bio 1500 schul exam 2

examples of lipids

olive oil, bees wax, bacon fat

Identify the wavelengths (i.e. colors) of light absorbed by chlorophyll

red, blue, and violet light is absorbed and green light is reflected into our eyes

Summary of photosynthesis

requires: sunlight, water and co2 produces: glucose and o2 as a by-product

Ribosomes

site of protein synthesis

Photosynthesis

the process by which light energy is used to make carbohydrate molecules from co2 and water, takes place in chloroplasts

describe the mechanism of diffusion at the level of single particles and as a whole

the single particle moves randomly while the particles as a group tend to move to an area of lower concentration

effect of the great oxygenation event

-catastrophic for all life forms including cyanobacter (caused it) -generated new niches, opportunity to diversify -set the stage for geology and biology as we know it

Process of ATP to ADP and vise versa

-chemical bond of the third phosphate group is broken, releasing energy and forming ADP plus and an extra phosphate -chemical bond is formed between second and third phosphate group, costing energy and forming ATP

forms of potential energy

-chemical: the energy stored in the bonds between atoms that holds molecules together -Nuclear energy: the energy stored in the nucleus of the atom that holds the nucleus together -Gravitational energy: the energy an object has because of its position or height -Elastic energy: or stored mechanical energy, is energy stored in an object by the application of force

Name the four classes of organic molecules & the chemical subunits that each one is made of

-Carbohydrates: simple sugars -Lipids: fatty acids -Proteins: amino acids -Nucleic acids: nucleotides

todays signs of the GOE

-antioxidants, protection from oxidation -photo-oxidation: if photosynthesis is too fast, too much o2 damages chlorophyll

process of light reactions

-chlorophyll absorbs light and excites the electrons. These electrons leave chlorophyll and travel along the 2 electron transport chains, resulting in the production of NADPH. The electrons are replaced when water is split into electrons, protons, and oxygen in the thylakoid. O2 is released as a byproduct of photosynthesis. As electrons move along the electron transport chains, protons move into the thylakoid and build up a concentration gradient. The movement of protons down this gradient of protons and through ATP synthase results in the synthesis of ATP through chemiosmosis -ATP is synthesized, NADPH is generated, water is split apart and releases o2 as a byproduct

Recall the processes that lead to the Great Oxygen Event

-cynaobacteria evolved photosynthesis, much more efficient than heterotrophs, autotrophs spread fast -o2 was produced as a side-effect, lead to some o2 levels (about 3%) in atmosphere -minerals and ozone (protection from uv) layer formed -the free o2 was toxic to cells,lead to global extinction -o2 then reacted with methane (snowball ice age) -prokaryotes evolved way to use o2, then eukaryotes w cholorplast, then evolution of multicellular life

Describe the difference between the various alleles of a gene.

-differ in DNA sequence and therefore in protein structure they code for -there may be many different alleles of the same gene -any one person can have max of two different alleles (bc 2 chromosomes)

alleles

-different possible forms of the same gene

types of radiation from sunlight

-electromagnetic (visible light) -ultraviolet (causes skin cancer)

What are the key characteristics of scientific explanations?

-focuses on the natural world, not supernatural -learning what the natural world is, how it works, and how it got to be the way it is -not a collection of facts but an understanding -relies on testing ideas by figuring out what expectations are generated by the idea and making observations to find out whether the expectations hold them -reliable bc they are test but can be revisited when new evidence arrives -relies on checks and balances

what happens with the glucose after it is produced?

-makes other organic molecules of the plant -make ATP out of it where needed

forms of kinetic energy

-mechanical: movement of objects -electrical: energy from movement of electrons -thermal: heat energy, movement of heat -radiant: light energy, travels in waves -sound energy: sound energy in form of waves

misconceptions about natural selection

-mutations occur randomly, natural selection sorts among alleles, but it does not create new alleles -mutations are random but natural selection is not, not random which individuals are most likely to survive -nat sel is not goal directed, no internal drive for perfection ot complexity, a trait doesn't evolve because the animal "needs" it

why does the particles random movement result in a movement from high concentration to low concentration?

-particles move randomly on both sides -there are more particles at the side of high concentration -thus, it is more likely one will move from high to low concentration -this continues until even on both sides

natural selection

-phenotype are variable in population -offspring leave same/similar phenotype as parents (phenotype is heritable) -survival and reproduction depend on phenotype -future generations= genetic composition of population changes

put blooms taxonomy in order from lower thinking to higher thinking

-remembering: recalling facts and basic concepts -understanding: explaining ideas or concepts -applying: using the knowledge gained in new ways -analyzing: breaking the concept into parts and understanding how each part is related to one another; drawing connections among ideas -evaluating: making judgements; justifying a stand or decision -creating: putting information together in an innovative way; producing new or original work

common misconceptions about scientists

-science is flexible and may take multiple paths -science is done by unique individuals -embedded w a global scientific community which is essential to the expansion of scientific knowledge

energy

-the capacity to do work, measured in joules

process of calvin cycle

-the energy from ATP and NAPH are used to build glucose from CO2 and water -each of the 3 CO2 molecules binds w/ 1 molecule of RuBP, forming a 6 carbon molecule which divides into 2 G3P molecules. 1 G3P molecule is used to make organic compounds, the rest is converted into RuBP again.

what happens when a molecule is struck by a photon

-the energy is absorbed and excites an electron into a higher electron state -the electron quickly drops to its ground state releasing the energy as light (of a longer wavelength)

Endoplasmic Reticulum

A cell structure that forms a maze of passageways in which proteins and other materials are carried from one part of the cell to another.

difference between a hypothesis and theory

A hypothesis is either a suggested explanation for an observable phenomenon, or a reasoned prediction of a possible causal correlation among multiple phenomena. In science, a theory is a tested, well-substantiated, unifying explanation for a set of verified, proven factors.

Flagella

A long, whip-like filament that helps in cell motility. Many bacteria are flagellated, and sperm are flagellated.

Vesicle

A membrane bound sac that contains materials involved in transport of the cell.

cell wall

A rigid layer of nonliving material that surrounds the cells of plants and some other organisms.

visible light

Electromagnetic radiation that can be seen with the unaided eye, allows us to see colors

what happens when light strikes an object

It can be reflected, absorbed, or transmitted

If a molecule is described as 'organic,' then which of the following statements must be true?

It contains carbon.

What molecule does the electron end up in at the end of the two light reactions (i.e. After Photosystems II and I)?

NADPH

Difference between plant and animal cells

Plant cells have larger vacuoles, a cell wall, and chloroplasts

Mitochondria

Powerhouse of the cell, organelle that is the site of ATP (energy) production

how did earth look before and after the great oxygenation event

before: all organisms were heterotrophic prokaryotes after: prokaryotes evolved a way to use o2 (leading to evolution of cellular respiration), eukaryotes with chloroplasts (more effective photosynthesis and even higher o2 levels), evolution of multicellular life

The product of the light-independent reactions is a molecule called G3P. What does the cell use it for?

building carbohydrates such as glucose

Lysosome

cell organelle filled with enzymes needed to break down certain materials in the cell

Bioluminescence

chemical reactions generate light energy

chloroplasts contain the pigment ________

chlorophyll

why are these misconceptions harmful

discoruging to potential scientists bc it makes it seem like scientific discovery is a lonley process that you have to be a genius to figure out

first law of thermodynamics

energy is neither created or destroyed, but it can be change form

population

group of organisms that reproduce with each other

when a fat is described as 'saturated,' what is it saturated with?

hydrogen

two types of energy

kinetic and potential

two steps of photosynthesis

light reactions and light-independent reactions (calvin cycle)

ATP

main transport and source of energy in cells

What is the proton gradient used for?

making atp

What does the term 'carbon fixation' refer to?

making organic compounds

Phospholipids are important components of which cellular structure?

membranes

pigment

molecules that absorb light of a particular wavelength

kinetic energy

movement

phenotype

observable traits

Chloroplast

organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy (photosynthesis)

what does chlorophyll do with its energy

photosynthesis

What type of organisms are responsible for the production of most of the oxygen on Earth?

phytoplankton

difference between prokaryotes and eukaryotes

prokaryotes lack a nucleus and membrane-bound organelles, have circular DNA, and are typically much smaller

Golgi apparatus

stack of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum

potential energy

stored energy

diffusion over distance formula

t=(x^2)/2D t-time x-distance D- diffusion coefficient (depends on absolute temp)

absorption

the energy is transferred to the molecules of the object

reflection

the light energy that bounces off objects

During the light-independent reactions, the Calvin Cycle requires NADPH and ATP. Where does the cell get these molecules?

they are produced during the light reactions of photosynthesis

cell membrane

thin, flexible barrier around a cell; regulates what enters and leaves the cell

What is the overall function of photosynthesis, i.e. why do cells perform this process?

to make carbohydrates like glucose

adaptation

trait that increases fitness of individual with this trait relative to others without it -adaptation is a trait produced by the process of natural selection

when and when not is diffusion efficient?

very efficient within most cells but is not very useful over greater distances

What molecule is the source of the electrons in the electron transport chain?

water

What molecule is the source of the oxygen that is released as a byproduct of photosynthesis?

water

What molecule is the source of the protons that are used to establish the proton gradient?

water

evolution

- a change in allele frequencies in a population -natural selection is one mechanism of evolution

4 postulated of natural selection

-1) individuals vary in their traits -2) some of the variation is heritable and is passed to the offspring -3) more offspring are produced than survive to reproduce -4) survival and reproduction are non-random those with favorable traits reproduce most and pass their genes to the next generation -FAVORABLE TRAITS BECOME MORE COMMON

gene

-A segment of DNA on a chromosome that has instructions for building a protein molecule -specifies the sequence of amino acids that make up a protein

hydrolysis

a water molecule is added to the reactants

dehydration synthesis

a water molecule is removed from the reactants

fitness

ability to survive and reproduce in an environment

examples of carbohydrates

glucose, cellulose, chitin

Vacuole

Cell organelle that stores materials such as water, salts, proteins, and carbohydrates

Nucleus

Control center of the cell

Describe the relationships between the terms chromosome, gene, allele, and DNA

DNA is arranged on chromosomes in segments called genes. One gene tells the cell how to make one protein. Different variations of a gene are called alleles. Each parent passes one allele to the child for each gene

What is the result of dehydration synthesis?

Two molecules form a chemical bond with each other

Explain your observations of reddish light coming from Chlorophyll when lit with bright white light. Include a description of fluorescence in your explanation

When isolated, chlorophyll cannot pass that energy to other molecules, and much of the energy is released in the form of fluorescence. (red light has a longer wavelength than green)

which of the following could be the outcome of hydrolysis

a starch is broken into simple sugar molecules

fluorescence

a substance absorbs light energy and then re-emits it at a longer wavelength