Bio 121 Mastering Biology Ch. 6 homework

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

What molecules belong in spaces E and F?

carbon dioxide and water

The O2 required for __________ is supplied by __________.

cellular respiration ... breathing

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

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

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

The final electron acceptor of cellular respiration is _____.

oxygen

What molecule is indicated by the letter D?

oxygen

What process occurs in structure H?

photosynthesis

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

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

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

four; 3 NADH and 1 FADH2

In the equation shown below, during cellular respiration __________ is oxidized and __________ is reduced.

glucose ... oxygen

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

Part complete 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

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

During electron transport, energy from _____ is used to pump hydrogen ions into the _____.

NADH and FADH2 ... intermembrane space

Which of the following best describes the electron transport chain?

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

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

What organelle is indicated by the letter C?

mitochondrion

What process occurs in Box A?

Glycolysis

Which of the following statements regarding glycolysis is FALSE?

Glycolysis evolved in an oxygen-rich environment.

inputs and outputs of cellular respiration

Inputs 1 Glucose+ 6 O2 ------ 6 CO2 + 6 H2o = ATP

In glycolysis, what starts the process of glucose breakdown?

ATP

The energy released from the redox reactions in the electron transport chain is used by the cell to make _____________.

ATP

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

ATP

Structure A is _____.

ATP synthase

Which of these is NOT a product of glycolysis?

FADH + H+

What molecule is broken down in cellular respiration, providing fuel for the cell?

Glucose

Given the relatively modest number of calories burned by anything but the most vigorous activities, why can people consume over 2,000 kilocalories a day, yet maintain a healthy body weight?

Most of the energy consumed in food is spent maintaining the body's functions, so only a fraction of food energy needs to be burned in exercise.

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

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

concept map about oxidative phosphorylation

a- cellular respiration b- ATP c- electron transport chain d-H+ concentration gradient e- NADH and FADH2 f- ATP synthase g- oxygen

Can you label these components of pathways that break down various food molecules?

a-carbohydrates b-fats c- proteins d-fatty acids e-amino acids f- glycolysis g- citric acid cycle h- ATP

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 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

What molecules belong in space A and B?

glucose and oxygen

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+

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

What process occurs within Box B?

the citric acid cycle