Crib death of infants when fasting (i.e., when sleeping and…

Crib death of infants when fasting (i.e., when sleeping and not eating – therefore a low blood glucose condition) is also known as sudden infant death syndrome (SIDS). SIDS was often blamed on lack of proper care by the parents of the child. It is now known that a significant number of SIDS cases are caused by a genetic defect in the gene that codes for fatty acyl-CoA dehydrogenase, the enzyme that catalyzes the first step in fatty acid β-oxidation (see question 34 for this reaction). If this enzyme is defective, energy from fatty acids is not available and, in addition, gluconeogenesis is inhibited resulting in severe and life-threatening hypoglycemia (low blood glucose). Why the hypoglycemia?

Avidin is a protein found in the eggs of birds that binds bi…

Avidin is a protein found in the eggs of birds that binds biotin with high affinity and is a strong inhibitor of biotin-requiring enzymes (recall that biotin is a necessary coenzyme for CO2 transfers). You perform an experiment using liver cells that are capable of gluconeogenesis growing in culture. You add each of the following (answers A, B, C, D, or E) as potential substrates (assume each is readily transported into the cell and/or mitochondria) and you measure the amount of glucose synthesized and record in your lab book that all these substrates will support glucose synthesis. For your test cultures, you add each of the substrates (answers A, B, C, D, or E) and include avidin in each culture. You measure the levels of glucose synthesized and record this in your lab book. Which substrate will NOT support synthesis of glucose in the presence of avidin?