exam Flashcards
(39 cards)
Which one of the following statements correctly describes “telomerase”?
Select one:
a. It creates repetitive DNA at the end of the chromosomes.
b. Telomerase uses the DNA as a template for synthesizing a new strand.
c. Activity of this enzyme is inhibited in many cancerous cells.
d. This enzyme is active in all dividing cells.
a. It creates repetitive DNA at the end of the chromosomes.
A young cat has never had much energy. He is brought to a veterinarian for help and is sent to the animal hospital for some tests. There they discover his cells produce much more lactate than normal cats. Of the following, which is the best explanation for his condition?
Select one:
a. His cells lack the transport protein that moves glucose across the mitochondrial membrane.
b. His cells cannot move NAD+ from glycolysis to the mitochondrial electron transport chain.
c. His cells have a low O2 concentration so he is using fermentation for energy.
d. ATP Synthase is overactive.
c. His cells have a low O2 concentration so he is using fermentation for energy.
Determine the type of reaction and ∆G demonstrated in the diagram below. Would you expect the products to store more or less energy than the reactants in this situation?
a. Exergonic; ∆G is negative; more energy stored in products. I
b. Endergonic; ∆G is positive; more energy stored in products.
c. Endergonic; ∆G is negative; less energy stored in products.
d. Exergonic; ∆G is positive; more energy store in products.
e. Exergonic; ∆G is negative; less energy stored in products.
e. Exergonic; ∆G is negative; less energy stored in products.
Which one of the following statements about nucleosomes is INCORRECT?
Select one:
a. The nucleosome core contains an octet of 8 histone proteins.
b. The nucleosome core is wrapped by the DNA double helix.
c. There are two copies of each histone protein in the nucleosome core.
d. Four copies of histone H1 are present in the nucleosome core.
d. Four copies of histone H1 are present in the nucleosome core.
Where is the electron transport chain associated with photosystem II found?
Select one:
a. Plasma membrane.
b. Thylakoid lumen.
c. Stroma of the chloroplast.
d. Thylakoid membrane.
d. Thylakoid membrane.
A thylakoid membrane is punctured/ripped (has a hole in it)! This damage will have the most direct effect on which of the following processes?
Select one:
a. The absorption of light energy by photosystem 1.
b. ATP synthesis by chemiosmosis.
c. The carbon fixation stage of the Calvin cycle.
d. The splitting of water for electrons.
b. ATP synthesis by chemiosmosis.
When would a cell utilize the process of exocytosis?
Select one:
a. When secreting protein and wastes from the cell.
b. When pumping protons down a concentration gradient.
c. When ingesting nutrients.
d. When replicating.
a. When secreting protein and wastes from the cell.
A membrane protein permits the movement of an ion into the cell along its concentration gradient. The energy from this movement is used to transport glucose out of the cell. This is an example of:
Select one:
a. primary active transport.
b. osmosis.
c. simple diffusion.
d. antiport.
d. antiport.
Why are fermentation reactions important for cell?
Select one:
a. They utilize oxygen.
b. They generate oxygen.
c. They regenerate NAD+ so that glycolysis can continue.
d. They produce alcohol used in alcoholic beverages.
c. They regenerate NAD+ so that glycolysis can continue.
White blood cells engulf bacteria through what process?
Select one:
a. Pinocytosis
b. Receptor-mediated exocytosis
c. Osmosis
d. Exocytosis
e. Phagocytosis
e. Phagocytosis
A metabolic pathway has the following series of coupled reactions. A→B→C
Reaction #A has a ΔG = -30kcal/mol
Reaction #B has a ΔG = +50kcal/mol
Reaction #C has a ΔG = -6kcal/mol
Identify each reaction as either endergonic or exergonic AND determine whether enough free energy is present for the coupled reactions to occur spontaneously.
Select one:
a. Exergonic, endergonic, exergonic, not spontaneous.
b. Endergonic, exergonic, endergonic, spontaneous.
a. Exergonic, endergonic, exergonic, not spontaneous.
A mutation to DNA polymerase that eliminated the 3¢-to-5¢ exonuclease activity would prevent: Select one: a. removal of base mismatches. b. ligation of the okazaki fragments. c. removal of the RNA primer. d. repair of deaminated bases.
a. removal of base mismatches.
Rotenone is a poison commonly added to insecticides. This molecule binds to the first electron carrier in the electron transport chain. Which of the following best describes the effect of rotenone on an insect?
Select one:
a. The insect will die because high levels of ethanol will be produced.
b. The insect will die because anaerobic respiration in unable to occur.
c. The insect will die because insufficient ATP was produced.
d. The insect will die because glucose can no longer be split to create pyruvic acid.
c. The insect will die because insufficient ATP was produced.
A cell whose cytoplasm has a concentration of 0.02 molar glucose is placed in a test tube of water containing 0.02 molar glucose. Assuming that glucose is not actively transported into the cell, which of the following terms describes the tonicity of the external solution relative to the cytoplasm of the cell?
Select one:
a. Hypertonic
b. Isotonic
c. Hypotonic
b. Isotonic
A chemical reaction with a negative ∆G fails to move forward (start). Why may this occur?
Select one:
a. The system is endergonic and requires the addition of ATP.
b. The activation energy has not been met.
c. A high concentration of the required enzyme is present.
d. The system is stable and thus not spontaneous.
b. The activation energy has not been met.
The conversion of NADH → NAD+ is known as \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_. The conversion of FADH2 FAD is known as \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_. Select one: a. Reduction, reduction b. Oxidation, reduction c. Reduction, oxidation d. Oxidation, oxidation
d. Oxidation, oxidation
The genome of a typical bacterium contains about 5 x 106 base pairs and can be replicated in about 30 minutes. The human genome is 600X larger (3 x 109 base pairs) and at the rate of a bacterium would require 300 hours (~12 days) to be replicated; yet the entire human genome can be replicated with several hours. How is this possible?
Select one:
a. Human DNA contains more origins of replication than prokaryotic DNA.
b. Human DNA polymerases work much faster than those of prokaryotes.
c. Eukaryotic DNA is simpler to replicate than prokaryotic DNA.
d. The nucleosomes of eukaryotic DNA allow for faster DNA replication.
a. Human DNA contains more origins of replication than prokaryotic DNA.
How does CO2 created during cellular respiration exit an animal cell?
Select one:
a. Antiport transporter.
b. Facilitated diffusion.
c. Carrier protein.
d. Simple (passive) diffusion.
a. Antiport transporter.
which of the following statements about energy and thermodynamics is correct?
a. earth is an isolated system
b. living organisms are closed systems
c. energy conversions can never be 100% efficient
d. the total amount of energy in the universe is always decreasing
b. living organisms are closed systems
for a reaction to be exergonic, which of the following must occur?
a. it must also be exothermic
b. there must be an input of energy to proceed
c. products must have less enthalpy than reactants
d. products must have less free energy that than reactants
e. the entropy of the products
d. products must have less free energy that than reactants
the inside of the cell has a high solute concentration relative to the surrounding solution. what’s the tonicity of the surrounding solution?
hypertonic
suppose 10 glucose molecules undergo glycolysis simultaneously. what’s the net total of ATP produced per glycolysis pathway?
a. 20
b. 40
c. 4
b. 40
which of the following is true regarding the KC
- CO2 is released
- ATP is produced by substrate level phosphorylation
- NADH and FADH2 will shuttle
- all of the above are correct
- all of the above are correct
a scientist studying respiration in algae observes that glycolysis has occurred but the KC is not active. what would be the most likely cause?
- lack of NADH
- lack of FADH2
- lack of acetyl coA
- lack of ATP
- lack of pyruvate
- lack of acetyl coA
