Biology Exam 2

1.

1 point

The number of ATP generated by oxidative phosphorylation varies from 32-34 because

ATP synthase is not very efficient

NADH and FADH2 enter the electron transport chain at different energy levels

FADH2 pumps more H+ across the inner membrane than NADH

NADH and FADH2 enter the electron transport chain at the same energy levels

NADH pumps less H+ across the inner membrane than FADH2

2.

1 point

Which of the following sequences correctly represents the flow of electrons during photosynthesis?

NADPH -> chlorophyll -> Calvin Cycle

NADPH -> O2 -> CO2

H2O -> photosystem I -> photosystem II

NADPH -> electron transport chain -> O2

H2O -> NADPH -> Calvin Cycle

3.

1 point

Where does the Calvin cycle take place?

thylakoid membranes

thylakoid space

outermembrane of the chloroplast

electron transport chain

stroma of the chloroplast

4.

1 point

The direct energy source that drives ATP synthesis during oxidative phosphorylation is

the oxidation of glucose and other organic compounds

the transfer of phosphate to ADP

the flow of electrons down the electron transport chain

the affinity of oxygen for electrons

the H+ concentration gradient across the inner mitochondrial membrane

5.

1 point

What is the relatoinship between wavelength of light and the quantity of energy per photon?

They have a direct, linear relationship

They are logarithmically related

They are separate phenomena

They are inversely related

They are only related in certain parts of the spectrum

6.

1 point

When electrons flow along the electron transport chains of mitochondria, which of the following changes occur?

the pH of the matrix increases

The electrons gain free energy

ATP synthase pumps protons by active transport

The ETC complex proteins phosphorylate ADP to form ATP

7.

1 point

Once an enzymatic reaction reaches saturation, the only way to increase the reaction rate is by

adding heat to the reaction

adding more enzyme

competitive inhibition

feedback inhibition

adding more substrate

8.

1 point

Which of the following factors would tend to increase membrane fluidity?

a high unsaturated protein content in the membrane

a greater proportion of unsaturated phospholipids

a lower temperature

a greater proportion of saturated phospholipids

adding phosphate groups to proteins in the membrane

9.

1 point

A chemical reaction that has a positive delta G is correctly described as

catabolic

downhill rxn

spontaneous

endergonic

exergonic

10.

1 point

Which of the following membrane activities require energy from ATP hydrolysis?

movement of water into a cell

Na+ ions moving into the cell

facilitated diffusion

K+ ions moving out of the cell

Na+ ions moving out of the cell

11.

1 point

Which of the following is most similar in structure to ATP?

an amino acid with three phosphate groups attached

an anabolic steroid

a phospholipid

an RNA nucleotide

a DNA helix

12.

1 point

Succinate dehydrogenase catalyzes the conversion of succinate to fumarate. The reaction is inhibited by malonic acid. Increasing the ratio of succinate to malonic acid reduces the inhibitory effect of malonic acid.

Based on this information, which of the following is correct?

Succinate dehydrogenase is the enzyme, and malonic acid is the substrate.

Succinate dehydrogenase is the enzyme, and fumarate is the substrate.

Fumarate is the product, and malonic acid is a noncompetitive inhibitor.

Malonic acid is the product, and fumarate is a competitive inhibitor.

Succinate is the substrate, and fumarate is the product.

13.

1 point

The sodium/potassium pump works to

use facilitated diffusion to pump Na+ outside of the cell and K+ inside of the cell

actively set up a higher concentrations of Na+ inside of the cell and K+ outside the cell

actively set up a higher concentrations of Na+ outside of the cell and K+ inside the cell

passively set up higher concentrations of Na+ inside the cell and K+ outside the cell

passively set up higher concentrations of Na+ outside the cell and K+ inside the cell

14.

1 point

Membrane proteins function to

tranduce (send) signals between cells

join cells together

attach cells to the extracellular matrix

transport hydrophilic substances across the membrane of cells

all of the above

15.

1 point

http://i48.tinypic.com/35arw5j.jpg

What wavelength of light in the figure is most effective in driving photosynthesis?

475 mm

625 mm

575 mm

730 mm

420 mm

16.

1 point

Which of the following processes includes all others?

passive transport

transport of an ion down its electrochemical gradient

facilitated diffusion

diffusion of a solute across a membrane

osmosis

17.

1 point

Carbon dioxide is released during which of the following stages of aerobic cellular respiration?

glycolysis and the oxidation of pyruvate to acetyl CoA

the citric acid cycle and oxidative phosphorylation

oxidative phosphorylation and fermentation

fermentation and glycolysis

oxidation of pyruvate to acetyl CoA and the citric acid cycle

18.

1 point

Which of the following metabolic processes can occur without a net influx of energy from some other system?

amino acid + amino acid -> protein

6CO2 + 6H2O -> C6H12O6 + 6O2

ADP + Pi -> ATP + H2O

glucose + fructose -> sucrose (disaccharide)

C6H12O6 + 6O2 -> 6CO2 + 6H2O

19.

1 point

ATP synthase synthesize ATP by protons diffusing through it and

turning the rod, which turns the stator, which opens catalytic sites in knob to make ATP

turning the rotor, which turns the stator, which opens catalytic sites in knob to make ATP

turning the rotor, which turns the rod, which opens catalytic sites in knob to make ATP

turning the stator, which turns the rod, which opens catalytic sites in knob to make ATP

turning the rod, which turns the rotor, which opens catalytic sites in knob to make ATP

20.

1 point

http://i48.tinypic.com/35arw5j.jpg

Using the figure above, what is the optimal temperature for enzyme curve 2?

57*C

37*C

62*C

77*C

20*C

21.

1 point

Which of the following occurs in the mitochondria of a eukaryotic cell?

citric acid cycle and electron transport chain

electron transport chain and fermentation

citric acid cycle and glycolysis

glycolysis and fermentation

fermentation and chemiosmosis

22.

1 point

In mitochondria, chemiosmosis pumps protons from the matrix into the intermembrane space, whereas in chloroplasts, chemiosmosis pumps protons from

the stroma to the photosystem II

ATP synthase to NADP+ reductase

the intermembrane space into the matrix

the stroma into the thylakoid space

the matrix into the stroma

23.

1 point

http://i49.tinypic.com/2dl3uzd.jpg

Which of the follow best describes the reaction?

positive theta G, spontaneous, exergonic

negative theta G, spontaneous, exergonic

negative theta G, spontaneous, endergonic

negative theta G, nonspontaneous, endergonic

positive theta G, nonspontaneous, endergonic

24.

1 point

Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle?

ADP, Pi, and NADP+

ATP and G3P

electrons and H+

ATP and NADPH

ATP and NADP+

25.

1 point

Ions diffuse across membranes down their

concentration gradients

chemical gradients

electrical gradients

electrochemical gradients

26.

1 point

During a laboratory experiment, you discover that an enzymatic reaction has a delta G = -20 kcal/mol. If you double the amount of enzyme in the reaction, what will be the delta G for the new reaction?

+20 kcal/mol

-20 kcal/mol

0 kcal/mol

-40 kcal/mol

+40 kcal/mol

27.

1 point

When oxygen is released during photosynthesis, it is a by-product of which of the following?

reducing NADP+

the electron transfer system of photosystem I

chemiosmosis

the electron transfer system of photosystem II

splitting the water molecules

28.

1 point

When Dorthy threw water on the Wicked Witch of the West, the witch melted. The autopsy report stated the Witch's cells actually exploded. There we can conclude

Dorthy threw pure water on the witch and the witch's cells were isotonic to the water.

Dorthy threw pure water on the witch and the witch's cells were hypertonic to the water

Dorthy threw pure water on the witch and the witch's cells were hypotonic to the water.

Dorthy threw salt water on the witch and the witch's cells were isotonic to the salt water.

Dorthy threw salt water on the witch and the witch's cells were hypotonic to salt water

29.

1 point

What is the primary function of the Calvin cycle?

split water and release oxygen

synthesize simple sugars (G3P) from carbon dioxide

use NADPH to release carbon dioxide

use ATP to release carbon dioxide

transport RuBP out of the chloroplast

30.

1 point

Which of the following is a true distinction between fermentation and cellular respiration?

Only respiration oxidizes glucose.

Substrate-level phosphorylation is unique to fermentation.

NAD+ functions as an oxidizing agent only in respiration.

Fermentation, but not respiration, is an example of a catabolic pathway.

NADH is oxidized by the electron transport chain in respiration only.

31.

1 point

Which of the following statements regarding enzymes is true?

Enzymes increase the rate of a reaction

Enzymes are permanently altered by the reactions they catalyze

Enzymes increase the activation energy of a reaction

Enzymes change the direction of chemical reactions

Enzymes increase the free energy change of a reaction

32.

1 point

Santa's elves living in the North Pole have a higher percentage of cholesterol in their cell membranes than elves living in Middle Earth. If an elf from Middle Earth goes to the North Pole to visit his cousins

his cells will freeze at 25*C, while his cousins' would freeze at 30*C

his cells will freeze at a higher temperature than his North Pole cousins' cells

his cells will not freeze at a higher temperature than his North Pole cousins' cells

his cells will freeze at a lower temperature than his North Pole cousins' cells

their cells would freeze at the same temperature.

33.

1 point

In order for a protein to be an integral membrane protein it would have to be which of the following?

hydrophilic

hydrophobic

full of unsaturated fatty acids

completely covered with phospholipids

amphipathic

34.

1 point

The sodium-potassium pump is called an electrogenic pump because it

is used to drive the transport of other molecules against a concentration gradient

contributes to the membrane potential

pumps equal quantities of Na+ and K+ across the membrane

pumps hydrogen ions out of the cell

ionizes sodium and potassium atoms

35.

1 point

Succinate dehydrogenase catalyzes the conversion of succinate to fumarate. The reaction is inhibited by malonic acid. Increasing the ratio of succinate to malonic acid reduces the inhibitory effect of malonic acid.

What is the purpose of using malonic acid in this experiment?

It blocks the binding of fumarate.

It is a competitive inhibitor.

It replaces the usual enzyme.

It is a noncompetitive inhibitor.

Is it able to bind to succinate.

36.

1 point

Goblins use alcohol fermentation as their main source of energy (which explains their silly behavior). During this process

CO2 is produced and acetaldehyde is reduced by NADH into ethanol (ETOH)

CO2 is produced and acetaldehyde is reduced by NAD+ into ethanol (ETOH)

CO2 is produced and acetaldehyde is oxidized by NADH into ethanol (ETOH)

CO2 is producted and acetaldehyde is oxidized by NAD+ into ethanol (ETOH)

CO2 is produced and pyruvate reduces acetaldehyde in ethanol generation NAD+

37.

1 point

Which kind of metabolic poison would most directly interfere with glycolysis?

an agent that reacts with NADH and oxidizes it to NAD+

an agent that closely mimics the structure of glucose but is not metabolized

an agent that reacts with oxygen and depletes its concentration in the cell

an agent that blocks the passage of electrons along the electron transport chain

an agent that binds to pyruvate and inactivates it

38.

1 point

Which process in eukaryotic cells will proceed normally whether oxygen is present or absent?

oxidative phosphorylation

electron transport chain

glyolysis

chemiosmosis

citric acid cycle

39.

1 point

Which of the following does not occur during the Calvin cycle?

consumption of ATP

release of oxygen

carbon fixation

regeneration of the CO2 acceptor

oxidation of NADPH

40.

1 point

Which of the following types of molecules are the major structural component of plasma membranes?

proteins and cellulose

phospholipids and proteins

glycoproteins and cholesterol

nucleic acids and proteins

phospholipids and cellulose

41.

1 point

In photosynthesis, which requires CO2?

both the light reactions and the Calvin cycle

the Calvin cycle alone

the first electron transport chain in PS II

neither the light reactions nor the Calvin cycle

light reactions alone

42.

1 point

The mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is known as

noncooperative inhibition

reversible inhibition

competitive inhibition

metabolic inhibition

feedback inhibition

43.

1 point

Which of the following statements describes NAD+?

NAD+ is reduced to NADH during both glycolysis and the citric acid cycle

NAD+ has more chemical energy than NADH

NAD+ is reduced by the action of kinases

NAD+ can donate electrons for use in oxidative phosphorylation

In the absence of NAD+, glycolysis can still function.

44.

1 point

What is the voltage across a membrane called?

chemical gradient

electrochemical gradient

water potential

osmotic potential

membrane potential

45.

1 point

What is the relationship between wavelength of light and the quantity of energy per photon?

They are separate phenomena.

They are only related in certain parts of the spectrum.

They have a direct, linear relationship.

They are inversely related.

They are logarithmically related.

46.

1 point

Cellular respiration harvests the most ATP from which of the following?

generating carbon dioxide and oxygen in the electron transport chain

transferring electrons from organic molecules to pyruvate

converting oxygen to ATP

substrate-level phosphorylation

chemiosmotic phosphorylation

47.

1 point

Protons (H+) diffuse into which location during oxidated phosphorylation?

mitochondrial outer membrane

mitochondrial intermembrane space

cytosol

mitochondrial matrix

mitochondrial inner membrane

48.

1 point

Which produces NADH?

the Calvin cycle alone

neither the light reactions nor the Calvin cycle

both the light reactions and the Calvin cycle

occurs in the chloroplast but is not part of photosynthesis

light reactions alone

49.

1 point

What is the change in free energy of a system at chemical equilibrium?

zero, no net change

slightly increasing

greatly decreasing

greatly increasing

slightly decreasing

50.

1 point

http://i49.tinypic.com/2dl3uzd.jpg

Which one correctly describes the graph labels?

b- activation energy with enzymes, e- activation energy without enzyme, a- free energy of rxn

e- activation energy with enzymes, a- activation energy without enzyme, d- free energy of rxn

c- activation energy with enzymes, b- activation energy without enzyme, e- free energy of rxn

a- activation energy with enzymes, d- activation energy without enzyme, e- free energy of rxn

b- activation energy with enzymes, c- activation energy without enzyme, d- free energy of rxn