Biochemistry: protein structure & DNA

Question 1

describe the primary structure of proteins

Answer 1

the amino acid sequence

Question 2

describe the secondary structure of proteins

Answer 2

the shape of the backbone
alpha-helix, beta sheets, triple helix
hydrophobic bonds

Question 3

describe the tertiary structure of proteins

Answer 3

3D structure including side chains

fibrous or globular

Question 4

what bonds/forces are in tertiary structure of proteins

Answer 4

covalent disulphide bridges, hydrophobic interactions, electrostatic interactions, hydrogen bonds, complex formation with metal ions

Question 5

describe the quarternary structure of proteins

Answer 5

spatial arrangement of protein subunits

Question 6

give an example of a protein and its structure

Answer 6

Collagen, triple helix, inter-chain H bonds, and intra- inter-molecular covalent bonds

Question 7

how does heat disrupt protein structure

Answer 7

increases vibrations in the protein

Question 8

how does pH disrupt protein structure

Answer 8

it interrupts electrostatic interactions

Question 9

how does detergents/urea/guanidine hydrochloride disrupt protein structure

Answer 9

disrupt hydrophobic interactions

Question 10

how do thiols/reducing agents disrupt protein structure

Answer 10

disrupt disulphide bonds

Question 11

describe the backbone of DNA

Answer 11

phosphodiester backbone, bonds forming between the free 3’ OH and the 5’ triphosphate

Question 12

what does helicase do in DNA replication

Answer 12

unwinds the DNA

Question 13

what is needed to start DNA replication

Answer 13

RNA primer/polymerase

Question 14

in what direction is DNA replicated, and how is the lagging strand replicated

Answer 14

It is replicated 5’ to 3’, and the lagging strand is done in Okazaki fragments