B. Competitive inhibitors increase both the apparent Michaelis constant (Km) and the apparent maximal velocity (Vmax).
C. Competitive inhibitors increase the apparent Km and have no effect on the Vmax.
D. Competitive inhibitors decrease both the apparent Km and the apparent
Vmax.
E. Competitive inhibitors have no effect on the Km and decrease the apparent Vmax. RQ4. In an MI, a blood clot forms as a result of injury to a blood vessel that leads to production of a platelet plug and a fibrin meshwork. The clot occludes the blood vessel, preventing blood flow and, therefore, delivery of O2. Destruction of the clot (thrombolysis) restores blood flow. Which one of the following is an example of a thrombolytic agent?
A. Activated protein C complex
B. Antithrombin III
C. Aspirin
D. Factor XIII
E. Heparin
F. Tissue plasminogen activator
G. Vitamin K
H. Warfarin
RQ5. Decreased tissue perfusion results in hypoxia (decreased O2 availability). Relative to normoxia, in hypoxia the:
A. electron transport chain will be upregulated to provide protons for ATP synthesis.
B. ratio of the oxidized form of nicotinamide adenine dinucleotide (NAD+) to the reduced form (NADH) will increase.
C. pyruvate dehydrogenase complex will be active.
D. process of substrate-level phosphorylation will be increased in the cytosol.
E. tricarboxylic acid cycle will be upregulated to provide the reducing equivalents needed for oxidative phosphorylation to occur.
RQ6. Genetic screening of BJ’s first-degree relatives would be accomplished by mutation analysis via polymerase chain reaction–based amplification followed by automated sequencing of the promoter region and the 18 exons of the LDL receptor gene. This process would involve the:
A. generation and use of complementary DNA (cDNA).
B. initiation of DNA synthesis with dideoxynucleotides.
C. isolation of genomic DNA from germ cells.
D. use of fluorescently labeled nucleotides.
TQ1. Relative to an individual with familial defective LDL receptors, what would be the expected phenotype in an individual with familial defective apolipoprotein B-100? With apolipoprotein E-2, the isoform that only poorly binds its receptor?
TQ2. Why was aspirin prescribed? Hint: What pathway of lipid metabolism is affected by aspirin?
TQ3. Heart muscle normally uses aerobic metabolism to meet its energy needs. However, in hypoxia, anaerobic glycolysis is increased. What allosteric activator of glycolysis is responsible for this effect? With hypoxia, what will be the end product of glycolysis?
TQ4. One of the reasons for encouraging smoking cessation and exercise for BJ is that these changes raise the level of HDL, and elevated HDL reduces the risk for CHD. How does a rise in HDL reduce the risk for CHD?
Case 2: Severe Fasting Hypoglycemia
Patient Presentation: JS is a 4-month-old boy whose mother is concerned about the “twitching” movements he makes just before feedings. She tells the pediatrician that the movements started ~1 week ago, are most apparent in the morning, and disappear shortly after eating.
Focused History: JS is the product of a normal pregnancy and delivery. He appeared normal at birth. On his growth charts, he has been at the 30th percentile for both weight and length since birth. His immunizations are up to date. JS last ate a few hours ago.