Biochemistry Test 2: Special Functions Of Proteins

Front 1

Protein 4 prime structure

Back 1

Arrrangmetn of 2 or more polypeps together
Each component is a subunit of an oligomer
2 subs=dimer, 3=trimer
Each subunit has a 3 prime structure
Oligomers could be identical or different
Joined together by non covalent bonds

Front 2

Hemoglobin normal subunits

Back 2

4 units of 2 types
alpha, and beta

Front 3

aspartate decarboxylase

Back 3

12 subunits of 2 types
alpha and beta

Front 4

lactate dehydrogenase

Back 4

4 subunits of 2 types coded by 2 diff genes
subunits all have the same function so they are designated by normal letters.
Combos of H and M

Front 5

Phosphorylase b Kinase

Back 5

Very large
16 subunits of 4 types
alpha, beta, gamma, sigma

Front 6

Immunoglobin G

Back 6

4 subunits of 2 types
gamma and kappa

Front 7

Shape of Hb

Back 7

Needs to be able to bend and flex in order to squeeze through capillares
Sickle cell makes it less flexible and clogs capillaries

Front 8

Hb function

Back 8

O2 transport
the dissolved O2 = the arterial PO2

Front 9

Prosthetic group of Hb

Back 9

Heme with one per fold = 4 in normal Hb

Front 10

Structural components of Hb

Back 10

Globin chains are the protein and four hemes

Front 11

Heme

Back 11

Prophyrin ring that holds iron/ Iron insertion causes the protoporphyrin to change into ferroporphyrin

Front 12

Hem and globin

Back 12

both are needed to for the O2 binding site

Front 13

Hb subunits and sickle cell

Back 13

Adults have alpha and beta
Fetus has Gamma and alpha. gamma by itself is poor transporter but with alpha it is much higher O2 affiinity
Attempt to stimulate this gene to combat sickle cell.
There are no fetal tests for sickle cell because gamma is there and the defect is in beta. Sickle cell is a 6 point mutation from glu to val

Front 14

Thalessemia(anemia)

Back 14

Diminished production fo alpha or beta chains leads to unstable Hb. Alpha 2 is a silent carrier, 1 gives mild anemia. HbH is moderate to severe anemia. Hydrops fetalis is death in utero

Front 15

Hb Barts

Back 15

A four genes deletion in alpha thalessemia. No alpha chain is produced. Epsilon gene compensates for a while until it turns off and only gamma is left. Then the fetus dies cause it doens't get enougn O2

Front 16

RBC and Hb synthesis and degradation

Back 16

Erythropoietin stimulates RBC synthesis. Released in response to hypoxia from teh kidneys.
RBC degrades into Bilirubin in the liver

Front 17

Components of porphyrin ring

Back 17

glycine and succinyl CoA

Front 18

RES

Back 18

Reticuloendothelial system that destroys RBCs

Front 19

Globin fold structure

Back 19

Made of 8 alpha helices

Front 20

Heme prosthetic group

Back 20

4 N atmos of imadazole rings hold the ferrous iron. Hisitidine do the work by binding O2 and changing the shape of the globin.

Front 21

Oxidation states of Hb

Back 21

are the same for oxy and deoxy Hb. They change in poisoning in forms of met-Hb and cyano-Hb

Front 22

Allosteric effectors of Hb

Back 22

Shift the binding curve right
H+, CO2, 2-3BPG, CL-

Front 23

Bohr effect

Back 23

High acidity = more O2 delivery(think about exercise and lactic acid)
Hb buffering capacity because deoxyHb is a weak acid.

Front 24

2-3BPG effect

Back 24

Binds to Hb and facilitates the release of O2 from Hb.

Front 25

Chloride effect and O2

Back 25

Interacts with Hb side chains and decrease the O2 affinity by stabilizing the ionic side chain interactions of deoxyHb

Front 26

Hill coefficient

Back 26

Degree of cooperative binding between subunits. for myoglobin it's 1 because only one subunit. For Hb its 2.8. P50 for Hb is 26 Torr and the P50 for myglobin is 2 torr

Front 27

Acidosis

Back 27

Transfers more O2 to the tissues

Front 28

CO poisoning

Back 28

Binds the O2 sites with higher affinity than O2. The remaining sites have a higher affinity and O2 is not released into the tissue

Front 29

Bohr/haldane effects

Back 29

Balance the CO2 and protons in teh lung tissues