Proteins

Question 1

Protein structure

Answer 1

Non-branching polymers

50 - 100Å

Question 2

1 Å =

Answer 2

10^-10 m

Question 3

Protein bonds

Answer 3

Peptide - covalent bond
2 cysteine = covalent bond = disulfate
Stabilses

Question 4

Cell signalling

Answer 4

Insulin (uptake glucose)

Question 5

Digestion

Answer 5

Trypsin (breakdown protein)

Amylase (starch to sugars)

Question 6

HIV protease

Answer 6

HIV replication

Question 7

Immune protection

Answer 7

Antibodies

Question 8

Replication and Maintainance

Answer 8

DNA and RNA polymerase

Question 9

Metabolism

Answer 9

Alcohol dehydrogenase (ethanol)
Hexokinase (add phosphate to glucose)
Hemoglobin (O2 transport)
ATP synthase

Question 10

CORN

Answer 10

L - most dominant

Clockwise

Question 11

Non - polar amino acid side chains

Answer 11

Methyl
-SH
-H
Aromatic
methyl + S
Imino acids

Question 12

Negatively charged polar a.a

Answer 12

-COO-

Question 13

Postively charged polar a.a

Answer 13

-NH3+
=NH2+
=NH+ -

Question 14

Uncharged polar a.a

Answer 14

-OH

Amino & carboxyl charges

Question 15

Peptide bond

Answer 15

Planar, trans, rigid

Alpha C on oppo sides

Question 16

Primary

Answer 16

Amino acid sequence

Question 17

Secondary

Answer 17

Local folding

3D arrangement of short adjacent a.a residues

Question 18

Tertiary

Answer 18

3D complete protein

Question 19

Quaternary

Answer 19

Multi subunit protein

Question 20

Alpha helix breakers

Answer 20

Glycine - too flexible

Proline - introduce a sharp turn

Question 21

Alpha helix reside/turns

bonding

Answer 21

3.6 residues/turn

h-bond b/w n and n+4

Question 22

Alpha helix angles

Answer 22

ɸ = ~-57
Ψ = ~-47

Question 23

Beta structure

Answer 23

Adjacent peptide chains - H bonding
Pleated
Parallel/antiparallel

Question 24

Beta sheet numbers

Answer 24

2 - 10 strands per sheet

Strand length = 6 - 15 residues

Question 25

Turns

Answer 25

High in Gly, Pro | H - bonds (stability)

Question 26

Turns numbers

Answer 26

3 - 4 residues | 33% residues in turns

Question 27

Function relates to

Answer 27

A.a sequence Higher order Structure

Question 28

ɸ

Answer 28

N - C⍺ | O - O collisions

Question 29

Ψ

Answer 29

C⍺ - C' (C'=O) | NH - NH collisons

Question 30

ω

Answer 30

Around peptide bond

Question 31

Supersecondary structures

Answer 31

``` Secondary structure + turns/loops/coils Helix - turn - helix β - hairpin Greek key Strand - helix - strand ```

Question 32

Domains

Answer 32

``` Hydrophobic core (stablises protein) Hydrophilic parts in contact with solvent ```

Question 33

Domain types

Answer 33

⍺ - domain (mostly helical) ⍺/β domain Anti-parallel β domain

Question 34

Protein folding instructions

Answer 34

In a.a sequence Proven by Afinsen Directed by internal hydrophobic residues, form core, hydrophilic exposed

Question 35

Afinsen's experiment

Answer 35

Native ribonuclease Denature Given essential componants Reformed

Question 36

Stablisation of Folding

Answer 36

Non - covalent interactions Covalent bonds Hydrophobic core

Question 37

Non - covalent interaction examples

Answer 37

van der Waals interactions | H - bonds

Question 38

Assistance by Chaperones

Answer 38

- independent - dependent Chaperonin - dependent

Question 39

Misfolding protein

Answer 39

Prions Other may induce misfolding ⍺ -> β

Question 40

Amino acid modification

Answer 40

``` Phosphorylation Hydroxylation Carboxylation Metal binding Iodination Glycosylation ```

Question 41

Phosphorylation

Answer 41

Control enzyme activity

Question 42

Hydroxylation

Answer 42

Prevent connective tissue diseases

Question 43

Carboxylation

Answer 43

Blood clotting

Question 44

PKA definition

Answer 44

The pH at which the group is 50% ionized (of ionizable group on an amino acid or protein)

Question 45

Pl definition

Answer 45

pH at which the net charge on an amino acid (or protein) is zero

Question 46

Sequence of protein folding

Answer 46

1) Formation of short secondary structure segments 2) Nuclei come together, form domain 3) Domains come together (tertiary structure partly disorganised) 4) Adjustments give compact native structure (tertiary)