Proteins

Question 1

Describe the formation of an Amino Acid

Answer 1

he side group consisting of RCH

An amino group consisting of NH2 which is bonded to the left of the C in the side group

A carboxyl group consisting of COOH which is bonded to the right side of the C in the side group

Question 2

How many naturally occurring AAs are there and what’s the difference between them

Answer 2

20

They all have different side groups- The R changes

Question 3

How are di/polypeptides formed

Answer 3

A condensation reaction between the carboxyl group of one Amino Acid and the amine group of another

Removes a water molecule and joined by a peptide bond

Question 4

What bond joins two amino acids

Answer 4

Peptide bond

Question 5

Describe the primary structure of protein

Answer 5

The sequence or order of AAs which make up the polypeptides of a protein

Linear chain of AAs joined by peptide bond and each has a different order of AAs

Question 6

Describe the secondary structure of protein

Answer 6

The particular folding of a chain of AAs in the polypeptide of a protein

Question 7

What are the two types of folds seen in a secondary structure of protein

Answer 7

helical and sheets

Question 8

What causes folding in a protein’s secondary structure to be helical

Answer 8

H-bonding forms between -COOH and -NH2

Question 9

What causes folding in a protein’s secondary structure to be sheets

Answer 9

H-bonding forms between -COOH and -NH2

Question 10

Describe the tertiary structure of protein

Answer 10

The particular folding of a whole polypeptide chain as determined by amino acids that make up the polypeptide

Bonding between the R-groups

Question 11

What times of bonds can form in the tertiary structure of protein and where

Answer 11

Hydrogen bond between O-H

Ionic bond between NH3-O

Disulphide bridge between S-S

Question 12

Describe the quaternary structure of a protein

Answer 12

2 or more polypeptide chains linked together in a precise structure and sometimes associated with a prosthetic group

Question 14

Describe how AAs join to form a polypeptide so NH2 is at one end and COOH is at the other end

Answer 14

one NH2 group joins a COOH group forming a peptide bond

there is a free NH2 at one end and a free COOH group at the other

Question 15

Describe a food test to confirm the presence of protein in a solution

Answer 15

Add biuret reagant to get a positive result of lilac

Question 16

Describe ways that Dipeptides are similar

Answer 16

Amine group at each end
Carboxyl group at each end
Two R groups
All contain C H N and O

Question 17

Describe ways that dipeptides differ

Answer 17

Different R groups