560D Biochem (my own - addl info)

Question 1

Antacids can reduce the absorption of iron and copper, leading to iron deficiency anemia because:

Answer 1

DMT1 requires cotransport of H+ ions to internalize divalent cations

Question 2

Sideroblastic anemia is an X-linked condition where the enzyme called ___________ is mutated, leading to excess iron in the RBC mitochondria.

Answer 2

Delta - aminolevulinic acid (ALA) synthase

also controls the rate limiting step in heme synthesis

Question 3

Thyroperoxidase (TPO) is responsible for catalyzing the following reaction(s):

A - Oxidation of iodide to iodine
B - Iodination, joining of iodine to thryoglobulin
C - Coupling of MIT with DIT to form T3
D - Coupling of DIT with DIT to form T4
E - All of the above

Answer 3

E - all of the above

Question 4

Clients may be diagnosed as overweight if their BMI is:

Answer 4

25 - 29.9

Question 5

Elevations of Cortisol have been implicated in insulin resistance. Which of the following is NOT an action of high cortisol levels?

A - Upregulation of GLUT4 receptors
B - Increased FA synthesis
C - Increased glycogenolysis
D - Increased gluconeogenesis

Answer 5

D - increased gluconeogenesis

GLUT4 is downregulated with high cortisol levels

Question 6

Phosphofructokinase 1, Glucokinase, and Pyruvate Kinase are all upregulated in response to insulin. TRUE or FALSE

Answer 6

TRUE

• phosphofructokinase (kinase enzyme that phosphorylates fructose 6-phosphate in glycolysis)
• glucokinase (facilitates phosphorylation of glucose to glucose-6-phosphate in the liver and pancreas)
• pyruvate kinase (last step in glycolysis; catalyzes the transfer of a phosphate group from phosphoenolpyruvate (PEP) to adenosine diphosphate (ADP), yielding one molecule of pyruvate and one molecule of ATP)

Question 7

Glucagon rises in a fasting state and control metabolism by:

Answer 7

1 - blocks glycolysis
2 - increased gluconeogenesis (PEP carboxykinase)
3 - decreases glycogenesis (glycogen synthase)

Question 8

High levels of ATP in the cell indicate increased energy reserves and will block the activity of _________.

Answer 8

High ATP will block the activity of phosphofructokinase and pyruvate kinase of glycolysis to further slow the production of ATP

Question 9

The correlation of hyperinsulinemia and increases in hypertension come from the hyperinsulinemia causing:

Answer 9

Increased sodium retention and uric acid retention

Question 10

Adiponectin assists in:

A - Decreased fat accumulation
B - Increased glucose uptake
C - Decreased inflammation
D - All of the above

Answer 10

D - All of the above

Question 11

During heme degradation, which degradation product of bilirubin gives urine its yellow color?

Answer 11

Urobilin

Question 12

The first step in heme degradation utilizes heme oxygenase to create biliverden. What reductant is required to this pathway to function?

Answer 12

NADPH

Question 13

Delta-aminolevulinic acid (ALA synthase) creates delta-aminolevulinic acid from what substrates?

Answer 13

Succinyl-CoA and glycine

Question 14

Which enzyme in the heme biosynthesis pathway contains zinc and is located in the cytosol?

Answer 14

Delta-ALA Dehydratase

This enzyme converts 2 ALA into porphobilinogen and is very sensitive to heavy metals like lead because they replace the zinc

Question 15

Glutamine synthetase requires the use of what minerals to assist in the conversion of glutamate to glutamine?

Answer 15

Mg++ and Mn++

enzyme plays an essential role in the metabolism of nitrogen by catalyzing the condensation of glutamate and ammonia to form glutamine: Glutamate + ATP + NH3 → Glutamine + ADP + phosphate

Question 16

In the urea cycle, CPS (mitochondrial carbamoyl phosphate synthase 1) converts ammonia + H2O + 2ATP + CO2 —->

Answer 16

Carbamoyl phosphate + PO4 + 2ADP

other options had SO4 – remember it is PO4

Question 17

The enzyme DDAH, which breaks down ADMA into citrulline + dimethylamine is upregulated with the assistance of what nutrients?

Answer 17

Vit A, Vit C, Vit E, and Zinc

ACEZinc helps to break down ADMA

Question 18

What enzyme requiring B6 converts Glutamate —-> Gamma-amino-N-butyric acid (GABA)

Answer 18

Glutamic acid decarboxylase (GAD)

Question 19

Taurine, which is utilized in skeletal muscle and bile, can be created from cysteine with the assistance of what nutrients?

Answer 19

Iron, P5P, NAD and FAD