Chapter 6: How Cells Harvest Energy

Babies; lean

Recent data suggests that heat-generating brown fat is most active in______ and ______ people exposed to cold temperatures.

NADH is an electron carrier. It is used in the citric acid cycle to transport electrons across the mitochondrial membrane.

What is the purpose of NADH in Cellular Respiration?

Substrate-Level Phosphorylation: The production of ATP by formation in glycolysis is powered by the addition/removal of phosphate groups (phosphorylation) to molecules of glucose (the substrate). Oxidative Phosphorylation: When oxygen accepts an electron while the gradient made by the movement of electrons powers the creation ATP.

What's the difference between oxidative phosphorylation and substrate-level phosphorylation?

A) Kinetic energy and heat

When a car engine burns gasoline, the results of the reaction are similar to when cells burn glucose. Both reactions release carbon dioxide and water. In cells, the chemical energy in food is converted to ATP and heat. In a moving car, the chemical energy in gasoline is converted to _____. A) Kinetic energy and heat B) Potential energy and heat C) Chermal energy and heat D) ATP and heat

D) Are converted mainly into intermediates of glycolysis or the citric acid cycle.

When proteins are used as a source of energy for the body, the proteins A) Donate electrons directly to the electron transport chain. B) Are converted into glucose molecules, which are fed into glycolysis. C) Are hydrolyzed to glucose and converted to acetyl CoA, which enters the citric acid cycle. D) Are converted mainly into intermediates of glycolysis or the citric acid cycle.

D) Hydrogen ion D

Which H+ has just passed through the inner mitochondrial membrane by diffusion? A) Hydrogen ion A B) Hydrogen ion B C) Hydrogen ion C D) Hydrogen ion D

D) Energy to make ATP and carbon dioxide

Which of the following are products of cellular respiration? A) Oxygen and energy to make ATP B) Oxygen and carbon dioxide C) Oxygen and glucose D) Energy to make ATP and carbon dioxide

C) Glycolysis, the citric acid cycle, and oxidative phosphorylation

Which of the following options lists the stages in cellular respiration in the correct order? A) The citric acid cycle, oxidative phosphorylation, and glycolysis B) Glycolysis, oxidative phosphorylation, and the citric acid cycle C) Glycolysis, the citric acid cycle, and oxidative phosphorylation D) Oxidative phosphorylation, glycolysis, and the citric acid cycle

D) Oxidative phosphorylation resulting from 1 glucose molecule yields 12 ATP molecules.

Which of the following statements about the energy yield of aerobic respiration is false? A) The citric acid cycle resulting from 1 glucose molecules yields 2 ATP molecules. B) The oxidation of pyruvate results in the production of 0 ATP molecules C) Glycolysis resulting from 1 glucose molecule yields 2 ATP molecules. D) Oxidative phosphorylation resulting from 1 glucose molecule yields 12 ATP molecules.

Glucose + O2 -> -> -> CO2 + O2 + Heat + ATP

What is the general equation for Cellular Respiration?

Oxidation

What is the loss of electrons?

Kilocalorie (kcal) (It is the same as a food Calorie, and used to measure the nutritional values indicated on food labels.)

A ______ is the quantity of heat required to raise the temperature of 1 kilogram (kg) of water by 1 degree Celsius the same as a food Calorie, and used to measure the nutritional values indicated on food labels.

B) Citrate

A culture of bacteria is fed glucose containing radioactive carbon and is then examined. During the citric acid cycle, radioactive carbon would first appear in A) NADH B) Citrate C) Oxaloacetate D) CO2

D) Loses electrons and becomes oxidized

A molecule that functions as the electron donor in a redox reaction __________. A) Loses electrons and becomes reduced B) Gains electrons and becomes oxidized C) Gains electrons and becomes reduced D) Loses electrons and becomes oxidized

C) Mitochondrial matrix

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? A) Plasma membrane B) Mitochondrial inner membrane C) Mitochondrial matrix D) Cytoplasm

A) Pyruvate is oxidized.

After glycolysis but before the citric acid cycle, A) Pyruvate is oxidized. B) A carbon atom is added to pyruvate to make a four-carbon compound. C) Glucose is split, producing two molecules of pyruvate. D) Coenzyme A is cleaved off pyruvate.

D) 2

As a result of glycolysis, there is a net gain of ________ ATP(s). A) 36 B) 0 C) 1 D) 2

32; 34%; 66%

Cellular respiration can produce up to __ ATP molecules for each glucose molecule, uses about __% of the energy originally stored in glucose, and releases the other __% as heat

Exergonic

Cellular respiration is an ______ process that transfers energy from the bonds in glucose to form ATP.

Mitochondria

Cellular respiration takes place in the ______ of eukaryotic cells.

D) Is carried by electrons.

During cellular respiration, the energy in glucose A) Is used to manufacture glucose. B) Is released all at once. C) Becomes stored in molecules of ammonia. D) Is carried by electrons.

D) ATP is synthesized when H+ ions move through a channel in ATP synthase.

During chemiosmosis, A) Energy is released as H+ ions move freely across mitochondrial membranes. B) H+ ions serve as the final electron acceptor. C) A concentration gradient is generated when large numbers of H+ ions are passively transported from the matrix of the mitochondrion to the mitochondrion's intermembrane space. D) ATP is synthesized when H+ ions move through a channel in ATP synthase.

B) NADH; NAD+

During fermentation, __________ that was produced during glycolysis is converted back to __________. A) ATP; ADP B) NADH; NAD+ C) NAD+; NADH D) Pyruvate; CO2; pyruvate

D) Glycolysis and the Citric Acid Cycle

During which of the following phases of cellular respiration does substrate-level phosphorylation take place? A) Glycolysis B) The Citric Acid Cycle C) Oxidative Phosphorylation D) Glycolysis and the Citric Acid Cycle

C) Four; 3 NADH and 1 FADH2

Each turn of the citric acid cycle generates one ATP and ___ additional energy-rich molecules: __________. A) Two; 1 NADH and 1 FADH2 B) Four; 2 NADH and 2 FADH2 C) Four; 3 NADH and 1 FADH2 D) Three; 2 NADH and 1 FADH

C) With their numerous hydrogen atoms, fats provide an abundant source of high-energy electrons

Fat is the most efficient molecule for long-term energy storage even compared to carbohydrates because _____. A) When compacted, fat occupies less volume than an equivalent amount of carbohydrate B) Compared to carbohydrates, fat produces fewer toxic by-products when it is metabolized C) With their numerous hydrogen atoms, fats provide an abundant source of high-energy electrons D) Fats can directly enter the electron transport chain, the phase of respiration that produces the most ATP

A) 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.

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? A) 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. B) People really should exercise vigorously for one to two hours per day. C) They can't, and this has led to a problem of obesity in the United States. D) Not all calories are created equal, so a person who consumes 2,000 kilocalories of sugar- and fat-laden processed food will gain weight, whereas a person who consumes 2,000 calories of nonprocessed, low-carbohydrate food will not.

C) Requires ATP to make ATP

Glycolysis is the only stage of cellular respiration that _____. A) Does not release carbon dioxide as a by-product B) Requires oxygen to function C) Requires ATP to make ATP D) Does not require ATP to make ATP

B) They produce ATP.

How do cells capture the energy released by cellular respiration? A) They store it in molecules of carbon dioxide. B) They produce ATP. C) The energy is coupled to oxygen. D) They produce glucose

During cellular respiration, electrons are transferred from glucose to oxygen and energy is released.

How do your cells extract energy from glucose?

D) Feedback inhibition slows down cellular respiration.

If ATP accumulates in a cell, A) Feedback inhibition speeds up cellular respiration. B) The cell receives a signal that there is a need for more energy. C) The rate of cellular respiration does not change. D) Feedback inhibition slows down cellular respiration.

Glucose is being oxidized since it loses some hydrogen atoms (and thus some electrons) and oxygen is being reduced since it is gaining some hydrogen atoms (with their electrons).

In Cellular Respiration what is being oxidized and what is being reduced?

Photosynthesis

In ______, some of the energy in sunlight is captured by chloroplasts, atoms of carbon dioxide and water are rearranged, and sugar and oxygen are produced.

Cellular respiration

In ______, sugar is broken down to carbon dioxide and water and the cell captures some of the released energy to make ATP.

Sun

In almost all ecosystems, energy ultimately comes from the ______.

D) Loses ... oxygen gains

In cellular respiration, glucose _____ electrons, whereas _____ electrons. A) Gains ... water loses B) Gains ... oxygen loses C) Loses ... water gains D) Loses ... oxygen gains

A) NADH; oxidized

In fermentation, ________ is ________. A) NADH; oxidized B) Ethanol; oxidized C) NADH; reduced D) NAD+; oxidized

B) Pump protons (H+) across the mitochondrial membrane

In oxidative phosphorylation, electrons are passed from one electron carrier to another. The energy released is used to _____. A) Form ATP during glycolysis B) Pump protons (H+) across the mitochondrial membrane C) Generate large amounts of NADH and FADH2 D) Synthesize carbon dioxide

Cytosol

Location of Glycolysis

Inner Membrane of Mitochondria

Location of Oxidative Phosphorylation

Mitochondrial matrix

Location of the Citric Acid Cycle

D) Mitochondria

Lungs are to breathing as _____ are to cellular respiration. A) Chloroplasts B) Bronchi C) Alveoli D) Mitochondria

1. Electron Transport Chain (ETC); 2. Chemiosmosis; 3; Oxidative Phosphorylation

Name the processes

B) Loss of electrons; gain of electrons

Oxidation is the ________, and reduction is the ________. A) Gain of electrons; loss of electrons B) Loss of electrons; gain of electrons C) Gain of oxygen; loss of oxygen D) Gain of protons; loss of protons

Inner

Oxidative Phosphorylation occurs in this membrane.

B) These two stages supply the electrons needed for the electron transport chain

Oxidative phosphorylation could not occur without glycolysis and the citric acid cycle, because _____. A) These two stages provide the water that is split during oxidative phosphorylation B) These two stages supply the electrons needed for the electron transport chain C) These two stages provide the oxygen used as the final electron acceptor D) The electron transport chain requires the ATP produced during the first two stages

2 Pyruvate; 2 Net ATP; 2 NADH

Products of Glycolysis

9 ATP; 2 H20

Products of Oxidative Phosphorylation

2 CO2; 2 NADH; 2 Acetyl CoA; 2 ATP

Products of Pyruvate Oxidation

4 CO2; 6 NADH; 2 FADH

Products of the Citric Acid Cycle

Glucose

Reactants of Fermentation

1 Glucose; ATP

Reactants of Glycolysis

O2; H20; 3 ATP

Reactants of Oxidative Phosphorylation

2 Pyruvate

Reactants of Pyruvate Oxidation

2 Acetyl CoA

Reactants of the Citric Acid Cycle

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

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 _____. A) Glycolysis could still continue indefinitely B) Proton gradient formation would continue, but ATP synthase function would stop C) Oxidative phosphorylation would come to a halt because there wouldn't be any oxygen to "pull" the electrons down the transport chain D) ATP production would continue because the cell would perform fermentation

A) The energy necessary to power the rearrangement of chemical bonds in H2O and CO2

Sunlight is essential for the varied life on Earth. Sunlight provides energy to photosynthetic organisms by providing __________. A) The energy necessary to power the rearrangement of chemical bonds in H2O and CO2 B) The energy required to drive cellular respiration C) Heat to leaves, which is used to synthesize chloroplasts D) Heat to leaves, which is converted to useful energy for work

Matrix

The Citric acid Cycle occurs in this location.

B) H+ will accumulate in the intermembrane space.

The antibiotic oligomycin works by inhibiting ATP synthase. You would expect that A) There will be an increase in ATP production. B) H+ will accumulate in the intermembrane space. C) NAD+ and FAD will pick up the extra H+. D) H+ will accumulate in the mitochondrial matrix.

D) NADH

The end products of glycolysis include A) Acetyl CoA B) Citric acid. C) O2 D) NADH

D) Matrix and inner mitochondrial membrane.

The enzymes of the citric acid cycle are located in the A) Nucleus. B) Outer mitochondrial membrane. C) Cytoplasm. D) Matrix and inner mitochondrial membrane.

B) A limousine driver dropping off a couple at the school prom.

The function of coenzyme A in the citric acid cycle is most like A) A kid jumping up and down on a trampoline. B) A limousine driver dropping off a couple at the school prom. C) A frog that turns into a prince. D) Throwing a baited hook into a lake and catching a fish.

Aerobic

The harvesting of energy utilizing oxygen is called...

Acetyl CoA

The starting molecule for the Citric Acid Cycle.

Lactic acid and Alcohol

The two types of Fermentation

Pyruvate

This is one of the products of Glycolysis.

NADH

This is the electron carrier for cellular respiration.

ATP

This is the energy produced at the end of cellular respiration.

Glucose

This is the starting molecule for cellular respiration.

Citric Acid Cycle

This process produces 2 ATP and CO2.

Glycolysis

This process produces 2 net ATP

Redox

This term refers to a reaction where electrons are exchanged.

Oxidative

This type of Phosphorylation utilizes a Hydrogen ion gradient.

Substrate

This type of Phosphorylation utilizes an enzyme.

B) Build amino acids, fats, and sugars

Using the ATP generated during cellular respiration, the intermediates of glycolysis and the citric acid cycle, such as pyruvate and acetyl CoA, can be siphoned off and used to __________. A) Create energy sources, such as glucose or amino acids, that are recycled back through respiration, thus allowing a continual source of ATP with relatively little food intake B) Build amino acids, fats, and sugars C) Generate the ADP that is used to power biosynthetic pathways D) Provide virtually all the heat needed to maintain body temperature

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

We inhale O2 and we exhale CO2. Carbon dioxide is produced... A) During the electron transfer steps of oxidative phosphorylation B) In the reaction that creates acetyl CoA (coenzyme A) from pyruvate C) During the formation of pyruvate D) When oxygen acquires electrons and protons at the end of the electron transport chain

Cellular respiration

What is the following formula demonstrating? Glucose + O2 ➞ CO2 + H2O + ATP

Reduction

What is the gain of electrons?

A) Cellular respiration is more efficient at harnessing energy from glucose than car engines are at harnessing energy from gasoline.

Which of the following statements about the energy yields from cellular respiration is true? A) Cellular respiration is more efficient at harnessing energy from glucose than car engines are at harnessing energy from gasoline. B) The heat produced during cellular respiration is only a tiny fraction of the chemical energy available in a glucose molecule. C) Cellular respiration converts all of the energy in glucose into high-energy ATP bonds. D) Cellular respiration converts the kinetic energy of glucose into chemical energy.

B) Cellular respiration is a single chemical reaction with just one step.

Which of the following statements regarding cellular respiration is false? A) Cellular respiration produces carbon dioxide. B) Cellular respiration is a single chemical reaction with just one step. C) Cellular respiration releases heat. D) Cellular respiration produces water.

D) O2 is reduced when it accepts electrons and forms water.

Which of the following statements regarding the movement of electrons during cellular respiration is true? A) Electrons tend to move away from O2. B) O2 is eventually oxidized by the electrons to form water. C) The electrons release large amounts of energy each time they are transferred from one molecule to another. D) O2 is reduced when it accepts electrons and forms water.

B) O2 is reduced when it accepts electrons and forms water.

Which of the following statements regarding the movement of electrons during cellular respiration is true? A) Electrons tend to move away from O2. B) O2 is reduced when it accepts electrons and forms water. C) The electrons release large amounts of energy each time they are transferred from one molecule to another. D) O2 is eventually oxidized by the electrons to form water.