3.1 Importance Of ATP

Question 1

What is ATP

Answer 1

Adenine triphosphate

The universal energy carrier found in all living cells

Question 2

Where is ATP produced

Answer 2

ATP is synthesised on the internal membranes of mitochondria and chloroplasts

Question 3

Describe how ATP is synthesised

Answer 3

• Involves ATP synthase, an enzyme found embedded in cellular membranes
• ATP synthase phosphorylates ADP to form ATP as protons flow through it

Question 4

Compare the flow of protons across the mitochondrial and chloroplast membranes

Answer 4

• mitochondrial membrane: H+ flow from the inter membrane space into the matrix, across the inner membrane
• Chloroplast membrane: H+ flow Tom the thylakoid space into the storms, across the the thylakoid membrane

Question 5

Define chemiosmosis

Answer 5

The synthesis of ATP through the movement of protons down their electrochemical gradient across a semi-permeable membrane, catalysed by ATP synthase

Question 6

How is the proton gradient maintained during chemiosmosis

Answer 6

There is a higher concentration of H+ ions in the inter-membrane space

Question 7

What is the electron transport chain?

Answer 7

A series of electron carrier proteins that transfer electrons in a chain of oxidation-reduction reactions, releasing energy.

Question 8

What colour change is observed when DCPIP is reduced?

Answer 8

Dark blue or colourless

Question 9

How can dehydrogenase activity be investigated?

Answer 9

Using artificial hydrogen acceptors such as DCPIP, methylene blue and tetrazolium compounds.

Question 10

What colour change is observed when methylene blue is reduced ?

Answer 10

Dark blue or colourless