Day 3 Flashcards
(53 cards)
The hemoglobin molecule is composed of what two molecules?
Heme(iron) and Globin(protein)
What element is required for hemoglobin to be capable of carrying oxygen?
Iron
In what state is CO2 carried from tissues cells to the lungs?
Bicarbonate
What percentage of the RBC mass is hemoglobin?
28%
What is the globin to heme ration in RBCs
1 globin : 4 heme
What is the composition of the globin molecule?
2 pairs polypeptide chains
2 alpha chains-141 amino acids
2 Beta chains- 146 amino acids
What is the composition of the heme molecule?
4 protoporphyrins w/ one Fe++(ferrous) atom
Fe++ binds reversibly with O2 or CO2
TRUE OR FALSE
Fe ++(ferrous ) atom can bind reversibly with oxygen and carbon dioxide
True
List the normal and abnormal hemoglobin variants
Normal -A -F Abnormal -S -C -D -E
Define hemoglobinopathy and what causes it.
A disorder in which the presence of abnormal hemoglobin causes a pathological condition;
may be inherited, may be caused by genetic mutation
What percentage of normal adult hemoglobin is Hgb A and Hgb F
A-95%
F-5%
What Hgb variant has a greater affinity for oxygen and is the most efficient for carrying oxygen?
Hemoglobin F
At what age does Hgb F drop below 5% of all circulating hemoglobin?
By 2 years of age
Which Hgb variant Causes sickle cell anemia, and what population is almost executively at risk?
Hemoglobin S; African American population
The Hgb S variant has the ________ amino acid in place of glutamic acid on the ________ chain.
Valine; beta
What Hgb variant causes chronic hemolytic anemia and in what region is it frequently seen ?
Hemoglobin C ****
The Hgb _____ variant has the lysine amino acid in place of the glutamic acid on the _______ chain.
C; beta
Which Hgb variant is thought to protect against Plasmodium falciparum infection?
Hemoglobin E
Name the normal and abnormal hemoglobin derivatives.
Normal -oxyhemoglobin -reduced hemoglobin Abnormal -carboxyhemoglobin -methemoglobin -sulfhemoglobin -cyanmethemoglobin
Which Hgb derivative is produced when oxygen is dissociated from iron and replaced by CO2?
Reduced Hemoglobin
Name two conditions that can occur if sufficient quantities of abnormal Hgb derivatives are circulating in the blood
Hypoxia- lack of oxygen
Cyanosis- bluish discoloration of skin
Which Hgb derivative has 200 times greater affinity for oxygen and can cause carbon monoxide poisoning?
Carboxyhemoglobin
At what level does carboxyhemoglobin cause asphyxiation?
Levels 50-70%
Which Hgb derivative has iron been oxidized from the ferrous to ferric state which renders Hgb incapable of combining reversibly with oxygen?
Methemoglobin
