test 2: HB and Mb part 2

Question 1

what is a protein family

Answer 1

evolutionaryily related proteins
globin fam

Question 2

what does a hyperbola mean of cooperativity and sigmoidal

Answer 2

hyperbola = no cooperativity
sigmoidal = coopeativiity

Question 3

what is the allosteric effect

Answer 3

binding at one site affects binding at others

Question 4

how many subunits are required for allosterism

Answer 4

more than 1 subunit

Question 5

what does the S curve indicate

Answer 5

allosterism

Question 6

what is HOMOtropic allosteric interaction

Answer 6

effector and ligand are regulated by the same molecule
O2 and Hb

Question 7

what is heterotropic allosteric interaction

Answer 7

effector and liganrd are differnt

Question 8

what is an activator and what is an inhibitor

Answer 8

• activator shifts the eq toward R state= positive interaction
  inhibitor shifts towards the T state meaning - interaction

Question 9

descrube Hb oxugen affinity

Answer 9

starts out high but then FAVORS T state in the eq between T and R

Question 10

what does BPg, h+ and co2 favor

Answer 10

tense low affinity

Question 11

what are BPG,H+ and Co2 involved in

Answer 11

the Bohr effect

Question 12

what does O2 favot

Answer 12

relaxed state

Question 13

what is the bohr effect

Answer 13

• increased temp = release of O2 from Hb
• increase Co2, increase H+, increasing temp = release of O2 = decrease in affinity of H2

Question 14

what happens to the curve if the affnity is decreased

Answer 14

curve shifts to the right

Question 15

what happens withn
Temp increase
ph increase (basic)
co2 decrease

Answer 15

curve shifts to the left

Question 16

how does temperature increase affect Hb affinity

Answer 16

high temp like fever will cause Yo2 to decrease wh

Question 17

where on T state do Bohr protons bind

Answer 17

• N terminal amino gprps and His 146 betal

Question 18

what amino group is responsiblel for 2-30% of the bohr effect

Answer 18

N terminal amino groups

Question 19

what happens to the pka during transition

Answer 19

changes the pka causing them to release coordinated H

Question 20

how much does his 146 account for bohr effect

Answer 20

40

Question 21

what protons ar released when Hb binds O2

Answer 21

H+ protons

Question 22

where on the T state does CO2 bind

Answer 22

-N terminal amino groups and it can form carbamates
- not present in the R state

Question 23

what metabolism is O2 apart of

Answer 23

aerobic

Question 24

oxidizing carbon cpds releases whawt

Answer 24

energy and O2 consume, CO2 is made

Question 25

is Co2 soluble in plasma

Answer 25

nowhat

Question 26

does cabonic anhydrase do

Answer 26

makes CO2 soluble by catalyzing the reaction

Question 27

how does carbonic anhydrse relate to pH

Answer 27

helps buffer blood at pH of 7.4

Question 28

how is carbonic anhydrase related to the bohr effecr

Answer 28

- increases H+ conc bc CO2 is converted to bicarbonate - conformational changes stabilizing the tense (T state)

Question 29

what do the lungs facor

Answer 29

decrease H+, increase in pH = lungs = R state

Question 30

what do the capillaries favor

Answer 30

- T state - high H+, low pH

Question 31

what is the most abundant organic phosphate in blood

Answer 31

2,3 BPG and it is made in glycolysis

Question 32

what does BPG do

Answer 32

- binds to T state and stabilizes it - shifts equ. toward T STATe

Question 33

can BPG bind to the R state

Answer 33

no it can't

Question 34

how is BPG helping with high altitude

Answer 34

- body increse BPG decreased pO2 - increase = more oxygen is being released to the tissues

Question 35

what does BPG do to Hb

Answer 35

- gives Hb a p50 of 26 and without BPG it is 12 torr - fine tines Hb O2 binding capability ( without it O2 delivery would be bad)

Question 36

what other allosteric effector causes O2 to release

Answer 36

Cl-what

Question 37

what is the role of Cl-

Answer 37

- netraulize the RBC electrosatic potential - binds to doexy Hb( causes O2 release) = chloride shift

Question 38

out of bPG, H+. CO2, Cl- and O2 what is the homotropic effector

Answer 38

O2

Question 39

what is the hill equation

Answer 39

E + nS = Es E= enzme S= substrate n = number of S mlcls bound

Question 40

what does the farctional saturation ys =

Answer 40

bound total n(Esn)/n(E+ESn)

Question 41

what does the slope of the hill coefficient show

Answer 41

the degree of cooperativity

Question 42

if n = 1. n>1, n<1

Answer 42

1. n = 1 means non cooperative n>1 means positive coop n< 1 means negative coop

Question 43

for Hb what is cooperative

Answer 43

n is close to 3

Question 44

if 1 o2 binds...

Answer 44

the rest binds, and if 1 is released the rest are released

Question 45

what is the concerted model for allosteric proteins

Answer 45

1. eq between t and r states 2. ligand bind to either conform 3. ligand absent = T state 4. binding of ligand shifts toward R state

Question 46

what is a limiattion of the concerted model

Answer 46

only shows positive cooperativity

Question 47

what is the induced fit model

Answer 47

- subinits can exits in T or R - presence of R = increased affnity - T to R is sequential process - accounts for both + and - cooperativity

Question 48

what are some effects of mutations on the protein

Answer 48

- inheritable or genetic diseases - core of protein: affect the function and structure

Question 49

how can mutations be good for Hb

Answer 49

- stabilize Metmoglobin like Hb boston - Fe+3 form is stabilized = O2 binding eliminated -cyanosis- blood is blue to chocolate brown

Question 50

describe pathological mutaions at surface of Hb

Answer 50

- not as dangerous ' - Hbe( glu 26 on beta chains turn to lys) no effect

Question 51

what can be a harfmul mutation

Answer 51

- Hbs sickle cell anemia Glu6 on beta to val

Question 52

what is similar about HBs and HbA

Answer 52

- same O2 binding - 4 hemes iron in Fe+2 same active site

Question 53

Hbs pathology

Answer 53

- E to V in beta chain making Hbs more hydrphobuc - ONLY IN T STATE( val fits into the pocket ) linear polymers

Question 54

what happens when Hbs loses O2

Answer 54

- Hbs starts to polymerize - polymersization causes blood cells to sickle - sickle = block capillaries and blood flow

Question 55

benefit of hBS gene

Answer 55

- protection from maleria