ATP

Question 1

describe the structure of ATP

Answer 1

• adenine purine base.. double carbon structure
• three phosphate groups
• pentose ribose sugar
• it is a nucleotide

Question 2

How does hydrolysis of ATP release energy?

Answer 2

• although breaking bonds require energy, the bond holding the last phosphate molecule is quite weak so requires little energy to break
• the liberated phosphate ion undergoes reactions and forms bonds which releases a great amount of energy
• this energy overrules the energy required to break the bond in the first place
• atp + water = adp + inorganic phosphate + water

Question 3

how is the bond between adp and inorganic phosphate formed again?

Answer 3

• using the energy produced by respiration in oxidative phosphorylation

Question 4

why is atp called the universal energy currency?

Answer 4

• it is used for energy transfer by all cells of all organisms

Question 5

why is atp not a good long term storage of energy?

Answer 5

• the bond holding the last phosphate group is weak
• fats and carbohydrates are better long term energy storage molecules
• when these are respired, the energy is used to form ATP

Question 6

Why is ATP a good immediate source of energy?

Answer 6

• ATP can be rapidly formed by the phosphorylation of ADP

- they can be interconverted

Question 7

What are the properties of ATP?

Answer 7

• it is small so it can move into, out of and within cells
• water soluble and this is important because metabolic reactions happen in aqueous environments
• easily generated so an immediate source of energy
• the bonds contain energy that is large enough to be useful for cellular reactions but not so large that energy is wasted

Question 8

What are some uses of ATP?

Answer 8

• muscle contraction so for movement
• active transport
• synthesis of polymers and macromolecules
• stimulates the breakdown of substrates in order to produce even more ATP for cellular reactions

Question 9

is the sugar in ATP ribose or deoxyribose?

Answer 9

• deoxyribose