Protein function

Question 1

Defense

Answer 1

antibodies recognize and bind to pathogens

Question 3

communication

Answer 3

hormone like insulin maintain shape travelling through blood to regulate blood glucose level

Question 4

Catalysis

Answer 4

alpha amylase begins digestion of starch in saliva
by binding to carbohydrate chain and break into 2 to 3 glucose units

Question 5

Transport

Answer 5

calcium pump reduce calcium level in muscle cell
ATP cause change in shape of transmembrane part of pump = calcium push down the channel

Question 6

Storage

Answer 6

Ferritin stores iron which allow iron movement
hollow space with iron atoms attached to inner wall
store iron in non toxic form

Question 7

Structure

Answer 7

collagen form strong triple helix for structural support

Question 8

Oxygen storage and transport

Answer 8

hemoglobin as oxygen carrier in blood stream

Question 9

Myoglobin

Answer 9

single polypeptide
non polar, polar, charged cannot bind O2 in terms of reactivity or chemical structure
globins require cofactor like prosthetic groups

Question 10

Hemogloin

Answer 10

tetramer
dimer of dimer bc 2 alpha 2 beta subunits
myoglobin beta alpha superimposed on each other

Question 11

prosthetic group

Answer 11

organic components that permanently associate with proteins needed for function

Question 12

Heme

Answer 12

contain porphyrin ring that act as oxygen binding site since R groups alone cannot bind

Question 13

Porphyrin ring

Answer 13

hydrocarbon containing iron that serve as binding site for oxygen
coordinate compounds can have more than 4 bonds
5th position bind to his and 6th for O2

Question 14

Carbon monoxide

Answer 14

strong competitor of O2 and has better affinity with globins than O2 but heme and CO binding assumes 90 orientation but histidine blocks this limiting orientation only possible at 120 angle favoring O2
asphyxiation can still happen at high CO concentration

Question 15

Myoglobin oxygen binding

Answer 15

hyperbolic
as concentration increase = concentration of bound O2 increase
when plateau saturation is reached no more available binding site = amount of bound O2 cannot increase

Question 16

Hemoglobin oxygen binding

Answer 16

sigmoidal there is slight delay bc tetramer has low affinity for O2
binding coopeative binding/ positive allosteric effect once first O2 binds it transitions to oxy/ relax state allowing succeeding O2 to bind with ease
this does not happen in myoglobin bc single peptide