Bios Chapter 7 Learning curve

Excess glucose is stored in large branched molecules of

Glycogen in animals

Proteins can be broken down to extract energy. They are typically broken down into amino acids, which then enter cellular respiration via:

Glycolysis or the citric acid cycle

During the citric acid cycle, the production of the CO2 is the result of the _______ of intermediate compounds of the citric acid cycle coupled to the production of ________

Oxidation; NADH

In cellular respiration, glucose is _______ to CO2 and oxygen is __________ to water

Oxidized; reduced

A simplified overall equation for respiration is as follows: C6H12O6 + 6O2 = 6CO2 + 6H2O + energy In this reaction, we can say that _______ is reduced and ________ is oxidized

Oxygen; glucose

During which phase(s) of glycolysis do we observe pyruvate production, ATP synthesis, and reduction of NAD+?

Payoff phase

Which statement is true regarding pyruvate and glucose

Pyruvate can be transported across both membranes of the mitochondrion to be further metabolized, but glucose cannot

Acetyl-CoA synthesis occurs during:

Pyruvate oxidation

Which stage of cellular respiration occurs following production of pyruvate?

Pyruvate oxidation

When you exhale, there is more CO2 than was present in the air that you inhaled. This CO2 comes from reactions in:

Pyruvate oxidation and the citric acid cycle

Which stages of cellular respiration produce CO2 as a waste product?

Pyruvate oxidation and the citric acid cycle

Which statement is true regarding pyruvate oxidation?

Pyruvate oxidation forms the same number of NADH (per glucose molecule) as glycolysis

In pyruvate oxidation, the electron donor is _________ and the electron acceptor is __________

Pyruvate; NAD+

The _______ forms of the electron carried NAD+/NADH and FAD/FADH2 have high potential energy

Reduced

The immediate source of electrons for the electron transport chain is:

NADH and FADH2

In which organisms would you expect ethanol fermentation to occur?

Fungi and plants

The final (terminal) electron acceptor of the electron transport chain is:

Oxygen

Both NAD+ and molecular oxygen serve as electron acceptors in cellular respiration

True

Tracing the metabolism of one glucose molecule, how many carbon atoms are fully oxidized to CO2 at the completion of glycolysis

0

Tracing the metabolism of one glucose molecule, how many carbon atoms are fully oxidized to CO2 at the completion of the pyruvate oxidation stage?

2

Which of the following is a net product of glycolysis?

2 pyruvate

Tracing the metabolism of one glucose molecule, how many carbon atoms are fully oxidized to CO2 at the completion of aerobic respiration?

6

Energy released by transferring electrons along the electron transport chain is stored as potential energy in the form of:

A proton gradient

Which of the following is required for the preparatory phase of glycolysis and then produced during the payoff phase

ATP

Which of the following is required for the preparatory phase of glycolysis and then produced during the payoff phase?

ATP

The conversion of the potential energy of a proton gradient to a form more useful to the cell is achieved by coupling the movement of protons down their electrochemical gradient with the synthesis of ATP. This coupling is made possible by:

ATP synthase

During the pyruvate oxidation stage of cellular respiration, which of the following occurs?

All of the choices are correct: -The oxidation of pyruvate -The formation of NADH -The formation of CO2 -The formation of acetyl-CoA

How did the earliest organisms on earth most likely produce ATP?

By glycolysis

What is the fully oxidized product that results from the pyruvate oxidation stage of cellular respiration?

CO2

Some bacteria run the citric acid cycle in reverse. Without any other modifications to the cycle, what inputs would be required to do this?

CO2, FADH2, NADH, and ATP

We consume a variety of carbohydrates that are digested into a variety of different monosaccharides. How do these different sugars enter glycolysis?

Different sugars can be modified to form different intermediates of glycolysis

Most of the proteins of the electron transport chain are:

Embedded in the inner mitochondrial membrane

The first phase of glycolysis required the input of two ATP molecules. It is therefore:

Endergonic

Fermentation occurs only in anaerobic conditions

False

Fermentation produces nearly twice as much ATP as aerobic respiration, which explains why it is preferred pathway for bacteria

False

Malate is both the starting and ending product of the citric acid cycle

False

Pyruvate oxidation produces a large amount of ATP through substrate-level phosphorylation

False

The citric acid cycle is believed to have developed fairly recently in the evolution of cellular life

False

The glycolysis stage is responsible for producing most of the ATP during cellular respiration

False

The majority of cells within the human body have a very high baseline amount of ATP, so cells are always prepared for any long-term activity

False

Which of the following is most likely to have been the first metabolic pathway or structure to evolve

Fermentation

In cellular respiration, oxygen:

Gains electrons and is reduced

Which of the following are inputs, but not outputs, of glycolysis?

Glucose

What happens when glucose is phosphorylated during phase 1 of glycolysis?

Glucose is destabilized so that it can be broken apart in phase 2

Which of the following is one explanation for why glycolysis is believed to have arisen very early in the evolution of life?

It does not require oxygen

Pyruvate oxidation is an important stage in cellular respiration because:

It links glycolysis with the citric acid cycle

During pyruvate oxidation, pyruvate is broken down into CO2 and an acetyl group. The CO2 is:

Less energetic than the acetyl group

The chemical bonds of carbohydrates and lipids have high potential energy because:

Many of these bonds are C-C and C-H bonds, in which electrons are shared equally between atoms

In eukaryotes, pyruvate oxidation takes place in the:

Mitochondrial matrix

In what organelle is pyruvate oxidation carried out in a cell?

Mitochondrion

What product of the pyruvate oxidation stage of cellular respiration will have the two electrons that are lost from pyruvate

NADH

Which of the following is an electron carrier in its reduced form?

NADH

In glycolysis, ATP is synthesized by:

Substrate-level phosphorylation

We can tell from their structure that fatty acids are a good source of energy because of:

The large number of carbon-carbon and carbon-hydrogen bonds they contain

Which statement is true regarding Earth's earliest organisms?

These organisms likely carried out fermentation and may have had rudimentary proton pumps

In addition to destabilizing glucose for subsequent breakdown, what else does phosphorylation of glucose do?

Traps glucose inside the cell

The ATP produced during glycolysis is the result of substrate-level phosphorylation

True

Although glycolysis produces four molecules of ATP by substrate-level phosphorylation, the net gain of ATP for the cell is two molecules. This is because:

Two molecules are used in the initial stage

Of the 6 carbons in a staring molecule of glucose, at the completion of pyruvate oxidation, __________ carbons are fully oxidized to ___________, while ____________ carbon remain in ____________

Two; CO2; Four; acetyl groups

Which of the following is a product (as opposed to a substrate) of at least one of the processes of cellular respiration

Water