Norm fxn- Biochemistry

Question 1

True or False: Mb has a higher affinity for O2 than Hb.

Answer 1

True

Question 2

True or false: Hb is made of 2 different pairs of subunits put together.

Answer 2

False. They’re identical subunits.

Question 3

How many alpha and beta subuntis are there in Hb?

Answer 3

2 alpha

2 beta

Question 4

Which state of Fe can accept the O2 in the middle of the Hb? (Fe++ or Fe+++)

Answer 4

Ferrous state (Fe++)

Question 5

True or False: when 1 O2 binds to a Hb subunit, it facilitates the binding of subsequent O2’s to the same Hb.

Answer 5

True

big point here

Question 6

How much stronger does CO bind to Hb than O2?

Answer 6

200x stronger (essentially irreversible)

Question 7

This is the type of Hb in 98% of adults, and is composed of a2b2

Answer 7

HbA

Question 8

This is the type of Hb in 2% of adults where the subunit structure is a2d2

Answer 8

HbA2

Question 9

This is the type of Hb where the subunit structure is a2g2, and is the trpincipal form of Hb from ~7mo before birth unity ~1mo after birth.

Answer 9

HbF

Question 10

True or False: HbF has a slightly lower O2 affinity than HbA.

Answer 10

False. It’s higher to ensure O2 delivery from mom’s blood to fetal blood.

Question 11

Since most CO2 is transported as HCO3 in the blood, what is the role of the Hb?

Answer 11

Hb binds the H+ forming HHb

Bohr effect

Question 12

Does the affinity of Hb for O2 increase or decrease with an increase in pH?

Answer 12

Increase

Question 13

Since Hb can bind to H+ ions and O2 ions, what is it’s role in the blood for regulation?

Answer 13

Buffer

Question 14

True or False- 2,3-DPG is a toxin that should never be present as it lowers the affinity for Hb binding to O2.

Answer 14

False- it’s a normal glycolysis product and is vital for regualting binding of O2 to Hb

Question 15

Does DPG bind to the oxygenated or deoxygenated form of Hb?

Answer 15

Deoxygenated

Question 16

How many DPG molecules bind to 1 Hb?

Answer 16

1

Question 17

When Hb is oxygenated, the central cavity becomes smaller, and what happens to DPG?

Answer 17

It’s expelled

Question 18

True or False: DPG binds HbF less strongly, giving a higher affinity of HbF for O2 than HbA.

Answer 18

True

Question 19

What replaces Glu at position 6 in the B-chain to cause sickle cell (HbS)?

Answer 19

Val

Question 20

In which state (deoxy or oxy) does the HbS become sticky by transforming the RBC into the sickle-cell shape?

Answer 20

Deoxygenated

Question 21

Do homozygous or heterozygous individuals get sickle-cell anemia?

Answer 21

Homozygous (it’s recessive)

Question 22

What is the incidence of SCA in african americans?

Answer 22

~1/500

Question 23

True or False: heterozygous sickle cell individuals are always asymptomatic.

Answer 23

False. they get symptomatic at high altitudes

Question 24

Heterozygous individuals are at an advantage when there is a prevalence of what?

Answer 24

Malaria

Question 25

What are the 2 ways of Dx SCA?

Answer 25

1. blood smear | 2. protein electrophoresis

Question 26

In HbC, what replaces the Glu on position 6 of the B-chain?

Answer 26

Lys

Question 27

When HbC crystalizes, what is the common pathology?

Answer 27

viscous blood and mild hemolysis

Question 28

Is HbC milder or more severe than HbS?

Answer 28

Milder

Question 29

True or False: metHb is a daily occurance where it's made and then reduced back to normal Hb.

Answer 29

True

Question 30

What is the enzyme to reduce metHb to Hb?

Answer 30

NADH-dependent methemoglobin reductase

Question 31

What is the condition where there is a deficiciency in the reductase or HbM?

Answer 31

Methemoglobinemia

Question 32

HbM favors which state of Fe?

Answer 32

Fe+++

Question 33

HbM can only exist in which state, heterozygous or homozygous? Why?

Answer 33

Heterozygous because homozygous is incompatible with life.

Question 34

What is the biggest Sx for methemoglobinemic patients?

Answer 34

Cyanosis

Question 35

This is a group of disorders where the synthesis of either Hb chain is reduced or absent.

Answer 35

Thalassemias

Question 36

What types of mutations typically cause a-Thalassemias?

Answer 36

deletions

Question 37

What types of mutations typically cause B-Thalassemias?

Answer 37

point mutations

Question 38

Which thalassemia is always fatal (a or B)?

Answer 38

alpha

Question 39

This is the group of disorders where the a-globin is reduced or absent.

Answer 39

a-thalassemia

Question 40

How many a-genes are missing in a-thalassemia 1?

Answer 40

1

Question 41

Is a-thalassemia 1 symptomless?

Answer 41

yes

Question 42

Mild anemia is present with a-thalassemia 2 because of how many a-genes missing?

Answer 42

2

Question 43

3 missing a-genes can cause which disease which causes moderately severe hemolytic anemia?

Answer 43

HbH disease

Question 44

4 missing a-genes (like we talked about before) is fatal and shows up with what condition as a fetus?

Answer 44

Hydrops fetalis

Question 45

This is the increased concentrations of red cells, usually from hemoglobinopathies which favor the oxyHb state.

Answer 45

Polycythemia

Question 46

Since the oxyHb is so strong in polycythemias, what happens to peripheral tissues?

Answer 46

Hypoxia from inadequate O2 supply

Question 47

This is a useful index for diabetes because of the glycosylated Hb.

Answer 47

HbA1c