micro exam ch. 6

The readily usable energy currency of cells is

CTP. the electron transport system. electricity. ATP. the electron transport system AND CTP.

Which of the following processes generates the greatest amount of energy?

Fermentation Fermentation AND the Entner-Duodoroff pathway Aerobic respiration The Entner-Duodoroff pathway Glycolysis

Fermentation is sometimes used as a means of slowing food spoilage. Why would fermentation lead tothis outcome?

Fermentation will lead to production of acidic by-products, dropping the pH of the food below a level that bacteria can tolerate. This is a trick question-fermentation actually IS food spoilage and cannot be used to prevent it under any circumstances. Fermentation is THE process that directly reduces sugars in food. Without sugars, bacteria cannot grow and spoil the food. Fermentation will lead to production of high levels of ethanol (95% or higher!)-ethanol will kill bacteria.

NAD in its reduced form is abbreviated as

NADH. NAD-. NAD. NADP.

In the electron transport system

NADP donates electrons in the middle of the chain. NADH and FADH2 both donate electrons at the same location. NADH donates electrons "upstream" of where FADH2 donates electrons. NAD donates electrons at the head of the chain.

In the electron transport system

NADP donates electrons in the middle of the chain. NADH donates electrons "upstream" of where FADH2 donates electrons. NADH and FADH2 both donate electrons at the same location. NAD donates electrons at the head of the chain.

Which is true regarding the three central metabolic pathways?

They form high-energy bonds that can be used to synthesize ATP. They form intermediates that can be oxidized to generate reducing power. They form precursor metabolites. All of the choices are correct.

How would cellulose-degrading bacteria in the rumen (stomachs) of a cow benefit the animal?

They wouldn't benefit the animal-only the bacteria within the animal. This is why cows must have food sources other than grass in order to survive. The bacteria would produce sugars as they digested the cellulose. These sugars would be given off to the cow as a symbiotic relationship in exchange for the protected location of the stomachs of the cow for the bacteria to grow and replicate in. They wouldn't benefit the animal-they would replicate and cause disease in the animal, leading to its death. The bacteria would produce, secrete, and incorporate organic molecules as they obtain energy from the cellulose in grass and replicate. The cow could then digest both the secreted organic molecules AND the bacteria that synthesized them.

Enzymes are changed by the reaction as they raise the activation energy.

TorF

The Calvin cycle produces six ATP for every six turns of the cycle.

TorF

The production of ATP via the electron transport system, in either eukaryotes or prokaryotes, requires the use of a membrane.

TorF

Bacteria that can absorb light energy and convert it into ATP are commonly called

cytotrophs. metatrophs. cytochromes AND chemotrophs. phototrophs. chemotrophs.

The small, non-protein molecules that can be readily separated from an enzyme and are responsible for transfer of atoms from one molecule to another are referred to as

enzymes. hormones. vitamins. coenzymes.

Pyruvate can be metabolized along two major routes. They are

fermentation and respiration. metabolism and anabolism. anabolism and catabolism. oxidation and reduction.

Enzymes act on _______ to generate ________.

glucose, anabolites products, substrates products, catabolites substrates, products

The most common starting pathway for the breakdown of sugars is

glycolysis. fermentation. oxidation. respiration.

The general term used to describe the anabolic and catabolic reactions in a cell is

hematic. aerobic respiration. enzymatic. metabolism.

In the phototrophic production of energy, the oxygen originates from

hydrogen peroxide. carbon dioxide. glucose. water.

The mutual interaction of substrate and enzyme is described as a(n)

induced fit. active site AND allosteric site. active site. lock and key arrangement. allosteric site.

Feedback inhibition

involves inhibiting the last of a series of reactions. results in raising the activation energy for the reaction. is a means of regulating the amount of product produced. rarely involves the use of allosteric enzymes.

Proton motive force

is used synthesize ADP. is used to produce FADH2. is used to synthesize ATP. is used to produce NADH.

Proton motive force

is used to produce FADH2. is used synthesize ADP. is used to synthesize ATP. is used to produce NADH.

Why would a cell ferment rather than respire?

it lacks the ability to respire (i.e. no electron transport chain). There is no oxygen present and it cannot use anaerobic respiration OR it lacks the ability to respire (i.e., no electron transport chain). More ATP is produced for the cell by fermentation than by aerobic respiration. There's no oxygen present, and it cannot respire anaerobically.

Environmental factors that may affect enzyme activity include

pH. salt. temperature, pH, AND salt. temperature.

Enzymes speed up reactions by

reducing entropy. lowering activation energy. producing heat. raising activation energy.

The name given to the reaction involving removal of electrons or hydrogen atoms from a compound is termed

reduction. oxidation. metabolism. glycolysis.

The use of the suffix "ase" on a word denotes a(n)

substrate AND electron acceptor. electron acceptor. substrate. product. enzyme.