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Flashcards in Principles Biochemistry Deck (25):
1

primary protein structure?

a sequence of amino acids

2

secondary protein structure and the 4 subtypes

a polypeptide backbone structure
1. alpha helix

2. beta sheets 1 - can involve >1 chain

3. beta sheets 2 - repeated zig zag antiparrallel structure

4. triple helix - 2 left handed helical chains twisted round each other

3

tertiary protein structure and the 2 types

3D structure of polypeptide
1. fibrous (collagen)
globular (haemoglobin)

4

quaternary protein structure

special arrangement of polypeptide chains with multiple (non-protein) subunits

5

which RNA polymerase synthesises all mRNA

Pol II

6

what does Pol II require to enable transcription to occur

TFIID

7

what are the 3 tRNA binding sites that ribosomes have

Exit
Peptidyl
Aminoacyl

8

what is a cofactor

a metal ion forms a coordination centre in the enzyme
most enzymes need a cofactor to function properly

9

what is an apoenzyme

enzyme without co factor

10

what is a holoenzyme

enzyme with a co factor

11

what is Km

the substrate conc when the reaction rate is 1/2 maximal

12

what is Vmax

the max rate achieved by the system

13

what happens to Vmax and Km in non-competitive inhibition

Vmax is varied
Km is unchanged

14

what happens to Vmax and Km in competitive inhibitor

Vmax unchanged
Km varied

15

what does the Warburg effect suggest

instead of fully respiring in presence of adequate oxygen, cancer cells FERMENT

16

advantages of warburg effect

rapid energy production
rapid cell proliferation

17

disadvantages of warburg effect

H+ and lactase as end products
high glucose consumption, very inefficient ATP synthesis

18

where are all but one of the enzymes of the TCA cycle located

the matrix of the mitochondria

19

what is the name of the one enzyme in TCA cycle located outwith the matrix of mitochondria

succinate dehydrogenase enzyme (located in inner mitochondrial membrane)

20

what are the 2 stages of oxidative phosphorylation

1. electron transport
2. ATP synthesis

21

what is the point of oxidative phosphorylation?

energy from the oxidation of NADH and FADH2 to NAD and FAD is used to pump protons from mitochondrial matrix into inter membranous space

the protons then flow back across the membrane, and this flow is used to phosphorylate ADP to ATP

22

what is gained from each TCA cycle

3NADH
1FADH2
2CO2
GTP

23

what are the 3 control points in glycolysis

1. hexokinase - controls substrate entry
2. phosphofructokinase - controls rate of flow
3. pyruvate kinase - controls product exit

24

what is the role of phosphofructokinase

phosphorylates fructose 6-phosphate, which eventually becomes pyruvate

25

what is the role of pyruvate dehydrogenase complex

catalyses the oxidative decarboxylation of pyruvate to acetyl - CoA

a complex of 3 enzymes allosterically regulated by phosphorylation