proteins amino acids - 2

Question 1

where are the hydrogen bonds in a beta sheet ?

Answer 1

between the peptide bonds

Question 2

whats stronger arrangement , parallel or antiparallel ?

Answer 2

antiparallel as bonds are better aligned and stronger.

Question 3

whats the arrangment of the side chains in a beta sheet ?

Answer 3

they stick out the front and face behind

Question 4

what determined if an amino acid reside becomes a helix , sheet or turn conformation ?

Answer 4

the side chains

Question 5

whats the role of PRO and GLY

Answer 5

PRO causes a turn in chain while GLY tucks in

Question 6

what is the tertiary structure ?

Answer 6

the final 3D shape of a protein

Question 7

what occurs during the packing together of the sections in a protein ?

Answer 7

it excludes solvent molecules from the interior

Question 8

in helix to helix packing what is mainly involved ?

Answer 8

the side chains that stick out from the helix surface

Question 9

in helix to sheet packing what is the tendency of the axes ?

Answer 9

tend to be nearly parallel

Question 10

in sheet to sheet packing what are the 2 main possibilities ?

Answer 10

aligned or orthogonal

Question 11

explain aligned

Answer 11

face to face packing of 2 sheets

Question 12

explain orthogonal ?

Answer 12

this is when one sheet folds back on itself

Question 13

what two bonds help to stabalise the tertiary structure ?

Answer 13

disulfide bridges between adjacent strands and hydrogen bonds between peptide bonds and side chains

Question 14

what are the domains like in large proteins ?

Answer 14

these are compact local folded regions of the polypeptide that have functions specific to each domains

Question 15

what is a quaternary structure ?

Answer 15

contains 2 or more subunits that are folded to give a complex , sub units are held together by h bonds and disulphide bridges

Question 16

are the subunits identical?

Answer 16

can be but also be different

Question 17

whats the 2 groups of proteins ?

Answer 17

fibrous and globular

Question 18

whats the role of fiborous proteins ?

Answer 18

they are long proteins that are mainly have a structural role in cell i.e keratin and collagen

Question 19

what is a globular protein ?

Answer 19

this is when theres a mixture of short helices and sheets , mainly water soluble

Question 20

features of collagen ?

Answer 20

it is rigid , fibrous composed of 3 helixes

Question 21

the collagen fibres pack together to form what and how is it stabilised ?

Answer 21

a collagen fibril is stabilised by hydrogen bonds

Question 22

what structure are prosthetic groups found in ?

Answer 22

tertiary

Question 23

what is tropocollagen ?

Answer 23

this is a glycoprotein , that has sugars glucose and galactose linked to its chains