BIOCHEM FINAL
All of the following are direct precursors to pyrimidine nucleotides except: A. The amino acid glycine B. Carbamoyl phosphate C. The amino acid aspartate D. All of the above are direct precursors to pyrimidine nucleotides. E. None of the above is a direct precursor to pyrimidine nucleotides
A
All of the following are true about nitrogen fixation except: A. The process requires oxygen. B. One of the enzymes involved is the molybdenum-containing nitrogenase. C. A small number of bacterial strains are capable of doing it. D. One of the enzymes involved is the iron-sulfur-containing nitrogenase reductase. E. Until the invention of the Haber-Bosch process, it created almost all biological N.
A
At what point does ketosis become dangerous? A. When the blood pH falls by 0.2 pH units or more. B. When the concentration of ketones is enough to damage neurons. C. When the lactate makes the blood acidic. D. When the concentration of acetyl-CoA rises above that of pyruvate. E. Ketosis is never dangerous, but always only helpful.
A
Based on what you know about phenylalanine, how many steps in its biosynthesis? A. Nine B. Four C. Two D. Just one E. From what we talked about in class, we shouldn't be expected to be able to guess.
A
Cholesterol is a precursor to all of the following except: A. Bile pigments B. Sex steroids C. Bile salts D. Vitamin D E. Corticosteroids
A
Conversion of the ribonucleotides to the deoxynucleotides involves: A. NADPH reducing power B. ATP energy C. NADH reducing power D. GTP energy E. No input of energy of any kind
A
How are fatty acids translocated into the mitochondrial matrix? A. By being covalently bound to carnitine. B. By going through the citrate transporter. C. By being activated. D. By going through the malate transporter. E. By being associated with albumin.
A
How do sequestrant drugs help lower blood cholesterol? A. They keep more bile salts in the feces. B. By inhibiting cholesterol biosynthesis. C. They help aid resorption in the intestine. D. By upregulating cholesterol breakdown. E. They don't actually affect blood cholesterol amounts.
A
Most of the amino acids from the proteins you eat end up: A. Being used to make your own proteins B. Being set aside as a form of nitrogen storage C. Being catabolized to provide metabolic energy D. Being broken down to provide carbon skeletons for anabolism E. All of the above are more or less equally common uses of them.
A
The Cori cycle includes all of the following pathways except: A. Glycogenesis B. Gluconeogenesis C. Fermentation D. It includes all of the above pathways. E. It doesn't include any of the above pathways.
A
The amino acid that cannot be hydroxylated in PKU is: A. Phenylalanine B. Glutamate C. Methionine D. Glutamine E. Tyrosine
A
The cyclic pathway that carbamoyl phosphate and aspartate feed into is: A. The urea cycle B. The Calvin-Benson cycle C. The citric acid cycle D. The Cori cycle E. None of the above
A
The enzyme that adds free ammonia onto alpha-ketoglutarate is: A. Glutamate dehydrogenase B. Aminotransferase C. Alpha-ketoglutarate aminase D. Ammonia-conjugase E. Glutamate synthetase
A
The following are true about where organisms principally obtain nitrogen except: A. Bacteria all get it by fixing atmospheric nitrogen. [Only a few strains do!] B. Plants can get it from ammonia. C. Animals get it mostly from the proteins they eat. D. All of the above are true. E. None of the above is true.
A
The hormone that hormone sensitive lipase (HSL) responds to (that we emphasized): A. Glucagon B. Insulin C. Leptin D. Epinephrine E. Testosterone
A
The nitrogen for biosynthesis of carbamoyl phosphate does not come from which of the following? A. Urea B. Ammonia C. Glutamate D. It comes from all of the above. E. It doesn't come from any of the above.
A
The non-standard pyrimidine nucleotide we discussed can be called: A. O B. Urotate C. Ornithine D. Cytamine E. Orthologous
A
The pathway for making all isoprenoids and steroids is usually called: A. Mevalonate metabolism B. IPP metabolism C. Lipogenesis D. HMG-CoA metabolism E. Sterosis
A
The tag recognized by the proteasome is: A. Polyubiquitination B. Phosphorylation C. Denaturation D. A "cap" E. The proteasome doesn't recognize anything as a "tag".
A
What differentiates the physiological between-meals state from the pathological state of starvation? A. Depletion of liver glycogen B. Switch from insulin dominating to glucagon dominating C. Use of the last glucose provided by the last meal D. Switch from glucagon dominating to insulin dominating E. The time since the last meal
A
What does the proteasome recognize to know that it should break down a protein? A. Polyubiquitin attached to the protein B. That the protein is oxidatively damaged C. Isoprenoid lipid attached to the protein D. That the protein is denatured E. Phosphorylation of the protein
A
Where does the ammonia for making carbamoyl phosphate usually come from? A. The deamination of glutamate B. The amino-transfer from glutamate C. The deamination of urea D. The amino-transfer from urea E. None of the above
A
Which B vitamin moiety carrier is used in the pathways of gluconeogenesis, lipogenesis, and nucleotide biosynthesis? A. Biotin B. Pyridoxal phosphate C. Nicotinamide D. Pantothenic acid E. Folic acid
A
Which hormone is it that activates hormone-sensitive lipase? A. Glucagon B. Insulin C. Leptin D. Growth hormone E. Testosterone
A
Which nucleotides are biosynthesized from inosine which was built on the backbone? A. The purines, including adenosine and guanosine B. The purines, including cytidine and uridine C. The pyrimidines, including cytidine and uridine D. The pyrimidines, including adenosine and guanosine E. None of the above are made in this way.
A
Which of the following amino acids is ketogenic? A. Phenylalanine B. Glutamate C. Alanine D. Aspartate E. All of the above are ketogenic, and one is also glucogenic.
A
Which of the following amino acids is not solely glucogenic? A. Phenylalanine B. Glutamate C. Aspartate D. Alanine E. All of the above are glucogenic and only glucogenic.
A
Which of the following contributes nitrogen directly to both hemes and purines? A. Glycine B. Alanine C. Glutamate D. Glutamine E. None of the above contributes nitrogen directly to both hemes and purines.
A
Which of the following does not contain the B vitamin pantothenic acid? A. Carnitine [This does not have a thiol at all.] B. Acyl carrier protein [Not correct, but credited.] C. Coenzyme A [Not correct, but credited.] D. All of the above do contain pantothenic acid. [Not correct, but credited.] E. None of the above contains pantothenic acid. [Not correct, but credited.]
A
Which of the following handles for carrying fatty acids is not needed for catabolism? A. Acyl carrier protein B. Carnitine C. Coenzyme A D. All of the above are needed for catabolism of fatty acids that have entered cells. E. None of the above is needed for catabolism of fatty acids that have entered cells.
A
Which of the following is a precursor of the porphyrin ring system of heme? A. Glycine B. Alanine C. Serine D. Aspartate E. Phenylalanine
A
Which of the following is not an input for the urea cycle? A. Glutamate B. Carbamoyl phosphate C. Aspartate D. All of the above are inputs for the urea cycle. E. None of the above is an input for the urea cycle.
A
Which of the following moiety carriers is certainly not used to modify xanthine in order to make the methyl-xanthine stimulant compounds caffeine and theobromine? A. Biotin B. SAM C. THF D. Any of the above might be used to make them, according to what we learned. E. None of the above could be used to make them, according to what we learned.
A
Which of these amino acids does not have the same single-step catabolic pathway? A. Glycine, with two carbons B. Alanine, with three carbons C. Aspartate, with four carbons D. Glutamate, with five carbons E. None of these amino acids has a same single-step catabolic pathway as the others.
A
Which pancreatic hormone dominates in the "fed-state"? A. Insulin, which upregulates glycogenesis B. Insulin, which upregulates glycogenolysis C. Glucagon, which upregulates glycogenolysis D. Glucagon, which upregulates glycogenesis E. Epinephrine, which upregulates glycolysis
A
While being biosynthesized, what is a growing fatty acid attached to? A. Acyl carrier protein (or ACP) B. Carnitine C. Coenzyme A (or CoA) D. Clandestine E. Acyl-CoA courier (or ACC)
A
Why can't brain neurons metabolize fatty acids? A. Their mitochondria lack a couple of the necessary enzymes. B. Fatty acids can't get across the blood-brain barrier. C. They don't have mitochondria. D. No one really knows. E. They can metabolize fatty acids, but they prefer to metabolize glucose.
A
Why did Dr T decide to spend time talking about the catabolism of methionine? A. Because an intermediate in this pathway is a moiety donor for biosynthesis. B. It is an example of an amino acid whose catabolism cannot be done in humans. C. Because there is a genetic disease involving this pathway, called PKU. D. It is a pathway in which there is no similarity to other catabolic pathways. E. Because it is exactly like the pathways for the catabolism of all other amino acids.
A
"Investment" in the Stage II metabolism of fatty acids involves: A. Reduction of fatty acids before oxidizing them B. Spending ATP in fatty acid activation C. Condensation of fatty acyl groups before hydrolyzing them D. Spending NADPH in fatty acid provisioning E. None of the above
B
All of the following are true in positive nitrogen balance except: A. You are bringing in more total nitrogen than you are using. B. You will not develop protein deficiency disease. C. You will be excreting nitrogen, principally as urea. D. All of the above are true. E. None of the above is true.
B
All of the following are true of the biosynthesis of all amino acids, except: A. The staring material is always an intermediate in energy metabolism. B. The process always includes more than one reaction. C. The biosynthesis always involves an amino-transfer reaction. D. All of the above are true. E. None of the above is true.
B
Bile pigments come from: A. Cholesterol B. Heme C. Acetyl-CoA D. Bilins E. Alanine
B
In what form do carbons cross the inner mitochondrial membrane for incorporation into fatty acids? A. Acetyl-CoA B. Citrate C. Carnitine D. Coenzyme Q E. HMG-CoA
B
In which form is the majority of excess nitrogen excreted in humans? A. Urate B. Urea C. Bilins D. Intact proteins in dead cells that are lost E. Nitrogen is excreted equally in all of the above forms.
B
Plasma lipoprotein particles include all of the following except: A. Apolipoproteins B. Phosphoribosyl pyrophosphate (PRPP) C. Cholesteryl esters D. Triglycerides E. Plasma lipoprotein particles include all of the above.
B
Since histidine is an essential amino acid, you would say that its biosynthesis takes: A. One reaction starting with an energy metabolism intermediate B. Eleven reactions starting with an energy metabolism intermediate C. Two reactions starting with an energy metabolism intermediate D. Three or four reactions starting with an energy metabolism intermediate E. There is no way to choose from these choices just knowing that it is essential.
B
The "vitamin" that we can actually make is: A. Biotin B. Vitamin D C. Pyridoxal phosphate D. Vitamin A E. Thiamine
B
The Cori cycle includes all of the following pathways except: A. Glycolysis B. The citric acid cycle C. Fermentation D. Gluconeogenesis E. The Cori cycle includes all of the above.
B
The Cori cycle includes all of the following pathways except: A. Lactate fermentation B. Pyruvate oxidation C. Gluconeogenesis D. The Cori cycle includes all of the above pathways. E. The Cori cycle doesn't include any of the above pathways.
B
The colors of what we excrete into the sewers come from: A. Bile salts B. Bile pigments C. Bile acids D. Bile ions E. Vile colorants
B
The difference between a uracil sidechain and a thymine sidechain is: A. A methyl group that comes from SAM B. A methyl group that comes from THF C. A formyl group that comes from SAM D. A formyl group that comes from THF E. A formal group that comes from Tuxedo Junction
B
The difference between thymine and deoxy-uracil is: A. A hydroxide on the ribose B. A methyl group C. One is a purine and the other a pyrimidine D. An acetyl group E. They have no significant similarities at all.
B
The main cause of death directly resulting from diabetes also can be caused by: A. Obesity B. Ketogenic diets C. Hypercholesterolemia D. Protein malnutrition E. A Mendelian genetic disorder
B
The oxidation of a fatty acid produces: A. The same number of acetyl-CoA molecules as NADH molecules B. The same number of NADH molecules as FADH2 molecules C. The same number of FADH2 molecules as acetyl-CoA molecules D. All of the above E. None of the above
B
The precursor of most phospholipids and of all triglycerides is: A. Malonyl-CoA B. Phosphatidate C. Mevalonate D. Phosphoribosyl pyrophosphate E. There is no one precursor to both most phospholipids and all triglycerides.
B
The precursor of triglycerides and most phospholipids is: A. Carnitine B. Phosphatidate C. Mevalonate D. Isopentylpyrophosphate E. Malonyl-CoA
B
The precursor to the emulsifiers of dietary fat is: A. Glucose B. Cholesterol C. Pyruvate D. Citrate E. Alpha-ketoglutarate
B
The reactions catalyzed by nitrogenase and reductase are poisoned by: A. Nitrogen gas B. Oxygen gas C. Hydrogen gas D. Carbon dioxide gas E. Carbon monoxide gas
B
What is the "handle" attached to a fatty acid during fatty acid translocation? A. Coenzyme A B. Carnitine C. Coenzyme Q D. Acyl carrier protein (ACP) E. None of the above
B
What is the source of the moiety that is added to deoxyuracil to make thymine? A. ATP B. Methylene-THF C. SAM D. Formyl-THF E. Acetyl-CoA
B
What is true about protein deficiency diseases and negative nitrogen balance? A. Protein deficiency diseases occur when negative nitrogen balance is extreme. B. Though they often occur together, there is no causal relationship between them. C. Negative nitrogen balance is when there are too many acidic amino acids. D. Protein deficiency diseases means that there is insufficient total protein. E. None of the above is true about these conditions.
B
What would you be able to say about the biosynthesis of carnitine - an amine-containing compound that we discussed? A. It cannot be synthesized in humans and must be an essential vitamin. B. One of its precursors must be an amino acid. C. It must have a long and complicated biosynthetic pathway. D. One of its precursors must be a purine nucleotide. E. From just what we talked about in class, we wouldn't be able to say anything.
B
When in positive nitrogen balance, what happens to "excess" nitrogen? A. It is stored as protein. B. It is excreted. C. It is stored as biogenic amines. D. It is turned into nitrogen gas. E. It is stored in some form, including A and C.
B
Where does the reducing power to make the deoxynucleotides come from? A. ATP B. NADPH C. Coenzyme A D. NADH E. FADH2
B
Which of the following amino acids is ketogenic? A. Alanine B. Phenylalanine C. Aspartate D. Glutamate E. All of the above are ketogenic.
B
Which of the following are involved in the Stage I metabolism of dietary fats? A. Bile pigments B. Bile salts C. Bilins D. Bill-outs E. All of the above
B
Which of the following can be used in both amino-transfer and in deamination? A. Glycine B. Glutamate C. Alanine D. Any amino acid E. None of the above
B
Which of the following compounds crosses the inner mitochondrial membrane in order to provide carbon for lipogenesis? A. Acetyl-CoA B. Citrate C. Acyl-CoA D. Carnitine E. ATP
B
Which of the following conditions leads to the Cori cycle? A. An extended glucagon signal B. Anaerobic exercise C. An insulin signal D. Aerobic exercise E. A starvation signal
B
Which of the following contributes the "backbone" of nucleotides, and is involved in both the salvage pathways and de novo pathways for all nucleotides? A. S-adenosylmethionine (SAM) B. Phosphoribosyl pyrophosphate (PRPP) C. Pre-adenosyl-monophosphate (PAMP) D. Sulfo-ribosyl phosphopyrate (SRPP) E. There is no one compound that is involved in all of those pathways.
B
Which of the following do we do more when we are in positive nitrogen balance? A. Use amino acids to provide more energy. B. Make more urea. C. Use amino acids to make more nitrogenous compounds. D. Make more protein. E. Use ammonia as a source of more positive charge.
B
Which of the following has a biosynthetic pathway that is longer than the others? A. Alanine B. Phenylalanine C. Aspartate D. Glutamate E. All of the above have biosynthetic pathways of the same number of steps.
B
Which of the following is not a component of plasma lipoprotein particles? A. Phospholipids B. Lipidated lipoproteins C. Cholesteryl esters D. Apolipoproteins E. Triglycerides
B
Which of the following is not a result of an extended glucagon signal? A. Ketogenesis B. An excess of oxaloacetate C. A decrease in blood pH D. All of the above are results of an extended glucagon signal. E. None of the above is the result of an extended glucagon signal.
B
Which of the following is not involved in any type of diabetes mellitus? A. Insufficient insulin signal B. Insufficient glucagon signal C. Insufficient signal response D. All of the above are involved in some type of diabetes mellitus. E. None of the above is involved in any type of diabetes mellitus.
B
Which of the following is not raised in the "fed-state"? (Or is E true?) A. Levels of the hormone insulin B. Gluconeogenesis C. Lipogenesis D. Glycogenesis E. All of the above are raised in the "fed-state".
B
Which of the following is not related to Stage I metabolism of fats? A. Emulsification using bile salts B. Partial digestion in the stomach C. Delivery through the body via chylomicrons D. All of the above are related to Stage I metabolism of fats. E. None of the above is related to Stage I metabolism of fats.
B
Which of the following is not true about all amino acid anabolic pathways? A. They all begin with energy metabolism compounds as substrates. B. They all include non-standard amino acids as intermediates. C. They all involve amino-transfer as one of the steps. D. All of the above are true about all amino acid anabolic pathways. E. None of the above is true about all amino acid anabolic pathways.
B
Which of the following is not true about all amino acid catabolic pathways? A. They all end with energy metabolism compounds as products. B. They all include non-standard amino acids as intermediates. C. They all involve amino-transfer as one of the steps. D. All of the above are true about all amino acid catabolic pathways. E. None of the above is true about all amino acid catabolic pathways.
B
Which of the following is not true about where organisms get their nitrogen from? A. Plants get it from ammonia. B. Animals get it from ammonia. C. Plants get it from protein (at least some plants can). D. Animals get it from protein. E. All of the above are true.
B
Which of the following is not true of the anabolism of every amino acid? A. It uses an intermediate of an energy metabolism pathway. B. It consists of a pathway of just one reaction. C. It involves an amino transfer reaction. D. All of the above are true of the anabolism of every amino acid. E. None of the above is true of the anabolism of every amino acid.
B
Which of the following is a metabolic disorder involving the insulin signal? A. Phenylketonuria B. Diabetes mellitus C. Severe combined immunodeficiency D. Diabetes insipidus E. Cardiovascular disease
B.
"Diabetes" means: A. Acetone breath B. Glucagon C. Excessive urine D. Insulin E. Ketosis
C
A disease that apes can get but cows can't relates to a build-up of: A. Phenylalanine B. Bile salts C. Urate D. Bile pigments E. Methionine
C
Alpha-ketoglutarate is not a product in which of the following reactions? A. The direct deamination of glutamate B. Amino-transfer involving glutamate C. The direct amination involving glutamate D. It is a product in all of the above. E. It is not a product in any of the above.
C
Beta oxidation includes all of the following except: A. An alcohol being oxidized to a carbonyl B. A double bond being hydrated C. A carbon-carbon bond being reduced to a double bond D. A ketone being oxidized to the level of a carboxyl E. None of the above are part of beta oxidation.
C
Carbamoyl phosphate and aspartate are inputs to which pathway? A. Purine biosynthesis B. Alanine catabolism C. The urea cycle D. Alanine anabolism E. The pentose-phosphate shunt
C
Excess acetyl-CoA (due to depletion of the citric acid cycle) is made into: A. Fatty acyl-CoA B. Glycogen C. Ketone bodies D. Glucose E. Triacylglycerides
C
How many steps do you think the pathway for the biosynthesis of phenylalanine has? A. One B. Three C. Thirteen D. Four E. Two
C
In positive nitrogen balance, what is done with the excess nitrogen? A. It is used to make amino acids and nucleotides. B. It is stored for later use. C. It is mostly excreted as urea. D. All of the above E. None of the above
C
In what form is cholesterol excreted from the body? A. Bile pigments B. Cholesteryl esters C. Bile salts D. Triglycerides E. Cholesterol is not excreted from the body in any form.
C
It doesn't matter what form the excess calories that you take in, your body can store the energy as fat. This is because _______ is made from any metabolic fuel. A. ATP B. Glucose C. Acetyl-CoA D. Pyruvate E. Carbon dioxide
C
Knowing that the chemical formula of dopamine is C8H11NO2, you would guess that: A. Dopamine is essential (i.e. we can't make it). B. A precursor to dopamine is ATP. C. Dopamine is made from at least one amino acid. D. A precursor is coenzyme-A. E. Dopamine is not biosynthesized.
C
Plasma lipoproteins include all of the following except: A. Apolipoproteins B. Cholesteryl esters C. Free fatty acids D. Phospholipids E. Triacylglycerols
C
Sequestrant drugs inhibit: A. The biosynthesis of cholesterol B. The binding of lipoprotein to LDL receptors C. The resorption of bile salts within the intestine D. The binding of lipoprotein to HDL receptors E. The consumption of high-cholesterol foods
C
The "handle" that enables fatty acid translocation is: A. Acyl carrier protein (ACP) B. Coenzyme A C. Carnitine D. Fatty acid translocation can use any of the handles above. E. Fatty acid translocation doesn't use any of the handles above.
C
The amino acid whose catabolism provides a moiety carrier for anabolism is: A. Phenylalanine B. Glutamate C. Methionine D. Glutamine E. Tyrosine
C
The catabolic side of protein turnover in cells involves all of the following except: A. Tagging of proteins by polyubiquitination B. Feeding proteins through the proteasome C. Denaturation of proteins by the acid in the lysosome D. All of the above are involved. E. None of the above is involved.
C
The drugs called statins inhibit which of the following enzymes? A. Mevalonate synthase B. Glutamate dehydrogenase C. HMG-CoA reductase D. Glutamine synthetase E. Acetyl-CoA carboxylase (or ACC)
C
The energy to form the thioester bond in an activated fatty acid comes from: A. Coenzyme A B. NADH C. ATP D. NADPH E. The fatty acid itself
C
The first starting material needed for de novo purine biosynthesis is: A. Glutamine B. Aspartate C. Phosphoribosyl pyrophosphate (PRPP) D. Carbamoyl phosphate E. Bicarbonate
C
The following are all directly made during beta oxidation except: A. NADH B. Acetyl-CoA C. ATP D. FADH2 E. All of the above are directly made during beta oxidation.
C
The hormone that dominates in the fed-state up-regulates all of the following except: A. Glucose uptake B. Glycogenesis C. Gluconeogenesis D. Lipogenesis E. That hormone up-regulates all of the above.
C
What do all amino acid anabolic pathways not have in common? (Or is it D or E?) A. They all involve amino-transfer. B. They all start with energy metabolism intermediates. C. They all involve about the same number of reactions. D. All of the above are true about the commonalities. E. None of the above is common to amino acid anabolic pathways.
C
What does the enzyme do that is encoded by the gene damaged in PKU? A. It catalyzes a step in the anabolism of phenylalanine. B. It catalyzes a step in the anabolism of tyrosine. C. It catalyzes a step in the catabolism of phenylalanine. D. It catalyzes a step in the catabolism of tyrosine. E. It catalyzes a phosphoryl transfer to urea (hence "protein kinase urea" or PKU)
C
What moiety needs to be added to the uracil side-chain to make thymine? A. A phosphate B. An amine C. A methyl group D. A carbonyl E. An acetyl group
C
Where does the reducing power for making deoxyribonucleotides come from? A. NADH B. ATP C. NADPH D. FADH2 E. GTP
C
Which intermediate of the citric acid cycle is usually depleted leading to ketosis? A. Citric acid B. Alpha-ketoglutarate C. Oxaloacetate D. Succinyl-CoA E. Glucose
C
Which nucleotides are biosynthesized from orotate after adding it to the backbone? A. The purines, including adenosine and guanosine B. The purines, including cytidine and uridine C. The pyrimidines, including cytidine and uridine D. The pyrimidines, including adenosine and guanosine E. None of the above are made in this way.
C
Which of the following compounds gets depleted the more you run gluconeogenesis? A. Acetyl-CoA B. NADH C. Oxaloacetate D. Alpha-ketoglutarate E. Glucose
C
Which of the following contributes both carbon and nitrogen atoms to the biosynthesis of the purine nucleotides? A. Formyl-THF B. Carbon dioxide C. Glycine D. Glutamine E. Though all of the above contribute nitrogen or carbon atoms to the biosynthesis of purine nucleotides, nothing contributes both carbon and nitrogen.
C
Which of the following does not contribute to ketoacidosis? (Or is D or E true?) A. An extended glucagon signal B. Depletion of the citric acid cycle C. The brain using ketone bodies D. All of the above do contribute to ketoacidosis. E. None of the above contributes to ketoacidosis.
C
Which of the following enzymes is not involved in nitrogen fixation? A. Nitrogenase B. Nitrogenase reductase C. Nitrogenase oxidase D. All of the above enzymes are involved in nitrogen fixation. E. None of the above enzymes is involved in nitrogen fixation.
C
Which of the following human diseases does not relate to purine catabolism? A. Gout B. Severe combined immunodeficiency disease (SCID) C. Familial hypercholesterolemia (FHC) D. All of the above do relate to purine catabolism. E. None of the above relates to purine catabolism.
C
Which of the following is false about the non-standard purine we discussed? A. It is called inosine. B. Its side-chain is hypoxanthine. C. It can be made into adenosine and from there into guanosine. D. It has two fused heterocyclic rings. E. It can be a part of a salvage pathway.
C
Which of the following is never a product of glutamate dehydrogenase? A. Glutamate B. Alpha-ketoglutarate C. Glutamine D. All of the above are products of glutamate dehydrogenase, at least sometimes. E. None of the above is ever a product of glutamate dehydrogenase.
C
Which of the following is not a direct precursor to carbamoyl phosphate? A. A carbon from bicarbonate B. A phosphate from ATP C. A nitrogen from aspartate D. An ammonia E. All of the above are direct precursors to carbamoyl phosphate.
C
Which of the following is not a direct precursor to the pyrimidine nucleotides? A. Carbamoyl phosphate B. Aspartate C. Glutamine D. All of the above are direct precursors. E. None of the above is a direct precursor.
C
Which of the following is not a reason that fat is efficient energy storage? A. It is so reduced. B. It does not associate with solvent water molecules. C. It is a complex mixture of triglycerides with different fatty acids. D. All of the above are reasons that fat is efficient energy storage. E. None of the above is a reason that fat is efficient energy storage.
C
Which of the following is not true about the amino acid glutamate? A. It is often a substrate in aminotransferase reactions. B. It can be directly deaminated. C. It is the central compound of energy metabolism. D. All of the above are true. E. None of the above is true.
C
Which of the following is not true of the biosynthesis of the purine nucleotides? A. Carbon dioxide provides carbon for it. B. The amino acid aspartate is used in it. C. The sidechain is built and then added to PRPP. D. Nitrogen from several amino acids can contribute to it. E. All of the above are true of this biosynthetic pathway.
C
Which of the following is not true of the catabolism of every amino acid? A. It produces intermediates of energy metabolism pathways. B. It involves an amino transfer reaction. C. It consists of a pathway of just one reaction. D. All of the above are true of the catabolism of every amino acid. E. None of the above is true of the catabolism of every amino acid.
C
Which of the following is required to convert the ribonucleotides into the deoxyribonucleotides? A. NADH B. ATP C. NADPH D. FADH2 E. Acetyl-CoA
C
Which of the following is true about purine nucleotide biosynthesis? A. It does not involve the "backbone" phosphoribosyl pyrophosphate (PRPP). B. It involves using PRPP during the middle of the biosynthetic pathway. C. PRPP is the starting material onto which the sidechain is synthesized. D. The sidechain is synthesized and then added onto the PRPP backbone. E. None of the above is true about purine nucleotide biosynthesis.
C
Which of the following is true about the precursor used for fatty acid biosynthesis? A. It is acetyl-CoA made in the same cellular location where the synthesis happens. B. It is HMG-CoA. C. It is acetyl-CoA that will have to cross the inner mitochondrial membrane. D. It is IPP. E. It is acetyl-CoA created in cytoplasmic metabolic pathways.
C
Which of the following is true of purine biosynthesis but not of that of pyrimidines? A. Aspartate is used. B. Carbon dioxide is used. C. The side-chain is built onto the backbone. D. Nitrogen from other amino acids is used. E. A non-standard nucleotide is made before any standard nucleotides.
C
Which of the following moieties is the most ambiguous in terms of where it comes from for biosynthesis? A. A phosphate B. An amine C. A methyl group D. A carbonyl E. An acetyl group
C
Which of the following pathways is not involved in the Cori cycle? A. Fermentation B. Gluconeogenesis C. The citric acid cycle D. Glycolysis E. All of the above pathways are involved in the Cori cycle.
C
Which of the following tissues or organs cannot do beta oxidation? A. Hepatocytes in the liver B. Acinar cells in the pancreas C. Neurons in the brain D. Mucosal cells in the intestine E. Muscle fiber cells
C
Which of these causes a decrease in intake of acetyl-CoA into the citric acid cycle? A. A depletion of NADH B. A lack of fructose-2,6-bisphosphate C. A depletion of citric acid cycle intermediates D. A lack of bisphosphoglycerate E. A depletion of ATP
C
Which pancreatic hormone dominates in the "between-meals-state"? A. Insulin, which upregulates glycogenesis B. Insulin, which upregulates glycogenolysis C. Glucagon, which upregulates glycogenolysis D. Glucagon, which upregulates glycogenesis E. Epinephrine, which upregulates glycolysis
C
Why can't brain neurons metabolize fatty acids? A. Fatty acids don't reach them, due to the blood-brain barrier. B. Because they down-regulate catabolic pathways. C. They lack enzymes in the beta oxidation pathway. D. Because they up-regulate anabolic pathways. E. Brain neurons - like all cells - can metabolize fatty acids.
C
A precursor of carbamoyl phosphate is: A. Free ammonia B. Carbon dioxide C. ATP D. All of the above E. None of the above
D
All of the following are accurate about protein malnourishment except: A. Negative nitrogen balance means not taking in sufficient total amino acids. B. Protein deficiency disease results from insufficient essential amino acid(s). C. You can have either of the above without having the other. D. All three of the above are accurate. E. None of the three above choices (A-C) is accurate.
D
All of the following are made from cholesterol except: A. Cortisol, a corticosteroid hormone B. Vitamin D C. Testosterone, a sex steroid D. All of the above are made from cholesterol. E. None of the above is made from cholesterol.
D
All of the following are plasma lipoproteins except: A. High-density lipoprotein B. Chylomicrons C. LDL cholesterol particles D. All of the above are plasma lipoproteins. E. None of the above is a plasma lipoprotein.
D
All of the following are true about the between-meals state except: A. Gluconeogenesis is favored over glycolysis. B. The glucagon hormone dominates. C. Glycogenolysis is favored over glycogenesis. D. Fatty acids are significantly accessed as a source of calories. E. All of the above are true about this state.
D
All of the following are true about the urea cycle except: A. An input is carbamoyl phosphate. B. The output is urea. C. An input is aspartate. D. All of the above are true. E. None of the above is true.
D
As acetyl-CoA concentrations within a liver cell grow, which of these follows? A. HMG-CoA is formed. B. Ketone bodies are formed. C. The liver cell releases compounds that could end up decreasing the blood's pH. D. All of the above E. None of the above
D
Carbon for fatty acid biosynthesis crosses the inner mitochondrial membrane as: A. Acetyl-CoA B. Pyruvate C. Oxaloacetate D. Citrate E. HMG-CoA
D
Dr T's favorite metabolic intermediate (a-ketoglutarate) can accept an amine from: A. Glycine B. Glutamate C. Alanine D. Any amino acid E. None of the above
D
During catabolism, the beta carbon of a fatty acid is each of the following except: A. An alcoholic carbon B. A carbonyl carbon C. A carbon with a double bond D. The beta carbon goes through being each of the above during catabolism. E. The beta carbon is found as none of the above during catabolism.
D
Excess nitrogen can be excreted as: A. Urea B. Urate C. Bilins (or bile pigments) D. All three of the above E. None of the above
D
Fat mobilization depends on which of the following? A. Hormone sensitive lipase B. Glucagon hormone activity C. Hydrolysis of triglycerides D. All of the above E. None of the above
D
In what form do the acetyl-CoA molecules that are going to be used to make fatty acids cross the inner mitochondrial membrane into the cytoplasm? A. Acetyl-CoA, of course B. Pyruvate C. Malate D. Citrate E. They don't cross into the cytoplasm; fatty acid synthesis happens in the matrix.
D
Precursors to the biosynthesis of the pyrimidine nucleotides include? A. Carbamoyl phosphate B. Phosphoribosyl-pyrophosphate (PRPP) C. The amino acid aspartate D. All of the above E. None of the above
D
Stage I metabolism of dietary fats includes: A. Hydrolysis by lipases B. Emulsification by bile salts C. Reassembly into TAGs and delivery via chylomicrons D. All of the above E. None of the above
D
The catabolism of which of these amino acids produces a one-carbon-moiety donor? A. Glycine B. Aspartate C. Glutamate D. Methionine E. Phenylalanine
D
The cause of atherosclerotic plaque is: A. Hypercholesterolemia B. An accumulation of LDL in the blood C. Probably oxidation of particles that have been around for a while D. All of the above E. None of the above
D
The difference between a uracil (U) sidechain and a thymine (T) sidechain is: A. An oxygen B. A phosphate C. An acetyl moiety D. A methyl moiety E. Two of the above
D
Two somatic gene therapy treatments have been approved by the FDA during the year 2017. The first gene therapy done experimentally replaced a dysfunctional gene encoding an enzyme used in which of the following pathways? A. The biosynthesis of phenylalanine. B. The biosynthesis of pyrimidine nucleotides. C. The catabolism of phenylalanine. D. The catabolism of purine nucleotides. E. The biosynthesis of immunoglobulin.
D
What do chylomicrons have in common with LDL particles? A. They both have amphipathic molecules coating their outsides. B. They both are referred to as plasma lipoproteins. C. They both have hydrophobic interiors for transporting lipids. D. All of the above are true. E. None of the above is true.
D
What is the "handle" attached to a growing fatty acid during fatty acid biosynthesis? A. Coenzyme A B. Carnitine C. Coenzyme Q D. Acyl carrier protein (ACP) E. None of the above
D
What is the direct precursor of both ATP and GTP? A. Orotate B. Carbamoyl phosphate C. UTP D. Inosine E. There is no one direct precursor for both of these nucleotides.
D
What moiety is added to uracil to make thymine? A. A carbonyl B. A PRPP C. A carboxyl D. A methyl E. A phosphate
D
Where does the reducing power come from to make the deoxyribonucleotides from the ribonucleotides? A. ATP B. NADH C. Reductase D. NADPH E. Coenzyme A
D
Which of the following amino acids involves a longer biosynthetic pathway? A. Alanine B. Aspartate C. Glutamate D. Phenylalanine E. Dr T doesn't expect us to know which of these pathways would be longer.
D
Which of the following best characterizes the process of nitrogen fixation? A. Only some bacteria can do it. B. It involves a reductase and reducing power. C. The process uses the enzyme nitrogenase, which is poisoned by oxygen. D. All of the above are true. E. None of the above is true.
D
Which of the following best describes the enzyme glutamate dehydrogenase? A. Glutamate can be a substrate or a product for it. B. Ammonia can be a substrate or a product for it. C. Alpha-ketoglutarate can be a substrate or a product for it. D. All of the above are true about this enzyme. E. None of the above is true about this enzyme.
D
Which of the following cell types cannot metabolize fatty acids? A. Hepatocytes in the liver B. Muscle fiber cells C. Adipocytes D. Neurons in the brain E. All of the above cell types can metabolize fatty acids.
D
Which of the following describes why fat is excellent for long-term energy storage? A. Triglycerides are very reduced. B. Fat droplets do not include solvent. C. Calories stored as chemical energy are densely stored in depot fat. D. All of the above together best describe why fat is excellent for this use. E. None of the above is relevant toward describing why fat would be excellent.
D
Which of the following do apes excrete but cows not excrete (as much, anyway)? A. Urea B. Bilins C. Excess nitrogen D. Urate E. Apes and cows excrete the same things.
D
Which of the following do you need to make deoxynucleotides from ribonucleotides? A. NADPH B. A ribonucleotide reductase enzyme C. Biosynthetic reducing power D. All of the above E. None of the above
D
Which of the following is a moiety-carrier of a single-carbon moiety? A. Formyl-tetrahydrofolate (formyl-THF) B. S-adenosyl methionine (SAM) C. Methylene-tetrahydrofolate (methylene-THF) D. All of the above E. None of the above
D
Which of the following is accurate about aminotransferase enzymes? A. They are central to amino acid catabolism. B. They all use a B vitamin coenzyme. C. They are critical for amino acid anabolism. D. All of the above E. None of the above
D
Which of the following is false about where organisms get nitrogen? (Or D or E?) A. Plants get it mostly from ammonia. B. Some bacteria can get it from the atmosphere. C. Animals get it from dietary protein. D. All of the above are true. E. None of the above is true.
D
Which of the following is involved in Stage I metabolism of dietary fat? A. Emulsification using bile salts B. Hydrolysis using dietary lipases C. Delivery through blood and lymph using chylomicrons D. All of the above are involved. E. None of the above is involved.
D
Which of the following is most accurate about the urea cycle? A. An input of it is the amine of aspartate. B. An output of it is the most common form of excreted nitrogen. C. An input of it is carbamoyl phosphate. D. All of the above are true. E. None of the above is true.
D
Which of the following is not true about glutamate? A. It is the amino acid most often involved in biosynthesizing other amino acids. B. Its carbon skeleton is an intermediate in the citric acid cycle. C. It is the amino acid most often involved in catabolizing other amino acids. D. All of the above are true. E. None of the above is true.
D
Which of the following is required of an acetyl-CoA or a malonyl-CoA before it can be incorporated into a growing fatty acid? A. The coenzyme A must be exchanged. B. The correct handle must be attached. C. A thioester bond to acyl carrier protein (ACP) must be formed. D. All of the above E. None of the above
D
Which of the following is true about "handles" for fatty-acyl moieties? A. Coenzyme A is a handle used during catabolism. B. The carnitine handle enables fatty-acid translocation. C. Acyl carrier protein (ACP) is a handle used during anabolism. D. All of the above are true. E. None of the above is true.
D
Which of the following is true about aminotransferases? A. They are a critical enzyme in amino acid catabolism. B. They have alpha-ketoglutarate as a substrate or a product. C. They are a critical enzyme in amino acid anabolism. D. All of the above are true. E. None of the above is true.
D
Which of the following is true about fatty acid activation? A. It happens in the cytoplasm. B. It involves forming a thioester bond. C. It represents an investment of ATP. D. All of the above E. None of the above
D
Which of the following is true about pyrimidine nucleotide biosynthesis? A. It does not involve the "backbone" phosphoribosyl pyrophosphate (PRPP). B. It involves using PRPP during the middle of the biosynthetic pathway. C. PRPP is the starting material onto which the sidechain is synthesized. D. The sidechain is synthesized and then added onto the PRPP backbone. E. None of the above is true about pyrimidine nucleotide biosynthesis.
D
Which of the following is true about where organisms get their nitrogen? A. Most plants get it from inorganic sources like ammonia. B. Animals get it from their dietary protein. C. Some (few) plants get it from proteins from animals. D. All of the above are true. E. None of the above is true.
D
Which of the following is true of plasma lipoproteins? A. Their interiors contain lots of esters, including TAGs. B. They are sort of like large micelles. C. Their exteriors contain amphipathic lipids and proteins. D. All of the above are true. E. None of the above is true.
D
Which of the following products that can subsequently be used to make ATP is not created during a round of beta oxidation? A. FADH2 B. Acetyl-CoA C. NADH D. All of the above are created during a round of beta oxidation. E. None of the above is created during a round of beta oxidation.
D
Which of these is a general rule that applies to the catabolism of all amino acids? A. The final product is an intermediate of an energy metabolism pathway. B. Glutamate is involved in the pathway. C. One of the reactions in the pathway is catalyzed by an aminotransferase. D. All of the above are general rules that apply to all amino acids' catabolism. E. None of the above is a general rule that applies to all amino acids' catabolism.
D
Which one of the following is not involved in the Stage I metabolism of dietary fat? A. Hydrolysis using digestive lipases B. Emulsification by bile salts C. Delivery to body cells in chylomicrons D. All of the above are involved in the Stage I metabolism of fat. E. None of the above is involved in the Stage I metabolism of fat.
D
Which step in the redox series does the beta carbon of a fatty acid not pass through during beta oxidation? A. A carbonyl B. An alcohol C. A carbon bound to another carbon with a double bond D. The beta carbon passes through all of the above during beta oxidation. E. The beta carbon passes through none of the above during beta oxidation.
D
Why are triglycerides excellent molecular forms in which to store energy? A. They don't need to be solvated in a fat droplet. B. They represent very efficient energy storage (high energy density). C. They are highly reduced. D. All of the above E. None of the above
D
Why can't brain neurons metabolize fatty acids? A. They can, but they choose not to. B. They are missing the carnitine translocase. C. They don't get them because of the blood-brain barrier. D. They are missing enzymes needed for beta oxidation. E. They do metabolize fatty acids.
D
All of the following are involved in fat mobilization except: A. The hormone glucagon B. The cleavage of fatty acids from triacylglycerides C. The activation of hormone-sensitive lipase D. The release of glycerol into the bloodstream E. All of the above are involved in fat mobilization
E
All of the following are true about bile salts except: A. They are products made from cholesterol. B. They are amphipathic. C. They are excreted into the intestine. D. They can be resorbed from the intestine. E. All of the above are true.
E
All of the following are true about carbamoyl phosphate except: A. It uses ATP in its biosynthesis. B. The product of deamination of glutamate contributes to it. C. An enzyme in its biosynthesis uses biotin. D. A precursor for it is bicarbonate. E. All of the above are true about carbamoyl phosphate.
E
All of the following are true about fatty acid activation except: A. It is a sort of investment, kind of like the investment phase of glycolysis. B. Fatty acid activation involves burning ATP. C. It results in a high-energy bond holding onto the fatty acid. D. Fatty acid activation incorporates a coenzyme A. E. All of the above are true.
E
All of the following are true about the bilins except: A. They are also called the bile pigments. B. They are responsible for the color of urine. C. They are responsible for the colors of bruises. D. They are responsible for the color of feces. E. All of the above are true about the bilins.
E
All of the following concerning fatty acid "handles" are true except: A. Acyl carrier protein is the handle during fatty acid biosynthesis. B. Carnitine is the handle for fatty acid translocation. C. Coenzyme A is the handle during beta oxidation. D. All fatty acid handles are attached to the carboxyl moiety of the fatty acid. E. All of the above are true; there isn't an exception among them.
E
Beta oxidation of a twelve-carbon fatty acid would produce: A. Six NADH, six FADH2, and six acetyl-CoA B. Six NADH, six FADH2, and five acetyl-CoA C. Six NADH, five FADH2, and six acetyl-CoA D. Five NADH, six FADH2, and six acetyl-CoA E. None of the above
E
Death from ketoacidosis-induced coma is a big risk from: A. Starvation B. Type I diabetes C. Ketogenic diets D. Type II diabetes E. Any of the above
E
Excess calories ingested in the form of which of the following metabolic fuels can be turned into acetyl-CoA and then stored as fat? A. Carbohydrates B. Glucogenic amino acids C. Lipids D. Ketogenic amino acids E. All of the above
E
Excess from which of the following macronutrient types cannot be made into fat? A. Carbohydrates B. Proteins C. Lipids D. Excess from all of the above macronutrient types cannot be made into fat. E. Excess from any of the above macronutrient types can be made into fat.
E
Ketone bodies are made from: A. Acetyl-CoA B. Material that accumulates when the citric acid cycle decreases C. Hydroxymethylglutaryl-CoA (HMG-CoA) D. The "central compound of energy metabolism" that builds up E. All of the above
E
Protein turnover entails all of the following except: A. Catabolism by the proteasome core. B. Tagging by polyubiquitination. C. Being unfolded by the proteasome in an ATP-dependent manner. D. Peptides being degraded to amino acids for use in future protein synthesis. E. All of the above are entailed in the process of protein turnover.
E
Stage I metabolism of dietary protein includes all of the following except: A. Absorption of amino acids in the intestine [This answer was mistakenly keyed.] B. Cleavage of some peptide bonds in the stomach C. Denaturation of protein using acid D. Protease activity in the intestine E. All of the above are included in Stage I metabolism of proteins.
E
The enzyme that always has ammonia and glutamate as substrate or product is: A. Amino transferase B. Urease C. Glutamine synthetase D. Aminase E. Glutamate dehydrogenase
E
The glucagon hormone dominates in: A. Starvation B. Type I diabetes C. Ketogenic diets D. Type II diabetes E. Any of the above
E
The product of direct deamination is: A. Alpha-ketoglutarate B. A carbon skeleton C. Free ammonia D. A precursor of carbamoyl phosphate E. All of the above
E
What are the starting materials for amino acid biosynthesis? A. Intermediates of glycolysis B. Intermediates of the pentose-phosphate shunt C. Intermediates of the citric acid cycle D. Energy metabolism pathway intermediates E. Any of the above might be such starting materials.
E
What do statin drugs do? A. They dramatically decrease cardiovascular disease risk in the right patients. B. They inhibit the enzyme HMG-CoA reductase. C. They decrease cholesterol biosynthesis. D. They usually reduce hypercholesterolemia. E. All of the above
E
What does the enzyme glutamate dehydrogenase do? A. It directly deaminates glutamate. B. It turns glutamate into glutamine. C. It biosynthesizes glutamate from a-ketoglutarate and ammonia. D. It makes NADH as part of the citric acid cycle. E. Both A and C
E
What leads to the building up of acetyl-CoA in liver cells? A. The depletion of oxaloacetate for gluconeogenesis B. An extended glucagon signal C. The cells' use of fatty acids as their energy source D. Not being able to use all of the acetyl-CoA in the citric acid cycle E. All of the above
E
What use is made of the amino acids from our dietary proteins? A. They provide cellular energy. B. They become a source of nitrogen for many compounds. C. They are incorporated into our own proteins. D. All of the above, with A being the most common. E. All of the above, with C being the most common.
E
Where are the first peptide bonds broken in the Stage I metabolism of dietary protein? A. In the mouth B. In the cytoplasm C. In the intestine D. In the mitochondrial matrix E. In the stomach
E
Which of the following accurately describes where some organisms get nitrogen? A. For animals, most of their nitrogen comes from dietary protein. B. Some few bacteria can actually get it out of the air. C. Animals get nitrogen from the plants or other animals in their diet. D. Plants get their nitrogen in the form of ammonia and other small compounds. E. All of the above are true.
E
Which of the following amino acids has a biosynthetic pathway that includes an aminotransferase reaction? A. Alanine B. Phenylalanine C. Aspartate D. Glutamate E. All of the above have biosynthetic pathways with an aminotransferase reaction.
E
Which of the following amino acids has a biosynthetic pathway that starts with an intermediate from an energy metabolism pathway? A. Alanine B. Phenylalanine C. Aspartate D. Glutamate E. All of the above have biosynthetic pathways that start with such an intermediate.
E
Which of the following amino acids has a single-step biosynthetic pathway? A. Alanine, with three carbons B. Aspartate, with four carbons C. Glutamate, with five carbons D. None of the above has a single-step biosynthetic pathway. E. All of the above have single-step biosynthetic pathways.
E
Which of the following amino acids has the most complex biosynthetic pathway? A. Alanine B. Glutamate C. Aspartate D. All of the above have very complex biosynthetic pathways. E. None of the above has a complex biosynthetic pathway.
E
Which of the following amino acids is most likely to be essential for human beings? A. An amino acid whose biosynthesis involves only one step. B. An amino acid whose biosynthesis involves two steps. C. An amino acid whose biosynthesis involves three steps. D. An amino acid whose biosynthesis involves four steps. E. An amino acid whose biosynthesis involves five steps.
E
Which of the following compounds provides the most atoms for heme biosynthesis? A. Glutamate B. Alanine C. Glutamine D. Aspartate E. Glycine
E
Which of the following directly contributes to de novo biosynthesis of pyrimidines? A. Carbamoyl phosphate B. Glycine C. Aspartate D. Carbonic acid E. Two of the above directly contribute.
E
Which of the following does not happen under an extended glucagon signal? A. It may lead to a change in the pH of the blood. B. Acetyl-CoA from beta-oxidation may accumulate. C. The citric acid cycle intermediate oxaloacetate may become depleted. D. Ketone bodies may be generated. E. All of the above can happen under an extended glucagon signal.
E
Which of the following happens during catabolism of fatty acids in the matrix? A. An alcoholic carbon is oxidized to a ketone carbonyl. B. The bond between the alpha and beta carbons goes from single to a double bond. C. A thiolysis produces a carbon at the oxidation state of a carboxyl. D. A double bond is hydrated, becoming an alcohol. E. All of the above happen in this process.
E
Which of the following happens during lipogenesis? A. A ketone carbonyl is reduced to an alcoholic carbon. B. The bond between the alpha and beta carbons goes from double to a single bond. C. A condensation produces a lengthened carbon chain. D. An alcohol is dehydrated, becoming a double bond. E. All of the above happen in this process.
E
Which of the following is a type of malnourishment related to dietary protein? A. Negative nitrogen balance because of insufficient total protein B. Gout C. Protein deficiency disease because of too little of at least one essential amino acid D. Proteinuria due to having too much protein in the diet E. Two of the above are types of malnourishment related to dietary protein.
E
Which of the following is involved in Stage I metabolism of dietary protein? A. Denaturation by stomach acid B. Partial hydrolysis using a stomach protease C. Digestion to completion using intestinal proteases D. Distribution and absorption of amino acids by body cells E. All of the above are involved.
E
Which of the following is involved in the catabolic side of protein turnover? A. Recognition of tagged proteins by the proteasome cap. B. Attachment of multiple ubiquitin proteins to a protein to be degraded. C. Proteolysis within the proteasome core. D. The cooperation of ubiquitinylation and proteasome activity. E. All of the above
E
Which of the following is most accurate about the purine nucleotides? A. The non-standard nucleotide made first is inosine (I). B. Inosine can be made directly into adenosine (A). C. The sidechain of the non-standard nucleotide is hypoxanthine. D. Inosine can be made directly into guanosine (G). E. All of the above are true.
E
Which of the following is not a glucogenic amino acid? A. Alanine B. Glutamate C. Aspartate D. Phenylalanine (which is also ketogenic) E. All of the above are glucogenic amino acids.
E
Which of the following is not an intermediate in the biosynthesis of cholesterol? A. Squalene B. Acetyl-CoA C. IPP D. HMG-CoA E. All of the above are intermediates in the biosynthesis of cholesterol.
E
Which of the following is not true about contribution of atoms to the heterocyclic ring system of purines? A. Carbon dioxide (in the form of bicarbonate) contributes a carbon. B. Nitrogen is contributed from aspartate. C. Glycine contributes more atoms than anything else. D. Nitrogen is contributed from glutamine E. All of the above are true.
E
Which of the following is not true about ketogenic diets? A. They don't affect lipogenesis (or the formation of fatty acids). B. They cannot lead to a dangerous decrease in blood pH. C. They are always completely safe under all conditions. D. All of the above are true about ketogenic diets. E. None of the above is true about ketogenic diets.
E
Which of the following is not true of the biosynthesis of the pyrimidine nucleotides? A. Carbon dioxide provides carbon for it. B. The amino acid aspartate is used in it. C. The sidechain is built and then added to PRPP. D. Nitrogen from several amino acids can contribute to it. E. All of the above are true of this biosynthetic pathway.
E
Which of the following is part of ketosis? A. A build-up of acetyl-CoA levels B. The intermediate hydroxymethylglutaryl-CoA (HMG-CoA) C. Condensation of acetyl-CoA moieties together D. The creation of ketone bodies E. All of the above
E
Which of the following is the activity of fatty acid synthase? A. Reduction of a carbonyl to an alcoholic carbon B. Reducing an alcoholic carbon to give a carbon-carbon double bond C. Reduction of a double bond to a single bond D. Adding two carbons from a malonyl group while releasing a CO2 from it E. All of the above are activities of fatty acid synthase.
E
Which of the following is true about nitrogen-fixing bacteria? A. They use either nitrogenase or nitrogenase reductase. B. The process depends on molecular oxygen (O2). C. There are many strains of bacteria that are nitrogen-fixing. D. All of the above are true. E. None of the above is true.
E
Which of the following is true about the amino acid glutamate? A. It can be a substrate for amino transfer but not for deamination. B. It is not widely used during amino acid catabolism or anabolism. C. It can be a substrate for deamination but not for amino transfer. D. All of the above are true. E. None of the above is true.
E
Which of the following is true about the amino acid glutamate? A. It is a substrate or a product of glutamate dehydrogenase. B. It can donate its amine to any other amino acid. C. It is a substrate or a product of aminotransferase. D. It can be formed with an amine from any other amino acid. E. All of the above are true about glutamate.
E
Which of the following is true about the biosynthesis of carbamoyl phosphate? A. It involves the contribution of three moieties, two of which are to be excreted. B. A contributor to it is ATP. C. It uses free ammonia. D. A carbon dioxide (in the form of bicarbonate) is a substrate for it. E. All of the above are true.
E
Which of the following is true about the catabolism of all amino acids? A. They lead to carbons being made into glucose. B. It always creates at least one energy metabolism intermediate. C. They lead to carbons being made into acetyl-CoA. D. It always involves an amino-transfer reaction. E. Both B and D are true.
E
Which of the following is true about the fed state? A. Glycolysis is favored over gluconeogenesis. B. The insulin hormone dominates. C. Glycogenesis is favored over glycogenolysis. D. Lipogenesis can happen. E. All of the above are true.
E
Which of the following is true of the nucleotide orotate? A. It is built onto a phosphoribosyl pyrophosphate (PRPP) backbone. B. It can be made directly into either uracil or cytosine. C. It is a non-standard pyrimidine. D. It is the precursor of one standard pyrimidine that can be made into another one. E. Two of the above statements are true of this compound.
E
Which of the following might accumulate as atherosclerotic plaque in arterioles? A. Chylomicrons B. Cholesterol in membranes C. High-density lipoprotein particles D. Cellular cholesterol E. Low-density lipoprotein particles
E
Which of the following statements is not true about nucleotide biosynthesis? A. We can make the pyrimidine nucleotides in a de novo pathway. B. We can make the pyrimidine nucleotides in a salvage pathway. C. We can make the purine nucleotides in a de novo pathway. D. We can make the purine nucleotides in a salvage pathway. E. All of the above statements are true.
E
Which of these amino acids' catabolic pathway does not end in an energy metabolism intermediate from a pathway that we have studied? A. Glycine, with two carbons B. Alanine, with three carbons C. Aspartate, with four carbons D. Glutamate, with five carbons E. All of these amino acids catabolic pathways end that way.
E
Which of these best explains the efficiency of triglycerides for storage of energy? A. They are very reduced, and so can be extensively oxidized during metabolism. B. They actually aren't as efficient energy storage as carbohydrates are. C. They are not solvated inside cells, so they can be densely packed. D. They actually aren't as efficient energy storage as fats are. E. Both A and C are true.
E
Which of these coenzymes is necessary in all amino acid metabolism pathways? A. Coenzyme A B. Biotin C. Coenzyme Q D. Heme E. Pyridoxal phosphate
E
While biosynthesizing new fatty acids, the "machinery" holds onto the acyl group: A. Using coenzyme A B. Through an amide bond C. Using carnitine D. It doesn't hold onto the acyl group. E. Using a handle not mentioned above.
E
The hormone the expression of which signals the transition from the between-meals state to the fasting or starvation state up-regulates all of the following except: A. Glycogenolysis B. Glycolysis C. Fatty-acid catabolism D. Fat mobilization E. There isn't a hormone that signals this transition.
E, the transition isn't signaled by a hormone, but instead by glycogen exhaustion.
You will know the answer to this question if you have been attending class (and coming on time). A. Annakin B. Boba Fett C. C-3PO D. Dantooine E. Ewok F. Falcon
F
