Biology Test 1
Major Themes Of Biology: Definition of Life (What Does It Mean To Be Alive?)
1. Organized (ordered structure) 2. Reproduce 3. Grow and Develop 4. Energy processing/control its own chemical reactions 5. Self-regulate (internal environment) 6. Responds to stimuli/environment 7. Evolutionary adaptation (adaptation over time: another type of adaptation is responding directly to environment)
Lipids: Phospholipids
2 fatty acids + glycerol & negatively charged phosphate group attached to glycerols third carbon (replace tail of fatty acid with phosphate head = phosphate head + 2 hydrocarbon tails -cells could not exist without: major component of cell membrane (form fits function: hydrophobic tails cluster in center and hydrophilic phosphate heads face into watery environment on either side of the membrane -membranes are fluid mosaics: diverse protein molecules in a fluid phospholipid bilayer ** SKIPPED SOME READING ON 5.1??
Intro to Organic Compounds: Carbohydrates: Disaccharides
2 monosaccharides linked through dehydration reaction (most common is sucrose: made of glucose + fructose (table sugar) -lactose (milk sugar): galactose + glucose -monosaccharides and disaccharides are simple sugars (glucose = blood sugar, fructose = fruit) -alpha linkages are candy, beta linkages are celery (SAME AMOUNT OF SUGAR)
The Cell: Prokaryotes
-DNA is coiled into a region "the nucleoid" -rigid, complex cell wall: protects cell and helps maintain its shape -some have sticky outer coat (capsule) that attaches to surfaces or other cells in a colony; capsule -> cell wall -> plasma membrane (big lump in cnenter = nucleoid with circular bacterial chromsomes) -surface projections (eg. flagella, fimbriae) -1/10 size of eukaryotic cell (.5um) -CYTOSOL = CYTOPLASM
The Nature of Scientific Inquiry Lab: Bacterial Ecology
-Ecology: relationship between organisms and their environment (physical (eg. temperature) & biological (organisms present)) **ENVIRONMENT has more to do with microbial communities that GENETICS of the host
The Chemical Basis of Life: Chemical Bonds: Electrons determine atom's chemical properties
-Electrons are located in different electron shells (number depends on atomic number: first shell has 2 e, others have 8) and travel in different orbitals (volumes of space where they are likely to be found: can only hold 2; how many e = # of orb x2); first shell has 1 orbital the rest have 4 -Only subatomic particle to be involved with chemical activity: number of electrons in valence/outer shell determines (more interactive if closer to filling shell; mores chemical bonds) -when two atoms interact to fill shells -> donate/take or share electrons -> result in them staying close together through attraction (chemical bonds) -ground state: e in least energetic state -how many in valence? 1-8 by column & draw lewis dot diagram around symbol
Intro to Organic Compounds: macromolecules: making/breaking them
-Enzymes (special macromolecules that speed up chemical reactions in cells) help with breaking & making bonds (end in -ase) 1) Making polymers: dehydration reaction (lose H20/water: one monomer loses H + another loses OH = lose H2O and make covalent bond) 2) Breaking polymers: hydrolysis (add H20/water: add H to one monomer and OH to adjacent monomer)
Intro to Organic Compounds: macromolecules
-Few important molecules for living things: carbohydrates, lipids, proteins, and nucleic acids (DNA/RNA) -Molecules of carbs, proteins, and nucleic can are gigantic macromolecules (cells make by making polymers: long chain of monomers (identical/similar building blocks) -Diversity: cells make from limited sets of small molecules (only 40-50: proteins have 20 amino acids and DNA has 4 nucleotides) -key to diversity is variation in arrangement/sequence of how they're strung together
The Nature of Scientific Inquiry Lab: Inquiry & steps
-Inquiry: search for explanations of natural phenomena 1) Observations (direct or indirect; qualitative or quantitative data; can make generalizations based on inductive reasoning) -> prompt us to ask questions -> seek answers through hypothesis 2) Hypothesis: a proposed explanation for a set of observations (must generate predictions that can be tested: if + and + then) 3) Testing hypothesis (use deductive reasoning to come up with ways to test)
The Chemical Basis of Life: Elements
-Matter (anything that occupies space & has mass) exists in three states: solid, liquid gas -Types of matter are composed of elements (a substance that cannot be broken down to other substances) -Combination of elements: compounds (example of emergent properties: compound has different properties than elements) -Organisms are composed of elements (96% of living matter is made of O, C, H, N)
The Cell: Eukaryotes vs. Prokaryotes
-Prokaryotic cells (prokaryotes): domain Bacteria and Archaea -Eukaryotic cells (eukaryotes): all the forms of life (protists, fungi, plants, animals): domain Eukarya -Share some features: 1) interior is filled with cytosol/cytoplasm 2) have 1 or more chromosomes (carry genes made of DNA) 3) ribosomes (make proteins)
The Nature of Scientific Inquiry Lab: Prokaryotes: Adapt Rapidly
-Reproduce quickly in a favorable environment: binary fissions allows doubling (but results in lots of genetic variation) -Genome is one long, circular chromosome (also have plasmids: small circular DNA molecules) -If environment becomes too harsh: endospore layer dehydrates and becomes dormant: will absorb water when it gets environmental cue that conditions are favorable -Diverse ways to obtain energy for cell work (sunlight: phototrophs or chemicals: chemotrophs) & carbon to build molecules (autotrophs: CO2; make it themselves & heterotrophs: organic compounds from other organisms)
The Nature of Scientific Inquiry Lab
-Science is a way of knowing: approach to understanding -Can never prove that hypothesis is true -Theory: supported by large and growing amount of evidence -Science is repetitive: reject hypothesis and make further testing to get closer & closer (best hypothesis is one that you want to disprove so you can eliminate) -Exploratory study: researchers explore what patterns exist before focusing on specific idea -Controlled experiment: designed to compare an experimental group with a control group (ideally, only differ in one factor: the one thats being tested) -Field study: done in nature instead of laboratory
Intro to Organic Compounds: CARBON: Functional Groups
-additions to carbon skeletons (add groups) change chemistry *all are hydrophilic/polar except methyl (C-O & O-H: polar, C-C & C-H: nonpolar) 1) hydroxyl group (-OH) 2) carbonyl group (-C=O) 3) carboxyl group (-COOH) *makes acids 4) amino group (-NH₂) 5) phosphate group (-OP₃²⁻) 6) methyl group (-CH₃)
Lipids
-all share one trait: do not mix well with water (hydrophobic) -neither macromolecules nor polymers -chains with just C-H (nonpolar) -important types: fats, phospholipids, and steroids -functions: 1) energy storage (fats) 2) structure (membranes) (phospholipid) 3) signals (steroids + hormones)
Intro to Organic Compounds: CARBON: Life's Molecular Diversity
-almost all molecules a cell makes are carbon + other elements -organic compounds: carbon based compounds that usually have hydrogen (just C + H = hydrocarbon) -carbon can form large & complex molecules: necessary for life (because C has 4 valences: can make 4 covalent bonds) -nearly all biological (organic) molecules are based on carbon skeleton/carbon chains: but same formula/different structure (shape) -> isomers -unique properties of organic compound depend on size/shape of carbon skeleton + the groups of atoms that attach to that skeleton (functional groups)
Protein: Amino Acids Linked Into Polypeptides
-amino acid: central C covalently bonded to: amino group (NH₂) + carboxyl group (COOH) + H + R (R= one or more C with various functional groups attached) [20 types of amino acids] -Amino acids are hydrophilic/hydrophobic depending on R groups -link to form polymers (polypeptides): dehydration reaction between carboxyl + amino of 2 different amino acids (results in covalent peptide bond) [peptide bond creates N-C-C backbone) -end of chain: n terminus (NH2 side) & c terminus
Lipids: Signaling Molecules
-carry messages between cells 1) prostaglandins 2) sterols -steroids: lipids in which carbon skeleton contains four fused rings eg) cholesterol: common component in animal cell membranes & precursor for making other steroids *don't look like lipids but they're hydrophobic = lipid
Lipids: Trans Fats
-cis is made naturally, trans is made by hydrogenation -unsaturated fats that have been converted to saturated by adding hydrogen -partially hydrogenated vegetable oils: desirable because they don't spoil as quickly as oils & associated saturated fat with heart disease in 1960s -now: know they are worse than saturated fats
Water's Life Supporting Properties: Hydrogen Bonds make liquid water cohesive
-cohesion: tendency of molecules of the same kind to stick together (water is stronger than most liquids: helps trees transport water from root to leaves -adhesion: clinging of one substance to another (in cell wall of plant veins pulls against gravity) -surface tension: how difficult it is to stretch/break surface of a liquid (high in water)
The Chemical Basis of Life: Chemical Bonds: Hydrogen Bonds
-dipole dipole interactions between polar molecules: dipole-dipole attraction (d+ of one molecule & d- of another) -living organisms are made of mostly strong covalent bonds but weak bonds are crucial to functioning: life cannot exist without water (eg. hydrogen bonds); weak but if you have lots they become stronger -water is a polar molecule: has an unequal distribution of charges (the ultimate hydrogen bonder) -positively charged H atom forms hydrogen bond with nearby partially negative O atom of another water molecule
Major Themes of Biology: Organisms exchange matter & energy
-ecosystem's two processes: recycling of chemicals & flow of energy -energy flow: enters as light -> plants make into chemical energy -> when animals consume food there is an outflow of heat -> leaves as heat (we exhange chemical energy: food: sun->heat) -matter cycles through
Water's Life Supporting Properties: ice is less dense than liquid water
-ice H bonds are stable (liquid H bonds are constantly breaking) -unusual property due to hydrogen bonds (usually solid is more dense) -as water freezes, each molecule forms stable hydrogen bonds with its neighbors, holding them farther apart, creating a 3D crystal shape
The Nature of Scientific Inquiry Lab: Prokaryotes
-lack membrane enclosed structures -diameters 1-5um -very important to life: found wherever life is (essential to health of the environment: decompose and return chemical elements to the environment, we would be doomed without them) -thrive in extreme environments -microbiota (microorganisms in our bodies) are more common then bacterial pathogens (disease causing agents) -2 types: archaea and bacteria
Major Themes of Biology: biology, technology, and society are connected ***
-science: understand natural phenomena (discoveries) -technology: apply scientific knowledge for some specific purpose (inventions) -interdependent: scientists use technology in research & scientific discoveries lead to development of technology -technology has improved standard of living but has consequences (climate change, toxic waste, deforestation) -> and solutions have to do with both science/technology & society (cultural values, politics, economy, etc.)
Major Themes of Biology: Cells are the fundamental unit of life
-smallest unit of life -lowest level of structure that has all the properties of life (smallest thing that can be alive: organelles and DNA are not alive) -two types: prokaryotic & eukaryotic -form a system: arrangements & interactions of structures -> properties of life
Water's Life Supporting Properties: Water is the near universal solvent
-solution: liquid mixture of two or more substances (solvent: dissolving agent & solute: substance that is dissolved) -aqueous solution: solution where water is the solvent -water's versatility as a solvent results from polarity of its molecules (dissolve ionic compounds because ions and water molecules (+H and -O) are attracted to opposite charges & dissolve polar molecules by surrounding with water molecules & forming H bonds with their polar regions); GOOD AT DISSOLVING POLAR MOLECULES (hydrophilic: can dissolve in water/has lots of polar bonds vs. hydrophobic: doesn't dissolve in water, NONPOLAR eg. oil)
Water's Life Supporting Properties: water can be acidic or basic
-some chemical compounds contribute additional H+ to an aqueous solution (acid: donates H+ ions) & some remove H+ (base: donates OH- ions) -pH scale: determines how acid/basic a solution is (0-14; 7 is neutral where H+ = OH-)
The Cell: Form & Function
-structural similarity underlies general function of each component (eg. manufacturing relies on connected membrane, breakdown/recycling/digestion occurs in membranous sac, etc.) -structure of cell is closely related to function (eg. cells that produce proteins have lots of ribosomes/rough ER)
Water's Life Supporting Properties: Hydrogen Bonds Moderate Temperature
-thermal energy: energy associated with random movement of atoms/molecules -heat: thermal energy transferring from warm to cooler matter -temperature: measures intensity of heat (average speed of molecules) -water has a stronger resistance to temperature change than most other substances (absorbs lots of heat) -heat is absorbed to break H bonds and released when they are made -evaporative cooling: when a substance evaporates, the surface of the liquid that remains behind cools down (breaking H bonds takes energy)
The Cell: Eukaryotes: Animals vs. Plants
1) Animals -lysosomes & centrosomes 2) plants -rigid/thick cell wall made of polysaccharide cellulose -plasmodesmata: channels that connect adjacent cells -chloroplast: where photosynthesis occurs -central vacuole: compartment that stores water & chemicals
Major Themes of Biology: examples of emergent properties
1) Biosphere (Florida) 2) Ecosystem (Florida Everglades) 3) Community (all organisms in the everglades) 4) Population (alligators in the wetlands) 5) Organism (alligator) 6) Organ System (nervous system) 7) Organ (brain) 8 Tissue (nervous tissue) 9) cell (nerve cell) 10) organelles (organelle nucleus) 11) molecule (DNA)
The Nature of Scientific Inquiry Lab: Prokaryotes: External Features That Contribute to their success
1) Cell Shape: -Sphere (cocci) -Rod shaped (bacilli) -Spiral (spirilla) 2) Cell Wall: enables them to live in a wide range of environments -Determine type with Gram Stain: gram-positive bacteria have simple walls with thick layer of peptidoglycan, gram-negative have thin layer -Cell wall can be covered by capsule: sticky layer to adhere to surface/others in colony 3) Projections -Flagella: tail -Fimbriae: hairlike projections; allow them to stick
The Cell: Energy Flow in Eukaryotes
1) Cellular respiration (plants + animals) sugar + O2 -> CO2 + H2O + energy 1) Photosynthesis (plants only) CO2 + H2O + energy -> sugar + O2
Major Themes of Biology
1) Definition of Life 2) Life is hierarchal with emergent properties at each level 3) Cells are the fundamental (smallest) unit of life (lowest level of structure that has all the properties of life) 4) Organisms exchange matter and energy with their environment 5) Form follows function 6) Unity and diversity of life are explain by evolution
Protein: Functional Shape Results from 4 Levels of Structure
1) Primary structure: amino acid sequence 2) Secondary structure: local folding (alpha helix or beta pleated sheet): segments of chain coil (a) or fold (b) into local patterns (maintained by hydrogen bonds) 3) Tertiary structure: shape of whole peptide chain; 3D shape (stabilized by interactions between R groups: hydrophobic R's cluster, hydrophilic R form hydrogen/ionic bonds or disulfide bridges) 4) Quaternary structure: arrangement of multiple chains (subunits); (four identical polypeptides/subunits associate into a functional protein)
The Nature of Scientific Inquiry Lab: Prokaryotes: Types of Bacteria
1) Proteobacteria: gram-negative & share a particular rRNA sequence 2) Gram-positive bacteria 3) Cyanobacteria: plantlike photosynthesis 4) Chlamydias: live inside eukaryotic host cells 5) Spirochetes: helical bacteria that spiral through their environment by rotating, internal filaments
Protein: Functions (Types)
1) enzymes: catalysts that speed up chemical reactions (lower energy necessary to make them happen) 2) membrane proteins: allow substances to enter/leave (membrane channels, membrane receptors), cell to cell communication, adhesion molecules, cellular identity (transport proteins & receptor proteins) 3) defensive & repair: antibodies in bloodstream, extracellular matrix proteins (wound healing, immune function), blood clotting 4) signal: hormones and other messengers that help coordinate activities 5) structural: bones, tendons & ligaments (long & thin: fibrous proteins), etc. 6) storage proteins: supply amino acids to developing embryos 7) movement: muscle contraction 8) determinants of cell shape: cytoskeletal proteins (fibers, microtubules, (cell mobility, cell shape),), DNA synthesis & repair
Intro to Organic Compounds: Carbohydrates: Polysaccharide Functions
1) function as energy storage (connected by alpha linkages: spiral, sugar + OH on own sides) -starch: in plants -glycogen: animals in liver/muscle to hydrolyze glycogen when need glucose 2) function as structural compounds (connected by beta linkages; long, flat and straight, OH & CH2OH together) -cellulose: tough plant cell walls: animals do not have enzymes to digest (passes through fiber) -chitin: structural polysaccharide in exoskeleton 3) function as "chemical signatures" on cells: ID tag to show its not an invader
Water's Life Supporting Properties
1) hydrogen bonds making liquid water cohesive 2) hydrogen bonds moderate temperature 3) ice floats because its less dense than liquid water 4) water is the solvent of life 5) chemistry of life is sensitive to acid/basic conditions
Cell: Small Size
1) surface-to-volume-ratio: need to have a surface area large enough to service the volume of a cell (small but have large surface-to-volume ratio) 2) plasma membrane: flexible boundary between living cell and its surroundings that regulates flow into/out of cell -phospholipids group into 2 layer sheet called phospholipid bilayer -nonpolar molecules can get across easily, but polar/ions need to go through membrane channels provided by membrane proteins
Major Themes Of Biology: Evolution
1) the unify theme of biology -Current forms of life evolved from a common ancestor in the distant past -The accumulation of small changes over (a lot of) time explains the diversity of life today 2) is genetic change -Many mechanisms of evolution -Natural Selection leads to adaptation
Major Themes of Biology: Evolution & Diversity/Unity of Life ***
Charles Darwin's book "On the Origin of Species" 1) Descent with modification: species living today arose from a successor of ancestors that differed from them (unity: descent from common ancestor, diversity: modifications) 2) mechanism of evolution: natural selection -observations: individual variation (in a population) & overproduction of offspring -inferences: unequal reproductive success (good traits reproduce, bad traits don't) & accumulation of favorable traits
Lipids: Fats
a large lipid made of glycerol (3c chain with OH attached to each C) & fatty acid (carboxyl group -COOH & a hydrocarbon chain 16-18 c long) -three fatty acids + glycerol = fat (eg. triglyceride) -unsaturated fatty acid: if hydrocarbon chain has double bonds (causes kinks and fewer H atoms can attach; bonds cannot rotate freely) mono or poly; essential nutrient (we cannot make ourselves), cis (bent more) or trans (liquid at room temp) -saturated fatty acid: fatty acid with no double bonds/maximum number of H (solid at room temp) -main function of fat: LONG TERM energy storage (9 cal vs. 4 cal in carbs); short term energy storage is glycogen (which can be used immediately)
The Cell: Cell Junctions (animals)
allow neighboring cells in animal tissue to adhere, interact, and communicate 1) tight junctions: two plasma membranes are knit tightly together by proteins; prevent leakage of fluid (eg. digestive tract) 2) anchoring junctions: fastening cells together into strong sheets (rivets); anchored to cytoplasm by intermediate filaments (eg. skin and muscle; tissues that stretch) 3) gap junctions (aka communicating junctions): channels that allow small molecules to flow through protein lined pores between them
The Cell: The Endoplasmic Reticulum
an extensive network of flattened sacs and tubules (major manufacturing site) 1) Smooth ER: metabolic processes -synthesis of lipids -process harmful substances/detox -storage of calcium ions 2) Rough ER (has ribosomes) -synthesis of membrane lipids/proteins, secretory proteins & hydrolytic enzymes -formation of transport vesicles (secretory proteins leave in vesicles-> golgi) -membrane making machine
Major Themes of Biology: Evolution: diversity of life ***
arises from differences in DNA sequences -entire library of an organisms genes: genome -diversity of life can be arranged into three domains: 1) bacteria 2) archaea 3) eukarya: protists (single-celled organisms), plantae, fungi, animalia)
The Chemical Basis of Life: Chemical Bonds: Ionic Bonds
attractions between ions of opposite charge (give/take electron so both get 8 valence) -Transfer of electrons moves one unit of negative charge from one atom to another -> results in -1 charge for atom that gained and +1 charge for atom that lost (atoms become ions: charged atom from gain/loss of electron) -when two opposite charges attract each other so much it holds them together -> ionic bond -environment affects strength
The Chemical Basis of Life: Chemical Bonds: Chemical Reactions
breaking existing chemical bonds and forming new ones -reactants (starting materials) -> product (material resulting from reaction) -same number of atoms before and after: just grouped differently (does not create/destroy matter; rearranged) -cells are constantly performing
The Cell: Mitochondria
carry out cellular respiration: convert chemical energy of food into chemical energy ATP (main energy for cellular work) -enclosed by two membranes -two internal compartments: 1) inter membrane space (outer inside) 2) mitochondrial matrix (inner inside) that contains mitochondrial DNA, ribosomes, and enzymes & is highly folded (cristae) to increase surface area to increase function
Major Themes of Biology: Life Is Hierarchal
emergent properties arise at each new level of complexity (properties don't exist until you get to next level of organization; eg. need brain to have personality) 1) Biosphere (environments that support life) 2) Ecosystem (all abiotic & biotic in an area) 3) Community (all biotic in ecosystem) 4) Population (1 species living in ecosystem) 5) Organism 6) Organ System 7) Organ (made of tissue) 8) Tissue 9) cell 10) organelle (membrane-enclosed structure in cell) 11) molecule (made of atoms)
Major Themes of Biology: evolution: direct observation of natural selection: coloration in guppies
female guppies are attracted to bright colored guppies 1) positive selective pressure: female mating preferences 2) negative selective pressure: detection by predators 3) observation: pools with few predators have brightly colored guppies & pools with aggressive predators have drab colored guppies -> experiment: move drab colored guppies to pool with fewer predators -> result: guppies because more brightly colored
Major Themes of Biology: Form
form (structure) has to be good enough to function -an animal's form is not a perfect design (just has to be good enough to do the function) -evolution works with what is available (natural selection: structure from past (ancestral) organism is adapted to function in descendant organism) -structure fits function at all levels of the body: tissue is made of similar cells that perform same function (specialized: structure allows them to perform a specific task) -> organ (made up of tissues that perform same function) -> organ system (made up of organs that perform same function) -> organism (many organ systems functioning together) -*** the integumentary system protects the body (skin, hair, and nails: section 20.11)
Tissue
groups of cells with a common structure and function (cells become specialized to perform special functions) -cells held together by sticky glue substance OR special junctions between adjacent plasma membrane -animals are made of 4 types: epithelial, connective, muscle, and nervous
The Cell: Eukaryotes
have a membrane enclosed nucleus/organelles: 1) genetic control (nucleus & ribosomes) 2) manufacture, distribution, and breakdown of materials -endomembrane system: rough ER, Smooth ER, golgi apparatus, lysosomes, vacuoles -peroxisomes 3) energy-processing (mitochondria & chloroplasts) 4) structural support, movement, and intercellular communication -cytoskeleton -plasma membrane -extracellular matrix (animals) -cell junctions -cell walls (plants)
The Nature of Scientific Inquiry Lab: Prokaryotes: Biofilms
highly organized colonies that prokaryotes attach to on surfaces -begin by secreting signal molecules to attract nearby cells into a cluster -eventually, produce gooey coating that glues them together: very difficult to remove
Major Themes of Biology: Evolution: unity of life ***
is based on DNA and common genetic code -DNA: chemical substance of genes (units of inheritance) -> genes are grouped into chromosomes -DNA controls all activities of a cell: provides blueprint for making proteins -DNA encodes cell's information based on arrangement of building blocks A, T, C, G,
The Cell: Vacuoles
large vesicles that have a variety of functions -in plants: act as a lysosome (digestive function), storage of chemicals & cell enlargement (central vacuole); water balance (contractile vacuole); pigments that attract, poisons to protect (large vacuoles holds water to help plant grow)
The Cell: The Extracellular Matrix
layers that helps hold cells together in tissues and protects and supports the plasma membrane (most cells synthesize and secrete materials EXTERNAL to the plasma membrane) -function: SUPPORT & REGULATION -made of glycoproteins (proteins bonded with carbohydrates) (mostly collagen) -may attach to the cell through other glycoproteins that bind to integrins (membrane proteins that transmit signals between ECM and cytoskeleton)
The Cell: Lysosomes
membrane-enclosed sac of digestive enzymes -compartmentalization: acidic environment, safe away from rest of cell 1) digest ingested food/bacteria: fuse with food vacuoles & release nutrients to cytosol (phagocytosis) 2) recycle: fuse to damaged organelles
The Cell: Peroxisomes
metabolic compartments that do not originate from endomembrane system (origin unknown) -diverse metabolic processes -breakdown of toxic hydrogen peroxide by-product -autophagy: digest other cells
The Cell: Endosymbiosis
mitochondria & chloroplasts were firmly small prokaryotes that began living within larger cells (after they were ingested) -they contain a single circular DNA molecule & reproduce similar to prokaryotes
The Cell: Golgi Apparatus
modifies, shorts, and ships macromolecules -also forms lysosomes and transport vesicles: after leaving ER, transport vesicles fuse to receiving dock (cis)-> products are modified (eg. add/remove sugars) -> shipping side dispatches protein into vesicle and it buds off (trans) (vesicles become lysosomes or vacuoles OR fuse to plasma membrane) -flattened sacs that are not attached
Intro to Organic Compounds: Carbohydrates: Monosaccharides
monomers (simplest): hook together to form polysaccharides -molecular formular: multiple of CH₂O: has OH (hydroxyl) group that makes sugar an alcohol & C=O (carbonyl) group that makes aldehyde sugar (glucose) or ketone sugar (fructose) -most common are glucose & fructose: isomers: only differ in arrangement of atoms (have 6c: C₆H₁₂O₆) -have 3-7 carbons: most common are 5c (pentose) or 6c (hexose) -convient to draw carbon skeleton as linear but hexose form rings: don't show C & H atoms at corners -hydrophilic: absorb water
Tissue: Organs
multiple tissues are arranged into organs that perform specific functions -in some organs, tissues are organized into layers -represent a higher level of structure than the tissues composing it
Names of Polymer Multiples
number of building blocks: 1) monomer 2) dimer 3) trimer 4) tetramer 5) oligomer 6) polymer
The Cell: The Endomembrane System
organelles that interact in the synthesis, distribution, storage, and export of molecules -includes: nuclear envelope, endoplasmic reticulum (ER), golgi apparatus, lysosomes, vacuoles, plasma membrane -physically connected OR tiny vesicles transfer membrane segments between them -largest component is the ER (membranes are continuous with nuclear envelope)
Tissue: Muscle Tissue
organized for contraction and movement -most abundant tissue; made of muscle fibers that contain contractile proteins -cytoskeleton arranged in parallel fibers; motor proteins pull on fibers to contract the muscle 1) Skeletal muscle: voluntary movements; striated appearance (for speed/strength), 2) Cardiac muscle: contractile tissue of the heart (involuntary); striated but fibers are branched (speed/stength but need uniform contraction) 3) Smooth muscle: involuntary body activities; lines walls of digestive tract, arteries, and other internal organs (spindle shaped (cylinder))
The Cell: Chloroplasts
photosynthesizing organelles of plants and algae (convert solar/light energy to chemical energy/sugar) -inner and outer membrane
Proteins
polymer of amino acids -every function in your body depends on! -functions depend on individual shape (eg. structural proteins are fibrous: long/thin & lysozyme are globular so they can attach to molecular target) -if shape is changed then function changes (denaturation: protein unravels and loses specific shape and thus function; can be from excessive heat) -primary structure determines final shape: interactions between side chains -> how it will fold (primary structure is recorded in DNA: gene (DNA: nucleic acids) -> transcription (RNA: nucleic acids) -> translation (protein: amino acid); 1 gene = 1 polypeptide
The Cell: Cell Wall (plants)
rigid extracellular structure that protects cells & provides skeletal structure to keep plant upright -fibers of cellulose embedded in matrix of polysaccharide & proteins -wood has secondary walls (lignin) -(does not isolate them) plasmodesmata: channels that connect adjacent plant cells (share water, nourishment, chemical messages)
Tissue: Nervous Tissue
sense stimuli and rapidly transmit information (communication network) -brain, spinal cord, and nerves -functional/structural unit: neuron (nerve cell): conducts electrical impulses (made of cell body, dendrites: receives impulses & axons: send impulses) 2 types: neurons (specialized to carry messages via electrical impulses) & glial cells (support cells)
Tissue: Epithelial Tissue
sheets of closely packed cells that cover the body surface and line internal organs and cavities (skin, inside of tubes/sac/blood vessels) -apical surface is exposed to outside (kertanized; makes more keratin as it moves from inside to outside; its dead for strong protective layer); the other side is basal surface & attached to rest of body -named according to number of cell layers (simple =1, stratified = multiple) & shape of cells (squamous: flat, cubodial (cube), columnar (columns)
The Chemical Basis of Life: Atoms
smallest unit of matter that retains properties of an element -subatomic particles: atoms are made of neutrons, protons, and electrons (p+n in nucleus, surrounded by e: balance charges to keep together) -e participates in reactions, p determines element, n is isotopes/atomic stability (radioactivity) -two most important Qs: how many e and where are they? -atomic number: number of protons in atom (make each element have unique type of own atom) -mass number: P+N in atom (similar to atomic mss) -isotopes: same P, different N (behave identical); radioactive isotopes decay nucleus spontaneously
Tissue: Connective Tissue: Loose Connective, Fibrous Connective, Adipose
sparse populations of cells scattered throughout a matrix that they produce themselves 1) loose connective tissue: bind epithelia to underlying tissues and hold organs in place (matrix of loose weave fibers in watery fluid) 2) fibrous connective tissue: forms tendons (attach muscle to bone) TMB and ligaments (bones to joints) LBJ (matrix of densely packed collagen: maximizes strength) 3) adipose tissue: stores fat in large, closely packed cells that pad/insulate body (matrix of loose fibers/fluid)
Tissue: Connective Tissue: Cartilage, bone, blood
sparse populations of cells scattered throughout a matrix that they produce themselves 4) cartilage: strong but flexible skeleton material that surrounds ends of bones (shock-absorbing) (matrix of collagen fibers in rubbery material) 5) bone: matrix of collagen fibers embedded in hard mineral substance of Ca, Mg, and P 6) blood: transports substance throughout body (extensive matrix of plasma: water, salts, dissolved proteins with red blood cells (carry O), white blood cells (defense), and platelets (clotting)
The Cell: Cytoskeleton
structural support, cell mobility, & intracellular transport -networks of protein fibers (3 types) that extend throughout cell Don't need to know?????? 1) microtubules (thickest): straight, hollow tubes of tubulins (types of globular protein) -readily disassembled; grow out of centrosome, which contains pair of centrioles -MOVEMENT OF ORGANELLES WITHIN CELLS (tracks them with motor proteins) -guide movement of chromosomes when they divide -main component of cilia and flagella 2) intermediate filaments: various fibrous proteins that supercoil into cables -REINFORCE CELL SHAPE, ANCHOR SOME ORGANELLES -more permanent fixtures 3) microfilaments (actin filaments): solid rods of actin (globular protein) twisted in double chain -3D network: helps support cell shape -CELL MOVEMENT: type of motor protein (myosin) interacts to cause contraction of muscle cells
Tissue: Epithelial Tissue: Functions
structure fits function 1) simple squamous: thin & leaky -> exchange materials by diffusion (eg. air sac of lungs) 2) cubodial/columnar: large amount of cytoplasm -> secretion/absorption of materials eg. cubodial: tube in kidney, columnar: apical surface have microvilli -> lines intestines) 3) stratified (many layers) lines surface subject to abrasion (protective barrier)
The Cell: Nucleus
the command center -contains genetic instructions encoded in DNA -> control the cell's activities by directing protein synthesis -DNA is organized into chromosomes: when not dividing, it is a complex mass of DNA/protein called chromatin -double membrane: nuclear envelope (pores to let molecules in/out and to connect to ER, the cells network of membranes) -nucleolus: where ribosomal RNA (rRNA) is synthesized -messenger RNA (mRNA) directs protein synthesis by moving into cytoplasm
The Chemical Basis of Life: Chemical Bonds: Covalent Bonds
two atoms share a pair of electrons (form a molecule) -valence capacity determines bonding capacity (how many bonds can be formed) -electronegativity: an atoms attraction for shared electrons -molecules with 1 element (eg. H2) exert equal pull because same electronegativity: nonpolar covalent bonds (C-H is nonpolar: C wants 4/8 & H wants 1/2 = equal pulling) -unequal sharing: polar covalent bond (more electronegative atom pulls electron closer to itself which makes itself more negative; slightly + and slightly - = uneven distribution); dipole d+ & d- (d- = more electroneg) -if pulling is so unequal one atom steals electron -> ionic bond -single, double, or triple bonds (eg. O has 6/8: wants to make 2 bonds or 1 double)
The Cell: Ribosomes
use instructions from the nucleus (written in mRNA) to build proteins -mRNA directs protein synthesis by moving into cytoplasm, attaching to ribosome, who translates it into amino acid sequence -free ribosomes are suspended in cytosol (proteins made here function within the cytosol) & bound ribosomes attach to outside of ER or nuclear envelope
The Chemical Basis of Life: Chemical Bonds: van der waals
weak interactions between weak nonpolar molecules (but lots of them=stronger)
