Globular Proteins

Question 1

Describe structure of hemoglobin (HbA)

Answer 1

2 alpha subunits, 2 beta subunits
Each have a heme inside which has a Fe2+ inside and an O2 inside each

Question 2

Oxygen bound hemoglobin

Answer 2

oxyhemoglobin

Question 3

non oxygen bound hemoglobin

Answer 3

deoxyhemoglobin

Question 4

CO2 bound hemoglobin

Answer 4

carbaminoglobin

Question 5

what does Hydrogen bound hemoglobin create?

Answer 5

buffer

Question 6

function of 2,3 BPG

Answer 6

regulates HbA affinity for Oxygen
binds on B subnunit for hemaglobin to unload Oxygen
Forces Oxygen unloading

Question 7

CO2 in blood causes

Answer 7

release of ions, increase in acidity, decrease in pH and shift curve to the Right

Question 8

Working muscle effect on oxygen hemoglobin dissociation curve

Answer 8

Goal is to send oxygen to the muscle (unload from hemoglobin)
decrease in pH, increase temperature, increase carbon dioxide, increase hydrogen concentration, increase 2,3 BPG (unloads Oxygen)
All causes shift right

Question 9

Bohr effect

Answer 9

Hb affinity for oxygen decreases in tissue as there is an increase of CO2

Question 9

Haldane effect

Answer 9

Hb affinity for CO2 decreases in lungs as increase in Oxygen

Question 10

What does a left shift on the oxygen hemoglobin dissociation curve correlate to ?

Answer 10

higher affinity for oxygen
Does not want to let go

Question 11

Fetal hemoglobin

Answer 11

much higher affinity for oxygen
alpha and gamma subunits

Question 12

How to treat sickle cell disease?

Answer 12

gamma subunit of fetal hemaglobin injected, induce changes to blood from mutated B subunit

Question 13

Myoglobin

Answer 13

No cooperativity in curve (one subunit)
final oxygen reserve for muscle, making it a high affinity for oxygen

Question 14

globular protein characteristics

Answer 14

spherical, water soluble, catalytic/reg/transport in metabolic function
often contain heme

Question 15

Myoglobin function

Answer 15

transport and store oxygen in skeletal and cardiac muscle cells

Question 16

hemoglobin function

Answer 16

transport oxygen, carbon dioxide, and hydrogen ions in red blood cells

Question 17

Structure of heme

Answer 17

4 rings goes from MP, MP, MP to PM (D ring shows orientation)

Question 18

Heme, CO and O2

Answer 18

CO much stronger in binding heme, creating asphyxiation
Overtime the CO binding weakens as is bent and allows Oxygen recovery

Question 19

Hemoglobin quarternary structure

Answer 19

between alpha and beta subunits, has hydrophobic interactions
Between dimers has polar bonds

Question 20

T form hemoglobin

Answer 20

tense, deoxygenated, tightly packed form with H bonds between dimers

Question 21

R form hemoglobin

Answer 21

relaxed, oxygenated, allow oxygen to enter with high affinity, poalr bonds rupture bewteeen dimers

Question 22

allosteric effects on the oxygen dissociation curve

Answer 22

partial pressure of Oxygen
pH
partial pressure of CO2
2,3 BPG
temperature

Question 23

Effect of CO2 in hemoglobin

Answer 23

10% carry as carbamate on Nterminal groups

can create T form of Hb and lead to right shift of curve as wants to offload oxygen

Question 24

binding of CO in hemoglobin

Answer 24

binds to Fe in heme shifting to R state making the tissue unable to release oxygen

Question 25

what chromosomes are important for organization of globin genes?

Answer 25

11 & 16

Question 26

hemoglobinopathies causes

Answer 26

decrease production of normal globin proteins abnormal structure of one of globin chains of Hb molecule (decrease ability to bind oxygen)

Question 27

Hemoglobin S disease

Answer 27

HbS red cell sickling, hemolytic anemia Glutamic acid to valine Screen in alkaline pH as migrate more slowly

Question 28

Hemoglobin C disease

Answer 28

HbC is variant of glutamic acid to lysine at position 6 of Beta chain

Question 29

Hemoglobin SC disease

Answer 29

compound of heterozygotes significant red cell sickling

Question 30

methemoglobinemia

Answer 30

higher than normal level of methemoglobin changes ferrous to ferric and decerases oxygen affinity

Question 31

Hepcidin

Answer 31

major regulator of ferroportin (exports Fe2+)

Question 32

important steps iron absorbtion

Answer 32

export of ferrous iron by ferroportin oxidation of ferrous iron to ferric iron load ferric iron onto transferrin clear ferroportin from membrane by hepcidin

Question 33

Transferrin receptor (TfR1)

Answer 33

transmembrane glycoprotein expresion incresaes when iron levels are low allows Fe to enter cell

Question 34

iron deficiency anemia

Answer 34

microcytic hypochromic anemia from chronic bleeding, malnutrition, or absorbtion disorder