M+C enzymes

Question 1

how do you regulate enzyme abundance?

Answer 1

feedback inhibition

Question 2

name 4 post transitional modifications

Answer 2

1) addition of functional groups
2) structural changes
3) changes to an amino acid
4) addition of proteins or peptides

Question 3

what is the advantage of PTMs

Answer 3

they increase protein diversity increasing the complexity of the proteome (cost effective)

Question 4

what are moonlighting proteins

Answer 4

when proteins have 2 or more functions

Question 5

what is a glycogen granule made up of

Answer 5

30,000 glucose units and a core protein of glycogenic

Question 6

what is the shape of a glycogen granule and the advantage of its shape

Answer 6

highly branched making it more soluble and can be degraded/synthesised much quicker

Question 7

what is a common PTM in eukaryotes?

Answer 7

kinase/phosphotase cascades acting as amplifiers adding and removing phosphate groups from proteins

Question 8

what do alpha and beta cells produce and where are they found?

Answer 8

alpha = glucagon
beta = insulin
found in the islets of langerhan in the nucleus

Question 9

what is the role of insulin?

Answer 9

decreasing blood glucose by stimulating glucose uptake and inhibiting the breakdown of glycogen and the glucose pathway

Question 10

what is the role of glucagon?

Answer 10

increases blood glucose by breaking down glycogen stores and increases the rate of glycolysis in muscles

Question 11

what is the role of adrenalin (epinephrine)?

Answer 11

hormone also involved in glucose degredation

Question 12

where is adrenaline produced?

Answer 12

the adrenal glands

Question 13

which cells have receptors for glucagon and insulin?

Answer 13

liver cells

Question 14

what is a special feature of adrenalin?

Answer 14

can cause glycogen breakdown without passing through the plasma membrane

Question 15

how is glycogen synthesis regulated?

Answer 15

by protein phosphorylation

Question 16

what are the 2 forms of glycogen synthase?

Answer 16

A) dephosphorylated and active

B) phosphorylated by protein kinase A and inactive

Question 17

what is protein kinase A activated by?

Answer 17

cyclic AMP

Question 18

what causes the formation of CAMP?

Answer 18

the binding of adrenalin or glucagon activates adenyl cyclase pathway

Question 19

what is the role of phosphodiesterase?

Answer 19

converts cAMP to AMP

Question 20

what is glycogen phosphorylase a?

Answer 20

active phosphorylated form on the enzyme that degrades glycogen

Question 21

what is glycogen phosphorylase b?

Answer 21

dephosphorylated inactive form

Question 22

what is the role of phosphorylase kinase?

Answer 22

phosphorylates glycogen phosphorylase a

Question 23

insulin produces protein phosphatase which does what?

Answer 23

dephosphorylates 3 enzymes which inactivates glycogen degradation and activates glycogen synthesis

Question 24

what are 3 features of secondary messengers?

Answer 24

1) small
2) watersoluble
3) spread easily by diffusion

Question 25

what is transduction?

Answer 25

when a small number of extracellular signal molecules are able to produce a large cellular response in a phosphorylation cascade