chapter 7

In which part of the cell is lipid synthesized?

Smooth endoplasmic reticulum

Which metabolic pathway is NOT reversible?

The step from pyruvate to acetyl CoA

Which statement accurately describes ketones?

After ten days of fasting, ketones will meet much of the nervous system's energy needs.

True or False: The small intestine is the most active nutrient-processing organ in the human body.

a. True b. False

b. False

True or False: When carbohydrates are unavailable, proteins can be converted to glucose.

a. True b. False

a. True

True or False: Fat cells enlarge if excess carbohydrate, protein, or fat is consumed.

a. True b. False

a. True

True or False: The amount of energy that cells expend to fulfill essential life functions is about 25 percent of all energy consumed by a healthy adult each day.

a. True b. False

b. False

True or False: Alcohol affects every organ in the body, but it is especially damaging to the liver.

a. True b. False

a. True

Metabolism is defined as the sum of all chemical reactions occurring in the body, including _____ reactions that break apart larger molecules into smaller molecules and ______ reactions that convert smaller molecules into larger ones.

Catabolic, anabolic

The ______ is the most active processing center in the body.

Liver

Characteristic	Anabolism or Catabolism
Requires energy
Breaks down glycerol
Hydrolysis occurs
Assembles proteins
Releases energy

Characteristic	Anabolism or Catabolism
Requires energy	Anabolism
Breaks down glycerol	Catabolism
Hydrolysis occurs	Catabolism
Assembles proteins	Anabolism
Releases energy	Catabolism

_____ is the high-energy compound that provides the energy that powers all the activities of living cells.

ATP

Many enzymes cannot function without the assistance of a _____

coenzyme

Fill in the term corresponding to each description.

	The final, common metabolic pathway for carbohydrates, fats, and amino acids
	The pathway that ends in the production of acetyl coenzyme A (acetyl CoA)
	The final pathway in energy metabolism, where ATP is made

TCA Cycle	The final, common metabolic pathway for carbohydrates, fats, and amino acids
Glycolysis	The pathway that ends in the production of acetyl coenzyme A (acetyl CoA)
Electron Transport Chain	The final pathway in energy metabolism, where ATP is made

For complete oxidation, acetyl CoA enters _____

The TCA cycle

The body derives most of its energy from _____ and _____ .

Glucose, fatty acids

Which product is made from pyruvate when oxygen is limited?

Lactic acid

Which pathway accurately describes what happens if excessive amounts of protein are consumed?

They are deaminated and made into either ATP or fat.

Gluconeogenesis is the process of making glucose from ____ and ____ when glycogen stores become depleted during a fast.

amino acids, glycerol

_____ are acidic compounds produced by the liver when glycogen is depleted.

Ketone bodies

Which organ is the primary site for alcohol metabolism?

Liver

Binge drinking is defined as the consumption of ____________ on a single occasion that raises blood alcohol concentration to 0.08 percent or higher.

Four to five drinks

When a person begins to drink alcohol, which of the following functions are the first to be affected?

Judgment and reasoning

Which statement is true of mitochondria inside the human body?

They are known as the "powerhouse" of the cell.

What is the key element in catabolic reactions?

They release energy.

Which of the following is true of anabolic reactions?

They convert small molecules to larger ones.

Which statement accurately describes glycolysis?

It results in the formation of pyruvate.

Which statement is true of anaerobic reactions?

They do not require oxygen.

Which compound plays a pivotal role in both the first and last steps of the tricarboxylic acid (TCA) cycle?

Oxaloacetate

Which statement is NOT true about energy metabolism?

Fatty acids can be used to make glucose.

The electron transport chain consists of a series of _____ that serve as electron carriers.

Proteins

When energy-yielding nutrients are consumed in excess, which of the following can lead to an enlargement of fat cells?

Fat, carbohydrate, and protein

Which of the following fat-formation pathways is the most efficient and direct?

Conversion of dietary fat to body fat

What is the outcome of amino acids if someone overeats protein and kcalories in general?

The amino acids are stored as fat.

Which of the following metabolic processes occurs during the first 2 to 3 hours of fasting?

Glucose is released from the liver, and fatty acids are released from the adipose tissue.

What is the source of the glucose needed by the brain and red blood cells when glycogen stores become depleted after a 24-hour fast?

Amino acids

What is the alternative fuel source produced during a prolonged fast?

Ketone bodies

Janelle always feels more "tipsy" than her same-size boyfriend after drinking the same amount of alcohol. Which organ produces more alcohol dehydrogenase in men, explaining Janelle's observation?

The Stomach

(Paths of pyruvate and acetyl CoA)

Glucose contains 6 carbon atoms

Glycerol contains 3 carbon atoms

Fatty acids contain even numbers of carbon atoms

Amino acids contain 2, 3 or more carbon atoms

Pyruvate contains 3 carbon atoms

Acetyl CoA contains 2 carbon atoms

***3-carbon compounds can be converted to glucose

***2-carbon compounds cannot be converted to glucose