Proteins

Question 1

What are proteins

Answer 1

Made up of monomers called amino acids

Question 2

What are the chains of amino acids called

Answer 2

Polypeptides

Question 3

What is a proteins shape determined by

Answer 3

Specific sequence of amino acid in the chain

Question 4

Draw a generalised amino acid

Answer 4

H. R. O
N - c-c
H H Oh

Question 5

List the names of the groups in a amino acid

Answer 5

Nh2 - amino group
Carboxyl group - cooh
Hydrogen atom
R group which is different in each amino acid

Question 6

How does a peptide bond form

Answer 6

Amino group of one end reacts with carboxyl group of another with the elimination of water

Question 7

When a condensation reaction of proteins happen what is formed

Answer 7

Dipeptide

Question 8

What is a primary structure

Answer 8

Order of amino acids in a polypeptide chain

Question 9

How is the primary structure determined

Answer 9

By the base sequence of one strand of the Dna molecule

Order of amino acid in polypepeptide chain

Question 10

How is the a helix of secondary structure formed

Answer 10

Shape of polypeptide chain forms as a result of bonding between double o and co groups and h on nh group forming a coil
Alpha helix or beta pleated sheet

Question 11

Structure of tertiary

Answer 11

A helix can be fooled and twisted to give more complex compact 3d structure

Question 12

How can tertiary structure be mainTained why are these important

Answer 12

Hydrogen bonds
Ionic bonds 
Disulphides 
Hydrophobic 
Give globular proteins e.g enzymes giving them their shape

Question 13

What is quarternAry structure

Answer 13

Some polypeptides are not able to function unless they are in combination. They may combine with another polypeptide molecule or associated with non protein groups and form a large comely molecule

Question 14

What does the role of proteins depend on

Answer 14

Their molecular shape

Question 15

Structure or fibrous proteins and what does this to their function

Answer 15

Long thin molecules which makes them insoluble I. Water so they have a structural feature cross link which makes them strong

Question 16

Examples of fibrous molecules in function

Answer 16

String and tough collagen is fibrous protein providing strength and toughness in the tendons
Single fibre - consists of three identical chains twisted around each other linked by hygrogen bonds making it stable tropocollagen

Question 17

What is a globular protein and structure and function

Answer 17

Compact and folded into spherical molecule makes the soluble I water
Function - enzymes , antibodies , plasma proteins, hormones
Expanse, haemoglonin consisting of four folded polypeptide chains, inside is haem

Question 18

What’s the difference between carbohydrates and lipids ?

Answer 18

Proteins always contains nitrogen as well as hydrogen and carbon also some proteins contain sulphur and some phosphorus

Question 19

Protein tests-

Answer 19

SProtein tests- blue rest regent turns from blue to purple
Cooper sulphate and react with peptide binds which cause biuret purple
Biuret in colour meter using hello filter gives an estimate of relative concentration of proteins present in sample
Detect concentration of proteins present in sample use a biosensor