Last Updated: September 13, 2022
Chapter 3 page 22 Question 4: The answer explanation correctly describes why choice B (plasmalogen) is the correct answer, however, the explanation starts by stating that choice D is the correct response.
Chapter 6 page 51 Question 13: The answer explanation correctly describes why choice B is the correct answer, however, in the second sentence of the explanation it states: “However, it forms such a strong bond with the iron in the heme that the binding is irreversible.” The binding of CO to heme is not irreversible but only appears to be since the affinity is so high. Therefore, the correct sentence should read: “However, it forms such a strong bond with the iron in the heme that the binding appears to be very nearly irreversible.”
Chapter 9 page 114 Question 18: The answer explanation correctly describes why choice C is the correct answer, however, choice E can be considered equally correct.
Chapter 10 page 121: The section discussing the hexokinase reaction lists the Km values for the various forms of the enzyme incorrectly. Hexokinases I, II, and III have Km for glucose in the range of 3μM–30μM (or 0.003mM–0.03mM) and that of glucokinase (hexokinase IV) is around 6mM NOT in the μM range as indicated on page 121.
Chapter 14 page 180 Question 22: in the explanation it is described that an increased rate of glycogenolysis (Choice B) will occur, in response to increased levels of cAMP due to increased phosphorylase activity. This is, of course, correct, but the answer also goes on to indicate there will be subsequent release of the glucose into the blood. This will happen in the liver but in skeletal muscle, due to the low Km of hexokinase, the released glucose will immediately be phosphorylated and thus, trapped in the skeletal muscle cell as necessary for glycolysis and ATP production.
Chapter 15 page 191 Question 7: The answer explanation correctly describes why choice A is a correct answer, however, the explanation also indicates that symptoms in choice E are correct. Indeed, both A and E are correct answer choices for this question.
Chapter 15 page 192 Question 10: The answer explanation correctly describes why choice E (transketolase) is the correct answer, however, the explanation starts by stating that choice D is the correct response.
Chapter 16 page 195: in the last sentence on this page the indication (Figure 16-2) should be (Figure 10-7)
Chapter 16 page 201: In the last sentence of the first paragraph, the abbreviation POAA should be OAA for oxaloacetic acid
Chapter 16 page 201: In the second to last sentence of this page the indication (see Figure 16-2) should be (see Figure 19-3)
Chapter 25 page 316 Question 4: The answer explanation correctly describes why E is the correct answer, however, the explanation starts by stating that “A” is the correct response.
Chapter 25 page 319 Question 22: The answer explanation correctly describes why A is the correct answer, however, the question stem itself should describe administration of triglycerides containing only short-chain fatty acids (NOT medium-chain), and also in the answer explanation, the last sentence should indicate that short-chain fatty acyl-CoAs enter the mitochondria without the need for the carnitine shuttle.
Chapter 27 page 345-346 Question 7: The answer explanation correctly describes why A is the correct answer, however, the explanation starts by stating that “B” is the correct response.
Chapter 27 page 342 Figure 27-3. The red arrow in the liver lobule image indicating flow of blood from lungs via branch of hepatic arteries should be in the opposite direction, i.e. into the lobule and not out from the lobule. This image is correct in the Bile Acids page of the website and will be corrected at the next printing of the textbook.
Chapter 29 page 383 Question 18: possible answer A should read “High ADP:ATP” ratio. A high ATP:ADP ratio would be as correct as choice C.
Chapter 30 page 405 Clinical Box 30-6, second sentence should read: “MSUD results from deficiencies in BCKD, leading to an accumulation of leucine, isoleucine, and valine and their corresponding branched-chain α-keto acids (BCKA). The error is that the third amino acid listed in that sentence is lysine
Chapter 32 page 442 Question 14: The answer explanation correctly describes why B is the correct answer, however, the explanation starts by stating that “E” is the correct response.
Chapter 32 page 445 Question 25: The correct answer “D” is incorrectly explained. The patient in this question most likely has the glycogen storage disease, von Gierke disease, and NOT a defect in hepatic HGPRT. The doll-like face and hepatomegaly are characteristic of von Gierke disease, as is the decreased serum glucose, increased serum lactic acid, and increased serum triglycerides during a fast. The hyperuricemia in von Gierke disease patients is due to the shunting of glucose-6-phosphate, especially in response to a fast, into the pentose phosphate pathway resulting in increased ribose-5-phosphate production which in turn stimulates purine nucleotide synthesis. The excess purines are then degraded resulting in increased urate production and the observed hyperuricemia.
Chapter 33 page 461 Question 23: The answer explanation correctly describes why D is the correct answer, however, the explanation starts by stating that “C” is the correct response.
Chapter 35 page 506 Question 24: The answer explanation correctly describes why D is the correct answer, however, the explanation starts by stating that “E” is the correct response.
Chapter 40 page 612 Question 19: The most correct answer for this question about T-cell receptor (TCR) activation of PKC should be choice “A” since the PKC isoforms activated by the TCR signal cascade are most responsive to Ca2+. The explanation indicates that choice “D” is correct, and although DAG is considered one of the second messengers from membrane PIP2 hydrolysis (the other being IP3), in this case the Ca2+ ions released as a result of the action of IP3 represent the most correct choice.
Chapter 44 page 689 Question 3: The answer explanation correctly describes why D is the correct answer, however, the explanation starts by stating that “C” is the correct response.
Chapter 44 page 689 Question 4: The answer explanation describes why B is the correct answer, however, choice D is equally correct since inhibition of both CPT1 and MCD will lead to increased levels of malonyl-CoA which triggers an anorexigenic response. Therefore, this choice will need to be changed in future printings.
Chapter 44 page 689 Question 6: The answer explanation describes why D is the correct answer, however, choice C is equally correct since PP binding to Y4 receptors in the ARC of the hypothalamus induces an anorexigenic response. Therefore, this choice will need to be changed for the next printing.
Chapter 52 page 837 Figure 52-1: This Figure is supposed to be the same as Figure 55-2 from the 29th edition of Harper’s Illustrated Biochemistry. Erroneously the Figure used shows the consequences of mutations in the G6PDH gene.