Amino acids proteins and DNA

How many hydrogen bonds between A and T

2

How many hydrogen bonds between G and C

3

State how amino acids can be made visible

Ninhydrin

State why each amino acid has a differnt Rf value

Each amino acid has diffferent solubility/attraction to the stationary and mobile phases

What structure does a zwitterion have vs HIGH ph and LOW ph

H3N+ amd COO-

High PH-acts as an acid

NH2 and COO- including H on any R groups

Low PH-acts as a base

NH3+ and COOH

Explain how a structural feature of this enzyme enables it to catalyse isomer G but not F

Enzyme has a specific tertiary structure and active site shape

So is only complementary and binds to enatiomers G

State the meaning of the term complementary

Two strand base sequences which match

Adenine to thymine and cytosine to guanine

Draw a nucleotide containing guanine with all correct bonds shown

Suggest one way in which cisplatin can be administered so side effects minimised

Small doses

Explain the origin of the hydrogen binds in the secondary structure

Nitrogen is more Electronegative

So C=O and N-H bonds polar

Hydrogen bondss form between O-H

Lone pair on O attracted to H partially positive

State and explain one risk associated with the use of cisplatin

Kill healthy cells

Attach to dna in normal cells

After cisplatin enters a cell one chloride ligand is replaced by a water molecule to form complex ion

Give equation

[Pt(NH3)2 Cl] + H20—→ [Pt(NH3)Cl(H20)]+ +Cl-

Where do hydrogen bonds form between adenine and thymine

NH2 adenine and O thymine

N adenine and NH2 thymine

Where do hydrogen bonds form between guanine and cytosine

H2N guanine and O cytosine

HN guanine N cytosine

O guanine and NH2 cytosine