21, 22, 24, 25, 26

What is an adipocyte?

An adipocyte is a cell, almost entirely filled with fat globules, in which triacylglycerols are stored and mobilized.

What is the major purpose of the pentose phosphate pathway?

Ribose 5-phosphate

The process of making glucose from noncarbohydrates is known as

gluconeogenesis

When fats are metabolized, the fatty acids enter the reactions of the

β-oxidation process.

Explain the differences in the fate of the energy released in each case.

-Energy from combustion is released to the surroundings as heat and is wasted. -Energy from metabolic oxidation is released in several steps and is stored in each step so that it is available for use in other metabolic processes.

What are the major monosaccharide products produced by digestion of carbohydrates?

-Galactose -Fructose -Glucose

What are the differences between the roles of LDLLDL and HDLHDL?

-LDL carries cholesterol from the liver to tissues. -HDLcarries cholesterol from tissues to the liver, where it is converted to bile and excreted.

Which of the following are reactive oxygen species?

-ROO⋅ -H2O2 -OH-

Which is exergonic?

-Succinyl−SCoA+GDP+Phosphate(Pi)→Succinate+CoA−SH+GTP+H2O -Acetyl−SCoA+Oxaloacetate→Citrate+CoA−SH

Select the electron carriers involved in the electron-transport chain.

-flavin mononucleotide -cytochrome C -iron-sulfur clusters

What are the two primary functions of the electron-transport chain?

-the conversion of ADP to ATP -the oxidation of the coenzymes NADH and FADH2the conversion of NADH to FADH2

Which steps involve decarboxylation (loss of CO2CO2)?

3, 4,

Which steps involve oxidation reactions?

3, 4, 6, 8

The overall yield of ATP molecules from the complete catabolism of one molecule of glucose in humans and other mammals is ________.

32

Which step or steps involve a hydration reaction?

7

What does the word aerobic mean?

A condition in which oxygen is plentiful.

What does the word anaerobic mean?

A condition where oxygen is absent.

What are chylomicrons?

Acylglycerols, fatty acids, and protein are combined to form chylomicrons.

High concentrations of ketone bodies in the bloodstream may indicate

All responses are correct. (starvation.diabetes mellitus.a decrease in the pH of the blood.)

Which of the following statements about free radicals is incorrect?

B vitamins provide protection from their harmful effects.

How is cholesterol transported around the body?

Cholesterol is transported by LDLs.

What are the characteristics of Type II diabetes?

Excessive thirst, frequent urination, high concentrations of glucose in the urine and blood, and weight loss.

What type of substrate is FAD associated with, and what is the type of product molecule after dehydrogenation?

FAD oxidizes −CH2CH2−−CH2CH2− to −CH=CH−

What is the form of FAD after dehydrogenation?

FADH2

Which statement is true concerning the relationship between FAD and FADH2?

FADH2 is the reduced form of FAD.

Why is it important that glycolysis be tightly controlled by the cell?

Glycolysis must be tightly controlled because the body must avoid extreme fluctuations in glucose concentration.

Which of the following are produced as a net result of glycolysis?I. NADHII. NAD+III. ADPIV. ATP

I and IV

When a person is deprived of food, in which order does the body use the following sources to produce glucose?I. protein breakdown to amino acids used for gluconeogenesisII. conversion of glycogen to glucoseIII. catabolism of lipids

II, I, III

What are the characteristics of Type IIII diabetes?

Insulin is in good supply, but cell membrane receptors fail to recognize insulin and to allow the passage of glucose into cells.

When it leaves the liver, what is its destination and use?

It is used in cell membranes and to synthesize sterols.

What is the difference between catabolism and anabolism?

Metabolic processes that break down molecules are called catabolism. Metabolic processes that assemble larger molecules from smaller molecules are known as anabolism.

Insulin increases the rate at which

More than one response is correct

Which statement is true concerning the relationship between NAD+ and NADH?

NAD+ is the oxidized form of NADH.

What cofactor (coenzyme) is used?

NADPH

Why is glycolysis called an anaerobic pathway?

None of the ATP produced in glycolysis results from oxidative phosphorylation

How are the processes of the citric acid cycle and the electron-transport chain interrelated?

One complete citric acid cycle produces four reduced coenzymes, which enter the electron transfer chain and ultimately generate ATP.

What is an organelle?

Organelles are subcellular structures that perform specialized tasks within the cell.

Which reaction produces a phosphate that later yields energy by giving up a phosphate group?

Succinyl−SCoA+GDP+Phosphate(Pi)→Succinate+CoA−SH+GTP+H2O

What is the Cori cycle?

The Cori cycle takes place in the muscles and liver and involves the conversions glucose (in muscle) →→ pyruvate →→ lactate (in muscles) →→ lactate (in liver) →→ pyruvate →→ glucose (in liver) →→ glucose (in muscle).

Why is it not possible for a person to sprint for miles?

The distance a person can sprint is limited by readily available energy that comes from creatine phosphate and glycogen, both of which are quickly used up.

How do fasting glucose levels in a diabetic person compare to those in a nondiabetic person?

The fasting level of glucose in a diabetic is 140 mg/dLmg/dL or greater, as compared to an average level of 90 mg/dLmg/dL for a nondiabetic.

What is the purpose of the citric acid cycle?

The purpose of the citric acid cycle is to break down acetyl groups to yield CO2CO2 and reduced coenzymes.

Name the substrate and the product of glycogenesis.

The substrate is glucose, the product is glycogen.

Name the substrate and the product of glycolysis.

The substrate is glucose, the product is pyruvate.

Name the substrate and the product of glycogenolysis.

The substrate is glycogen, the products are glucose and chain-shortened glycogen.

Name the substrate and the product of gluconeogenesis.

The substrates are pyruvate, lactate, amino acids, glycerol, the product is glucose.

What is the final fate of the carbons in acetyl-CoA after several turns of the citric acid cycle?

The two acetyl-CoA carbons are oxidized to CO2CO2 in the citric acid cycle.

What are the ultimate products of the electron-transport chain?

The ultimate products of the electron transport chain are water, energy in the form of ATP, and the oxidized coenzymes FAD and NAD+.

How are they involved in lipid metabolism?

They used to transport lipids from the diet into the bloodstream.

Which of the following is not used as an energy source in metabolism?

UTC

Glycolysis

When glucose is in good supply and energy is needed

Gluconeogenesis

When glucose is in short supply and during fasting and early stages of starvation

What key metabolic intermediate is formed from the catabolism of all three major classes of foods: carbohydrates, lipids, and proteins?

acetyl-SCoA

When energy is needed and adequate oxygen is available, pyruvate is converted to ________.

acetyl-SCoA

Which chemical is produced from pyruvate when it is metabolized in muscle cells under aerobic conditions?

acetyl-SCoA

The common molecule produced from all foods at the second stage of catabolism is

acetyl-SCoA.

Metabolism is composed of which process(es)?

anabolism and catabolism

The biochemical process in which simple molecules are combined to make larger ones and energy is consumed is referred to as

anabolism.

The biochemical process in which complex molecules are broken down into simpler ones and energy is released is referred to as

catabolism.

The mitochondria are the location where ________ takes place and most ________ is produced.

citric acid cycle; ATP

Glycolysis occurs mainly in the

cytosol of all cells.

All of the following statements concerning digestion are correct except

digestion begins in the stomach and is completed in the large intestine.

Photosynthesis is an ________ process because the free energy of the products is ________ the free energy of the reactants.

endergonic; greater than

Which chemical is produced from pyruvate when it is metabolized by yeast cells?

ethanol

Which of the following carbohydrates can also be used as fuel in glycolysis?

galactose, fructose, and mannose

All of the following are possible metabolic fates of the acetyl-SCoA intermediate except

gluconeogenesis.

The most important monosaccharide for energy production is

glucose.

Which pathway converts glucose to its storage form in animals?

glycogenesis

Which pathway produces glucose from its storage form in animals?

glycogenolysis

In an individual who is starving or fasting, the body meets its need for glucose first by the process of ________, and then by the process of ________.

glycogenolysis; gluconeogenesis

The pathway followed by glucose when energy is needed is

glycolysis.

All of the following chemicals except ________ provide protection against potentially harmful oxygen species.

hydrogen peroxide

A lack of insulin causes ________, a state in which the concentration of blood sugar is ________ than normal.

hyperglycemia; higher

When blood sugar levels are lower than normal, this condition is called

hypoglycemia.

Overproduction of insulin causes ________, a state in which the concentration of blood sugar is ________ than normal.

hypoglycemia; lower

The diseases identified as diabetes are primarily associated with a malfunction of the hormone

insulin.

The pain and cramps that occur during physical exhaustion are associated with the formation of excess

lactate

Which chemical is produced from pyruvate when it is metabolized in muscle cells under anaerobic conditions?

lactate

Which is endergonic?

l−Malate+NAD→Oxaloacetate+NADH+H+

The cellular organelle associated with energy production is the

mitochondrion.

The major products of carbohydrate digestion are

monosaccharides

Glycogen is most commonly found in ________ cells and ________ cells.

muscle; liver

Exergonic reactions are those that have a ________ value of ΔG and ________ spontaneous.

negative; are

Endergonic reactions are those that are ________ and that ________ liberate free energy.

nonspontaneous; do not

Is FAD an oxidizing agent or a reducing agent?

oxidizing agent

Endergonic reactions are those that have a ________ value of ΔG and ________ spontaneous.

positive; are not

The major function of the pentose phosphate pathway when energy for anabolic reactions is a priority is

producing NADPH.

The most important goal of glucose metabolism is

production of ATP as an energy source for all cells.

The products of glycolysis important in metabolism are

pyruvate, ATP, and NADH.

When a molecule is dehydrogenated, is FAD oxidized or reduced?

reduced

In addition to producing ATP, the citric acid cycle produces ________ as high energy molecules and ________ as its major chemical waste product.

reduced coenzymes; CO2

Pyruvate is converted to lactate under anaerobic conditions because ________.

reduction of pyruvate provides NAD+ which is needed for glycolysis

Exergonic reactions are those that are ________ and that ________ liberate free ene

spontaneous; do

When ATP is produced by direct transfer of a phosphate group instead of from reactions coupled to electron transport, the process is referred to as ________ phosphorylation.

substrate-level

Harmful byproducts of biochemical oxidation include

superoxide ions and hydroxyl free radicals.

All of the following statements concerning digestion are correct except

the same enzymes are used in the digestion of carbohydrates, lipids, and proteins.

The ultimate source of energy for all but a very few biochemical reactions is

the sun

Which type of molecule is the major form for long term storage of chemical energy in the body?

triglycerides

The purpose of coupling two biochemical reactions is to

use an exergonic reaction to drive an endergonic reaction.

After O2 has been reduced in the electron transport chain, the oxygen atoms are part of what molecules?

water