BIOL homework 6

For each glucose that enters glycolysis, _____ NADH enter the electron transport chain

10

How many NADH are produced by glycolysis?

2

In glycolysis there is a net gain of _____ ATP.

2

In glycolysis, what starts the process of glucose breakdown?

ATP

Which energy-rich molecule produced by cellular respiration directly powers cell work?

ATP

Which of the following molecules is broken down in cellular respiration, providing fuel for the cell?

glucose

during cellular respiration __________ is oxidized and __________ is reduced.

glucose ... oxygen

A chemist has discovered a drug that blocks phosphoglucoisomerase, an enzyme that catalyzes the second reaction in glycolysis. He wants to use the drug to treat people with bacterial infections. However, he can't do this because

human cells also perform glycolysis; the drug might also poison them

We inhale O2 and we exhale CO2. Carbon dioxide is produced

in the reaction that creates acetyl CoA (coenzyme A) from pyruvate

The proximate (immediate) source of energy for oxidative phosphorylation is

kinetic energy that is released as hydrogen ions diffuse down their concentration gradient

In muscle cells, fermentation produces

lactate and NAD+

Sports physiologists at an Olympic training center want to monitor athletes to determine at what point their muscles begin to function anaerobically. They could do this by checking for a buildup of

lactic acid

A scientist wants to study the enzymes of the citric acid cycle in eukaryotic cells. What part of the cell would she use as a source of these enzymes?

mitochondrial matrix

The O2 required for __________ is supplied by __________.

Cellular Respiration; Breathing

electron transport chain

Electrons pass from one carrier to another, releasing a little energy at each step

Which of the following statements regarding glycolysis is FALSE

Glycolysis evolved in an oxygen-rich environment.

Through respiration, humans breathe in O2 and breathe out CO2. However, what would happen if we did not breathe in O2?We would not make enough ATP to meet our energy requirements

We would not make enough ATP to meet our energy requirements

Which of these enters the citric acid cycle (also called the Krebs cycle)?

acetyl CoA

Which of these is NOT a product of the citric acid cycle (also called the Krebs cycle)?

acetyl CoA

In an experiment, mice were fed glucose (C6H12O6) containing a small amount of radioactive carbon. The mice were closely monitored, and in a few minutes, radioactive carbon atoms showed up in __________.

carbon dioxide

In nutrient-rich environments (like your mouth), bacteria can use the provided amino acids to synthesize their proteins. However, should the environmental conditions change and become nutrient-poor, bacteria would need to synthesize their amino acids. They can do this using

citric acid cycle intermediates

A single glucose molecule produces about 38 molecules of ATP through the process of cellular respiration. However, this only represents approximately 34% of the chemical energy present in this molecule. The rest of the energy from glucose is

converted to heat

The transfer of ______ from one molecule to another is an oxidation-reduction reaction, or redox reaction.

electrons

Each turn of the citric acid cycle generates one ATP and ___ additional energy-rich molecules: __________

four; 3 NADH and 1 FADH2

In cellular respiration, most ATP molecules are produced by

oxidative phosphorylation

Some human cells, such as nerve cells, are restricted to aerobic respiration to recycle NADH and FADH2. If these cells are deprived of oxygen, then

oxidative phosphorylation would come to a halt because there wouldn't be any oxygen to "pull" the electrons down the transport chain

In cellular respiration, glucose becomes _____ to carbon dioxide (CO2) as it loses electrons (in hydrogen atoms)

oxidized

In cellular respiration, organic molecules become _____ as NAD+ picks up electrons and H+ and becomes reduced to NADH.

oxidized

The final electron acceptor of cellular respiration is

oxygen

Bacteria have no membrane-enclosed organelles. However, some still generate ATP through cellular respiration. Where might the electron transport chain be found in these organisms?

plasma membrane

NADH delivers electrons to an electron transport chain, which passes the electrons through carrier molecules in a series of

redox reactions to the final electron acceptor, oxygen

In eukaryotes, most of the high-energy electrons released from glucose by cellular respiration

reduce NAD+ to NADH, which then delivers them to the electron transport chain

In cellular respiration, oxygen becomes _____ to water (H2O) as it gains electrons (in hydrogen atoms) that came from glucose.

reduced

In glycolysis, ATP molecules are produced by _____.

substrate-level phosphorylation

In the citric acid cycle (also called the Krebs cycle), ATP molecules are produced by

substrate-level phosphorylation

Most NADH molecules generated during cellular respiration are produced during

the citric acid cycle

A gram of fat oxidized by cellular respiration produces approximately __________ as much ATP as a gram of carbohydrate.

twice