Dec 14, 2009
423
1
0
Status
Pre-Dental
1. From which molecule could a cell extract the greatest amount of energy through the normal pathways of aerobic respiration?
a) FADH2
b) ATP
c) NADH
d) Pyruvic acid



2. Biological oxidation of glucose resulting in which of the following metabolic end products would yield the largest number of ATP molecules?

a) CH3CHOHCOOH
b) CH3COCOOH (pyruvic acid)
c) CO2 + N2 + H2O
d) CO2 + H2S
e) CO2 + H2O

3. From which of the following molecules could extract the greatest amount of energy through the normal pathways of aerobic respiration?
a) Water b) CO2 c) ATP d) NADH e) Pyruvic acid
 

Maygyver

10+ Year Member
5+ Year Member
Jun 14, 2008
2,309
27
91
Status
Pre-Dental
1. D
2. A (not sure if this is supposed to be like a fatty acid?)
3. E

Where are you getting these from? And can you actually post answers this time?
 

Dion

Junior Member
10+ Year Member
Jul 6, 2006
133
0
241
Status
Pre-Dental
I think the first answer is NADH. I know that during aerobic respiration NAD+ is reduced to NADH, which is responsible for three ATP's.

The second answer may be choice B, though I am not too certain about it. At the end of glycolysis, pyruvate may be made into acetyl-CoA and then enter the Kreb Cycle to yield more NADH, FADH, GTP, and ATP.

I think the answer for the third question is also NADH but I do not see how this question differs from the first.
 

AmpedUp

The Legend Still Lives
7+ Year Member
Dec 1, 2009
657
6
151
Status
Dentist
I think the first answer is NADH. I know that during aerobic respiration NAD+ is reduced to NADH, which is responsible for three ATP's.

The second answer may be choice B, though I am not too certain about it. At the end of glycolysis, pyruvate may be made into acetyl-CoA and then enter the Kreb Cycle to yield more NADH, FADH, GTP, and ATP.

I think the answer for the third question is also NADH but I do not see how this question differs from the first.
I agree for the first two questions...but I think the third answer is ATP? NADH doesn't extract energy (to my knowledge). I hope someone comes through with the facts.
 

Maygyver

10+ Year Member
5+ Year Member
Jun 14, 2008
2,309
27
91
Status
Pre-Dental
This is essentially the same questions you asked before:Krebs cycle. Here, http://library.thinkquest.org/C004535/aerobic_respiration.html the pyruvate molecule has the most energy because it can be broken down to form ATP, NADH, FADH2. I really don't think these questions are all that challenging. I would try to just get down the Krebs cycle.
 
Jun 14, 2009
800
3
0
Status
Pre-Dental
Ill go with pyruvate for the first and third question. Using the normal pathways of aerobic respiration, you get 4 NADH's, an FADH2, and an equivalent of ATP in the form of GTP out of a single pyruvate. As for the second, my take is that [E) complete oxidation of glucose into CO2 and H2O] will yield the most reducing equivalents which are shuttled to the ETC, leading to the most ATP produced.
 

akeurogh

7+ Year Member
Jun 22, 2009
166
0
141
Los Angeles
Status
Dental Student
Ill go with pyruvate for the first and third question. Using the normal pathways of aerobic respiration, you get 4 NADH's, an FADH2, and an equivalent of ATP in the form of GTP out of a single pyruvate. As for the second, my take is that [E) complete oxidation of glucose into CO2 and H2O] will yield the most reducing equivalents which are shuttled to the ETC, leading to the most ATP produced.
thats exactly what im thinking. :thumbup:
 

dentalWorks

Nights Watchmen
7+ Year Member
Jun 25, 2009
5,646
157
181
Sterling Hts, Mi
Status
Dentist
Answer = blue

1. From which molecule could a cell extract the greatest amount of energy through the normal pathways of aerobic respiration?
a) FADH2
b) ATP
c) NADH
d) Pyruvic acid
This is biochemistry 101. ATP can't be the answer cause thats the most basic (lowest) unit of energy. FADH2 gives you about 2 ATPs. NADH gives you about 3 ATPs. However, Pyruvic acid can enter crebs cycle and give you BOTH FADH2 and NADH... answer = D

2. Biological oxidation of glucose resulting in which of the following metabolic end products would yield the largest number of ATP molecules?

a) CH3CHOHCOOH
b) CH3COCOOH (pyruvic acid)
c) CO2 + N2 + H2O
d) CO2 + H2S
e) CO2 + H2O
Well, complete oxidation of glucose meaning that one of your products MUST be CO2 (that automatically eliminates a & b). Then c and d make zero sense, Nitrogen and Sulfer are not involved with glucose oxidation, leaving you with E as correct answer

3. From which of the following molecules could extract the greatest amount of energy through the normal pathways of aerobic respiration?
a) Water b) CO2 c) ATP d) NADH e) Pyruvic acid
Well, you can't really extract Energy from water, CO2 is a very oxidized molecule meaning you just can't extract any more electrons from it to provide energy, ATP vs NADH vs pyruvic.... Reading my explanation frop question 1 above, Pyruvic is the correct answer.
 

Maygyver

10+ Year Member
5+ Year Member
Jun 14, 2008
2,309
27
91
Status
Pre-Dental
Yeah, I change my answer to the middle one to E. I misread it late at night and thought it was asking the same as the other two (what would give the most energy).
 

MatthewLeeDDS

10+ Year Member
7+ Year Member
Jan 5, 2009
302
24
151
Status
Dentist
Yeah, dentalWorks is correct. :thumbup:

I'll be another voice for D, E, D.

kpark102, if this stuff is hard for you, focus more on aerobic respiration in general. This question tests to see if you know how the three steps (glycolysis, krebs, ETC) are all related. In this question you have to understand where one of the 3 steps starts and another ends, what you get from each, what you start with on each, and how much energy each step can yield.