Biochem Hemoglobin And Gas Transport

Front 1

What are the 2 O2 storers?

Back 1

Hemoglobin and myoglobin

Front 2

What are the three Fe +3 storers?

Back 2

Ferritin and hemosiderin

Front 3

What is the % of total iron in hemoglobin and myoglobin?

Back 3

65% and 10%

Front 4

What is the % of total iron in ferritin and hemosiderin?

Back 4

10% and 9 %

Front 5

What is the % of total iron in transferrin?

Back 5

less than %1 (that 1% is combined with cytochromes, heme enzymes, and nonheme enzymes

Front 6

What is the % iron in compound for hemoglobin and myoglobin?

Back 6

.34% for both

Front 7

What is the % iron in compound for ferritin and hemosiderin?

Back 7

23% and 37%, the highest level of iron

Front 8

What is the % iron in compound for transferrin?

Back 8

.15%, the lowest level of iron

Front 9

What are the daily dietary levels of iron?

Back 9

20 mg

Front 10

What is the average absorption for how much is ingested?

Back 10

less than 10%, so only about 2 mg added to body per day

Front 11

would the percentage of iron absorbed increase or decrease with iron deficiency?

Back 11

increase

Front 12

Which is the reduced state of iron?

Back 12

Fe 2+ (ferrous)

Front 13

Which is absorbed more rapidly, ferrous or ferric?

Back 13

Ferrous

Front 14

T/F Iron in the form of heme favors absorption.

Back 14

T

Front 15

Absorption is increased or decreased by a reducing agent (Vitamin C)

Back 15

increased

Front 16

T/F Fe+++ absorption is favored by acid

Back 16

F Fe ++ is

Front 17

Which enhances absorption, soluble or insoluble chelates?

Back 17

soluble

Front 18

What is an example of a soluble chelate?

Back 18

ascorbate

Front 19

What are 4 examples of insoluble chelates?

Back 19

phosphate, hydroxide, oxalate, or phytic acid (inositol hexaphosphate)

Front 20

What is ferritin?

Back 20

a ferric hydroxide phosphate complex with apoferritin

Front 21

What is hemosiderin?

Back 21

large granules; protein plus up to 37% iron

Front 22

Iron is stored in protein complexes in the ferric or ferrous state?

Back 22

ferric

Front 23

How is iron transported?

Back 23

Transferrin

Front 24

What is transferrin?

Back 24

transports iron, .15% ferric iron bound to histidine and tyrosine

Front 25

What is hemopexin?

Back 25

binds free heme to prevent loss of iron in the kidneys

Front 26

What is haptoglobin?

Back 26

binds hemoglobin making particles too large to pass through the kidneys

Front 27

What color is oxyhemoglobin?

Back 27

bright red

Front 28

What is oxyhemoglobin?

Back 28

One O2 molecule bound at each of the four hemes with the iron remaining as Fe++

Front 29

What is oxygenation?

Back 29

addition of O2 to hemes in oxyhemoglobin

Front 30

What color is deoxyhemoglobin?

Back 30

dull red color

Front 31

What is deoxyhemoglobin?

Back 31

Reversible formed from oxyhemoglobin by lowering the oxygen tension or removing the oxygen chemically

Front 32

What color is methemoglobin?

Back 32

brownish red

Front 33

What is methemoglobin?

Back 33

The FERROUS iron in the heme that has been oxidized to the FERRIC state and will not carry oxygen

Front 34

What color is carboxyhemoglobin?

Back 34

Bright red

Front 35

Another name for carboxyhemoglobin?

Back 35

Carbonmonoxyhemoglobin

Front 36

What is carboxyhemoglobin?

Back 36

Formed by the reversible combination of carbon monoxide with the heme iron; competitive inhibitor for O2 transport

Front 37

Which direction would carboxyhemoglobin shift the saturation curve?

Back 37

to the left

Front 38

What is Cyanomethemoglobin?

Back 38

Cyanide combines with heme iron in the FERRIC state, but not ferrous state. It combines with methemoglobin and with cytochrome oxidase

Front 39

What does cyanomethemoglobin actually do?

Back 39

inhibits electron transport

Front 40

What color is sulfhemoglobin?

Back 40

green

Front 41

What is sulfhemoglobin?

Back 41

exposure to sulfur compounds or certain drugs can result in the addition of sulfur to hemoglobin with reduced binding of O2 and CO

Front 42

How do hemoglobin types differ from each other?

Back 42

In the primary structure of the protein (globin) part of the molecule

Front 43

What is the short hand notation for Hemoglobin A?

Back 43

alpha2Abeta2A

Front 44

What is hemoglobin A?

Back 44

the main adult hemoglobin (about 95%)

Front 45

What is the short hand notation for Hemoglobin A2?

Back 45

alpha2Abeta2A2

Front 46

What is hemoglobin A2?

Back 46

a minor component of normal hemoglobin (about 2.5%)

Front 47

What is the short hand notation for Hemoglobin F?

Back 47

alpha2Agamma2F

Front 48

What is hemoglobin F?

Back 48

the principal fetal form

Front 49

How much hemoglobind F do you have at birth? when does that change?

Back 49

80% at birth, diminishing quickly to less than 10% by 3 months

Front 50

What is the short hand notation for hemoglobin A1C?

Back 50

there is none

Front 51

What is Hemoglobin A1C?

Back 51

One of a number of glycosylated hemoglobins

Front 52

How does hemoglobin A1C differ from hemoglobin A?

Back 52

hemoglobin A1C has glucose attached to the N-terminal of the beta chain, and normally makes up about 5% of the total hemoglobin

Front 53

What disease would you find an increase in hemoglobin A1C?

Back 53

Diabetes mellitus

Front 54

A1C levels in blood represent what?

Back 54

an average of glucose levels over several weeks

Front 55

Draw the evolutionary pattern for formation of globin

Back 55

Precursor globin
alpha beta myoglobin
zeda gamma, delta
epsilon

Front 56

T/F Defects in beta and delta chains are hard to detect before birth

Back 56

true

Front 57

What is the partial pressure of a gas?

Back 57

part of the total pressure in a mixture of gases which is due solely to that gas

Front 58

Partial pressure of a gas is directly related to what?

Back 58

the fractional volume of that gas in the entire volume

Front 59

T/F The partial pressure of a gas within a liquid is the same as the partial pressure of that gas in an atmosphere above the liquid which is in equilibrium with that liquid

Back 59

True

Front 60

What does partial pressure represent?

Back 60

driving forces for gas diffusion since the direction of diffusion is from high to low pressure

Front 61

What is the partial pressure for oxygen for arterior and benous?

Back 61

100 and 40

Front 62

What is the partial pressure for CO2 for arterial and venous?

Back 62

40 and 46

Front 63

Higher pH would bind weaker or stronger to O2 than a lower pH?

Back 63

stronger

Front 64

Why do more acidic levels bind O2 weaker?

Back 64

because then it can release the O2 to the tissues that need it (ex: working out, acidic, need more O2)

Front 65

How many heme and poslypeptide chains does myoglobin have?

Back 65

only one of each

Front 66

Does myoglobin bind tighter than oxyhemoglobin?

Back 66

Yes

Front 67

Does myoglobin show allosterism?

Back 67

no

Front 68

What does a curve shift to the right indicate?

Back 68

increase O2 transport

Front 69

What does the sigmoidal shape of the curve facilitate?

Back 69

greater O2 transport at tissue PO2 levels

Front 70

Increased PCO2 (and thus increased acidity) allosterically shifts the curve in which direction

what is another name for this term?

Back 70

to the right

the bohr effect

Front 71

Which direction does the allosteric effector 2,3-bisphosphoglycerate (BPG) shift the curve?

Back 71

to the right, so it improves O2 transport

Front 72

Where is 2,3-bisphosphoglycerate derived from?

Back 72

glycolysis

Front 73

During anemia, what happens to 2,3-BPG?

Back 73

it increases, compensating for it

Front 74

What happens fo 2,3-BPG levels as an adaptation to high altitudes?

Back 74

they increase

Front 75

Does hemoglobin F have a higher or lower O2 affinity than oxyhemoglobin?

Back 75

higher since it binds BPG less strongly

Front 76

Higher temps would shift the curve in which direction?

Back 76

to the right, enhancing transport

Front 77

What is the type of interaction between the alpha1-beta1 (or alpha 2 beta2)?

Back 77

tight hidrophobic bonding with little movement of the two chains with respect to each other

Front 78

Are specific amino acid sequences important in the alpha and beta chains?

Back 78

VERY at the contacts between the chains

Front 79

Oxygenation increases or decreases 2,3-BPG binding?

Back 79

decreases

Front 80

What happens in 2,3-BPG binding?

Back 80

a negatively charge phosphate binds to six positively charged goups on the two beta chains around the central cavity of the hemoglobin molecule

Front 81

What does cross-linking of the beta chains do during 2,3-BPG binding?

Back 81

stabilizes the deoxyhemoglobin form

Front 82

What does oxygenation to the hemoglobin molecule do?

Back 82

decreases the cavity size by conformational changes and forces the 2,3-BPG out

Front 83

What happens in hemoglobin F?

Back 83

It has a different structure in the gamma chain
Serine replaces histidine
Reduces the positive charge of the cavity
Holds 2,3-BPG less tightly

Front 84

T/F Oxygenation makes hemoglobin a weaker acid

Back 84

False Stronger (reverse of the bohr effect)

Front 85

What are three groups that show a decrease in pK upon oxygenation?

Back 85

1. the C-terminal histidines-146 of the beta chains
2. Histidines-122 of the alpha chains
3. The N-terminal valines-1 of the alpha chains

Front 86

Oxygen increases or decreases the binding of carbon dioxide as carbaminohemoglobin?

Back 86

Decreases

Front 87

Carbond dioxide binds to what part of the beta chain?

Back 87

the n-terminal (valine)

Front 88

How much greater is the CO2 binding for deoxyhemoglobing compared to oxyhemoglobin?

Back 88

3 times greater, which is important to get CO2 out of the body