Proteins

Question 1

2-amino acid condensation reaction

Answer 1

2-amino acids contain amino and carboxyl functional groups, and can undergo condensation reactions with each other to produce peptides joined by an amide group (peptide bond).
Two amino acids produce a di-peptide
Water is also a product

Question 2

Polypeptides

Answer 2

A polymer made from many amino acids

Question 3

Polypeptide hydrolysis

Answer 3

Polypeptide reacts with water. Reversal of condensation reaction

Question 4

Proteins

Answer 4

Biopolymers that have many different functions.
Enzymes, structural, hormones, transport

Question 5

Primary Protein Structure

Answer 5

Sequence of amino acids
The specific sequence of amino acids in the peptide chain including number, type and sequence.

Question 6

Secondary Protein Structure

Answer 6

Localised folding of a protein chain due to hydrogen bonding between the oxygen on the carbonyl group of one amino acid, and the hydrogen on the carbonyl group of the other amino acid. Can be Alpha Helix or Beta-Pleated Structure.

Question 7

Alpha Helix

Answer 7

Molecule coils into a spiral shape due to a hydrogen bond between an oxygen on one amino acid, and a hydrogen four amino acids down the chain

Question 8

Beta-Pleated Sheet

Answer 8

Sections of the peptide chain line up parallel to each other due to hydrogen bonds between adjacent parts of the chain

Question 9

Tertiary Structure

Answer 9

The overall 3-D shape of the protein due to different functional groups in the R groups interacting, causing proteins to fold in places.

Question 10

Quaternary Structure

Answer 10

Two or more polypeptide chains interact to produce a larger unit

Question 11

Enzymes

Answer 11

Proteins that behave as biological catalysts to lower activation energy.
Very specific actions - holding molecules in correct orientation, providing acidic/basic sites to catalyse steps of a reaction
Shape-dependent - a change in temp or pH can denature enzyme by interfering with forces within the quaternary structure

Question 12

Isoelectric Points

Answer 12

The pH of a solution at which the net charge of an amino acid is 0

Question 13

Low pH Solution (Below Isoelectric Point)

Answer 13

Zwitterion becomes positive as hydrogen ions attach to negative carboxyl site

Question 14

High pH Solution (Above Isoelectric Point)

Answer 14

Zwitterion becomes negative as hydroxide ions attach to positive amino site