Quiz Chapter 21 (20) Biochemical Energy

A metabolic pathway in which a series of steps, each using different enzymes, regenerates one of the early reactants, is a(an) ________ pathway.

cyclic

Which of the following is common to the structures of NAD+, and FAD?

ADP

The synthesis of ATP from ADP and monohydrogen phosphate ________ 7 kcal/mol of energy and is an ________ reaction.

consumes; endergonic

The electrons brought into the electron transport chain are transferred in the following order of

complex I; CoQ; complex III; cytochrome c; complex IV.

The process by which the cell produces ATP in the mitochondria is called

oxidative phosphorylation.

The driving force which provides the energy for synthesis of ATP in the fourth stage of metabolism is the

concentration gradient of hydrogen ions between the two sides of the inner mitochondrial membrane.

In the first step of the citric acid cycle, acetyl-CoA reacts with ________ to produce ________, which is isomerized to ________ in the second step.

oxaloacetate; citrate; isocitrate

Which of the following statements about free radicals is incorrect?

B vitamins provide protection from their harmful effects.

The fourth stage of metabolism, in which the high energy molecules from stage three (NADH and FADH2) are oxidized to produce ATP is referred to as

the electron transport chain.

The abbreviation ATP stands for

adenosine triphosphate.

The common molecule produced from all foods at the second stage of catabolism is

acetyl-CoA.

A spiral metabolic sequence can best be described as one in which

the same set of enzymes progressively builds up or breaks down a molecule.

Metabolism is composed of which process(es)?

anabolism and catabolism

The cellular organelle associated with energy production is the

mitochondrion.

Which group of compounds includes only low-energy molecules?

ADP; CO2; NAD+; FAD

In a pair of coupled reactions, if the favorable reaction releases more energy than the amount required by the unfavorable reaction, the excess energy is

released as heat and used to maintain body temperature.

How many ATP molecules are formed for each NADH molecule brought into complex I?

3

Which statement concerning coenzymes and redox reactions is incorrect?

FAD is the reduced form of FADH2.

Which of the following is not true of NAD+ and FAD?

They donate electrons to the electron transport system.

The ultimate source of energy for all but a very few biochemical reactions is

the sun

Which of the following reactions is the least energetic?

AMP + H2O → Adenosine + Pi

The biochemical process in which simple molecules are combined to make larger ones and energy is consumed is referred to as

anabolism

How many ATP molecules are formed for each FADH2 molecule brought into complex II?

2

Photosynthesis is an ________ process because the free energy of the products is ________ the free energy of the reactants.

endergonic; greater than

Harmful byproducts of biochemical oxidation include

superoxide ions and hydroxyl free radicals.