Hemoglobin synthesis

Question 1

• main component of RBC (95%)
• respiratory pigment
• 4 heme, 4 polypeptide chains

Answer 1

Hemoglobin

Question 2

main function of hemoglobin

Answer 2

responsible for oxygen & carbon dioxide carrying capacity of RBC

Question 3

primary function of rbc

Answer 3

manufacture Hgb

Question 4

• enzymatic reaction

- begins in mitochondria

Answer 4

heme synthesis

Question 5

• genetic control

- ribosomes in the cytoplasm

Answer 5

globin synthesis

Question 6

1 RBC= how many Hgb

Answer 6

34 g/dL Hb

Question 7

1 gm of Hgb can carry how many O2

Answer 7

1.34 mL

Question 8

1 gm of Hgb carries a constant ____ iron

Answer 8

3.47 mg

Question 9

Hgb molecule is commposed of four subunits, each containing ___ and ____

Answer 9

heme, globin

Question 10

• belongs to the class of pigment

- is a porphyrin ring w/ an iron atom at its center

Answer 10

heme

Question 11

heme is also known as

Answer 11

protoporphyrin IX or ferroprotoporphyrin IX

Question 12

most functional protein in iron

Answer 12

hemoglobin

Question 13

most storage protein in iron

Answer 13

ferritin

Question 14

most transport protein in iron

Answer 14

transferrin

Question 15

site where maximum iron absoprtion

Answer 15

duodenum & jejunum

Question 16

membrane protein in enterocyte tansports iron from intestinal lumen into the enterocyte

Answer 16

divalent metal transporter 1

Question 17

membrane protein that transports iron from macrophage, hepatocytes & enterocytes going towards the blood

Answer 17

Ferroportin

Question 18

responsible for the transport of iron in plasma

Answer 18

apotransferrin/transferrin

Question 19

saves free hem & hemoglobin especially in hemolysis

Answer 19

haptoglobin

hemopexin

Question 20

absorption of ionic iron in the _____

Answer 20

small intestine

Question 21

ferric iron reduction by ____

Answer 21

DMT1

Question 22

ferrous iron oxidation by ______

Answer 22

hephaestin

Question 23

stronger form of iron

Answer 23

ferric

Question 24

functional form of iron

Answer 24

ferrous

Question 25

DMT1 transfer iron into ____

Answer 25

cytosol

Question 26

iron is stored as ____

Answer 26

ferritin

Question 27

inactive the absorption & recycling of iron by acting on enterocytes, macrophages & hepatocytes

Answer 27

hepcidin

Question 28

most functional iron in humans

Answer 28

hemoglobin | myoglobin

Question 29

how many iron is in storage form

Answer 29

1/4

Question 30

average american diet iron/day

Answer 30

10-20 mg

Question 31

average american diet iron/day that is absorbed

Answer 31

1-2 mg

Question 32

iron is absorbed from the ___

Answer 32

gut

Question 33

comprises of 141-146 amino acids

Answer 33

globin

Question 34

heme synthesis occurs in the ___

Answer 34

bone marrow

Question 35

heme synthesis is from ____ stage to ____ stage

Answer 35

pronormoblast, reticulocyte

Question 36

synthesis is under genetic control

Answer 36

globin synthesis

Question 37

alpha and zeta genes of globin is from ___

Answer 37

chromosome 16

Question 38

beta, delta, epsilon & gamma is from ___

Answer 38

chromosome 11

Question 39

the production of globin chains takes place in

Answer 39

pronormoblast-polychromatophilic erythrocyte or immature RBC

Question 40

embryonic normal hemoglobins

Answer 40

- gower I - portland - gower II

Question 41

fetal normal hemoglobin

Answer 41

HbF

Question 42

variants of normal hemoglobin (adult)

Answer 42

- HbA1 | - HbA2

Question 43

- 95% of adult normal hemoglobin | - post natal life

Answer 43

HbA1

Question 44

- less than 3.5% of adult normal hemoglobin | - small amnt only is found in RBCs

Answer 44

HbA2

Question 45

formed by post synthetic, non-enzymatic reactions of various sugars w/ amino groups of the globin chains

Answer 45

HbA1c

Question 46

normal & functional hemoglobin

Answer 46

1. Oxyhemoglobin (HbO2) | 2. Deoxygenated or Reduced Hemoglobin (HbCO2)

Question 47

- in arterial blood | - bright red in color

Answer 47

Oxyhemoglobin

Question 48

- in venous blood | - dark red in color

Answer 48

Reduced hemoglobin

Question 49

unable to act as an oxygen carrier

Answer 49

abnormal or non functional hemoglobin

Question 50

abnormal or non functional hemoglobins

Answer 50

1. carboxyhemoglobin (hbco) 2. methemoglobin 2. sulfhemoglobin

Question 51

- hemoglobin bound to carbon monoxide - REVERSIBLE - affinity of Hb for CO is 240x greater than for oxygen at 37C - hypoxia because HbCO is not capable of transporting oxygen - elevated in heavy smokers

Answer 51

Carboxyhemoglobin

Question 52

other name of methemoglobin

Answer 52

ferrihemoglobin

Question 53

- contains iron in the ferric state - REVERSIBLE because it is unstable - when Hb is exposed to oxidizing agent - if inc more than 30% px is with hypoxia and cyanosis

Answer 53

Methemoglobin

Question 54

methemoglobin increases in:

Answer 54

1. presence of oxidants (nitrite) 2. dec activity of methemoglobin reductase (gene defect) 3. mutations in the gene fo r NADH-cytochrome b5 reductase 3 (CYB5R3) 4. Hb M disease

Question 55

treatment of methemoglobin

Answer 55

a. removal of offending subs | b. administration of ascorbic acid or methylene blue (IV)

Question 56

color of blood with carboxyhemoglobin

Answer 56

cherry red

Question 57

color of blood with methemoglobin

Answer 57

chocolate brown

Question 58

color of blood in vitro with sulfhemoglobin

Answer 58

green pigment

Question 59

- caused by chemical or drugs like aromatic amines or sulfonamides - IRREVERSIBLE - caused by prolonged constipation, sulfa drugs or trinitrotoluene

Answer 59

Sulfhemoglobin

Question 60

RBCs containing HbS have _____ & _____

Answer 60

normal survival & osmotic fragility