Exam 2- 307

Fatty acids are converted into glucose by gluconeogenesis and used for energy during starvation. T/F

False

Glycogenolysis occurs exclusively in the liver. T/F

False

Ketogenesis occurs under conditions of excess glucose, such as in the fed state. T/F

False

Most enzyme-catalyzed reactions are irreversible. T/F

False

The amino acid pool is solely made up of amino acids obtained from the diet. T/F

False

The gallbladder is the key organ responsible for maintaining cholesterol homeostasis in the body. T/F

False

Glycogenolysis in muscle cells provides glucose that can be transported through the bloodstream. T/F

False Because muscle cells lack glucose-6-phosphatase, glycogenolysis in liver cells is the only source of free glucose for transport

Glycogenolysis in muscle cells provides glucose that can be transported through the bloodstream. T/F

False Because muscle cells lack glucose-6-phosphatase, glycogenolysis in liver cells is the only source of free glucose for transport.

A vegan would not benefit from measures that help to reduce intestinal cholesterol absorption because their diet does not included any cholesterol. T/F

False Endogenous sources of cholesterol generally make up the majority of cholesterol found in the intestinal tract as a result of enterohepatic circulation.

Because they do not have mitochondria, red blood cells generate a lot of lactate from glycolysis, which they in turn convert into glucose to meet their energy needs. T/F

False The lactate must travel from the RBC via the blood to the liver; in the liver, lactate is converted into glucose (via gluconeogenesis), which is then secreted back into the bloodstream.

The muscle is an important tissue in gluconeogenesis because it can use amino acids from protein breakdown and convert them to glucose, which it then secretes into the circulation for other tissues. T/F

False The muscle cannot convert amino acids to glucose and then secrete it because of a lack of glucose-6-phosphatase.

Glucose-6 phosphatase dephosphorylates glucose-6-phosphate (G6P) releasing free glucose. In which pathway(s) does this enzyme play a role? Choose all that apply. -gluconeogenesis -glycogenolysis -glycogenesis -glycolysis -pentose phosphate pathway

Gluconeogenesis and glycogenolysis

Which of the following carries out reverse cholesterol transport that removes cholesterol from peripheral cells and returns it to the liver? a. chylomicrons b. lipoprotein lipase c. HDL d.LDL

HDL

The oxidation of ethanol increases the concentration of NADH. What effect does this have on tissues that metabolize ethanol? a. Increased triacylglycerol synthesis b Increased lipolysis c. Increased protein synthesis d. Increased bile acid synthesis

Increased triacylglycerol synthesiss

An example of homeostasis gone awry in type 2 diabetes is the _______ action of uncoupling proteins in pancreatic B-cells, which results in ______ insulin secretion.

Increased, decreased

Brain and muscle cells adapt to using ketones during low- energy/low-carbohydrate diets. T/F

True

Brain and muscle cells adapt to using ketones during low-energy/low-carbohydrate diets. T/F

True

Glutamine and alanine remove excess nitrogen generated by muscle protein breakdown during the fasting state. T/F

True

In addition to displacing cholesterol from micelles, phytosterols lower cholesterol by stimulating LDL receptor expression thereby increasing clearance of LDLs from circulation. T/F

True

In step four of glycolysis, two trioses are produced and both continue through the glycolytic pathway, which means that a single molecule of glucose will generate two pyruvate, not one. T/F

True

LDL that accumulates in the bloodstream due to poor hepatic clearance is a known risk factor for atherosclerotic cardiovascular disease. T/F

True

Maintenance of normal blood glucose concentration is coordinated between tissues such as the small intestine, the liver, the kidneys, skeletal muscle, and adipose tissue and hormonal influences like glucagon and insulin. T/F

True

Maintenance of normal blood glucose concentration is coordinated by the liver and hormonal influences like glucagon and insulin. T/F

True

One reaction in glycolysis and two reactions in the TCA cycle produce ATP by substrate-level phosphorylation. T/F

True

Phosphorylating glucose serves to "prime" the glycolytic pathway by trapping glucose in the cell and energizing the molecule for subsequent reactions. T/F

True

The Cori cycle would be active under anaerobic conditions, such as excessive muscle exertion. T/F

True

The key organ responsible for LDL clearance (removal of LDL from circulation) is the liver. T/F

True

The regulation of fatty acid synthesis and oxidation is closely linked to carbohydrate status. T/F

True

Without PDCAAS testing, food manufacturers may not include %DV on nutrition facts labels nor make protein-related health claims. T/F

True

The RDA for protein for an adult who weighs 80 kg is 64 g of protein. T/F

True Multiple BW in kg by 0.8 to get amount

The oxidation of ethanol increases the concentration of NADH. What effect does this have on tissues that metabolize ethanol? a. Increased triacylglycerol synthesis b. Increased bile acid synthesis c. Increased protein synthesis d. Increased lipolysis

a. Increased triacylglycerol synthesis

The poison, sodium cyanide, inhibits the enzyme cytochrome c oxidase. Why is ingestion of this poison usually fatal? a. It blocks the production of ATP in the cells. b. It changes membrane permeability allowing important molecules to leave the cell. c. It causes cells to rupture. d. It causes changes in the acetyl-coenzyme A molecule.

a. It blocks the production of ATP in the cells.

Fatty acids with an even number of carbons are degraded exclusively into ____. a. acetyl-CoA b. glucose c. pyruvate d. triacylglycerols

a. acetyl-CoA

Tryptophan is considered glucogenic, because it can yield pyruvate, and ketogenic, because it can yield ___________. a. acetyl-CoA b. fumarate c. oxaloacetate d. succinyl CoA

a. acetyl-CoA

What is the end product of β-oxidation? a. acetyl-CoA b. glycerol c. triacylglycerol d. pyruvate

a. acetyl-CoA

What mechanism is most often utilized by ATP, ADP and AMP to regulate metabolism? a. allosteric modulation b. enzyme translocation c. hormonal activation d. genetic regulation

a. allosteric modulation

The interaction between the receptors and which of the following components is key to the cell's internalization of LDL? a. apolipoprotein B-100 b. apolipoprotein C-100 c. HMG-CoA reductase d. cholesterol acyltransferase e. apolipoprotein B-48

a. apolipoprotein B-100

Which of the following lipoproteins is normally NOT present in blood in the fasting state? a. chloymicrons b. LDL c. HDL d. VLDL

a. chylomicrons

Abnormal LDL clearance due to genetic variants that reduce LDL receptor expression and translocation is associated with: a.familial hypercholesterolemia b. high dietary fiber intake c. low serum LDL cholesterol concentrations d. hyperglycemia

a. familial hypercholesterolemia

Which of the following catalyzes phosphorylation of glucose in the liver? a. glucokinase b. hexokinase c. phosphorylase d. glucagon

a. glucokinase

Which substance is converted into glycogen in the process of glycogenesis? a. glucose-1-phosphate b. glyceraldehyde-3-phosphate c. phosphoglyceraldehyde d. fructose-1-phosphate

a. glucose-1-phosphate

Legumes are limited in sulfur-containing amino acids, methionine, and cysteine. What food group is considered complementary because it supplies these amino acids? a. grains b. fruits c. nuts d. starchy vegetables

a. grains

Which of the following foods has the lowest glycemic index? a. kidney beans b. white bread c. mashed potatoes d. bananas

a. kidney beans

In the determination of glycemic index, for what period of time after ingestion of the specific food, is the elevation of blood glucose measured? a. 4 hours b. 2 hours c. 1 hour d. 30 minutes

b. 2 hours

Which glucose transporter is insulin-dependent? a. GLUT3 b. GLUT4 c. GLUT1 d. SGLT1 e. GLUT2

b. GLUT4

The oxidation of ethanol increases the concentration of NADH. What effect does this have on tissues that metabolize ethanol? a. Increased bile acid synthesis b. Increased triacylglycerol synthesis c. Increased lipolysis d. Increased protein synthesis

b. Increased triacylglycerol synthesis

Ketones are produced from ____. a. amino groups b. acetyl-CoA c. cholesterol d. glucose

b. acetyl-CoA

What mechanism is most often utilized by ATP, ADP and AMP to regulate metabolism? a. causing directional shifts in reactions b. allosteric modulation c. alternate translocation of enzymes d. hormonal activation

b. allosteric modulation

What is the most important unsaturated fatty acid in membrane phospholipids that serves as a precursor for eicosanoid synthesis? a. linoleic acid b. arachidonic acid c. stearic acid d. oleic acid

b. arachidonic acid

Which of the following can adapt to using ketone bodies during prolonged energy deficit? a. liver b. brain c. muscle d. kidneys

b. brain

Which of the following lipoproteins is normally NOT present in blood in the fasting state? a. HDL b. chylomicrons c. LDL d. VLDL

b. chylomicrons

When would ketogenesis be the HIGHEST? a. after a high-fat meal b. during prolonged starvation c. after a high-CHO meal d. after prolonged low-intensity exercise

b. during prolonged starvation

Insulin is an anabolic hormone. Which process does insulin stimulate? a. lipolysis b. glycogenesis c. glycogenolysis d. gluconeogenesis

b. glycogenesis

The poison, sodium cyanide, inhibits the enzyme cytochrome c oxidase. Why is ingestion of this poison usually fatal? a. It causes cells to rupture b. it blocks the production of ATP in the cells c. It causes changes in the acetyl-coenzyme A molecule d. It changes membrane permeability allowing important molecules to leave the cell.

b. it blocks the production of ATP in the cells

The purpose of the hexose monophosphate shunt is to produce __________. a. ATP b. pentose phosphates and NADPH c. fatty acids d. DNA and RNA

b. pentose phosphates and NADPH

Epinephrine responds to hypoglycemia by stimulating hepatic glucose production, suppressing insulin secretion, reducing glucose utilization, and ________________. a. stimulating glycogenesis b. stimulating lipolysis c. stimulating the pentose phopshate pathway d. stimulating fatty acid synthesis

b. stimulating lipolysis

A manufacturer can claim that its product is an "excellent" source of fiber if the product contains at least what percentage of the recommendations for fiber? a. 25 b. 10 c. 20 d. 15

c. 20

At rest, the brain uses what percentage of available energy? a. 30-40% b. 15-20% c. 20-25% d. 5-10%

c. 20-25%

Which of the following is true regarding BMR and RMR? a. BMR is typically 10% higher than RMR b. BMR and RMR are virtually the exact same measurement c. BMR is difficult to obtain in most people, whereas RMR is more easily measured d. RMR is more difficult to obtain than BMR

c. BMR is difficult to obtain in most people, whereas RMR is more easily measured

The difference between the malate-aspartate and glycerol-3- phosphate shuttle systems is ____________. a. Only the malate-aspartate shuttle transports NADH from the cytosol to the mitochondrial matrix b. All of the possible answers are correct. c. Glycerol-3-phosphate shuttle system transfers its reducing equivalents to FAD generating less ATP d. One system generates energy as heat and the other genera

c. Glycerol-3-phosphate shuttle system transfers its reducing equivalents to FAD generating less ATP

Gluconeogenesis is essentially the reversal of which pathway? a. TCA cycle b. glycogenesis c. glycolysis d. glycogenolysis

c. Glycolysis

Which of the following is the rate-limiting enzyme in cholesterol synthesis? a. hormone-sensitive lipase b. desaturase c. HMG-CoA reductase d. lipoprotein lipase

c. HMG-CoA reductase

Which drug therapy is associated with reduced cholesterol synthesis in the liver? a. niacin b. glucagon inhibitors c. HMG-CoA reductase inhibitors d. insulin

c. HMG-CoA reductase inhibitors

The translocation of GLUT4 from storage vesicles to the cell membrane in adipose and muscle tissue following exercise stimulates the following: a. The release of insulin from insulin receptors thereby releasing glucose into the blood b. Increased expression of GLUT4 storage vesicles c. Increased uptake of glucose from the blood thereby lowering blood glucose levels d. Insulin resistance and reduced expression of GLUT4

c. Increased uptake of glucose from the blood thereby lowering blood glucose levels

What does the liver synthesize to transport endogenous triacylglycerol? a. LDLs b. Chylomicrons c. VLDLs d. HDLs

c. VLDLs

What does the liver synthesize to transport endogenous triacylglycerol? a. LDLs b. chylomicrons c. VLDLs d. HDLs

c. VLDLs

What is the term used to represent maximum oxygen consumption relating to exercise capcacity? a. lactic acid system b. alanine-glucose cycle c. VO2 max d. ATP-phosphocreatine

c. VO2 max

What is the end product of β-oxidation? a. triacylglycerol b. pyruvate c. acetyl-CoA d. glycerol

c. acetyl-CoA

What is the most important unsaturated fatty acid in membrane phospholipids that serves as a precursor for eicosanoid synthesis? a. stearic acid b. oleic acid c. arachidonic acid d. linoleic acid

c. arachidonic acid

Which one of the following is stimulated by the cascade of events mediated by epinephrine and natriuretic peptides? a. elongation of the fatty acid chain b. formation of ketones c. complete hydrolysis of triacylglycerols d. hormone-sensitive lipase gets de-phosphorylated

c. complete hydrolysis of triacylglycerols

All of the following are substrates for gluconeogenesis EXCEPT ____. a. ATP b. lactate c. fatty acids d. glycerol

c. fatty acids

Which sugar is not present in the systemic circulation due to efficient removal and metabolism by the liver? a. galactose b. sucrose c. fructose d. glucose

c. fructose

Which of the following is a strong regulator of liver phosphorylase? a. insulin b. AMP c. glucagon d. glucose-6-phosphate

c. glucagon

Under the influence of insulin, which of the following is stimulated? a. debranching enzymes b. glycogenolysis c. glycogenesis d. phosphorylation of glycogen synthase

c. glycogenesis

Which hormone has the primary responsibility for directing energy metabolism in the fed state? a. cortisol b. glucagon c. insulin d. glucagon

c. insulin

Which of the following relies solely on glucose for energy? a. muscle b. liver c. red blood cells (erythrocytes) d. adipose tissue

c. red blood cells

Which tissue has the least activity of the pentose phosphate pathway? a. red blood cells b. adrenal cortex c. skeletal muscle d. liver

c. skeletal muscle

Which of the following lipoproteins is normally NOT present in blood in the fasting state? a. chylomicrons b. VLDL c. HDL d. LDL

chylomicrons

Which drug therapy is associated with reduced cholesterol synthesis in the liver? a. niacin b. glucagon inhibitors c. insulin d. HMG-CoA reductase inhibitors

d. HMG-CoA reductase inhibitors

The oxidation of ethanol increases the concentration of NADH. What effect does this have on tissues that metabolize ethanol? a. Increased bile acid synthesis b. Increased lipolysis c. Increased protein synthesis d. Increased triacylglycerol synthesis

d. Increased triacylglycerol synthesis

As an "amphibolic" pathway, what is the TCA cycle capable of in addition to participating in oxidative catabolism? a. It functions both inside and outside the mitochondria. b. It functions in muscle growth processes. c. It participates in digestive processes. d. It provides precursors for biosynthetic pathways. e. It functions in both hydrophilic and hydrophobic environments.

d. It provides precursors for biosynthetic pathways.

Adequate oxaloacetate is needed to keep the TCA cycle moving forward and the following substrate may be used to replenish it for continual use: a. Succcinyl-CoA b. NADH c. acetoacetate d. Pyruvate

d. Pyruvate

Which of the following amino acids is glucogenic and returns glucose to the muscle during exercise or periods of fasting? a. taurine b. leucine c. lysine d. alanine

d. alanine

The conversion of pyruvate to oxaloacetate in gluconeogenesis allows which molecules to enter the gluconeogenic pathway? a. polysaccharides b. fatty acids c. monosaccharides d. amino acids

d. amino acids

Which apolipoprotein is key to the delivery of triacylglycerol to tissues? a. apoA-4 b. apoB-100 c. apoE d. apoC-2

d. apoC-2

Which apolipoprotein is key to the delivery of triacylglycerol to tissues? a. apoB-100 b. apoA-4 c. apoE d. apoC-2

d. apoC-2

What is the carrier molecule needed for mitochondrial membrane transport of long-chain fatty acids and their CoA derivatives? a. glutathione b. creatine c. cysteine d. carnitine

d. carnitine

When would ketogenesis be the HIGHEST? a. after prolonged low-intensity exercise b. after a high-fat meal c. after a high-CHO meal d. during prolonged starvation

d. during prolonged starvation

When glucose exceeds the glycogen storage capacity of the liver, what is the excess glucose converted to? a. lactate b. pentose phosphates c. glucose-6-phosphate dehydrogenase d. fatty acids and triacylglycerols

d. fatty acids and triacylglycerols

Which of the following hormones or molecules increases the urge to eat? a. insulin b. leptin c. obesogens d. ghrelin

d. ghrelin

Which nonessential amino acid, that is beneficial for the health and integrity of the gut mucosa, is supplemented to individuals who are critically ill? a. proline b. tyrosine c. methionine d. glutamine

d. glutamine

Under the influence of insulin, which of the following is stimulated? a. phosphorylation of glycogen b. phosphorylation of glycogen synthase c. glycogenolysis d. glycogenesis

d. glycogenesis

In which cellular site is most of the energy released when carbohydrates are oxidized to carbon dioxide and water? a. endothelium b. Golgi body c. lysosome d. mitochondrion

d. mitochondrion

A person with a BMI of 31 would fall into what category? a. normal b. overweight c. underweight d. obese

d. obese

Glycemic load considers the ______________ in food. a. protein and carbohydrate content b. fat and carbohydrate content c. fat to carbohydrate ratio d. quantity and quality of carbohydrate

d. quantity and quality of carbohydrate

What are apoproteins unable to do? a. confer specificity for recognition by receptors on cells b. increase solubility of circulating lipoproteins in the blood c. decrease the density of the lipoprotein d. stimulate enzymatic reactions

decrease the density of the lipoprotein

How can muscle and adipose tissue obtain glycerol-3-phosphate? a. glycogenesis b. gluconeogenesis c. glycolysis d. lipogenesis

glycolysis

Where are the enzymes that catalyze the TCA cycle located? a. nucleolus b. endoplasmic reticulum c. mitochondrial matrix d.cytoplasmic matrix

mitochondrial matrix

The synthesis of which of the following would be disrupted in an individual with a deficiency of glycerol-3-phosphate? a. fatty acids bacetyl-CoA c. carnitine d. triacylglycerols

triacylglycerols