Biochem Exam 3

Four enzymes serve regulatory roles in the conversion of pyruvate to CO2. They are all inhibited by:


Acetyl-CoA is considered a central metabolite because:

It is the entry point to the TCA cycle for both fats and carbohydrates

The following molecule is _____ and is produced by the enzyme ______.

acetyl-CoA, pyruvate dehydrogenase

The following molecule is _____ and is produced by the enzyme ______.

fumerate, succinate dehydrogenase

What drives the reductive fusion of acetyl CoA and oxaloacetate?

hydrolysis of the acetyl CoA thioester linkage

The net result of the glyoxylate cycle is the conversion of two ____ to one net ____ which can be used for gluconeogenesis.

acetyl-CoA, oxaloacetate

What are the products of the pyruvate dehydrogenase complex?

NADH, acetyl CoA

Much of the O2 we inhale is used directly in the activity of:

None of these

A full rotation of the Fo-F1 ATP synthase uses ____ protons to make ____ ATP

12, 3

Which of the following received electrons directly from NADH?

complex 1

The following table shows redox potentials for transporters in an electron transport chain. Which statement about these data is most accurate?

More energy can be gained from the transport of electrons from NADH to water than from FADH2 to water

Hydrogen oxidizing bacteria react hydrogen with ____, making ____.

None of these

Nitrobacter carry out the following reaction:

oxidation of nitrite to nitrate

The hydrogenase enzyme used by hydrogen oxidizing bacteria contains an active site which includes which metal ions?

nichel and iron

Iron oxidizing bacteria ultimately make their respiratory ATP using which of the following mechanisms?

Membrane bound ATP synthase

Given the following list of reduction potentials, transfer between which two (listed with the electron donor on the left, and acceptor on the right) would theoretically yield the largest amount of energy?

FAD/FADH, Mn(4+)/Mn(2+)

The terminal electron receptor in denitrification is

could be many different ones, nitrate, nitrite, nitric oxide, etc.

Which of the following metabolites would be best suited to serve as a terminal electron receptor?


Humans can be classified as:


If a particular reaction has a positive value of ?G, is it likely to occur?

yes, if coupled with an offsetting spontaneous reaction

A catabolic pathway is:

the degradative path, whereby complex organic molecules are degraded to simpler molecules

Gluconeogenesis is:

all of the above

To capture the energy released by oxidation of organic molecules, catabolic enzymes often:

All of these

Processes that require molecular oxygen are termed:


The conversion of NAD+ to NADH can be best described as:

The reduction of NAD+ resulting from it gaining pair of electrons and a proton

ATP occupies a pivotal position among high-energy phosphorylated molecules because:

ATP has a position in the middle of the p. group

Starting with glucose and going through glycolysis and fermentation to two molecules of ethanol and two molecules of CO2, what is the net yield of NADH molecules synthesized?


Gluconeogenesis occurs in

the liver

Gluconeogenesis produces


In the conversion of pyruvate to lactic acid, what happens to NADH?

It is chemically oxidized

What enzyme catalyzes the conversion of fructose-6-phosphate to fructose 1,6-biphosphate?


In the enzymatic conversion of pyruvate to ethanol, what happens to NAD+?

It is produced

pyruvate carboxylase is activated in conditions when

glucose concentrations are low and lactate concentrations are high

During glycolysis, the net yield of the steps between glucose and glyceraladehyde-3-phosphate

consumes 2 ATP

The following molecule is _____ and is made by _____ during gluconeogenesis

fructose-1,6-bisphosphate, aldolase

The Cori cycle

the cycle of lactate to glucose between the muscle and liver

In an ATP synthase with a c ring composed of 12 c subunits, how many protons are required to produce one molecule of ATP?


Which of the following lists metabolites correctly by increasing oxidation number on nitrogen?

Ammonium, hydroxyl amine, nitric oxide, nitrite, nitrate

Nitrate, sulfate, and metals can be terminal electron acceptors under ____ conditions.


Methanotrophs use ____ as a terminal electron acceptor.


what kind of energy metabolism do humans use?

aerobic chemo-organotroph