2.3 — ATP

Question 1

what is ATP a derivative of?

Answer 1

nucleotides

Question 2

what does ATP stand for?

Answer 2

adenosine triphosphate

Question 3

what does ATP consist of?

Answer 3

1. adenine — nitrogenous base
2. ribose — pentose sugar
3. phosphates — 3 phosphate groups

Question 4

what are the uses of ATP?

Answer 4

1. movement — such as muscle contraction or for sperm cells to swim
2. active transport of molecules across the concentration gradient — such as ions entering plant roots
3. synthesis of large molecules — such as DNA and proteins
4. secretion of substances from cells — such as releasing hormones from glands

Question 5

what are some examples of ATP being used for movement?

Answer 5

muscle contraction or for sperm cells to swim

Question 6

what is an example of ATP being used for active transport of molecules against the concentration gradient?

Answer 6

ions entering plant roots

Question 7

what are some examples of ATP being used for synthesis of large molecules?

Answer 7

DNA and proteins

Question 8

what is an example of ATP being used for secretion of substances from cells?

Answer 8

releasing hormones from glands

Question 9

how can ATP activate molecules?

Answer 9

by phosphorylating them

Question 10

what is phosphorylation?

Answer 10

when ATP is hydrolysed, the phosphate can be added to other molecules, such as enzymes, to make them more reactive

Question 11

how is ATP broken down?

Answer 11

through hydrolysis

Question 12

what is hydrolysis?

Answer 12

the addition of water to break a chemical bond between two molecules

Question 13

how is ATP re-synthesised?

Answer 13

through condensation

Question 14

what is condensation?

Answer 14

the removal of water to form a chemical bond between two molecules

Question 15

what forms after ATP is hydrolysed?

Answer 15

adenosine diphophate (ADP) and an inorganic phosphate (Pi)

Question 16

what does ADP stand for?

Answer 16

adenosine diphosphate

Question 17

what enzyme catalyses the hydrolysis of ATP?

Answer 17

ATP hydrolase

Question 18

what does the hydrolysis of ATP do?

Answer 18

produces ADP and Pi alongside energy that is released and used in cells

Question 19

what enzyme catalyses the condensation of ADP and Pi?

Answer 19

ATP synthase

Question 20

what does the condensation of ADP and Pi do?

Answer 20

produces ATP and requires energy, trapping it as chemical energy in the bond formed

Question 21

what type of energy source is ATP?

Answer 21

ATP is an immediate energy source and does not function well as a long-term energy store

Question 22

what features allow ATP to work well as an immediate energy source?

Answer 22

1. the hydrolysis of ATP releases a small amount of energy, meaning little energy is lost to heat
2. ATP is broken down in one step, meaning energy is released quickly
3. ATP is rapidly re-synthesised so that ATP is always readily available
4. the inorganic phosphate from ATP hydrolysis can phosphorylate other compounds, which makes them more reactive
5. the bonds between the phosphate groups are unstable, have a low activation energy and are easily broken
6. ATP is soluble, so it can be easily transported around cells