Cells: photosynthesis + cellular respiration Flashcards
What is Photosynthesis?
Process by which plants convert light energy into chemical energy stored in glucose.
What are light dependant reactions?
Require: Sunlight (to excite electrons) and water
Where: Thylakoid membrane
Used for: Converting light energy into chemical energy
What is the process of light dependant reactions?
1.Sunlight Absorption: Chlorophyll in the plants’ chloroplasts absorbs sunlight
2. Water Splitting: The absorbed light energy splits water molecules into oxygen (which is released into atmosphere), hydrogen ions, and electrons
3. Energy Transfer: Excited electrons move through proteins in the thylakoid membrane, called the electron transport chain, creating a flow of energy
4. ATP and NADPH Formation: The energy from the electrons converts ADP and phosphate into ATP, and electrons reduce NADP+ to form NADPH
5. Oxygen Release: Oxygen is released as a byproduct from the splitting of water
What is light independant reactions?
Require: CO2
Where: Stroma
Used for: Use ATP and NADPH from the light-dependent reactions to convert carbon dioxide into glucose
What is the process of light independant reactions (calvin cycle)?
Carbon Fixation: CO₂ is attached to a 5-carbon sugar called RuBP. This forms a 6-carbon compound that is splits into two 3-carbon molecules called 3-PGA.
Reduction: The 3-PGA molecules are converted into a sugar called G3P from ATP and NADPH.
Regeneration: Some of the G3P molecules are used to regenerate RuBP, enabling the cycle to continue which requires ATP.
What are the three main stages of cellular respiration, and what occurs in each stage?
Glycolysis: Glucose is broken down into pyruvate, producing a small amount of energy.
Citric Acid Cycle (Krebs Cycle): Pyruvate is further broken down, releasing carbon dioxide and transferring high-energy electrons to carrier molecules.
Electron Transport Chain: High-energy (excited) electrons are used to produce ATP, the energy currency of the cell.
How does cellular respiration differ from photosynthesis in terms of energy conversion?
Cellular respiration converts chemical energy from glucose into ATP, releasing carbon dioxide and water as byproducts. Photosynthesis, on the other hand, converts light energy into chemical energy stored in glucose, using carbon dioxide and water and releasing oxygen as a byproduct.
What are factors affecting photosynthesis ROR?
- light
- Chlorophyll
- C02
- Temperature
How does light affect photosynthesis ROR?
Photosynthesis relies on energy from the sun. The more sun, the higher the ROR
How does chlorophyll affect photosynthesis ROR?
Chlorophyll absorbs light energy which is needed for process. The greater the concentration of chlorophyll, the faster the plant can catch and convert light to chemical energy
How does C02 affect photosynthesis ROR?
CO2 is a needed factor for the Calvin cycle, (it is fixed into glucose) With more CO2 available, plant can produce more glucose faster
How does temperature affect enzymes ROR?
Optimal temperatures maximises enzyme activity due to more collisions. Extreme temperatures, too high/low, can disrupt reactions and lower ROR
What is cellular respiration?
how cells generate energy from nutrients e.g. aerobic, anaerobic
What is the primary difference between aerobic and anaerobic respiration?
Aerobic respiration requires oxygen to produce energy, while anaerobic respiration occurs without oxygen. Anaerobic respiration produces less energy.
What does aerobic respiration use to produce energy?
Aerobic respiration uses oxygen to produce energy.
