biochem midterm (practice questions) Flashcards

What information does the G6PD assay suggest regarding the inheritance of this enzyme abnormality?

Why does G6PD deficiency seem to have the most adverse effect on red blood cells?

The pentose phosphate pathway, sometimes referred to as the pentose phosphate shunt takes place in the-

Unconjugated bilirubin is poorly soluble in aqueous solution and is transported in plasma by-

Which of the following pathways is considered to be an ANABOLIC pathway that produces new carbohydrate molecules?

What is the purpose of the pentose phosphate pathway?

Which one of the following gas is produced as a direct result of heme catabolism to bilirubin IXa?

Pentose phosphate pathway can occur in-

What percent of G6P can be OXIDIZED to CO2 in the pentose pathway?

An elderly couple living in the suburbs of Hanover, New Hampshire, was snowbound for several days in their home during a blizzard, during periods of electrical outage they relied on an unvented gas heater to warm one room in their home where they stayed throughout the blizzard. As soon as the roads cleared, their granddaughter came to check on them and found them disoriented, complaining of headache, fatigue, and nausea, and breathing and walking with a stumbling gait.

Lab data shows a remarkably increased carboxyhemoglobin level in the blood . The best explanation for this finding is that CO has which of the following affects?

Which of the following treatment strategies is the most effective remediation for CO poisoning?

In addition to forming carboxyhemoglobin, the toxic effects of CO include inhibition of which of the following enzymes involved in the oxidation-reduction reactions?

Myoglobin contains hemes, pigments responsible for the color of red meat. The color that meat takes is partly determined by the degree of oxidation of the myoglobin. In fresh meat, the iron atom is the ferrous state bound to an O2. Meat cooked well done is brown because the iron atom is now in the ferric oxidation state, having lost an electron. Hormel and Cargill are both reported to use a meat-packing process, that artificially induced pink color meat that can persist for up to one year. Pink color meat is usually associated in consumers minds with fresh meat. The meat treated this way has been in the consumer market since 2003. How do Hormel and Cargill have fooled consumer for so long?

Administration of 5-7% of CO2 to the O2 is sometimes used to treat CO poisoning. The advantage of CO2 addition is _________ and the disadvantage of CO2 addition is __________.

Why is HbF (fetal hemoglobin) suboptimal postpartum for delivery of O2?

After releasing O2 at the tissues, hemoglobin transports-

Why does HbF have higher affinity for O2 that HbA?

Mutations that favor the R state (hemoglobin Chesapeake) leads to-

The genetic defects known as thalassemias result from the partial or total absence of-

Inhibitions of oxidative phosphorylation by cyanide ion leads to increases in which of the following?

The reduction half-reaction in the last step of the electron transport chain is-

Which of the following procedures best describes the emergency intervention for cyanide poisoning?

A 16-month-old girl was found to have ingested approximately 30mL of an acetonitrile-based cosmetic nail remover. When she vomited 15 minutes post ingestion, the poison control center was contacted; however, no treatment was recommended because it was confused with an acetone based nail polish remover. The child was put to bed at her normal time, which was 2 hours post ingestion. Respirtory distress dveleoped sometime after the child was put to bed, and she was found dead the next morning.

Inhibition of which of the following enzymes was most likely cause of this child's death?

Respitory distress is induced when exposed to rotenone because it inhibits the complex that catlyzes which of the following?

Which of the follwing statemeents is correct?

True or False: For every pair of electrons passing down the chain from NADH or FADH2, 2H+ are pumped across the membrane by complex IV

The ability to exist in both an oxidized and a reduced state is a chrateristic of -

NADH can not penetrate the mitochondrial membrane, but it is produced continously in the cytosol by glycolysis. How do we transport this NADH from cytosol to mitochondria?

The major metabolic consequence of disturbance of the electron transfer in mitochondria is which of the following?

FMN and FAD are dervived from the vitamin riboflavin (B2) and are called flavin coenzymes. Coenzymes are small organic molecules that are mostly derived from vitamins and are involved in enzyme catalyzed reactions. Sources of riboflavin are milk,cheese,leaf vegtables, liver, kidneys, mushrooms, and almonds.

If someone has a B2 deficiency, which one of the follwoing energy pathways are most likely effected by this deficiency?

Genetic defects in fatty acid oxidation can account for severe weakness during exercise and up to 10% of sudden infant deaths, Could people with this defect produce glucose by gluconeogenesis?

In discussions of nutrition, energy is often expressed in units of calories. In this context a calorie means-

oxidative pathways are-

ATP production in RBC is totally dependent upon glucose and anareobic glycolysis because there are no mitochondria (no TCA cycle operating) in these cells. Why are there no mitochondria in RBC?

Which of the following options has the highest to lowest caloric content (kcal/g)

The major carbohydrates in the diet are-

Conversion of pyruvate to acetyl CoA is an irreversible reaction, acetyl CoA cannot be converted to pyruvate then to OAA. In the future, we may have a mutation in the enzyme that converts pyruvate to acetyl CoA. If acetyl CoA could be converted to pyruvate and then to OAA, would we still need to have glucose in our diet for the production of energy?

Nicotinamide adenine dinucleotide (NAD) is derived from niacin (B3 vitamin) and is a coenzyme used for many dehydrogenases. If someone has niacin deficiency, what kind of symptoms can you expect this person to have?

Imagine a mutation happens to an individual and she ends up having a channel that lets H+ leak into the matrix of the mitochondria. What would be the consequence of the H+ leak?

What hormone(s) raises cAMP?

Why is the glycolytic pathway not 100% reversible

What steps are irreversible in glycolysis?

During an extended fast , acetyl CoA is converted into

What is the primary source of glucose after fasting for a few hours?

Glucose uptake outside the liver is regulated by what hormone?

What is the level of glucose and insulin in diabetic ketoacidosis?

What hormone is the opposite of glucagon?

What molecule is used in glycogen synthesis, glycolysis, and the pentose phosphate pathway?

In the first step of glycolysis, how many ATPs are used to phosphorylate glucose?

What are the relaxation steps in the sliding filament model?

What drug is administered to treat malignant hyperthermia?

Why does rigor mortis occur?

Which troponin binds to calcium?

Which bands shorten during contraction

What breaks when hemoglobin does a conformational change?

In what scenario would myoglobin release O2?

Hemoglobin __________ oxygen

Myoglobin _________ oxygen

What happens when carbon monoxide binds to hemoglobin in the red blood cells?

What promotes hemoglobin to transition from a high-oxygen-affinity state to a low-oxygen-affinity state?

If there is no oxygen in hemoglobin, what state is it in

If there is oxygen present in hemoglobin, what state is it in?

What is the function of the enzyme carbonic anhydrase?

How many helices does myoglobin have?