Biochemistry Final Smart Work: Lipids and Metabolism.
A net yield of __________ ATP would be produced from the conversion of three (3) molecules of glucose into pyruvate.
6
In gluconeogenesis, how many molecules of pyruvate are required to synthesize three molecules of glucose? ______ molecules of pyruvate
6 molecules of pyruvate.
Which fatty acid depicts palmitate?
A.
What is the net reaction for stage I of glycolysis if the pathway begins with 2 moles of glucose? Choose one: A. 2 Glucose + 4 ATP → 4 Glyceraldehyde-3-phosphate + 4 ADP. B. 2 Glucose + 2 ATP → 2 Glyceraldehyde-3-phosphate + 2 Dihydroxyacetone phosphate + 2 ADP. C. 2 Glucose + 2 ATP → 2 Glyceraldehyde-3-phosphate + 2 ADP. D. 2 Glucose + 4 ATP → 2 Glyceraldehyde-3-phosphate + 2 Dihydroxyacetone phosphate + 4 ADP.
A. 2 Glucose + 4 ATP → 4 Glyceraldehyde-3-phosphate + 4 ADP.
Kinases most commonly use which substrate as a source of phosphate for phosphoryl transfer reactions? Choose one: A. ATP-Mg2+. B. ADP. C. Pi. D. ATP.
A. ATP-Mg2+.
For humans, ω-3 is an essential fatty acid, which means it is obtained from which of the following? Choose one: A. Dietary sources. B. Synthesis in the liver. C. Combining saturated fatty acids to make more complex lipids. D. Breakdown of the body's existing cells.
A. Dietary sources.
Which of the following is NOT an outcome of glycolysis? Choose one: A. Generation of 1 Pyruvate. B. Generation of 2 H2O. C. Generation of 2 net ATP molecules. D. Generation of 2 NADH.
A. Generation of 1 Pyruvate.
Free fatty acids inside cells would also act like soap and disrupt biological membranes, except that fatty acids inside cells are chemically neutralized by covalent linkage to what small molecule for energy storage? Choose one: A. Glycerol. B. Ubiquitin. C. Glucose. D. Biotin.
A. Glycerol.
Which of the following enzymes catalyze rate-determining steps in glycolysis? Choose one or more: A. Hexokinase. B. Phosphoglycerate kinase. C. Phosphofructokinase. D. Pyruvate kinase.
A. Hexokinase. C. Phosphofructokinase. D. Pyruvate kinase.
What is the effect of cholesterol on membrane fluidity at physiologic temperatures? Choose one: A. High local concentrations of cholesterol prevent lateral movement of phospholipids and thereby decrease membrane fluidity in that region. B. Cholesterol has a flexible ring structure that increases membrane fluidity. C. Cholesterol causes the outer leaflet of the membrane to swell, increasing membrane fluidity. D. Cholesterol has no effect on membrane fluidity.
A. High local concentrations of cholesterol prevent lateral movement of phospholipids and thereby decrease membrane fluidity in that region.
Lipases are water-soluble enzymes in the small intestine that... Choose one: A. Hydrolyze triacylglycerols to fatty acids. B. Covalently attach lipids to glucose. C. Break down free fatty acids into acetate. D. Convert sphingolipids to triacylglycerols.
A. Hydrolyze triacylglycerols to fatty acids.
In which situation is glycolysis alone likely to be a major contributor to ATP generation? Choose one: A. In erythrocytes. B. Under aerobic conditions. C. In muscle cells. D. In liver cells.
A. In erythrocytes.
Many people do not realize that animal fat is used to make most soap, which is interesting because we use soap to remove animal fat from our hands and clothing. Soap is made by subjecting animal lard to saponification, in which heat and a strong alkali (NaOH or KOH) release fatty acids in the form of sodium or potassium salts from triacylglycerols. When mixed with water, the fatty acids in soap function as amphipathic molecules forming what? Choose one: A. Micelles. B. Vesicles. C. Monolayers. D. Bilayers
A. Micelles.
Which enzyme, shown as 4 in the figure below, processes oxaloacetate that has been shuttled from the matrix via malate transport to enter gluconeogenesis? Choose one: A. Phosphoenolpyruvate carboxykinase. B. Malate dehydrogenase. C. Pyruvate carboxylase. D. Glyceraldehyde-3-P dehydrogenase.
A. Phosphoenolpyruvate carboxykinase.
Sucrose, maltose, and lactose are common dietary disaccharides. Their monosaccharide components are substrates for the glycolytic pathway, but some must participate in additional reactions before they can act as substrates for a glycolytic enzyme. As a result, all do not enter glycolysis at the same step. In muscle cells, which enzyme would act as the rate-limiting step to regulate entry of products from all three dietary disaccharides into glycolysis? Choose one: A. Phosphofructokinase-1. B. Phosphoglucose isomerase. C. Aldolase. D. Hexokinase.
A. Phosphofructokinase-1.
Which enzymes in glycolysis catalyze a phosphoryl transfer reaction? Choose one or more: A. Phosphofructokinase. B. Hexokinase. C. Pyruvate kinase. D. Glyceraldehyde-3-phosphate dehydrogenase.
A. Phosphofructokinase. B. Hexokinase. C. Pyruvate kinase.
Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most common pain-relief medicines in the world. Every day more than 30 million Americans use them to soothe headaches, sprains, arthritis symptoms, and other daily discomforts. NSAIDs work by blocking the effects of specific enzymes. These enzymes play a key role in making prostaglandins. By blocking the enzymes, NSAIDs stop the body from making as many prostaglandins, which means less swelling and less pain. A COX-2-specific NSAID would have which effect? Choose one: A. Prevent pain and swelling. B. Stomach tissue damage due to lack of cellular protection from low pH. C. Angiogenesis, the development of new blood vessels. D. Lead to the overproduction of mucins (the high molecular weight, heavily glycosylated proteins that are a key component in most gel-like secretions that serve functions from lubrication to cell signaling to forming chemical barriers
A. Prevent pain and swelling.
Which of the following fates of pyruvate is correct? Choose one: A. Pyruvate enters the citrate cycle under aerobic conditions. B. Pyruvate is converted to lactate under aerobic conditions. C. Pyruvate enters the citrate cycle under anaerobic conditions. D. Pyruvate is fermented to ethanol under aerobic conditions.
A. Pyruvate enters the citrate cycle under aerobic conditions.
Use this map of the major metabolic pathways to answer the following question (Map is in answer). Which of the following statements are true? Choose one or more: A. Pyruvate is a product of the catabolism of all major biomolecules. B. Glucose is a product of the catabolism of all major biomolecules. C. Acetyl CoA is a product of the catabolism of all major biomolecules. D. Ammonia is a product of the catabolism of all major biomolecules.
A. Pyruvate is a product of the catabolism of all major biomolecules. C. Acetyl CoA is a product of the catabolism of all major biomolecules.
Triacylglycerols synthesized in the liver are packaged in which of the following? Choose one: A. VLDL particles. B. Chylomicrons. C. Secretory vesicles. D. HDL particles.
A. VLDL particles.
Gluconeogenesis is what kind of process? Choose one: A. anabolic. B. catabolic. C. futile cycle. D. unregulated.
A. anabolic.
For lactate transported to the liver, which of the following conversions reduces NAD+ to form the NADH required for generation of glyceraldehyde-3-phosphate by GAP dehydrogenase? Choose one: A. lactate to pyruvate. B. pyruvate to oxaloacetate. C. glycerol to DHAP. D. DHAP to GAP.
A. lactate to pyruvate.
The Cori cycle involves the transport of what molecule, produced under anaerobic conditions, from the muscles to the liver? Choose one: A. lactate. B. cholesterol. C. pyruvate. D. ATP. E. valine.
A. lactate.
Glycogen branching occurs by the formation of what type of glycosidic bond? Choose one: A. α-1,6. B. ß-1,6. C. α-1,4. D. α-1,3.
A. α-1,6.
Sort the listed pathways to indicate the effects of insulin and glucagon on activity in the liver. 1. Glycogenolysis 2. Glucose release 3. Gluconeogenesis 4. Glycogen synthesis 5. Glucose uptake 6. Glycolysis
Activated by glucagon Glycogenolysis Glucose release Gluconeogenesis Activated by insulin Glycogen synthesis Glucose uptake Glycolysis
Given that fructose-2,6-BP alters the activity of the reciprocal enzymes PFK-1 and FBPase-1, which of the following activity curves would be expected for PFK-1 during glycolysis when fructose-2,6-BP is abundant? _________________________________
Activity Curve B.
Fill in the blank to correctly identify the relative melting points for the fatty acid pairs indicated: (a) Myristate (14:0) has a ____________ melting point than stearate (18:0). (b) Palmitate (16:0) has a ____________ melting point than palmitoleate [cis 16:1 (Δ9)]. (c) α-Linolenate [cis 18:3 (Δ9,12,15)] has a _________ melting point than oleate [cis 18:1 (Δ9)].
Answer: (a) Myristate (14:0) has a lower melting point than stearate (18:0). (b) Palmitate (16:0) has a higher melting point than palmitoleate [cis 16:1 (Δ9)]. (c) α-Linolenate [cis 18:3 (Δ9,12,15)] has a lower melting point than oleate [cis 18:1 (Δ9)].
Which of the following lipids can be found in cellular membranes? Choose one or more: A. Cholesterol. B. Triacylglycerols. C. Sphingolipids. D. Glycerophospholipids.
Answer: A. Cholesterol. C. Sphingolipids. D. Glycerophospholipids.
Put into chronological order the following steps by which glucagon causes the release of fatty acids from adipocytes. A. cAMP activation of PKA. B. Perilipin phosphorylation. C. Glucagon binds to GPCR, G sα activated. D. Albumin transports free fatty acids through the circulatory system. E. Lipase activation generates free fatty acids.
Answer: C. Glucagon binds to GPCR, G sα activated. A. cAMP activation of PKA. B. Perilipin phosphorylation. E. Lipase activation generates free fatty acids. D. Albumin transports free fatty acids through the circulatory system.
Which of the following statements are true about cell membranes? Choose one or more: A. The protein content of a cell membrane can never exceed the lipid content. B. Cell membranes form a continuous and completely impermeable barrier surrounding the cell. C. The membranes of animal cells generally contain cholesterol. D. The major constituents of cell membranes are lipids and proteins.
Answer: C. The membranes of animal cells generally contain cholesterol. D. The major constituents of cell membranes are lipids and proteins.
Sort the following fatty acids into the appropriate categories. A. 16:0 B. 14:0 C. Palmitate D. 16:1 E. Oleate F. 18:2 (Δ^9,12) G. 18:1
Answer: Saturaded Fatty Acids: A. 16:0 B. 14:0 C. Palmitate Unsaturated Fatty Acids: D. 16:1 E. Oleate F. 18:2 (Δ^9,12) G. 18:1
Sort the following into saturated, monounsaturated, and polyunsaturated fatty acids:
Answer: - Saturated: Myristate (14:0). - Monounsaturated: (Check image). - Polyunsaturated fatty acids: Cis 18:2 (Δ9,12).
Identify the following as either a glycerophospholipid or sphingolipid. A. B. C. D.
Answer: Check image. The structure of glycerophospholipids is similar to triacyl glycerol except that C-3 carbon of the glycerol backbone is esterified to phosphoric acid. In sphingolipid, the glycerol backbone is absent. - A and D are glycerophospholipid. - B and C are sphingolipid.
Sort the following lipids by their major role in the cell. Major Role in Cell -> Energy Storage, Cell Membranes and Endocrine Signaling. Lipids -> Triacylglycerols, Fatty Acids, Glycerophospolipids, Sphingolipids, Steroids and Eicosanoids.
Answer: Major Role in Cell: - Energy Storage: Triacylglycerols, Fatty Acids. - Cell Membranes: Glycerophospolipids, Sphingolipids. - Endocrine Signaling: Steroids and Eicosanoids.
The major lipid precursor of eicosanoid signaling is _____________________.
Arachidonic Acid.
What is the common name for the fatty acid designated by cis 20:4 (Δ^5,8,11,14)?
Arachidonic Acid.
How many enzymes catalyze irreversible reactions in stage II of glycolysis under cellular conditions? Choose one: A. 3. B. 1. C. 4. D. 2
B. 1.
The figure below shows the activity curves of phosphofructokinase-1 (PFK-1) in the presence of allosteric regulators. Which allosteric regulator is responsible for curve C? Choose one: A. AMP. B. ATP. C. ADP. D. Fructose-2,6-bisphosphate.
B. ATP.
Which of the following lipid signaling molecules is NOT derived from cholesterol? Choose one: A. Progesterones. B. Eicosanoids. C. Estrogens. D. Androgens.
B. Eicosanoids.
Fructose intolerance is due to a deficiency in the aldolase B isozyme in the liver. What metabolic intermediate accumulates as a result of this deficiency? Choose one: A. Glyceraldehyde-3-phosphate. B. Fructose-1-phospate. C. Fructose. D. Dihydroxyacetone phosphate.
B. Fructose-1-phospate.
Label the hormones and enzymes that control activity of the bifunctional enzyme phosphofructokinase-2/fructose-2,6-bisphosphatase (PFK-2/FBPase-2). A. Insulin B. Glucagon C. Protein kinase A D. Protein phosphatase 1
B. Glucagon. C. Protein kinase A. D. Protein phosphatase 1. A. Insulin.
Lactose intolerance is a condition caused by a deficiency in the lactase enzyme. Individuals with this deficiency can experience unpleasant symptoms if they eat lactose-containing foods such as dairy products. The human gene for lactase is expressed at high levels in infants to aid in the digestion of lactose in breast milk; however, lactase expression normally declines in adults, with the notable exception of people of Scandinavian descent. What reaction is catalyzed by lactase? Choose one: A. Hydrolysis of lactose to produce two glucose molecules. B. Hydrolysis of lactose to produce glucose and galactose. C. Hydrolysis of all disaccharides in the small intestine. D. Hydrolysis of lactose to produce glucose and fructose.
B. Hydrolysis of lactose to produce glucose and galactose.
What purpose do glycogen degradation and synthesis serve in animals? Choose one: A. Muscles do not store glycogen. B. Liver glycogen is a short-term energy source providing a means to store and release glucose in response to blood glucose levels. C. Liver glycogen is not utilized, except after multiple days of starvation. D. Muscles break down glycogen for immediate use when insulin is secreted by the pancreas.
B. Liver glycogen is a short-term energy source providing a means to store and release glucose in response to blood glucose levels.
A student on the cross country team wishes to improve her performance in an upcoming race. The student normally eats small amounts of glucose gel for energy during a long run, and she decides that the best course of action is to triple the amount of glucose gel she eats each time so that her muscles can have access to more glucose. Will this strategy work? Choose one: A. Yes; ingesting more glucose gel will increase the activity of all enzymes in glycolysis, which will result in more ATP. B. No; ingesting additional glucose gel will raise the blood glucose level but will not increase the reaction rate of hexokinase. Instead, the increase in glucose will increase the reaction rate of glucokinase, which could have negative effects on the athlete's performance. C. No; ingesting additional glucose will lead to inhibition of both hexokinase and glucokinase, which will prevent the additional glucose from being oxidized.
B. No; ingesting additional glucose gel will raise the blood glucose level but will not increase the reaction rate of hexokinase. Instead, the increase in glucose will increase the reaction rate of glucokinase, which could have negative effects on the athlete's performance.
Which of the following proteins is activated by phosphorylation during glucagon-activated fatty acid release from adipocytes? Choose one: A. Adipose triglyceride. B. Perilipin. C. Monoacylglycerol. D. Fatty acid binding protein 4.
B. Perilipin.
The primary biological function of triacylglycerols is energy storage. In animals, triacylglycerols are stored in fat cells called adipocytes. Triacylglycerols are either obtained from the diet (primarily from animal fat or nuts) or synthesized in the liver, using glucose and amino acids as a source of acetyl-CoA. Triacylglycerols are transported through the blood as components of lipoprotein complexes. When losing weight, which of the following happens naturally in the human body? As energy demand rises and/or caloric intake decreases, Choose one: A. The number of adipocytes increases, but very slowly. B. The number of adipocytes is unchanged. C. The number of adipocytes is reduced. D. The number of adipocytes increases rapidly.
B. The number of adipocytes is unchanged.
The primary biological function of triacylglycerols is energy storage. In animals, triacylglycerols are stored in fat cells called adipocytes. Triacylglycerols are either obtained from the diet (primarily from animal fat or nuts) or synthesized in the liver, using glucose and amino acids as a source of acetyl-CoA. Triacylglycerols are transported through the blood as components of lipoprotein complexes. When losing weight, which of the following happens naturally in the human body? As energy demand rises and/or caloric intake decreases, Choose one: A. The size of adipocytes increases. B. The size of adipocytes decreases. C. The size of adipocytes is unchanged. D. The adipocyte lyses itself to release its contents.
B. The size of adipocytes decreases.
Which of the following is correct concerning waxes? Choose one: A. They always consist of unsaturated carbon chains. B. They consist of long-chain fatty alcohols linked to long-chain fatty acids. C. They always consist of saturated carbon chains. D. They are often liquid under most conditions.
B. They consist of long-chain fatty alcohols linked to long-chain fatty acids.
Glucokinase is important for the regulation of glycolysis because it... Choose one: A. Inhibits insulin release in pancreatic cells in response to high glucose. B. Traps extra glucose in liver cells for glycogen production. C. Is inhibited by glucose-6-phosphate. D. Has a high affinity for glucose.
B. Traps extra glucose in liver cells for glycogen production.
Which of the following is FALSE concerning triacylglycerol transport? Choose one: A. Dietary triacylglycerols are transported as chylomicrons. B. Triacylglycerols from adipose tissue are transported as free triacylglycerols. C. Triacylglycerols synthesized by the liver are transported as VLDL particles. D. Free fatty acids are transported by albumin
B. Triacylglycerols from adipose tissue are transported as free triacylglycerols.
For glycogen synthesis, glucose is activated by what molecule being attached at the C-1 position? Choose one: A. pyrophosphate. B. UDP. C. ATP. D. uridine.
B. UDP.
Which of the following is NOT a major type of plasma membrane lipid? Choose one: A. Cholesterol. B. Wax. C. Glycerophospholipid. D. Sphingolipid.
B. Wax.
The flux of which of the following reactions would depend only on substrate availability? Choose one or more: A. fructose-6-phosphate + ATP → fructose-1,6-bisphosphate + ADP. B. glucose-6-phosphate → fructose-6-phosphate. C. glucose + ATP → glucose-6-phosphate + ADP. D. dihydroxyacetonephosphate → glyceraldehyde-3-phosphate
B. glucose-6-phosphate → fructose-6-phosphate. D. dihydroxyacetonephosphate → glyceraldehyde-3-phosphate.
For animals, identify the major sources of carbon for gluconeogenesis. Choose one or more: A. acetate. B. lactate. C. ribose. D. amino acids.
B. lactate. D. amino acids.
In humans, to maintain flux through the glyceraldehyde-3-phosphate dehydrogenase reaction in the gluconeogenic pathway, NADH equivalents must be moved from the... Choose one: A. exosome to the cytosol. B. mitochondrial matrix to the cytosol. C. cytosol to the mitochondrial matrix. D. cytosol to the extracellular space.
B. mitochondrial matrix to the cytosol.
Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most common pain-relief medicines in the world. Every day more than 30 million Americans use them to soothe headaches, sprains, arthritis symptoms, and other daily discomforts. NSAIDs work by blocking the effects of specific enzymes. These enzymes play a key role in making prostaglandins. By blocking the enzymes, NSAIDs stop the body from making as many prostaglandins, which means less swelling and less pain. COX-2-specific NSAIDs were developed to: Choose one: A. prevent the undesired increase in corticosteroid synthesis. B. prevent swelling and avoid the unwanted side effect of stomach damage. C. prevent swelling and elevate thromboxane production. D. avoid cardiac development issues associated with nonselective NSAID use.
B. prevent swelling and avoid the unwanted side effect of stomach damage.
How many enzymes catalyze irreversible reactions in stage I of glycolysis under cellular conditions? Choose one: A. 4. B. 1. C. 2. D. 3.
C. 2.
Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most common pain-relief medicines in the world. Every day more than 30 million Americans use them to soothe headaches, sprains, arthritis symptoms, and other daily discomforts. NSAIDs work by blocking the effects of specific enzymes. These enzymes play a key role in making prostaglandins. By blocking the enzymes, NSAIDs stop the body from making as many prostaglandins, which means less swelling and less pain. What enzyme(s) are targeted by nonselective NSAIDs? Choose one or more: A. Phospholipase A2 B. Aldosterone synthase C. Cyclooxygenase-2 D. Cyclooxygenase-1 E. Lipoxygenase
C. Cyclooxygenase-2. D. Cyclooxygenase-1.
Label the graph below to show the effect of high ATP, ADP, or fructose-2,6-bisphosphate on phosphofructokinase-1 (PFK-1) activity. A. ADP. B. ATP. C. Fructose-2,6-bisphosphate.
C. Fructose-2,6-bisphosphate. A. ADP. B. ATP.
Which of the following statements best describes the effect of ADP on the activity of PFK-1? Choose one: A. High concentrations of ADP lead to increased formation of fructose-2,6-bisphosphate and enhanced activity of PFK-1. B. High concentrations of ADP enhance the activation of PFK-1 by fructose-2,6-bisphosphate by stabilizing the allosteric site. C. High concentrations of ADP block the inhibitory effect of ATP by competing for the same allosteric site on PFK-1. D. High concentrations of ADP block the synthesis of ATP, which reduces inhibition of PFK-1.
C. High concentrations of ADP block the inhibitory effect of ATP by competing for the same allosteric site on PFK-1.
What does gluconeogenesis accomplish for the organism? Choose one: A. It allows hormonal control of glucose uptake. B. It provides muscle cells with a cytosolic pathway to generate more glucose when oxygen is limiting. C. It allows the liver and kidneys to generate glucose from noncarbohydrate sources to export to other tissues. D. It allows storage of glucose in crystalline form.
C. It allows the liver and kidneys to generate glucose from noncarbohydrate sources to export to other tissues.
Which enzymes in glycolysis catalyze the isomerization of an aldose to a ketose or vice versa? Choose one or more: A. Enolase. B. Phosphoglycerate mutase. C. Phosphoglucoisomerase. D. Triose phosphate isomerase.
C. Phosphoglucoisomerase. D. Triose phosphate isomerase.
Which enzyme is readily reversible, and can therefore be used in both glycolysis and gluconeogenesis? Choose one: A. Pyruvate kinase. B. Hexokinase. C. Phosphoglycerate mutase. D. Phosphofructokinase-1.
C. Phosphoglycerate mutase.
Animals and plants share many common pathways, but some are unique to each organism. Which energy conversion pathway is present in plants but not in animals? Choose one: A. Glycolysis. B. Oxidative phosphorylation. C. Photosynthesis. D. Glycogen synthesis.
C. Photosynthesis.
In adipocytes, glucagon activation leads to... Choose one: A. inactivation of lipases. B. sequestration of fatty acids in lipid droplets. C. release of free fatty acids. D. an increase in chylomicron production.
C. Release of free fatty acids
The concentration of allosteric effectors in a cell is constantly changing with metabolic flux. Consider a skeletal muscle cell where [ATP] > [ADP]. Which of the following scenarios will result in the greatest increase in phosphofructokinase-1 activity? Choose one: A. The glucose concentration inside the cell increases as muscle activity decreases. B. The glucose concentration inside the cell decreases along with muscle activity. C. The glucose concentration inside the cell increases as muscle activity also increases. D. The glucose concentration inside the cell decreases as muscle activity increases.
C. The glucose concentration inside the cell increases as muscle activity also increases.
Brewer's yeast, Saccharomyces cerevisiae, has been used for hundreds of years inthe production of beer. The image below illustrates this process. (Image in the asnwer) A consequence of skipping step 4 (adding yeast straight into anaerobic culture conditions) would cause the total amount of ethanol produced to... Choose one: A. increase. B. increase or decrease depending on the type of hops used. C. decrease. D. remain unchanged.
C. decrease.
Which form of glucose is required by UDP-glucose pyrophosphorylase? Choose one: A. glucose-6-P. B. glucose. C. glucose-1-P. D. glucose-2,6-BP.
C. glucose-1-P.
Glycogen phosphorylase activity is regulated by the phosphorylation state (phosphorylation of Ser14). What enzyme is responsible for phosphorylating, and thereby activating, glycogen phosphorylase? Choose one: A. protein phosphatase 1. B. glycogen debranching enzyme. C. phosphorylase kinase. D. protein kinase A.
C. phosphorylase kinase.
Brewer's yeast, Saccharomyces cerevisiae, has been used for hundreds of years inthe production of beer. The image below illustrates this process. (Image in the asnwer) In which step would the majority of pyruvate produced from glycolysis be converted to acetyl CoA? Choose one: A. step 5. B. step 3. C. step 4. D. step 6.
C. step 4.
Which glycolytic enzymes are bypassed and which are utilized by gluconeogenesis? 1. Pyruvate kinase 2. Phosphofructokinase-1 3. Hexokinase 4. Phosphohexose isomerase 5. Phosphoglycerate mutase 6. GAP dehydrogenase
Categories Bypassed Pyruvate kinase Phosphofructokinase-1 Hexokinase Utilized Phosphohexose isomerase Phosphoglycerate mutase GAP dehydrogenase
Sort the following enzymes according to those required for glycogen synthesis and those required for glycogen breakdown.(Note: Not all enzymes may be used.) 1. Pyruvate Carboxylase. 2. Phosphoglycerate Kinase. 3. Glycogen Synthesis. 4. UDP-glucose pyrophosphorylase. 5. Glycogen synthase. 6. Glycogen branching enzyme. 7. Glycogen Breakdown. 8. Glycogen phosphorylase. 9. Glycogen debranching enzyme.
Categories Glycogen Synthesis UDP-glucose pyrophosphorylase Glycogen synthase Glycogen branching enzyme Glycogen Breakdown Glycogen phosphorylase Glycogen debranching enzyme
Sort the following enzymes into those specific to gluconeogenesis and those specific to glycolysis. 1. Glucose-6-phosphatase 2. Fructose-1,6-bisphosphatase-1 3. Pyruvate carboxylase 4. Phosphoenolpyruvate carboxykinase 5. Pyruvate kinase 6. Hexokinase 7. Phosphofructokinase-1
Categories Only Gluconeogenesis Glucose-6-phosphatase Fructose-1,6-bisphosphatase-1 Pyruvate carboxylase Phosphoenolpyruvate carboxykinase Only Glycolysis Pyruvate kinase Hexokinase Phosphofructokinase-1
The major lipid precursor to steroid production is _________________.
Cholesterol.
Which of the following reactions from glycolysis is an example of substrate-level phosphorylation? Choose one: A. Fructose-6-phosphate + ATP → Fructose-1,6-bisphosphate + ADP. B. 2-Phosphoglycerate → Phosphoenolpyruvate. C. Glyceraldehyde-3-phosphate + NAD+ + Pi → 1,3-Bisphosphoglycerate + NADH. D. 1,3-Bisphosphoglycerate + ADP → 3-Phosphoglycerate + ATP.
D. 1,3-Bisphosphoglycerate + ADP → 3-Phosphoglycerate + ATP.
Label the figure below (Check diagram on answer). A. 2,3-bisphosphoglycerate is in the active site. B. 3-phosphoglycerate enters the active site. C. 2-phosphoglycerate is in the active site. D. 3-phosphoglycerate is in the active site. E. 2-phosphoglycerate is released from the active.
D. 3-phosphoglycerate is in the active site. A. 2,3-bisphosphoglycerate is in the active site. B. 3-phosphoglycerate enters the active site. E. 2-phosphoglycerate is released from the active. C. 2-phosphoglycerate is in the active site.
In animals, triacylglycerols are stored predominantly in what type of cells? Choose one: A. Hepatocytes. B. Pancreatic islets. C. Kidney cells. D. Adipocytes.
D. Adipocytes.
Arachidonic acid is a precursor of all of the following except: Choose one: A. Thromboxanes. B. Prostaglandins. C. Leukotrienes. D. Androgens
D. Androgens.
Which of the following is correct concerning the regulation of glycogen metabolism by hormones? Choose one: A. Epinephrine has the same effect as insulin. B. Glycogen phosphorylase is active when phosphorylated, which occurs in response to insulin. C. Insulin activates protein kinase A, which inactivates glycogen synthase. D. Glucagon activates protein kinase A, which inactivates glycogen synthase.
D. Glucagon activates protein kinase A, which inactivates glycogen synthase.
Which metabolic pathway is an example of a catabolic pathway in animals? Choose one: A. Pentose phosphate pathway. B. Fatty acid synthesis. C. Gluconeogenesis. D. Glycogen degradation.
D. Glycogen degradation.
Which of the following is correct concerning the Cori cycle? Choose one: A. Pyruvate is converted to glucose in muscle. B. Pyruvate is converted to lactate in the liver. C. Glycolysis occurs in liver while gluconeogenesis is occurring in muscles. D. Glycolysis is occurring under anaerobic conditions.
D. Glycolysis is occurring under anaerobic conditions.
How would the oxygen saturation of hemoglobin in an individual with bisphosphoglycerate mutase deficiency compare to that in an unaffected individual? Choose one: A. Hemoglobin oxygen saturation would be the same in the erythrocytes of individuals with bisphosphoglycerate mutase deficiency as compared to a normal individual. B. Hemoglobin oxygen saturation could be increased or decreased in the erythrocytes of individuals with bisphosphoglycerate mutase deficiency as compared to a normal individual. The effect of this deficiency would depend on glycolytic flux. C. Hemoglobin oxygen saturation would be decreased in the erythrocytes of individuals with bisphosphoglycerate mutase deficiency as compared to a normal individual. D. Hemoglobin oxygen saturation would be increased in the erythrocytes of individuals with bisphosphoglycerate mutase deficiency as compared to a normal individual.
D. Hemoglobin oxygen saturation would be increased in the erythrocytes of individuals with bisphosphoglycerate mutase deficiency as compared to a normal individual.
Label the graph below by dragging the labels to the correct targets. A. 10 mM B. Glucokinase C. 0.10 mM D. Hexokinase
D. Hexokinase B. Glucokinase C. 0.10 mM A. 10 mM
Cancer cells have many alterations in their metabolic pathways, including some that alter the way they metabolize and use glucose. This is known as the Warburg effect. One component of the Warburg effect is the inhibition of the enzyme that converts pyruvate to acetyl CoA. Under these conditions, what metabolite will be elevated in cancer cells as compared to noncancerous cells even under normal oxygen saturation? Choose one: A. NADH. B. CO2. C. Pyruvate. D. Lactate.
D. Lactate.
What would be the consequence if 2,3-bisphosphoglycerate dissociated from the active site of the enzyme? Choose one: A. The reaction could proceed in either direction, depending on whether 3-phosphoglycerate or 2-phosphoglycerate enters the active site first. B. 2-phosphoglycerate would then be able to bind to the active site, and the reaction would reverse, forming 3-phosphoglycerate. C. A new molecule of 3-phosphoglycerate would bind and the reaction would resume. D. The enzyme would be inactivated until 2,3-bisphosphoglycerate enters the active site again.
D. The enzyme would be inactivated until 2,3-bisphosphoglycerate enters the active site again.
What conclusion is supported if a patient is found to have an intermittent deficiency of progesterone released from the adrenal gland, which is temporarily alleviated whenever the patient eats greasy fast food with high cholesterol content? Choose one: A. The patient has problems absorbing cholesterol in the intestine. B. The patient has a rare genetic disease in which cytochrome P450 is inactive. C. The patient is suffering from acute inflammation. D. The patient has a deficiency in cholesterol synthesis.
D. The patient has a deficiency in cholesterol synthesis.
Glycogen __________ uses UDP-glucose as a substrate. Choose one: A. phosphorylase. B. debranching enzyme. C. branching enzyme. D. synthase.
D. synthase.
The reaction catalyzed by phosphofructokinase-1 can be activated and inhibited by a number of allosteric factors. Sort the allosteric effectors listed below to indicate if they activate or inhibit this reaction. 1. AMP 2. Fructose-2,6-bisphosphate 3. ADP 4. Citrate 5. ATP
Effect on PFK-1 Activity. Activate AMP Fructose-2,6-bisphosphate ADP Inhibit Citrate ATP
The activity of phosphofructokinase-1 is regulated based on the energy charge of the cell. Sort the phrases to correctly describe the role of ADP and ATP in this regulation. Energy charge of the cell 1. [ADP]/[ATP] <1. 2. Affinity for F6P decreased. 3. ATP bound to effector site. 4. Predominant form is T-state. 5. Predominant form is R-state. 6. ADP bound to effector site. 7. [ADP]/[ATP] >1. 8. Affinity for F6P increased.
Energy charge of the cell High [ADP]/[ATP] <1 Affinity for F6P decreased ATP bound to effector site Predominant form is T-state Low Predominant form is R-state ADP bound to effector site [ADP]/[ATP] >1 Affinity for F6P increased
Catabolic products of some pathways can be used as the substrates for anabolic pathways. During times of starvation or fasting, the liver uses many noncarbohydrate precursors to synthesize glucose. However, the catabolic products of _______________ cannot be used to synthesize glucose.
Fatty acids
High levels of fructose-2,6-BP reciprocally regulate glycolysis and gluconeogenesis. Fructose-2,6-BP ________________ flux through the glycolytic pathway by increasing the activity of _______________. Flux through the gluconeogenic pathway is inhibited by fructose-2,6-BP, which decreases the activity of _________________. .
High levels of fructose-2,6-BP reciprocally regulate glycolysis and gluconeogenesis. Fructose-2,6-BP stimulates flux through the glycolytic pathway by increasing the activity of phosphofructokinase-1. Flux through the gluconeogenic pathway is inhibited by fructose-2,6-BP, which decreases the activity of fructose-1,6-bisphosphatase-1.
Palmitate is a common biological fatty acid. It is composed of 16 carbons and is _______________.
Saturated.
Reactions that occur in glycolysis can all be described in terms of the chemical changes that occur within each. Place the descriptions of these chemical reactions in the order that they occur in stage II of glycolysis (from beginning to end). Stage II Beginning A.Oxidation of aldose coupled with phosphorylation. B. Dehydration of a phosphoglyceric acid. C. Isomerization of a phosphoglyceric to a positional isomer D. Substrate-level phosphorylation and production of a phosphoglyceric acid. E. Substrate-level phosphorylation and production of an alpha-keto acid. End.
Stage II Beginning. A.Oxidation of aldose coupled with phosphorylation. D. Substrate-level phosphorylation and production of a phosphoglyceric acid. C. Isomerization of a phosphoglyceric to a positional isomer. B. Dehydration of a phosphoglyceric acid. E. Substrate-level phosphorylation and production of an alpha-keto acid. End.
Sort the following into either ω-3 or ω-6 fatty acids. Remember that numbering starts from the "omega" end for these fatty acids. A. B. C. D. E.
The difference between ω-3 and ω-6 fatty acids is the position of the first carbon-carbon double bond. For ω-3 fatty acids, it occurs at C-3. For ω-6 fatty acids, it occurs at C-6. For the examples shown, only B and D are ω-6 fatty acids. The others are ω-3 fatty acids.
The enzyme ______________ is required for fermentation of pyruvate to lactate. Fermentation of pyruvate to ethanol requires the enzyme ______________.
The enzyme Lactate dehydrogenase is required for fermentation of pyruvate to lactate. Fermentation of pyruvate to ethanol requires the enzyme Alcohol dehydrogenase.
Sort the following into either ω-3 or ω-6 fatty acids. Remember that numbering starts from the "omega" end for these fatty acids. A. B. C. D. E.
We can classify fatty acids into ω-3 and ω-6 based on the position of the first double bond from the methyl end of the fatty acid chain. As the name suggests in ω-3 fatty acids the first double bond is at the third carbon from the methyl end and is at the 6th carbon in ω-6 fatty acids. So, from the diagrams we can determine the following: ω - 3 A, C, E. ω - 6 B, D.
