everything? Flashcards
At what organelle does anaerobic cellular respiration occur?
Anaerobic cellular respiration doesn’t occur in any organelles, it occurs in the cytosol
Explain what happens when lactic acid builds up in muscles due to anaerobic respiration.
Lactic acid lowers the pH of cells which can reduce enzyme function. Once oxygen is present again, lactic acid is metabolised back into pyruvate and used for aerobic cellular respiration.
What is the equation for aerobic respiration?
Glucose + Oxygen → Carbon dioxide + Water + 30 or 32 ATP
or
C6H12O6 + 6O2 → 6CO2 + 6H2O + 30 or 32 ATP
Where does each stage of aerobic respiration take place?
Glycolysis -cytosol
Kreb’s cycle - mitochondria matrix
Electron transport chain - cristae of the mitochondria
What are the 3 key coenzymes involved in aerobic respiration?
ATP, NAD+, FAD
What factors influence enzymes?
- Temperature
- pH level
- concentration
Why are enzymes used in biological reactions?
Enzymes catalyse and speed up reactions by providing a lower energy, alternate pathway for the reaction to take place.
Explain the ‘induced fit’ model.
The induced fit model explains how enzymes are flexible and change shape slightly when a substrate binds to them, which causes a reaction to occur.
What are the inputs and outputs of glycolysis?
Inputs:
* 1 Glucose
* NAD+ + 2 H+
* 2ADP + 2Pi
Outputs:
* 2 Pyruvate
* NADH
* 2 ATP
What are the inputs & outputs of the Krebs cycle?
Inputs:
* 2 acetyl-CoA
* 2 ADP + 2 Pi
* 6 NAD+ + 6 H+
* 2 FAD + 4 H+
Outputs:
* 2 ATP
* 4 CO2
* 6 NADH
* 2 FADH2
What are the inputs & outputs of the electron transport chain?
inputs:
* 6 O2 + 12 H+
* 2 FADH2
* 10 NADH
* 26 or 28 ADP + Pi
outputs:
* 26 or 28 ATP
* 6 H2O
* 10 NAD+ + 10 H+
* 2 FAD + 4 H+
Explain why the rate of cellular respiration increases when the temperature was increased from 0 to 33°C.
The rate of cellular respiration increased due to more frequent enzyme-substrate collisions between rubisco and CO2, thus increasing the rate of fixing CO2 into organic glucose and increasing photosynthetic rate.
Why do enzymes in the cytoplasm and mitochondrial matrix have different optimal pH levels.
The pH levels of different locations vary due to the cycling of H+ ions through FAD and NAD+, and thus the enzymes that support those functions have evolved to also have the same optimal pHs as their environments.
What are two reasons why a light-saturation point can be reached?
- Enzymes within chloroplasts are operating at full capacity.
- There is another limiting factor, such as CO2 availability, temperature, water availability, light colour or etc that is restricting the rate of photosynthesis.
Plants absorb light mostly at the:
short (blue) and long (red) wavelength ends of the visible light spectrum.
when does photorespiration occur
Photorespiration occurs in hot weather when Rubisco has a greater affinity for O2 than CO2
or when the concentration of O2 is greater than CO2
how does C4 photosynthesis work
- This separation allows for higher concentrations of CO2 than O2 around RuBisCO, which increases the chances for it to bind to CO2 which reduces photorespiration and increases photosynthesis.
how does CAM photosynthesis work
- In dry habitats plants lose their turgor due to water loss via transpiration, which causes the stomata to close.
- O2 from the light-dependent stage of photosynthesis builds up, and increases the likelihood that rubisco binds to O2 rather than CO2 and initiate photorespiration.
- CAM plants open their stomata at night to bring in CO2, and store fixed CO2 in vacuoles within mesophyll cells. During the day the stomata
What are the inputs & outputs of the light-dependent stage of C3 photosynthesis?
inputs:
* 12 H2O
* 12 NADP+
* 18 ADP + 18 Pi
outputs:
* 6 O2 molecules
* 12 NADPH
* 18 ATP
What are the inputs & outputs of the light-independent stage of C3 photosynthesis?
inputs:
* 6 CO2(g) molecules
* 12 NADPH
* 18 ATP
outputs:
* C6H12O6
* 6 H2O
* 12 NADP+
* 18 ADP + 18 Pi
What is chlorophyll?
Chlorophyll is the green pigment, found in thylakoid disks within chloroplasts, that absorbs light energy for use in photosynthesis.
Where do the stages of C3 photosynthesis occur?
light-dependent - On thylakoid membranes
light-independent - In the stroma within chloroplasts
What are the factors that affect the rate of photosynthesis?
- Light intensity
- Light colour
- Water availability
- Temperature
- CO2 concentration
- O2 concentration
What are C3 plants?
C3 plants are plants that conduct photosynthesis normally and have no evolved adaptations to minimise photorespiration.