Chapter 22 - Intro to Orgo & Biochem

The net number of ATP formed when one molecule of glucose is converted to pyruvate is - 1. - 2. - 3. - 4. - 5.

- 2.

How many ATP are generated from the 10 NADH molecules formed during complete oxidation of glucose? - 20 - 38 - 30 - 32 - 25

- 30

How many ATP are generated from the 10 NADH and 2 FADH2 molecules formed during complete oxidation of glucose? - 20 - 30 - 34 - 25 - 38

- 34

The overall yield of ATP molecules from the complete catabolism of one molecule of glucose in humans and other mammals is - 56. - 38 - 18. - 24. - 42.

- 38

Which reaction(s) of glycolysis is(are) key regulation step(s) in the process? - formation of fructose-6-phosphate from glucose-6-phosphate - formation of glucose-6-phosphate from glucose - cleave of fructose-1,6-bisphosphate - formation of fructose-1,6-bisphosphate from fructose-6-phosphate - Both B and D.

- Both B and D.

A high energy phosphate molecule involved in gluconeogenesis is - UDP. - ADP. - UTP. - GDP. - GTP.

- GTP.

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

- I and IV

Which of the following monosaccharides is generated during digestion of milk? -galactose - mannose - fructose - xylose - ribose

-galactose

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 gluconeogenesis II. conversion of glycogen to glucose III. catabolism of lipids - III, II, I - II, III, I - I, II, III - II, I, III - III, I, II

- II, I, III

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

- More than one response is correct.

What cofactor is needed by the pyruvate dehydrogenase complex to convert pyruvate into acetyl CoA? - NAD+ - ATP - FADH2 - ADP - NADH

- NAD+

Which of the following is not used as an energy source in metabolism? - UTC - UTP - GTP - ATP - More than one choice is correct.

- UTC

When a body is deprived of glucose it will begin to break down fats in order to conserve protein. As a consequence acetyl-CoA will begin to build up. What compound is this excess by-product converted into? - lactate - citric acid - acetone - pyruvate - galactose

- acetone

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

- acetyl-CoA

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

- acetyl-CoA.

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

- alcoholic fermentation.

All of these enzymes used in glycolysis involve the transfer of a phosphate group except - pyruvate kinase. - hexokinase. - phosphglycerate kinase. - aldolase. - phosphofructokinase.

- aldolase.

The enzyme that catalyzes cleavage of fructose 1,6-bisphosphate to dihydroxyacetone phosphate and D-glyceraldehyde-3-phosphate is - aldolase. - hexokinase. - phosphofructokinase. - D-glyceraldehyde-3-phosphatase. - none of the above

- aldolase.

Which polysaccharide is not broken down by alpha-amylase? - cellulose - amylopectin - glycogen - amylase

- cellulose

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

- consume ATP instead of producing it.

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

- 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 - 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. - 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.

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

The dehydration of 2-phosphoglycerate to phosphoenolpyruvate uses the enzyme - pyruvate kinase. - hexokinase. - enolase. - phosphoglycerate kinase. - aldolase.

- enolase.

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

- esterification; glucose-6-phosphate

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

- ethanol

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

- galactose, fructose, and mannose

Steps 6-10 of glycolysis are referred to as the "energy generation" portion of the process because these steps - generate ATP instead of consuming it. - consume ATP instead of producing it. - release phosphate groups upon hydrolysis. - involve several endergonic reactions. - generate ADP.

- generate ATP instead of consuming it.

The hormone that stimulates the breakdown of glycogen is - epinephrine. - insulin. - glucagon. - sorbitol. - cortisone

- glucagon.

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

- gluconeogenesis

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

- glucose to pyruvate

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

- glucose-6-phosphatase

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

- glucose.

The chemical produced in steps 3-5 of glycolysis and oxidized in step 6 is - citrate. - glucose. - acetyl-CoA. - glyceraldehyde 3-phosphate. - oxaloacetate.

- glyceraldehyde 3-phosphate.

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

- glycogen ---> glucose

The synthesis of glycogen from excess glucose is - gluconeogenesis. - glycogenolysis. - glycogenesis. - the pentose phoshate pathway. - glycolysis.

- glycogenesis.

Which pathway produces glucose from its storage form in animals? - glycolysis - lipogenesis - glycogenolysis - gluconeogenesis - glycogenesis

- glycogenolysis

All of the following are reactions in the oxidation of glucose which produce energy except - the citric acid cycle. - glycogenolysis. - reaction of reduced coenzymes in the electron transport chain. - oxidation of pyruvate to acetyl-CoA. - glycolysis.

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

- glycogenolysis; gluconeogenesis

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

- glycolysis.

A lack 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

- hyperglycemia; higher

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

- hypoglycemia.

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

- hypoglycemia; lower

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

- insulin.

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

- insulin; glucagon; epinephrine

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

- isomerization

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

- isomerization.

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

- lactate

During gluconeogenesis, pyruvate is formed from glycerol, certain amino acids, and - lactate. - glucose. - glycogen. - acetyl CoA.

- 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 - cytosol of all cells. - liver. - muscle. - mitochondria of all cells. - brain.

- liver.

The major products of carbohydrate digestion are - monosaccharides .- pyruvic acid. - acetyl CoA. - monosaccharides and disaccharides.

- monosaccharides

Glycogen is most commonly found in ________ cells and ________ cells. - muscle; white blood - bone; 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 - phosphorylation. - oxidation. - reduction. - dehydration. - isomerization.

- phosphorylation.

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

- producing NADPH.

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

- producing ribose.

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

- production of ATP as an energy source for all cells.

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

- pyruvate

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

- pyruvate, ATP, and NADH.

All of the chemicals below are associated with the pentose phosphate pathway except - glucose 6-phosphate. - NADP. - NADPH. - pyruvate. - ribose.

- pyruvate.

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

- reduction of pyruvate provides NAD+ which is needed for glycolysis.

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

- starch and glycogen.

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 - oxidative - catabolic - reductive - anabolic

- substrate-level

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. - glycogenolysis. - glycogenesis.

- the pentose phosphate pathway.

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

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

Entry of monosaccharides other than glucose into the glycolysis pathway initially involves - breakdown into pyruvate. - oxidation into acetyl groups. -conversion into phosphates - hydrolysis of 2-carbon units. - reduction of carbonyl groups.

-conversion into phosphates