8.2 Cell respiration Flashcards
What is ATP?
A high energy molecule that functions as an immediate power source for cells
What does one molecule of ATP contain three of?
Three covalently bonded phosphate groups
What do the three covalently bonded phosphate groups store in their bonds?
Potential energy
Why is ATP a readily reactive molecule that contains high energy bonds?
Because phosphorylation makes molecules less stable
What happens to the energy when ATP is hydrolysed?
It is stored in the terminal phosphate bond and released for used by the cell
What are the two functions of ATP in the cell?
- functions as the energy currency of the cell by releasing energy when hydrolysed to ADP
- transfers phosphate groups to other organic molecules
What is ATP synthesised from?
ADP
What are two sources of energy used to synthesise ATP?
Solar energy
Oxidative processes
What is solar energy?
Photosynthesis converts light energy into chemical energy that is stored as ATP
What are oxidative processes?
Cell respiration breaks down organic molecules to release chemical energy that is stored as ATP
What is cell respiration?
The controlled release of energy from organic compounds to produce ATP
What does anaerobic respiration involve?
The incomplete breakdown of organic molecules for a small yield of ATP
No oxygen is required
What does aerobic respiration involve?
The complete breakdown of organic molecules for a larger yield of ATP
Oxygen is required
How does the breakdown of organic molecules occur?
Via a number of linked processes
What does staggering the breakdown into several processes do?
Reduces the energy requirements
What happens to released energy during the overall breakdown of organic molecules?
It is transferred to activated molecules via redox reactions
How is chemical energy transffered when organic molecules are broken down by cell respiration?
Redox reactions
What do redox reactions involve?
The oxidation of one chemical species and the reduction of another
What do most redox reactions typically involve?
The transfer of electrons, hydrogen or oxygen
What is reduction?
Gain of electrons/ hydrogens or the loss of oxygen
What is oxidation?
The loss of electrons/ hydrogen or the gain of oxygen
What does cell respiration transfer to carrier molecules?
Hydrogen atoms and electrons
What is the energy stored in the organic molecule transferred with to the carrier proteins?
Protons and electrons
What are carrier molecules called?
Hydrogen carriers or electron carriers