4) Unit 1 - Binding Ligands

Question 1

define a ligand

Answer 1

a substance that can bind to a protein

Question 2

how do ligands bind to proteins

Answer 2

R groups not involved in the folding of a protein allow binding to ligands.

Question 3

Binding sites of a protein will have a _________ _______ & ______ to the the ligand

Answer 3

complementary shape and chemistry

Question 4

Give an example of the importance of ligand binding to the function of some proteins

Answer 4

A ligand can be a molecule that affects the activity/ function of a protein

example:
oxygen is a ligand that binds to haemoglobin, which allows it to transport oxygen around the body

Question 5

what is the name given to he proteins DNA interacts with

Answer 5

Nucleosomes

Question 6

what is the benefit of DNA interacting with proteins

Answer 6

allows massive amounts of DNA to compact tightly enough to fit into the nucleus.

Question 7

What makes it possible for DNA to interact with histones

Answer 7

DNA is negatively charged and histones are positively charged.

Question 8

a nucelosome is made from?

Answer 8

a group of 8 histones

Question 9

how is a group of histones of disassembled

Answer 9

•the tails on them are cleaved
•the histones will under go conformational change and disassemble to allow the DNA to uncoil
e..g for processes like replication

Question 10

Describe how DNA can interact with OTHER ligands (other than histones)

Answer 10

• other ligands bind to specific sequences on DNA
• when bound they can stimulate or inhibit transcription
• this is important for the control of gene expression