Muscle Fibers and Cellular Processes

Questions and Answers

Which of the following statements about the energy yield of aerobic respiration is false?

Less than 50% of the chemical energy available in glucose is converted to ATP energy.

Glycolysis and the 'grooming' of pyruvate together produce more NADH per glucose molecule than does the citric acid cycle. (correct)

Oxidative phosphorylation resulting from 1 glucose molecule may yield 32—34 ATP molecules.

Most of the ATP derived during aerobic respiration results from oxidative phosphorylation.

Each FADH2 molecule yields 2 ATP molecules and each NADH molecule generates 3 ATP molecules.

Cyanide and dinitrophenol affect cellular respiration in different ways. What is true about their effects?

Dinitrophenol blocks the passage of electrons through electron carriers.

Cyanide makes the membrane of mitochondria leaky to H+ ions and prevents a concentration gradient.

Cyanide increases the rate of H+ crossing to the intermembrane beyond the capacity to synthesize ATP. (correct)

Cyanide inhibits the production of ATP by inhibiting ATP synthase. (correct)

Which of the following statements regarding muscle fibers is false? (Select all that apply)

Fast fibers are better able to produce ATP anaerobically.

Training usually converts one type of muscle fiber into another. (correct)

All human muscles contain fast and slow muscle fibers.

The percentage of each fiber type varies from person to person.

The proportion of fast and slow fibers is genetically determined.

The term anaerobic means:

without O2. Signup and view all the answers

Which of the following statements regarding fast-twitch muscles is false? (Select all that apply)

Fast-twitch muscles produce more ATP per glucose than slow-twitch muscles. Signup and view all the answers

Which of the following statements regarding photosynthesis and cellular respiration is true?

Photosynthesis occurs in chloroplasts, and cellular respiration occurs in mitochondria. Signup and view all the answers

How do cells capture the energy released by cellular respiration?

They produce ATP. Signup and view all the answers

During these energy conversions, some energy is:

lost in the form of heat. Signup and view all the answers

Respiration , and cellular respiration .

is gas exchange...produces ATP Signup and view all the answers

Which of the following are products of cellular respiration?

energy to make ATP and carbon dioxide Signup and view all the answers

Which of the following statements regarding cellular respiration is false?

Cellular respiration is a single chemical reaction with just one step. Signup and view all the answers

The overall equation for the cellular respiration of glucose is:

C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + energy. Signup and view all the answers

Which of the following statements about the energy yields from cellular respiration is true?

Cellular respiration is more efficient at harnessing energy from glucose than car engines are at harnessing energy from gasoline. Signup and view all the answers

Humans use the calories they obtain from ________ as their source of energy.

food Signup and view all the answers

Humans use about ________ of their daily calories for involuntary life-sustaining activities such as digestion, circulation, and breathing.

75% Signup and view all the answers

A kilocalorie is defined as:

the quantity of heat needed to raise the temperature of 1 kg of water by 1°C. Signup and view all the answers

The label on the box of breakfast cereal lists one serving as containing 200 calories per serving. How many calories are actually in one serving?

200,000 Signup and view all the answers

During cellular respiration, the energy in glucose:

is carried by electrons. Signup and view all the answers

During redox reactions:

electrons are lost from one substance and added to another substance. Signup and view all the answers

Oxidation is the , and reduction is the .

loss of electrons...gain of electrons Signup and view all the answers

In biological systems, an important enzyme involved in the regulation of redox reactions is:

dehydrogenase. Signup and view all the answers

During cellular respiration, NADH:

delivers its electron load to the first electron carrier molecule. Signup and view all the answers

During cellular respiration, electrons move through a series of electron carrier molecules. Which of the following statements about this process is true?

Molecular oxygen is reduced when it accepts electrons and forms water. Signup and view all the answers

The functioning of an electron transport chain is analogous to:

a Slinky toy going down a flight of stairs. Signup and view all the answers

Which of the following options lists the stages in cellular respiration in the correct order?

glycolysis, the citric acid cycle, and oxidative phosphorylation Signup and view all the answers

A drug is tested in the laboratory and is found to create holes in both mitochondrial membranes. Scientists suspect that the drug will be harmful to human cells because it will inhibit:

the citric acid cycle and oxidative phosphorylation. Signup and view all the answers

During which of the following phases of cellular respiration does substrate-level phosphorylation take place?

glycolysis and the citric acid cycle Signup and view all the answers

Which of the following metabolic pathways is common in aerobic and anaerobic metabolism?

glycolysis Signup and view all the answers

As a result of glycolysis there is a net gain of ________ ATPs.

2 Signup and view all the answers

How many molecules of NADH are produced during glycolysis?

2 Signup and view all the answers

Which of the following is a result of glycolysis?

conversion of glucose to two three-carbon compounds Signup and view all the answers

A culture of bacteria growing aerobically is fed glucose containing radioactive carbon and is then examined. As the bacteria metabolize the glucose, radioactivity will appear first in:

glucose-6-phosphate. Signup and view all the answers

The end products of glycolysis include:

NADH. Signup and view all the answers

Pyruvate:

forms at the end of glycolysis. Signup and view all the answers

Between glycolysis and the citric acid cycle:

pyruvate is oxidized while a molecule of NAD+ is reduced to NADH. Signup and view all the answers

Which of the following statements regarding the chemical grooming of pyruvate is false?

Each pyruvate molecule has a CO2 added and then joins with an NADH. Signup and view all the answers

Pyruvate is considered a(n) ________ in aerobic cellular respiration.

intermediate in Signup and view all the answers

The enzymes of the citric acid cycle are located in the:

matrix and inner mitochondrial membrane. Signup and view all the answers

The end products of the citric acid cycle include all of the following except:

pyruvate. Signup and view all the answers

The function of coenzyme A in the citric acid cycle is most like:

a limousine driver dropping off a couple at the school prom. Signup and view all the answers

A culture of bacteria growing aerobically is fed glucose containing radioactive carbon and is then examined. During the citric acid cycle, radioactivity would first appear in:

citrate. Signup and view all the answers

At the end of the citric acid cycle, most of the energy remaining from the original glucose is stored in:

NADH. Signup and view all the answers

During chemiosmosis:

ATP is synthesized when H+ ions move through a protein port provided by ATP synthase. Signup and view all the answers

Which of the following statements about the inner mitochondrial membrane is false?

The inner mitochondrial membrane plays a role in the production of pyruvate. Signup and view all the answers

The mitochondrial cristae are an adaptation that:

increases the space for more copies of the electron transport chain and ATP synthase complexes. Signup and view all the answers

A mutant protist is found in which some mitochondria lack an inner mitochondrial membrane. Which of the following pathways would be completely disrupted in these mitochondria?

oxidative phosphorylation Signup and view all the answers

If you were able to stop the process of cellular respiration after completing electron transport but prior to chemiosmosis, you would find the pH of a mitochondrion to be at its lowest:

in the intermembrane space. Signup and view all the answers

By-products of cellular respiration include:

carbon dioxide and water. Signup and view all the answers

In the electron transport chain, the final electron acceptor is:

an oxygen atom. Signup and view all the answers

Rotenone is a poison commonly added to insecticides. Insects exposed to rotenone will die because:

they will no longer be able to produce adequate amounts of ATP. Signup and view all the answers

Study Notes

Muscle Fibers and Their Types

Muscle fibers are categorized as slow-twitch and fast-twitch.
Fast-twitch muscles generate short bursts of power but have fewer mitochondria and less myoglobin compared to slow-twitch muscles.
Genetic makeup determines the proportion of fast and slow muscle fibers in an individual.
Training cannot convert one type of muscle fiber into another.

Anaerobic Processes

The term "anaerobic" refers to processes that occur without oxygen (O2).
Fast-twitch muscles utilize anaerobic processes effectively.

Photosynthesis and Cellular Respiration

Photosynthesis takes place in chloroplasts, while cellular respiration occurs in mitochondria.
Cellular respiration produces ATP, carbon dioxide, and water but consumes glucose.
Energy released during cellular respiration is captured in the form of ATP.

Energy Conversion in Cells

Some energy is lost as heat during energy conversions in cellular respiration and photosynthesis.
The overall equation for cellular respiration of glucose is:
- C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + energy.

ATP Production and Usage

Humans derive energy from food, using about 75% of daily calories for vital functions like digestion and circulation.
A kilocalorie is defined as the amount of heat needed to raise the temperature of 1 kg of water by 1°C.

Glycolysis and Citric Acid Cycle

Glycolysis and the citric acid cycle yield a net gain of 2 ATP molecules per glucose.
Glycolysis converts glucose into two three-carbon compounds (pyruvate).
Oxygen is eventually oxidized during the electron transport process to form water.

Electron Transport and Chemiosmosis

The inner mitochondrial membrane houses ATP synthase and electron carriers.
ATP is synthesized during chemiosmosis when H+ ions move through ATP synthase.
A drug that creates holes in mitochondrial membranes would disrupt oxidative phosphorylation and the citric acid cycle.

Cellular Respiration Efficiency

Cellular respiration is more efficient in harnessing energy from glucose than traditional fuel engines.
Less than 50% of glucose's chemical energy is converted to ATP, with FADH2 contributing 2 ATP and NADH contributing 3 ATP.

Mitochondrial Functions

Coenzyme A functions similarly to a chauffeur, transporting inputs for energy cycles.
The end products of the citric acid cycle include CO2, NADH, and FADH2 but not pyruvate.

Experimental Insights

Radioactive carbon will first appear in glucose-6-phosphate during aerobic bacteria metabolism.
Mitochondrial cristae increase the surface area for more electron transport chains, enhancing ATP production.

Genetic and Biochemical Interactions

Redox reactions in biochemical pathways highlight the coupling of electron loss and gain.
NADH plays a crucial role in carrying electrons and is converted into NAD+ during its oxidative phase.

Poison Effects on Respiration

Rotenone inhibits ATP production in insects by preventing efficient electron transport.
Cyanide acts as an electron transport blocker, while dinitrophenol disrupts the proton gradient for ATP synthesis.

Key Definitions

Substrate-level phosphorylation occurs in glycolysis and the citric acid cycle.
Oxidative phosphorylation yields the majority of ATP during cellular respiration.
By-products of cellular respiration primarily include carbon dioxide and water.

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Description

Explore the types of muscle fibers, their functions, and how they relate to anaerobic processes in this quiz. Additionally, examine the roles of photosynthesis and cellular respiration in energy conversion within cells. Test your knowledge on these essential biological concepts.