Plasma & RBC Metabolism- Goueli

Question 1

What is hereditary spherocytosis?

Answer 1

a defect in erythrocyte cytoskeleton proteins

Question 2

What is the affect of 2,3-BPG on hemoglobin?

Answer 2

2,3 BPG increases energy required for the conformational changes that facilitate binding of oxygen

Lowers affinity of hemoglobin for oxygen (less readily bound, more readily released)

SHIFTS CURVE TO THE RIGHT

Question 3

What is the affect or pH on hemoglobin?

Answer 3

binding of protons to hemoglobin lowers its affinity for oxygen (promotes release)

pH decreases as it enters tissues due to increasing carbonic acid

LOWER pH (acidic) SHIFTS CURVE TO THE RIGHT

Question 4

What is the affect of covalent CO2 binding on hemoglobin?

Answer 4

High CO2 = low pH, SHIFTS CURVE TO RIGHT

Question 5

What is the affect of temperature on hemoglobin?

Answer 5

increased temp, reduced the affinity of hemoglobin for oxygen, facilitates release of Oxygen into tissues

Question 6

How is G6PD deficiency inherited?

Answer 6

It is an x-linked disease

Question 7

What state must hemoglobin be in to bind oxygen?

Answer 7

hemoglobin must be in the ferrous (+2) state

Question 8

What happens when ROS oxidize iron to ferric state (+3)?

Answer 8

Hemoglobin becomes methemoglobin (which NADH regenerates to hemoglobin)

Question 9

How does benzocaine effects RBC metabolism?

Answer 9

Benzocaine turns Fe2+ to Fe3+ (hemoglobin to methemoglobin) and causes aquired methemoglobinemia

Question 10

How does cirrhosis of the liver affect oncotic pressure?

Answer 10

Cirrhosis results in reduced albumin synthesis —-> reduction in oncotic pressure due to reduced plasma protein concentration —> unable to draw fluid out of the tissues at venous end of capillary