Protein Structure And Function

Question 1

How many different enzymes (approximately) does an e.coli cell contain?

Answer 1

2000

Question 2

What type of protein is haemoglobin?

Answer 2

A transport protein. Haemoglobin transports oxygen around the body.

Question 3

What two main things to transport proteins do?

Answer 3

Move molecules around the body and move molecules across membranes.

Question 4

What are some examples of structural proteins?

Answer 4

Fibroid -> in silk
Collagen -> in connective tissue
Keratin -> In hair, skin, and feathers

Question 5

What type of protein is a hormone?

Answer 5

Communication

Question 6

What are some examples of movement proteins?

Answer 6

Actin and myosin

Question 7

What type of proteins are antibodies?

Answer 7

Defence

Question 8

What is the basic structure of a protein?

Answer 8

Carbon in the middle, amine group, carboxylate group, and the rest of the structure

Question 9

Proteins are polymers of what?

Answer 9

Amino acids!

Question 10

Proteins fold into 3D structures stabilised by non-covalent interactions. What are these interactions?

Answer 10

Hydrogen bonds
Ionic bonds
Hydrophobic bonds

Question 11

What are hydrogen bonds?

Answer 11

Weak electrostatic bonds formed when a highly electronegative element (N, O, F, S) bond to a hydrogen. They are collectively strong.

Question 12

What are ionic bonds?

Answer 12

Electrostatic interactions between +ve and -ve charges

Question 13

What are hydrophobic interactions?

Answer 13

Non-polar sidechains cluster together excluding water and allowing H2O to form H bonds between themselves

Question 14

What are Van der Waals?

Answer 14

Weak forces between adjacent neutral atoms

Question 15

What is the primary structure of proteins ?

Answer 15

The amino acid sequence

Question 16

What is the secondary structure of proteins?

Answer 16

An alpha helix or a beta sheet.

Question 17

How is the secondary structure of proteins stabilised?

Answer 17

By hydrogen bonding

Question 18

How is the tertiary structure of proteins stabilised?

Answer 18

Hydrogen bonding, ionic bonds, hydrophobic interactions and disulphide bonds

Question 19

What is the quaternary structure of proteins?

Answer 19

The arrangement of subunits in proteins containing two or more polypeptide chains

Question 20

Protein conformation is flexible. What does this mean?

Answer 20

Proteins are not rigid, their structure can change

Question 21

What is the main way that protein conformation can be destroyed/denatured?

Answer 21

Heat!!!!

Question 22

What are protein domains?

Answer 22

An Independently stable part of a polypeptide, usually with a specific function

Question 23

How can evolution of new proteins occur (domains)?

Answer 23

Domain swopping

Question 24

An antibody will recognise a small part of an antigen, what is this called?

Answer 24

The epitope

Question 25

Protein function is regulated, what is this crucial in?

Answer 25

Homeostasis

Question 26

What are some of the functions that membrane proteins can play?

Answer 26

Cell-cell recognition, signal transduction via hormone receptors, transport