Chapter 22- Chem 306

The most important goal of glucose metabolism is synthesis of carbon skeletons for amino acid production. production of acetyl-SCoA for synthesis of lipids. synthesis of glycogen for later use. production of ATP as an energy source for all cells. synthesis of oxidized coenzymes.

production of ATP as an energy source for all cells.

The overall yield of ATP molecules from the complete catabolism of one molecule of glucose in humans and other mammals is ________. 42 56 18 24 32

32

Which of the following are produced as a net result of glycolysis? I. NADH II. NAD+ III. ADP IV. ATP I and III III and IV II and III I and IV I and II

I and IV

Insulin increases the rate at which glucose is converted to glycogen. glucose enters the cell. glucose is converted to fat. glucose is converted from glycogen. More than one response is correct.

More than one response is correct.

When energy is needed and adequate oxygen is available, pyruvate is converted to ________. acetyl-SCoA lactate ethanol glucose glycogen

acetyl-SCoA

Which chemical is produced from pyruvate when it is metabolized in muscle cells under aerobic conditions? glucose ethanol acetyl-SCoA phosphoenol pyruvate lactate

acetyl-SCoA

The action of yeast on pyruvate is a process referred to as anaerobic reduction. substrate-level phosphorylation. glycolysis. aerobic oxidation. alcoholic fermentation.

alcoholic fermentation.

Steps 1-5 of glycolysis are referred to as the "energy investment" portion of the process because these steps involve several endergonic isomerizations. produce NADH which is less energy-rich than ATP. generate waste products which cost ATP for disposal. consume ATP instead of producing it. none of the above

consume ATP instead of producing it

Glycolysis occurs mainly in the brain. mitochondria of all cells. liver. muscle. cytosol of all cells.

cytosol of all cells.

If a glucose tolerance test shows an abnormally high level of glucose in the blood after several hours, the person is possibly anemic. overweight. hypoglycemic. diabetic.

diabetic.

All of the following statements concerning digestion are correct except the major chemical reaction in digestion is enzyme-catalyzed hydrolysis of large molecules. the major physical processes in digestion are mixing, softening and grinding of food. different foods are digested by different enzymes. digestion begins in the stomach and is completed in the large intestine. digestion can be considered a catabolic process in which bulk food is broken down into individual small molecules.

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

The first step of glycolysis involves ________ to form ________. oxidation; glucose -6-phosphate addition; fructose-1,6-diphosphate isomerization; fructose-6-phosphate esterification; glucose-1-phosphate esterification; glucose-6-phosphate

esterification; glucose-6-phosphate

Which chemical is produced from pyruvate when it is metabolized by yeast cells? acetyl-SCoA ethanol phosphoenol pyruvate glucose lactate

ethanol

Which of the following carbohydrates can also be used as fuel in glycolysis? fructose glucose glucose and fructose galactose, fructose, and mannose fructose and galactose

galactose, fructose, and mannose

The process of making glucose from noncarbohydrates is known as lipogenesis. gluconeogenesis. glycolysis. glycogenolysis. glycogenesis.

gluconeogenesis.

Which conversion is accomplished during glycolysis? glycogen to glucose glucose to glycogen pyruvate to glucose glucose to pyruvate starch to glucose

glucose to pyruvate

Glycogenolysis does not occur in muscle tissue because it lacks which of the following enzymes? phosphoglucomutase glycogen phosphorylase glucose-6-phosphatase pyruvate kinase

glucose-6-phosphatase

The most important monosaccharide for energy production is ribose. glucose. mannose. fructose. galactose.

glucose.

Glycogenolysis can be correctly represented by which of the following pathways? glycogen → glucose pyruvate → glycogen glucose → glycogen glycogen → pyruvate glucose → pyruvate

glycogen → glucose

Which pathway converts glucose to its storage form in animals? glycolysis lipogenesis gluconeogenesis glycogenesis glycogenolysis

glycogenesis

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 ________. lipogenesis; glycogenolysis glycogenesis; lipogenesis glycolysis; gluconeogenesis glycogenolysis; gluconeogenesis gluconeogenesis; glycogenesis

glycogenolysis; gluconeogenesis

The pathway followed by glucose when energy is needed is glycogenesis. lipogenesis. gluconeogenesis. the pentose phosphate pathway. glycolysis.

glycolysis

A lack of insulin causes ________, a state in which the concentration of blood sugar is ________ than normal. hyperglycemia; higher hypoglycemia; higher hyperglycemia; lower hypoglycemia; lower none of the above

hyperglycemia; higher

When blood sugar levels are lower than normal, this condition is called diabetes mellitus. glucosuria. hyperglycemia. hypoglycemia.

hypoglycemia.

Overproduction of insulin causes ________, a state in which the concentration of blood sugar is ________ than normal. hyperglycemia; lower hypoglycemia; higher hyperglycemia; higher hypoglycemia; lower none of the above

hypoglycemia; lower

The diseases identified as diabetes are primarily associated with a malfunction of the hormone sorbitol. insulin. epinephrine. glucagon. cortisone.

insulin.

Hormones which regulate glucose metabolism are ________, ________, and ________. growth hormone; cortisone; thyroxine estrogen; progesterone; testosterone insulin; glucagon; epinephrine insulin; cortisone; thyroxine estrogen; glucagon; epinephrine

insulin; glucagon; epinephrine

The conversion of glucose 6-phosphate to fructose 6-phosphate in the second step of glycolysis is a(an) ________ reaction. oxidation dehydration isomerization reduction phosphorylation

isomerization

Conversion of dihydroxyacetone phosphate to D-glyceraldehyde 3-phosphate is a(an) ________. condensation esterification oxidation isomerization reduction

isomerization. Acetone becomes aldehyde

Which chemical is produced from pyruvate when it is metabolized in muscle cells under anaerobic conditions? glucose acetyl-SCoA lactate ethanol phosphoenol pyruvate

lactate

The pain and cramps that occur during physical exhaustion are associated with the formation of excess glucose. lactate. acetaldehyde. pyruvate. acetyl-CoA.

lactate.

Gluconeogenesis occurs mainly in the mitochondria of all cells. cytosol of all cells. muscle. brain. liver.

liver.

Glycogen is most commonly found in ________ cells and ________ cells. bone; white blood muscle; white blood muscle; liver red blood; liver red blood; white blood

muscle; liver

In the first step of glycolysis, the conversion of glucose to glucose 6-phosphate is known as dehydration. reduction. phosphorylation. oxidation. isomerization.

phosphorylation.

The major function of the pentose phosphate pathway when energy for anabolic reactions is a priority is providing intermediates for glycogenesis. producing NADPH. providing intermediates for the citric acid cycle. producing ribose. meeting the need for large amounts of ATP.

producing NADPH.

Which of the following is not a product of digestion? glucose fatty acids glycerol pyruvate amino acids

pyruvate

The products of glycolysis important in metabolism are CO2 and H2O. CO2, ATP, and NADH. acetyl-SCoA and ATP. pyruvate, ATP, and NADH. pyruvate, ADP, and NAD+.

pyruvate, ATP, and NADH.

Pyruvate is converted to lactate under anaerobic conditions because ________. reduction of pyruvate provides NAD+ which is needed for glycolysis lactate is storage for of pyruvate for use later when more ATP is needed lactate releases oxygen upon conversion to acetyl-CoA reduction of pyruvate provides NADH which is needed for gluconeogenesis none of the above

reduction of pyruvate provides NAD+ which is needed for glycolysis

The target molecule(s) for α-amylase is (are) starch and glycogen. glucose. sucrose. all disaccharides. starch.

starch and glycogen.

When a cell's need for NADPH or ribose-6-phosphate exceeds its need for ATP, glucose-6-phosphate is metabolized by the pentose phosphate pathway. glycolysis. gluconeogenesis. glycogenesis. glycogenolysis.

the pentose phosphate pathway.