Unit 2 - ATP Flashcards
ATP cell currency
the energy ‘currency’ of our cell is know as ATP
- Adenosine Triphosphate
- a derivative of nucleotides
- large amts of free energy
- short term energy
ATP made of
1) a nitrogenouse base A
2) ribose sugar (pento)
3) chain of three phosphate groups
ATP powers what…
cellular work by coupling exergonic (exothermic) rxn to endergonic (endothermic) rxn
3 kinds of ATP cellular work
1) mechanical work
2) transport work
3) chemical work
Mechanical work
beating of cilia contractions of muscle cells and movement of chromosomes
Transport work
pumping substances across membrane against the direction of spontaneous movement
Chemical work
driving endergonic rxn such as the synthesis of polymers from monomers
Hydrolysis
bond between phosphate group can be broke by hydrolysis (end terminal)
- as bonds in these new products from free energy is release
- additionally H+ ions is released into the solution
How ATP works
1) third phosphate is the hardest one to keep attached
2) phosphate from bonds w water
3) entropy increases
third phosphate is the hardest one to keep attached
- repulsion in oxygen groups
- breaking O-P bond requires less energy
phosphate form bonds w water
- this releases lots of energy
- it creates v stable structure
entropy increases
- 1 mol broke into 2
- exergonic rxn - energy relseased
ATP and Energy Coupling
in the cell, the energy from the hydrolysis of ATP is coupled directly to endergonic processes by transferring the phosphate group to another mol.
- 2nd mol is phosphorylated
- more reactive
- use of an enzyme to bring ATP and reactant close together
Phosphorylation
the transfer of a phosphate group to an organic mol (usually from ATP to another mol)
Example within the cell
a) ammonia is adding to glutamic acid to form glutamine. This is a non-spontaneous endergonic rx
b) in the presence of ATP, a phosphate is transferred to glutamic acid this forms glutamly phosphate which spontaneously reacts w ammonia to form glutamine
Regeneration of ATP
ATP is a renewable resource that is continually regenerated by adding a phosphate group to ADP
-the energy ti support renwal come from catabolic rxn in the cell.
- break down of carbohydrates, fats, proteins
Redox rxn release energy when e- move closer to electronegative atoms
- The catabolic pathway relocates the electrons stored in food molecules releasing energy that is used to synthesize ATP
- Transfer of electrons
Redox = Oxidation and Reduction
Oxidation
= loss of e-
Reduction
= gain of e-
Oxidation
loss of e-
oxygen gained
hydrogen lost
Reduction
gain of e-
oxygen lost
hydrogen gained
Phosphorylation
The addition of a phosphate group
Decarboxylation
The removal of a carbon
The ways to recognize a redox reaction
1) electron transfer
2)Change in degree
3) Transferring H from organic mol of O
Electron Transfer
-The formation of table salt from sodium and chloride is a redox rxn
-sodium is oxidized
-chlorine is reduced
-needs a donor and acceptor
a Change in the degree of electron sharing in covalent bonts
(compound reacts w oxygen)
-electrons shift to the more electronegative atom
Transferring H from organic mols to Oxygen
(dehydrogenation reaction; removal of H)
- mols w H’s r sourced of e- that FALL closer to oxygen and is why hydrocarbons make good source of energy
