1. Acetyl CoA can produce all of the following except

a. Glucose

b. Fatty acid

c. Cholesterol

d. Ketone bodies

ANSWER a

• Acetyl-CoA is produced by the breakdown of both carbohydrates (by glycolysis) and lipids (by β-oxidation). It then enters the citric acid cycle in the mitochondrion by combining with oxaloacetate to form citrate
• Acetyl-CoA is generated in the mitochondria for oxidation or other possible fates. In the liver, mitochondrial acetyl-CoA is used to synthesize ketone bodies (acetoacetate and β-hydroxybutyrate) as alternative fuel sources for the brain and heart under conditions of carbohydrate scarcity

2. Increased pyruvate and lactate are found in deficiency of

a. Thiamine

b. Niacin

c. Vitamin C

d. Pyridoxine

ANSWER a

• Thiamin deficiency can cause loss of weight and appetite, confusion, memory loss, muscle weakness, and heart problems.
• Severe thiamin deficiency leads to a disease called beriberi with the added symptoms of tingling and numbness in the feet and hands, loss of muscle, and poor reflexes.
• Beriberi is not common in the United States and other developed countries.
• A more common example of thiamin deficiency in the United States is Wernicke-Korsakoff syndrome, which mostly affects people with alcoholism.
• It causes tingling and numbness in the hands and feet, severe memory loss, disorientation, and confusion.
• Lack of thiamine can lead to potentially life-threatening events. Inadequate stores of thiamine result in the failure of pyruvate to enter the tricarboxylic acid cycle, thus preventing aerobic metabolism, which may lead to profound lactic acidosis through anaerobic metabolism.

3. During a routine urine examination of an adult precipitation occurs at 60* C and on increasing at temperature further it dissolves completely it is indicative of

a. Ketosis

b. Bence jones proteins

c. Uremia

d. Nephrotic syndrome

ANSWER b

• A small protein made by plasma cells (white blood cells that produce antibodies). It is found in the urine of most people with multiple myeloma (cancer that begins in plasma cells).
• Bence Jones protein (BJP) was first described in a patient admitted to St. George’s Hospital in London under the care of Drs. Watson and MacIntyre for vague continuous pain to the chest, back, and pelvis in 1845.
• Dr. Henry Bence Jones tested this urine and found a substance in it that was precipitated by the addition of nitric acid. Jones proceeded to call this substance “hydrated deutoxide of albumen.”
• The actual term, Bence Jones Proteins, was used in 1880 by Dr. Fleischer.
• Its peculiar characteristics on heating first characterized BJP: precipitation of the urine at 40 to 60 degrees C and re-dissolving of the precipitate at 100 degrees C

4. All are caused amino acid deficiency except

a. Phenylketonuria

b. Homocysteinemia

c. Alkaptonuria

d. Galactosemia

ANSWER d

Galactosemia is a disorder that affects how the body processes a simple sugar called galactose. A small amount of galactose is present in many foods. It is primarily part of a larger sugar called lactose, which is found in all dairy products and many baby formulas. The signs and symptoms of galactosemia result from an inability to use galactose to produce energy.

CAUSE

Mutations in the GALT, GALK1, and GALE genes cause galactosemia. These genes provide instructions for making enzymes that are essential for processing galactose obtained from the diet.

SYMPTOMS

• Initial signs usually present in the first few weeks of life and include refusal to feed, vomiting, lethargy, jaundice, cataracts, and sepsis (infection).
• Babies born with galactosemia need to be put on a special lactose-free diet shortly after birth in order to prevent serious multiorgan involvement including death.
• Delayed growth and development
• Intellectual disability
• Liver disease
• Kidney problems etc

5. Within the RBC hypoxia stimulates glycolysis by which of the following regulating pathways

a. Hypoxia stimulates pyruvate dehydrogenase by increased 2,3 DPG

b. Hypoxia inhibits hexokinase

c. Hypoxia stimulates release of glycolytic enzyme from BAND 3 on RBC membrane

d. Activation of the regulatory enzyme by high pH

ANSWER c