Lecture 3: Proteins Intro

Question 1

What are proteins polymers of?

Answer 1

A specific sequence of amino acids joined together by chemical bonds called peptide bonds

Question 2

How many standard amino acids are there?

Answer 2

20 different amino acids, order and length can vary protein function

Question 3

What is the name of the bond that links amino acids in the polypeptide chain?

Answer 3

Peptide bonds

Question 4

Does each protein have a unique sequence of amino acids? Explain.

Answer 4

Yes, each proteins sequence and length of A.A varies which determines shape and function

Question 5

What are the main techniques used to determine protein structure?

Answer 5

• Protein crystallography
• Cryo-electron microscopy
• NMR spectroscopy

Question 6

Name a protein that is involved in DNA replication:

Answer 6

DNA polymerase: binds to one strand of DNA and adds the complementary strand to it

Question 7

Name a protein that is involved in RNA replication:

Answer 7

RNA polymerase: creates a single strand of RNA that is complementary to one of the strands of DNA

Question 8

Name a protein that is involved in oxygen transport:

Answer 8

Haemoglobin:
Haemoglobin binds oxygen in the lungs and carries it in the blood to tissues for use in metabolism.

Question 9

Name a protein that is involved in immune protection:

Answer 9

Antibody:
Antibodies bind to antigens found on cellular invaders like bacteria and viruses. Antibody binding to antigens can help protect the body from infections.

Question 10

Name a protein that is involved in digestion:

Answer 10

Trypsin:
Trypsin is an enzyme that breaks down proteins during digestion.

Amylase:
Amylase is an enzyme that breaks down starch into sugars. It is found in saliva as well as pancreatic juices

Question 11

Name a protein that is involved in metabolism:

Answer 11

Alcohol dehydrogenase:
Alcohol dehydrogenase is an enzyme that helps to metabolise ethanol.

Hexokinase:
Hexokinase is an enzyme that adds a phosphate to glucose, after glucose is taken up by the cell

ATP synthase:
ATP synthase is a membrane protein that generates ATP for use in cellular functions.

Question 12

What does a kinase do?

Answer 12

Kinases are enzymes that usually add phosphate to molecules

Question 13

What does a protease do?

Answer 13

Enzymes that breakdown proteins are called proteases