topic 1 - ATP

Question 1

what is respiration

Answer 1

the process, which occurs in living cells, that releases energy stored in organic molecules such as glucose

Question 2

what does ATP stand for

Answer 2

adenosine triphosphate

Question 3

what is used to make ATP

Answer 3

the energy released from glucose in respiration as a cell can’t get its energy directly from glucose

Question 4

what is ATP made from

Answer 4

the nucleotide base adenine, combined with a ribose sugar and three phosphate groups - it’s what’s known as a nucleotide derivative as it’s a modified form of a nucleotide

Question 5

where is the energy in ATP stored

Answer 5

in high energy bonds between the phosphate groups

Question 6

how is ATP released

Answer 6

via hydrolysis reactions

Question 7

what is the first step to how ATP is made and used

Answer 7

when energy is needed by a cell, ATP is broken down into ADP (adenosine diphosphate) and Pi (inorganic phosphate)

Question 8

what is the second step to how ATP is made and used

Answer 8

this is a hydrolysis reaction - a phosphate bond is broken and energy is released, the reaction is catalysed by the enzyme ATP hydrolase

Question 9

what is the third step to how ATP is made and used

Answer 9

ATP hydrolysis can be ‘coupled’ to other energy requiring reactions in the cell - meaning the energy released can be used directly to make the coupled reaction happen, rather than being lost as heat

Question 10

what is the fourth step to how ATP is made and used

Answer 10

the released inorganic phosphate can also be put to use - it can be added to another compound (known as phosphorylation) which often makes the compound more reactive

Question 11

what is the fifth step to how ATP is made and used

Answer 11

ATP can be re-synthesised in a condensation reaction between ADP and Pi - this happens during both respiration and photosynthesis and is catalysed by the enzyme ATP synthase