BIO 110 Exam 2

Enzymes

100

What is an enzyme? (Think: what kind of molecule is it, and what does it do?)

Protein(s) that catalyze reactions.

200

Name the two sites that molecules may bind to (on an enzyme).

What is the active site and the allosteric site.

300

When a substrate binds, it's shape must be similar to that of the active site. What is the model that best describes the specificity of the active site?

What is the "lock and key" model.

400

An enzyme ______ is the material upon which an enzyme acts. (Think: This is a reactant, and this + enzyme --> product)

What is the substrate. The substrates are the reactants that undergo the chemical reaction catalyzed by the enzyme.

500

You are a scientist studying the effects of a new drug (X) on an enzyme (Y) that controls levels of dopamine in the brain by catalyzing a series of reactions. Your control group consists of mice/-X and your experimental group consists of mice/+X. You have gathered information regarding your drug, and found that the molecular structure of drug X is slightly different than that of the substrate. The results are as follows: Controls have normal and expected levels of dopamine. Experimental mice have significantly lower levels of dopamine than the controls. After recording this data, you decide to study the structure of your enzyme using protein crystallography with and with out drug X. You find that the structure of your protein has been altered. What can you determine from this information? (Think: is this enzyme being inhibited? What sites are being taken up by drug X?)

Drug X is acting as a noncompetitive inhibitor. "the molecular structure of drug X is slightly different than that of the substrate..." - so it does not bind to the active site. It binds at the allosteric site. "The structure of your protein has been altered" is also characteristic of noncompetitive inhibition......................................................................... When a molecule binds to the allosteric site, it alters the shape of the active site and prevents the substrate from binding - no product is made.

Cellular Respiration

100

What are the three processes of cellular respiration?............. Which process produces the most ATP?............................... Do all cells go through all three processes?..........................

1. Glycolysis - some cells stop here (such as RBC's).............. 2. Citric Acid Cycle............................................................ 3. Oxidative phosphorylation..............................................

200

Where does each process occur within the cell?

Glycolysis: is a cytoplasmic reaction, occurs in the cytoplasm Citric Acid Cycle: mitochondria Oxidative Phosphorylation: Mitochondrial membrane

300

What are the inputs and outputs of glycolysis? How many carbons are in one glucose molecule? How many carbons are in one pyruvate molecule?

Inputs: 1 molecule of glucose, 2 ADP, 2 NAD+ Outputs: 2 pyruvate**, net 2 ATP, 2 NADH Glucose is a 6 carbon molecule, pyruvate is a 3 carbon molecule. Glycolysis involves "lysing" glucose (6C) to yield two pyruvates (3C + 3C).

400

Let's say you've got a complex cell that requires a lot more energy to operate its machinery. What molecules enter the next process and what are they converted to? Can you briefly describe this next step of cellular respiration?

Both (2) pyruvate enter the mitochondria and are converted to acetyl-CoA (2C molecule... the other carbon is grabbed by an oxygen to form carbon dioxide). Then, both acetyl-CoA molecules go into the cycle and are further broken into carbon dioxide... then a series of redox reactions occur. 1. Acetyl-CoA enters (2C) which sets off series of rxn's. 2. A chain of REDOX rxn's strips off electrons and carbons Yields: (2)CO2, lots of NADH, FADH, and a few ATP. 3. Empty carriers restart the process

500

What is the "series of special enzymes" within the mitochondrial membrane referred to during oxidative phosphorylation? What molecule is the last electron acceptor of the chain? (Think: this acts as a "magnet" to pull electrons) Chemiosmosis is used by which enzyme during oxidative phosphorylation? Explain briefly how chemiosmosis is used in ox. phosph. (what ion is being transported across the membrane and is acting as the driving force?)

What is the Electron Transport Chain Oxygen. ATP Synthase H+ is being pumped into the intermembrane space, so there is a higher concentration on one side of the membrane that the other, creates a concentration gradient which is the driving force to move ATP synthase ---> which converts ADP to ATP. thehttps://en.wikipedia.org/wiki/File:ATP-Synthase.svg http://12knights.pbworks.com/f/1272466806/chemiosmosis.jpg

Photosynthesis

100

_____ is used to synthesize ____ from _____ during photosynthesis.

"Light" is used to synthesize "sugar" from "CO2" Equation: 6H20 + 6CO2 --Light energy--> 6O2 + C6H12O6

200

Where does photosynthesis occur in a plant cell?

The chloroplast

300

What are the "disks" in the chloroplast called? What is their purpose?

Thylakoid: fluid filled membrane disks. "This structure increases stability and surface area for the capture of light"

400

What gives plants a green color, and how do plants absorb light?

Plant pigments, chlorophyll. These molecules selectively absorb light energy at specific wavelengths. They do not absorb green light, so it is reflected and that is why we see plants as green.

500

What are the three stages of the calvin cycle for dark reactions? Inputs/outputs?

1. Carbon Fixation 2. Reduction (6NADPH --> 6NADP+ + H+) 3. Regeneration Inputs: CO2, ATP, NADPH Outputs: G3P, 6-carbon molecule = glucose?

Cellular ReproductionMitosis/Meiosis

100

What does the chromosome of a prokaryotic cell look like? Does it undergo mitosis/meiosis?

One circular chromosome. Eukaryotes have many linear chromosomes. No- prokaryotes undergo "binary fission".

200

What are the 6 phases of mitosis (in order)

Pro, prometa, meta, ana, telo, cyto P P M A T/C

300

What gene, when mutated, causes cancer? What are the names of the non-mutated and the mutated genes?

When protooncogenes (good) become MUTATED (not good), they are called oncogenes (bad) which cause cancer ---> uncontrolled growth of cells.

400

Mitosis produces ___ 2n daughter cells, and meiosis produces ___ n daughter cells. So, mitosis produces 2n cells which are called _____ cells, and meiosis produces n cells which are called ____ cells. Mitosis is for the reproduction/production of _____ cells, and meiosis is for the production of _____ cells.

Mitosis produces "two" 2n daughter cells, and meiosis produces "four"n daughter cells. So, mitosis produces 2n cells which are called "diploid" cells, and meiosis produces n cells which are called "haploid" cells. Mitosis is for the reproduction/production of "somatic" cells, and meiosis is for the production of "gametic" cells.

500

During (meiosis or mitosis?), the process of ______ ______ of homologous chromosomes happens during (prophase I/II?), allowing each gamete to be unique and different from every other gamete. The egg (ovum) of a rabbit contains 22 chromosomes. How many chromosomes are in the somatic cells of a rabbit? a. 11 c. 22 b. 12 d. 44 Humans have 46 chromosomes. This number of chromosomes will be found in _____.

During meiosis, the process of crossing over of homologous chromosomes happens during prophase I...... Somatic, "soma", are diploid = 2n Gametes, sperm/egg, are haploid = n Rabbit gametes n=22 somatic 2n.... so 2(22) = 44. Haploid cells contain half as many chromosomes as diploid somatic cells. http://highered.mheducation.com/novella/MixQuizProcessingServlet

Genetics

100

How many alleles do diploid organisms have for each gene?

Two alleles for each gene, one on each homologous chromosome.

200

Suppose you met a couple that is expecting a child, and the mother and father are both heterozygous for brown eyes (represent using dominant (B) and recessive (b)). Brown is a dominant trait and blue is recessive. What are the chances of having a child with brown eyes? Blue eyes?...................................................... Let’s say the child is born and has blonde hair (which is a recessive trait). We do not know the exact hair colors of the mother or the father. What are the possible genotypes of the parents?

75% chance they will have brown eyes, 25% chance they will have blue eyes. 50% chance they will be a carrier......................... Possible genotypes are Rr x rr or rr x rr or Rr x Rr.

300

If there is the blending of two alleles, what is this called? What must both parents be in order for this to happen?............. What is it called when the phenotypes of both alleles are equally expressed?

Incomplete dominance, both parents must be heterozygotes.............. Codominance e.x.) blood typing

400

In summer squash, red fruit color (R) is dominant over yellow fruit color (r) and disk-shaped fruit (D) is dominant over sphere-shaped fruit (d).. If a squash plant true-breeding for red, disk-shaped fruit is crossed with a plant true-breeding for yellow, sphere-shaped fruit, what will the phenotypic and genotypic ratios be for:...... a. the F1 generation?.............. b. the F2 generation?.............. c. What is the ratio that you will always see for the F2 generation when you cross the F1 generation(of the true breeding parents?

a. the F1 generation? All F1 progeny will be heterozygous for both characters (RrDd) and will have white, disk-shaped fruit ..................................... b. the F2 generation? RrDd (red, disk-shaped fruit) X RrDd (red, disk-shaped fruit)........... c. What is the ratio that you will always see for the F2 generation when you cross the F1 generation(of the true breeding parents?- so RrDd x RrDd?........ 9:3:3:1 phenotypic ratio

500

In a disputed parentage case, the child is blood type O while the mother is blood type B. What blood type would exclude a male from being the father?....... A. O.... B. A.... C. B.... D. AB... Red-green color blindness is X-linked recessive. A color-blind woman has a child with a man having normal vision. Which phenotype is definitely NOT expected for the child? A. color-blind female B. color-blind male C. female with normal vision D. all of the above are possible phenotypes for the child.

D. AB Child is ii. Mother is I^a i Father can either be I^a i or I^b i. Cannot be I^a I^b, because some children will only be carriers of i. A. color-blind female XrXr crossed with XRY yields 2 XRXr, 2 XrY. 100% females non-colorblind carriers, 100% males colorblind.