Exam 3

Question 1

In glycolysis, __ molecules of ATP are hydrolyzed to ADP in the energy investment phase in the energy payoff phase ____ molecules of ATP, ____ molecules of pyruvate, and ___ molecules of NADH are produced. Thus, the net ATO yield from glycolysis id ___ ATP.

Answer 1

2, 4, 2, 2, 2

Question 2

What is the job of NADH in aerobic respiration?

Answer 2

NADH is the electron carrier during the catabolic redox reactions involved in aerobic respiration and NADH delivers electrons to the mitochondrial electron transport chain.

Question 3

During pyruvate oxidation, what also occurs?

Answer 3

The formation of acetyl-CoA

Question 4

Once they have been processed through the citric acid cycle, the acetyl-CoA molecules from a single glucose molecule produce:

Answer 4

2 ATP, 6 NADH, 2 FADH, 4 CO2

Question 5

What is the correct sequence of steps as energy is extracted from glucose during cellular respiration?

Answer 5

Glycolysis -> acetyl CoA -> Citric acid cycle -> electron transport chain

Question 6

Describe the citric acid cycle:

Answer 6

The process produces ATP, NADH, FADH2, and CO2 in the mitochondria.

Question 7

What is the difference between oxidation and reduction?

Answer 7

The molecule that is reduced gains electrons while the molecule that is oxidized loses electrons.

Question 8

Consider the reaction below. In this reaction, _____ is oxidized and ____ is reduced.
2 H-H + O=O -> 2 H-O-H

Answer 8

Hydrogen; Oxygen

Question 9

Remembering that rotenone blocks aerobic respiration at Complex 1, which of the following treatments could have been effective for a case of rotenone poisoning?

• Extra NAD+
• Extra Oxygen gas
• Neither

Answer 9

Neither

Question 10

Rotenone blocks aerobic respiration at Complex 1 of the electron transport chain (ETC). what would have happened as a result of Rotenone poisoning?

Answer 10

The production of ATP in the mitochondria will be reduced, but the production of ATP in the cytoplasm will be normal. Glycolysis will shut down. Excessive amounts of NADH will build up.

Question 11

Which produces the most ATP when glucose is completely oxidized to carbon dioxide and water?

Answer 11

Oxidative phosphorylation (ETC + chemiosmosis)

Question 12

The diet drug DNP allows protons to bypass ATP synthase when they cross the mitochondrial membrane. In other words, DNP uncouples respiration just like the proton channel in the mitochondria of brown adipose tissue. you would expect cells exposed to DNA to produce LESS ___ and produce MORE ____.

Answer 12

ATP; heat

Question 13

When a glucose molecule loses a hydrogen atom as the result of an oxidation-reduction reaction, the glucose molecule becomes:

Answer 13

Oxidized

Question 14

The following molecules are all participants in the electron transport chain. which molecule functions first in the pathway when electrons are delivered to the chain from FADH2?

• Ubiquinone
• Complex I
• cytochrome c
• Complex II
• Complex III

Answer 14

Complex II

Question 15

During oxidative phosphorylation, the amount of ATO produced from the electrons provided by one NADH molecule is different than the amount of ATP produced from the electrons provided by one FADH2 molecule. Why?

Answer 15

The electrons provided by FADH2 enter the ETC at a different point than the electrons provided by NADH. Because of this, they pass through fewer of the protein complexes that actively transport H= ions across the inner mitochondrial membrane, resulting in fewer ATP being produced by ATP synthase.

Question 16

What is the correct order by which electrons move through the electron transport chain in mitochondria?

Answer 16

NADH -> Complex I -> ubiunone -> Complex III -> cytochrone c -> Complex IV -> Oxygen

Question 17

One result of the action of the proton transporters in the mitochondrial electron transport chain is that the stroma ___ than the intermembrane

Answer 17

Has a higher pH (is more basic)

Question 18

Proton (H+) transports in the mitochondrial electron transport chain transport protons from the ___ to the ___; ATP synthase, in turn, is powered by the movement of protons from the ____ to the _____.

Answer 18

Matrix, intermembrane space, matrix, intermembrane space

Question 19

What is the correct pathway by which electrons follow through the photosystems during the light reactions of photosynthesis?

Answer 19

H2O -> chlorophyll reaction center in Photosystem II -> ETC that makes ATP -> chlorophyll reaction center in Photosystem I -> ETC that makes NADH

Question 20

Proton (H+) transporters in the chloroplast ETC transport protons from the ____ to the ___; ATP, in turn, is powered by the movement of protons from the ___ to the ___.

Answer 20

Stroma, thylakoid lumen (thylakoid space), stroma, Thylakoid lumen (thylakoid space)

Question 21

One result of the action of the proton transporter in the chloroplast ETC is that the thylakoid lumen (thylakoid space) _____ than the stroma.

Answer 21

Has a higher pH (is more basic)

Question 22

Incoming photons of light energy initiate photosynthesis by ___.

Answer 22

Exciting electrons in pigment molecules within the photosystems, raising them to a higher energy level

Question 23

What does not occur in the Calvin cycle?

Answer 23

splitting of water and the formation of oxygen gas does not occur.

Question 24

The leaves of most plants appear green to the human eye because chlorophyll ____ green light and ____ other wavelengths of light, especially high-energy wavelengths.

Answer 24

Reflects; absorbs

Question 25

____ has lower energy than ___.

Options: Yellow and Red

Answer 25

Red (700 nm); yellow (625nm)

Question 26

What does not happen during the light reactions of photosynthesis?

Answer 26

CO2 reacts with RuBP to produce 3-phosphoglycerate (does not happen)

Question 27

Centrosomes are the…

Answer 27

poles toward which chromosomes move during chromosome segregation in mitosis and meiosis

Question 28

What distinguishes kinetochore microtubules from polar microtubules in the mitotic spindle?

Answer 28

Kinetochore microtubules pull sister chromatids apart during anaphase. whereas polar microtubules push the poles of the spindle further apart.

Question 29

____ code for proteins that tent to block cell division. in contrast, ___ code for proteins that promote cell division.

Answer 29

Tumor suppressor genes, proto-oncogenes

Question 30

Proto-oncogenes are often mutated into cancer cells, giving rise to proteins that are ____ in contrast, mutant tumor suppressor genes give rise to proteins that are ___ in cancer.

Answer 30

Constitutively active; inactive

Question 31

How does a nucleus in G2 differ from a nucleus in G1?

Answer 31

The G2 nucleus has twice the amount of DNA as the G1 nucleus.

Question 32

Name one difference between mitosis and meiosis I. (chromosomes)

Answer 32

Homologous chromosome pairs synapse during meiosis but not mitosis

Question 33

During meiosis, the sister chromatids separate during:

Answer 33

Anaphase I

Question 34

How does mitotic prophase differ from the prophase I of meiosis?

Answer 34

Crossing over is characteristic of prophase I of meiosis nut not of mitotic prophase.

Question 35

When a person has Down syndrome, he or she has an extra chromosome 21. Therefore, Down syndrome is a kind of ___ and results from ___.

Answer 35

Trisomy; nondisjunction of chromosome 21 during meiosis I.

Question 36

Chromosome number is reduced during meiosis because the process consists of…

Answer 36

Two cell divisions and only a single round of chromosome replication before Meiosis I.

Question 37

True or False:

Each cyclin is made continuously during the cell cycle.

Answer 37

False

Question 38

Vinblastine is a chemotherap drug used to treat cancer. it halts division in cancerous cells by blocking the assembly and function of microtubules. What would happen is cancer cells were treated with this drug at the end of phase? (right before mitosis begins)

Answer 38

The mitotic spindle would not form.

Question 39

True or False:

Crossing over occurs during anaphase I of meiosis

Answer 39

False

Question 40

The four haploid nuclei found at the end of meiosis differ from one another in their exact genetic composition. Some of this difference is the result of…

Answer 40

Independent assortment of homologous during anaphase I.

Question 41

The difference between asexual and sexual reproduction is that:

Answer 41

Asexual reproduction results in an organism that is identical to the parent, whereas sexual reproduction results in an organism that is not identical to either parent.