What is the photosynthesis equation?
6CO2 + 6H2O → C6H12O6 + 6O2
What distinguishes organic and inorganic molecules?
Organic = weaker bonds between C-H
Inorganic = strong bonds, no C-H binds
Where does energy for ATP synthesis come from?
- Large organic molecules break down to inorganic ones during respiration; excess energy released used to synthesise ATP
- light energy also used to form bonds in ATP
Describe structure of ATP
Nucleotide of adenine, ribose sugar and three phosphate groups
How does ATP provide energy?
Releases energy when phosphate bond broken —> goes from ATP to ADP (adenine diphosphate)
What reactions are involved in the breakdown and buildup of ATP?
- breakdown = hydrolysis using enzyme ATPase
- buildup = phosphorylation, using enzyme ATP synthase
- same amount of energy for both
Define phosphorylation
Adding an inorganic phosphate to ADP
Describe the three types of phosphorylation
1) oxidative phosphorylation —> occurs on mitochondria membrane in anaerobic respiration
2) photophosphorylation —> occurs in thylakoid membrane of chloroplasts
3) substrate-level phosphorylation —> occurs when phosphate groups transferred from donor molecules
What are advantages of ATP
- only one enzyme needed to release energy (more for glucose)
- ATP releases energy in small amounts; glucose contains larger (sometimes unnecessary)
- common sources of energy in chem reactions; increases efficiency of cells
What is the electron transport chain?
Series of proteins found in thylakoid membrane
Describe the process of chemiosmosis
1) Electrons excited (gain energy) by light
2) Move through proteins in ETC, transferring energy to them
3) Hydrogen ions move to intermembrane space via active transport
4) Move through final protein (=chemiosmosis)
5) enzyme ATP synthase attaches, transferring energy from H+ to ATP synthase
6) Energy used to make ATP
