lecture 2 - proteins

Question 1

what is an acid

Answer 1

• proton donor

- IN equilibrium with its conjugate base

Question 2

What is a zwitter ion?

Answer 2

H from the carboxylic acid group transferred to the amine group

Question 3

What happens to amino acids in a low pH ?

Answer 3

positive charge

Question 4

What happens to amino acids in a high pH ?

Answer 4

negative charge

Question 5

How to determine isomers by optical rotatio?

Answer 5

Rotates light one way or another depending on their chirality . Can rotate + or -

Question 6

Why is wine important with L and D isomers?

Answer 6

Find gritty parts. When you optically rotate, no change in light direction , therefore racemic

Question 7

who discovered the isomers of tartaric acid with wine crystals?

Answer 7

Louis Pasteur in 1849

Question 8

What is the Fisher convention?

Answer 8

Chiral centres assigned to D or L configuration by comparison with glyceraldehyde

Question 9

What is the Cahn - Ingold - Prelog system?

Answer 9

Substituent atoms assigned priority by atomic number

Question 10

why are isomers important?

Answer 10

wrong shape means no reaction and enzymes are nearly always geared to recognise the d -form of sugar and the L - form of amino acids =