walls rupture

gametogenesis

spermatogenesis = sperm creation in the testes of males oogenesis = oocyte creation in the ovaries of females common basic stages: -mitosis to generate large # of diploid cells -cell growth to have resources for 2 divisions in meiosis -meiosis to produce haploid cells -differentiation so the haploid cells form gametes with the structures needed for fertilization

anaphase 1

spindle fibers contract pulling apart homologous pairs by the centromere to opposite poles of the cell reduction division bc separates homologous pairs forming haploid sets

Anaphase

spindle microtubules pull the sister chromatids apart into chromosomes to opposite poles

cytokinesis

splitting of the cell after mitosis animals: plasma membrane pinches in at the equator (cleavage furrow) until it meets in the center dividing the cytoplasm and organelles plants: new cell wall (cell plate) develops at the equator splitting the cell

metastasis

spread of cancerous cells from the primary tumor to a secondary tumor in another tissue caused by cells detaching and traveling through blood or lymph vessels

seed dispersal

spreading seeds away from parent plant so they can grow without competing for resources methods include: fruits, wind, water, animals

granum

stack of thylakoids to maximize light absorption

flower drawing

stamen = male -filament -anther = pollen grains carpel/pistil=female -stigma -style -ovary = ovules/eggs -sepal -petal -receptacle -peduncle

pluripotent

stem cells able to form any type of cell in the body except tissues that surround embryo (ex. embryonic stem cells)

totipotent

stem cells able to form any type of cell in the body including extra-embryonic tissue

multipotent

stem cells that can only differentiate into limited selection of closely related cell types (ex. bone marrow forms different blood cells only)

Binding (fertilization)

step 2: several sperms reach the egg and try pushing through the follicle cells (corona radiata) until one of them binds to the zona pellucida which triggers the acrosome rxn

acrosome rxn

step 3: sperm that is binded to zona pellucida releases the enzymes in its acrosome which digest the glycoprotein layer so that the sperm can push through to the egg cell membrane

fusion (fertilization)

step 4: the sperm binds to a receptor on the egg cell membrane which causes it to fuse with the sperm cell membrane which pulls in its haploid nucleus to join the egg's nucleus, triggers oocyte to undergo meiosis 2 and the cortical rxn

cortical rxn

step 5: to prevent polyspermy fast block: Na+ diffuse accross egg membrane causing depolarization which repels sperms slow block: small vesicles called cortical granules fuse with the cell membrane and release their content into the zona p through exocytosis, the Ca 2+ ions and enzymes released cause cross-linking of the glycoproteins which hardens the zona p preventing any more sperm to push through it

flowering trigger

stimulus (length of night) causes change in gene expression in the shoot apex which makes it enlarge and differentiate into a flower

chromosome

structure in nucleus that contains/organizes genetic material either linearly (eukaryotes) or circularly (prokaryotes)

cellulose

structure: polysaccharide found in plants made of B glucose that alternate orientation creating linear strands. bonds between carbon 1 and 4 only so no branching function: linear strands held together by hydrogen bond cross links forming microfibrils w/ tensile strength. give plant cell walls turgidity/resistance to lysing when water absorbed. can't be digested bc humans lack enzymes

glycogen

structure: polysaccharide in animal cells made of A glucose that are all oriented the same way forming helical structure. bonds b/w C1 and C4 and C6 allows for branching every 10 glucose (more compact/dense than amylopectin). insoluble. function: glucose/energy storage in liver+muscle of humans (also in some fungi) bc insoluble so no osmosis issue. can easily add or remove glucose from ends

starch

structure: polysaccharide in plant cells made of A glucose that are all oriented in the same direction forming helical structure. amylose: bonds b/w C1 and C4 only amylopectin: bonds b/w C1 and C4 and C6 creating branching every 20 glucose function: insoluble glucose/energy storage so no issues w/ osmosis. branching allows glucose to be added or removed more rapidly bc more ends. can be digested

epidemiology

study disease distribution, pattern and causes in a population to determine where vaccination program necessary

epigenetics

study of reversible heritable changes (gene expression) that occur w/o changing DNA nucleotide sequence -small chemical markers attached to DNA determine pattern of gene expression = epigenome (ex. methyl groups) -patterns inherited by daughter cells through mitosis but are lost during gamete formation -new evidence suggests that a small % of markers can be inherited by offspring

antigen

substance (protein or glycoprotein) on the cell membrane of foreign organisms (pathogens, donor organs, blood transfusions, food) that identify them as "not self" and what type of pathogen to elicit the appropriate targeted immune response/antibody production viruses = protein coat / capsid

cohesion in living things

surface tension: insects walk on water capillary action: water travels against gravity through veins in humans or through xylem tubes in plants

embryonic stem cells

taken from blastocyst (formed from fertilized egg). pluripotent: can divide and differentiate into any type of cell in an organism (could form a complete organism). very useful in medicine ethics: harvesting kills embryo/technically murder. patient's immune system may reject donor cells so must be on immunosuppressant drugs for their whole life

chromatin

tangle of DNA strands and histone proteins contained in the nucleus or eukaryotic cells when not replicating

autoradiography

technique to capture image of the decay emissions of radioactive atoms from within a substance on photographic film using an emulsion to find where radioactively labelled substances are located in cells using an electron microscope

climate

temperature and precipitation patterns in a region over an extended period of time (thousands of years)

denaturing

tertiary and secondary structure of proteins falls apart but primary remains due to pH or temperature changes. protein loses shape so can no longer carry out its function. may be reversible or a permanent change.

structure of a seed

testa = protective outer layer micropyle = pore through which water enters cotyledon = food stores that turn into leaves plumule/epicotyl = embryonic shoot radicle = embryonic root

Genetic code

the 64 codons in the genetic code have the same meaning in cells of all organisms (some small variations) suggesting that all life evolved from the same og cells

membrane potential

the charge difference (voltage) across a membrane created by unequal distribution (concentration gradient) of ions on opposite sides of the membrane measured in millivolts (mV)

sense strand

the coding strand of DNA in transcription which has the same nitrogen base sequence (thymine instead of uracil) as the messenger RNA = isn't copied

genotype

the combination of alleles for a gene that an organism carries ex. Dd, DD, dd

genome

the complete set of genetic information of an organism expressed in # of base pairs (bp) in a haploid gamete, the total length of DNA note: the number of bases not the number of genes

importance of genetic variation

the creation of new combinations of alleles through sexual reproduction (crossing over, random orientation, fertilization) is crucial for the survival of species as new combinations could be formed that make populations more resilient/increase their chance of survival if there was no genetic diversity then a change in environmental conditions or a pathogen could wipe out an entire species

ventilation

the cycling/movement of fresh air in and stale air out of the lungs and alveoli via inspiration and expiration to maintain a favorable concentration gradient of CO2 and O2 b/w the air in the alveoli and the blood in the surrounding capillaries for passive diffusion of CO2 into the air and of O2 into the blood

maintenance of homeostasis

the endocrine system and autonomous nervous system cooperate to maintain homeostasis through negative feedback loops

zygote

the first cell of an offspring that develops into a fetus through mitosis

origin of the first cell

the first cells must have evolved from non-living matter (spontaneous generation). one of greatest challenges of biology

making human insulin

the gene that codes for insulin is extracted from human pancreatic cells and is inserted into a DNA plasmid from e. coli bacteria when the recombinant plasmid is inserted back into the bacteria they start producing human insulin which can be extracted to treat ppl w type 1 diabetes insulin used to be extracted from meat which caused allergic reactions

# of chromosomes

the number of chromosomes (use diploid number) is a characteristic feature of the cells of a certain species (e.g. all human cells contain 46 chromosomes) the number of chromosomes is indicative of the complexity of the organism (simple = few, complex = many)

antisense strand

the template strand of DNA in transcription which has the complementary base sequence to create a copy of the gene in the form of mRNA = is copied

ventricles

thick walled + muscular pumping chambers on both sides of the heart that pump blood out to the lungs and body through arteries left ventricle = thicker bc needs to pump blood further

end-product inhibition example

threonine is converted into the amino acid isoleucine in a 5 step metabolic chain in bacteria. isoleucine acts as a competitive inhibitor to the first enzyme in the reaction.

FOIL method

to determine the gametes of each parent in a dihybrid cross: first outer inner last

screening for transgenic organisms

to isolate the organisms in which the gene was successfully transferred: - can insert an antibiotic resistant gene along with the gene of interest and then apply an antibiotic to the population so only the successfully modified organisms survive -can insert GFP gene along with gene of interest so they glow in the dark

biomass

total mass of living matter within a given area or trophic level expressed in terms of living or dry weight per unit area (kg/m^2)

kidney failure

toxins build up in blood and solute concentrations aren't regulated so eventually fatal

respiratory system structures

trachea left + right primary bronchi lungs bronchioles alveoli ribs intercostal muscles diaphragm

health risks of trans fats and saturated fatty acids

trans: hydrogenation adds hydrogen to unsaturated fatty acid in food processing to straighten it. correlation b/w trans fat consumption and rates of coronary heart disease (CHD). in CHD deaths, fatty deposits in arteries have high trans fats concentration. tested other factors but no correlation found so likely causation. saturated fats: occur naturally. positive correlation for rate of CHD but some populations don't fit. Maasai in Kenya consume lots of saturated fats but have low CHD rates. Mediterranean consume lots of olive oil but have low CHD rates.

regulating gene expression

transcription activity regulated by 2 groups of proteins to control which genes are expressed: transcription factors: form complex w/ RNA polymerase at promoter to allow transcription to proceed regulator proteins: bind to DNA section outside of promoter and interact w/ transcription factors -activators: bind to enhancer sequence and promote complex formation = increase transcription -repressors: bind to silencer sequence and prevent complex formation = decrease transcription

HIV transmission

transfer of body fluids from infected to uninfected person: -any form of unprotected sex (vagina, penis, mouth, intestines) -hypodermic needle use by intravenous drug users -mother to child (placenta, child birth, breast milk) -blood transfusions + blood products (Factor 8 to treat hemophiliacs)

pollination

transfer of pollen grain containing male gamete from anther to nectar covered stigma with the help of external agents such as wind, water, and pollinators hermaphroditic flowers can self-pollinate (transfer w/in same flower or to another flower on the same plant) although cross pollination is better for genetic diversity

Genetic Modification

transferring the gene from an organism of one species (donor) to another (host) in order to introduce a new trait possible bc the genetic code is universal so the same bases and codons will code for the same amino acids

integral proteins

transmembrane (hydrophobic side in center, hydrophilic on outside) ex. carrier or channel

endoplasmic reticulum

transports material throughout the cell smooth ER = no ribosomes rough ER = ribosomes for protein development + transport

hemodialysis

treatment for kidney failure: -blood is pumped out of patients arm into machine for 3-4 hrs every 1-3 days -machine contains dialysis membrane w/ dialysate solution (fluid) on the other side -solute concentrations in the fluid are manipulated to control diffusion of urea, ions, glucose, and water out of the blood -filtered blood is pumped back into the patient

lipid bonds

triglyceride = glycerol + 3 fatty acids joined by 3 ester bonds phospholipid = phosphate group + 2 fatty acids joined by 2 ester bonds condensation reactions = produce 3 and 2 water molecules respectively

urethra (male)

tube via which semen and pee leaves the penis

dialysis tubing

tubing used to model absorption in epithelium of small intestine: -coca cola placed in tube made of dialysis material and placed in pure water -overtime, water is tested for presence of substances -glucose expected to diffuse through tubing bc small enough but caramel is made of large polymers doesn't diffuse

artery structure

tunica externa: thick/tough layer of collagen fiber tunica media: thick layer of muscle and elastin tunica intima: smooth layer of endothelial cells, lining, lumen/hole = narrow

vein structure

tunica externa: thin tunica media: thin elastic fiber + muscle layer tunica intima: endothelial cells/lining lumen/hole = wide valves present at intervals preventing blood back flow (leaks occur w/ age causing build up of blood)

cholesterol

type of lipid in animal cell membranes: amphipathic: 4 hydrophobic steroid rings that interact w/ fatty acid tails to control membrane fluidity at various temperatures. have small hydrophilic hydroxyl group aligned w/ phosphate groups

stem cells

undifferentiated cells that retain ability to divide and differentiate along different pathways: -self-renewal = ability to divide while remaining undifferentiated - potency = ability to differentiate into specialized cells necessary for embryonic development into multicellular organism as are source from which all other cell-types are derived

shoot apical meristem

undifferentiated meristem cells located at the tip of the shoot (stem + leaves) that provide cells for primary growth/vertical elongation of the stem and new leaves -undifferentiated cells in the center divide pushing other cells to the edge -cells at the edge differentiate then form auxiliary buds or extend stem

types of organism distributions in ecosystems

uniform = equal spacing b/w organisms random = unpredictable spacing clumped = cluster or group

gene

unit of inheritance: specific sequence of nitrogen bases found on specific location on DNA strand that codes for a specific polypeptide chain/protein and hence determines a trait

chi-square test purpose

used to compare 2 sets of categorical data/raw counts in order to determine if the difference bw them is statistically significant or by chance for goodness of fit: compare experimental results vs expected values for independence: association b/w 2 variables (ex. 2 species, or abiotic factor)

BMI

used to determine healthy body mass levels BMI= mass (kg) / height^2(m)

chi-square test of goodness of fit

used to determine whether a population follows the expected frequency of phenotypes (Mendelian ratio) or if they are significantly different which indicates that the genes are linked or affected by a factor 1) observed values are the frequencies of each phenotype in the population 2) turn Mendelian ratios (9:3:3:1) into percentages out of 16 and multiply by the total observed population to get the expected frequencies of each phenotype 3) degrees of freedom = 1 less than the # of possible phenotypes, p = 0.05 4) calculate chi-squared 5) accept null hypothesis if chi-squared is less than critical value from the table, accept alternative hypothesis if it is greater

potometer

used to measure rate of water uptake/transpiration: -fresh shoot is attached to capillary tube w/o letting air into it -the capillary tube is narrow and has an air bubble so as the water is taken up by the plant the bubble moves down -measuring the distance travelled per minute is the rate of transpiration

phloem

vascular tissue that transports sugars and hormones up and down the plant from source to sink

xylem

vascular tissue that transports water and dissolved minerals up the stem of plants from roots to leaves

monitoring ventilation

ventilation rate = inhalations or exhalations per minute -measured through observation -pressure sensores tidal volume = volume of air taken in or out with each breath -spirometer : breathe into tube to measure expired volume of air

Autosomal Genetic Diseases

very rare inherited diseases (1 in 2000 to 10,000 ppl) that are caused by certain alleles of genes found on autosomal chromosomes most are caused by recessive alleles of autosomal genes so can be passed on by carriers but only expressed by homozygous individuals for that gene, e.g. cystic fibrosis only a small proportion are caused by dominant or codominant alleles of autosomal genes, e.g. Huntington's disease Other examples: sickle cell disease, albinism

viruses + antibiotics

viruses use host-cell apparatus to carry out metabolic processes so cannot block viruses w/o harming the human host cell antibiotics don't work on viruses

spectrum of visible light

visible light (ROYGBIV)= range of wavelengths absorbed by pigments during photosynthesis R = longest wavelength of 700 nm V = shortest wavelength of 400 nm

Solvent properties of water

water able to dissolve polar substances bc "like dissolves like". also dissolve ions bc attracted to opposite dipoles so pulled apart from compound

hydrogen bonds

weak intermolecular force/ attraction between slightly positive hydrogen in polar molecule to slightly negative fluorine, oxygen or nitrogen atom in another polar molecule.

thyroxin

what: hormone made of 4 iodine ions and amino acids (iodine deficiency prevents its synthesis) that regulates body temp. and metabolic rate gland: thyroid in the neck trigger: body temperature target cells: all body cells but particularly the most metabolically active ones = liver, brain, and muscle cells effect: enters the nucleus of cells and acts as a transcription regulator which increases mRNA production and protein synthesis, the greater metabolic rate of the reactions causes heat to be produced which increases body temp.

polygenic inheritance

when 2+ genes influence the phenotype of a single trait forming an array of different phenotypes bc there are 2+ allelic pairs controlling it at different locis e.g. skin tone and height

threshold and impulse propagation

when a part of the axon membrane reaches threshold membrane potential of -50mV (rises from -70mV resting potential) an action potential occurs the action potential in one part of the axon triggers an action potential in the next part through local currents: -when Na ions diffuse into the axon during depolarization they diffuse along the axon horizontally into the adjacent resting potential section (current) causing positive increase in charge inside the section so potential rises to -50mV threshold at synapses: -threshold depends on the amount of neurotransmitters secreted/that bind so may need several neurons in the same location to pass threshold potential

positive feedback

when a receptor detects a stimulus and activates an effector to INCREASE the intensity or frequency of the effect until the stimulus is removed e.g. orgasm, child birth, lactation

negative feedback

when a receptor detects a stimulus/change in conditions out of normal range it activates an effector (gland, organ, or muscle) to induce an OPPOSITE effect until the stimulus is removed

random orientation

when bivalents line up during metaphase 1 and sister chromatids during metaphase 2, the direction of each chromosome is random --> since all 4 sister chromatids in a pair are different due to crossing over, each side of the cell will receive a different set of alleles creates genetic diversity because there are 2^n possible orientations for each chromosome in metaphase 1 and 2 so different combinations of alleles can be produced (2^23 = 8 million combinations per parent in humans)

blood clotting

when blood escapes from blood vessels = rapid cascade of rxns to block pathogens and limit blood loss, happens only when wound 1) damaged cells release clotting factors causing platelets to stick to area and activate releasing more clotting factors 2)clotting factors activate prothrombin into thrombin enzyme 3) thrombin catalyzes activation of soluble fibrinogen into insoluble fibrin 4) fibrin = fibrous protein that forms a mesh at the wound site trapping blood cells and platelets forming a clot 5) if exposed to air clot dries into a scab which falls off when the wound heals

herd immunity

when enough ppl in a population are immune to a disease/pathogen due to exposure or vaccination, it becomes harder for the pathogen to spread even b/w non-immune individuals so disease is eradicated

depolarization

when neuron passes its threshold potential (rises from -70 to -50 mV) gated Na channel proteins in the axon membrane open: -concentration gradient allows Na ions to passively diffuse (facilitated diffusion) along gradient through channel proteins into the cell causing inside to be instantaneously positively charged (+30mv) relative to outside -flips the charge /reverses potential