Tag Archives: Biochemistry

The initial velocity of an enzyme-catalyzed reaction is followed at various substrate concentrations. At very high substrate concentrations it is observed that the initial velocity no longer increases as more substrate is added. The velocity under these conditions is known as ____________.

Biological membranes partition aqueous environments to permit life processes to maintain regions of low entropy within the high entropy state of the surrounding environment. What key chemical characteristic do the major biomolecules in membranes have that allows for the formation of hydrophobic barriers separating aqueous environments?

An infant who obtains nourishment from milk and who has galactosemia is unable to convert____________.

Which two functional groups are involved in producing a peptide bond?

The introduction of 14CO2 into a cell actively synthesizing fatty acids results in 14C labeled _______________.

What is the approximate net charge of the molecule shown below at pH 7?

A young child was admitted to a hospital emergency room several hours after consuming a meal containing large amounts of fat. A sample of her blood was found to have extremely high levels of triacylglycerols in the form of chylomicrons suggesting an undiagnosed metabolic disease. What is the most likely enzyme defect she could have?

Why do people with an enzyme deficiency in carnitine acyltransferase have severe hypoglycemia, but do not manifest an increase in plasma ketones during starvation?

Acetylcholinesterase is an important enzyme in the nervous system. Acetylcholinesterase activity is blocked by the nerve agent sarin gas, which forms a covalent bond with a Ser in the active site of the enzyme. Sarin gas is a(n)__________.

A 10-year-old female presents with chest pain and xanthomas over her elbows and knees. Her father died of a heart attack at age 35. Her mother has high cholesterol. Her physician suspects heterozygous familial hypercholesterolemia in the parents with homozygous disease in the daughter. This disease results from mutations in the receptor for low-density lipoproteinContinue reading “MCAT Style Quiz Question 12.1”

A reduction in the catalytic activity of carbonic anhydrase would lead to __________ efficient oxygen delivery to tissues by hemoglobin as a result of a(n) __________ Bohr effect.

Albinism is characterized by white skin due to a defect in the enzyme arginase (1) tyrosinase (2), which leads to a block in the pathway needed to synthesize adrenaline (3) / melanin (4).  Animals with this condition have a(n) increased (5) / decreased (6) risk of skin cancer. The genetic disease phenylketonuria is caused byContinue reading “MCAT Style Quiz Question 14.1”