module 2 - 3.11 ATP Flashcards
what do cells require energy for?
- 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
what is ATP?
the steps between energy-yielding and energy-requiring cellular reactions
what is the difference between energy-yielding and energy-requiring cellular reactions?
energy-yielding - transferring energy out of the molecule
energy-requiring - transferring energy into the molecule
what does ATP stand for?
adenosine triphosphate
ATP is classified as a nucleoside triphosphate, what does this mean?
it consists of 3 components:
- a nitrogenous base (adenine)
- the sugar ribose
- the triphosphate
why is ATP universal?
it is an energy transfer in all cells of all living things
how many phosphates attached to the 5’ carbon are in ATP?
3
how many phosphates attached to the 5’ carbon are in DNA?
1
what is the difference between a nucleotide and a nucleoside?
nucleotide - sugar, base, phosphate
nucleoside - sugar, base
what can ATP also be called?
a phosphorylated nucleotide
what do nucleosides consist of?
pentose sugar connected to a nitrogenous base through 1’ glycosidic bond
why is the bond between the second phosphate group and the third phosphate group on ATP a very high energy bond?
because it is pushing 2 negative phosphate bonds together
what is required to break bonds?
energy
what is released when bonds are made?
energy
what is P i?
an inorganic phosphate
what is the equation for making ATP/ADP?
ATP + H2O ⇌ ADP + P i
what does terminal gamma phosphate require to break weak bonds? and what are the bonds holding it to?
- little energy required
- held to the middle beta phosphate
what happens when the bond breaking is coupled?
a large amount of energy is released
how much energy does ATP + H2O ⇌ ADP + P i release?
30.6 kJ mol-1
how do living cells maintain the ration of ATP to ADP?
concentration of ATP is five-fold higher than the concentration of ADP
what are the phosphate to phosphate bonds frequently referred to as?
high-energy bonds
where is ATP production by a non photosynthetic aerobic eukaryotic cell?
mitochondria
why is ATP constantly being made? and why does the cell not burst?
the ATP that’s made is broken down and used almost straight away
what is a non-photosynthetic cell?
any cell without chloroplasts
what is a coupled reaction?
a reaction that happens at the same time as another reaction
how does the hydrolysis of ATP happen if it cannot happen on its own?
it is coupled with another chemical reaction
how strong are the bonds between the phosphate groups?
relatively weak
if the bonds between phosphate groups are weak, what does this mean for ATP?
this means that ATP is not used as long term energy storage
what is used for long term energy storage?
lipids and carbohydrates
what are the properties of ATP?
- 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
what is the difference in structure between ADP and ATP?
ADP - base (adenine), ribose, TWO phosphate groups
ATP - base (adenine), ribose, THREE phosphate groups
