module 2 - 3.11 ATP

Question 1

what do cells require energy for?

Answer 1

• synthesis of molecules e.g. protein synthesis
• transport of molecules or ions e.g. transport of vesicles from the Golgi into plasma membrane
• cellular movement e.g. contraction of cardiac muscles

Question 2

what is ATP?

Answer 2

the steps between energy-yielding and energy-requiring cellular reactions

Question 3

what is the difference between energy-yielding and energy-requiring cellular reactions?

Answer 3

energy-yielding - transferring energy out of the molecule
energy-requiring - transferring energy into the molecule

Question 4

what does ATP stand for?

Answer 4

adenosine triphosphate

Question 5

ATP is classified as a nucleoside triphosphate, what does this mean?

Answer 5

it consists of 3 components:
- a nitrogenous base (adenine)
- the sugar ribose
- the triphosphate

Question 6

why is ATP universal?

Answer 6

it is an energy transfer in all cells of all living things

Question 7

how many phosphates attached to the 5’ carbon are in ATP?

Answer 7

3

Question 8

how many phosphates attached to the 5’ carbon are in DNA?

Answer 8

1

Question 9

what is the difference between a nucleotide and a nucleoside?

Answer 9

nucleotide - sugar, base, phosphate
nucleoside - sugar, base

Question 10

what can ATP also be called?

Answer 10

a phosphorylated nucleotide

Question 11

what do nucleosides consist of?

Answer 11

pentose sugar connected to a nitrogenous base through 1’ glycosidic bond

Question 12

why is the bond between the second phosphate group and the third phosphate group on ATP a very high energy bond?

Answer 12

because it is pushing 2 negative phosphate bonds together

Question 13

what is required to break bonds?

Answer 13

energy

Question 14

what is released when bonds are made?

Answer 14

energy

Question 15

what is P i?

Answer 15

an inorganic phosphate

Question 16

what is the equation for making ATP/ADP?

Answer 16

ATP + H2O ⇌ ADP + P i

Question 17

what does terminal gamma phosphate require to break weak bonds? and what are the bonds holding it to?

Answer 17

• little energy required
• held to the middle beta phosphate

Question 18

what happens when the bond breaking is coupled?

Answer 18

a large amount of energy is released

Question 19

how much energy does ATP + H2O ⇌ ADP + P i release?

Answer 19

30.6 kJ mol-1

Question 20

how do living cells maintain the ration of ATP to ADP?

Answer 20

concentration of ATP is five-fold higher than the concentration of ADP

Question 21

what are the phosphate to phosphate bonds frequently referred to as?

Answer 21

high-energy bonds

Question 22

where is ATP production by a non photosynthetic aerobic eukaryotic cell?

Answer 22

mitochondria

Question 23

why is ATP constantly being made? and why does the cell not burst?

Answer 23

the ATP that’s made is broken down and used almost straight away

Question 24

what is a non-photosynthetic cell?

Answer 24

any cell without chloroplasts

Question 25

what is a coupled reaction?

Answer 25

a reaction that happens at the same time as another reaction

Question 26

how does the hydrolysis of ATP happen if it cannot happen on its own?

Answer 26

it is coupled with another chemical reaction

Question 27

how strong are the bonds between the phosphate groups?

Answer 27

relatively weak

Question 28

if the bonds between phosphate groups are weak, what does this mean for ATP?

Answer 28

this means that ATP is not used as long term energy storage

Question 29

what is used for long term energy storage?

Answer 29

lipids and carbohydrates

Question 30

what are the properties of ATP?

Answer 30

• soluble in water, dissolves in cytoplasm
• small, allows easy transport around and between cells
• allows energy transfer - when hydrolysed it transfers right amounts of energy into coupled reactions (notwaste energy as heat)
• easily remade from ADP by condensation reaction

Question 31

what is the difference in structure between ADP and ATP?

Answer 31

ADP - base (adenine), ribose, TWO phosphate groups
ATP - base (adenine), ribose, THREE phosphate groups