Bio 1002B: Cycle 4 (Primary
Metabolism), Cycle 5 Outcomes And
cycle 6 Practice Questions All Solved
Correctly.
What is photosynthesis? - Answer Light-dependent conversion of carbon dioxide into
carbohydrates, an endothermic process. The carbon dioxide is reduced into glucose, and water
is oxidized into oxygen.
What is the structure of chloroplast? - Answer 1. Thylakoid membranes:
- Light reactions
- Separates the lumen (interior) from the stroma
2. The stroma:
- Calvin cycle (dark reactions)
3. Circular genome (its own):
- Complete with T&T (transcription & translation)
- ex. D1 protein
Describe the photosynthetic electron transport (the light reactions). - Answer 1. Photos
come from the stroma into the lumen via photosystem II.
2. As electrons flow, protons are being moved from stroma into lumen to produce electron
gradient. The electron flow relates to free energy. The pH lumen is much larger than the pH of
the stroma.
2. NADP+ is reduced into NADPH that then goes into the Calvin cycle.
3. Protons go back to the stroma via ATP synthase, and so ATP is produced for the Calvin cycle.
What are supermolecular complexes? - Answer Multiple molecules held together by
covalent bonds. Examples include photosystem I & II, Cytochrome complex, Photosystem I , and
ATP synthase.
Describe how photosystem I & II work together. - Answer
What drives photosynthesis? - Answer P680+, the strongest oxidant known in biology. A
photon is added to P680 to make P680*, then an electron is removed to make P680+. An
electron from water splitting/oxidation is added, and P680* becomes P680 again to be reused.
, What if PSII is damaged? - Answer It is constantly being damaged and repaired. Damage can
be caused by exposure to light, so the damaged D1 protein is removed, inactivating the PSII. A
new D1 protein is inserted with cofactors such as P680, and PSII is active again.
What is the Calvin cycle? - Answer Also known falsely as the dark reactions, it includes
carbon fixation of organic molecules to create bigger organic molecules. It is typically defined by
3 full turns/cycles.
What is rubisco? - Answer An enzyme that incorporates carbon dioxide into an already
existing organic molecule.
What are the Calvin cycle steps? - Answer 1. Fixation:
- 3 carbon dioxide molecules go in with rubisco
- Becomes 6 3-Phosphoglycerate (PGA)
2. Reduction:
- PGA reduced by ATP from light reactions
- Becomes 6 1-3-Bisphosphoglycerate
- Becomes 6 Glyceraldehyde-3-phosphate (G3P)
- From 3 turns, 1 extra G3P is produced
- Makes gluclose and related molecules
3. Regeneration:
- 5 G3P is reduced by ATP
- Becomes 3 ribulose-1,5-bisphophate (RuBP)
- Ready for more carbon dioxide
What are the parts of the mitochondria? - Answer 1. Outer mitochondrial membrane.
2. Inner mitochondrial membrane (ETC).
3. Intermembrane space.
4. Matrix (Citric Acid Cycle/Krebs Cycle)
What is oxidative phosphorylation? - Answer Includes the electron transport chain and 4
super-molecular complexes. The goal of oxidative phosphorylation is to turn free energy from
NADH into ATP.
How does oxidative phosphorylation work? - Answer 1. Complex I has a binding site for
NADPH and takes the proton while pushing the NAD+ back into the matrix.
2. The electron from NADPH goes down the chain until it meets with oxygen to make water.
Metabolism), Cycle 5 Outcomes And
cycle 6 Practice Questions All Solved
Correctly.
What is photosynthesis? - Answer Light-dependent conversion of carbon dioxide into
carbohydrates, an endothermic process. The carbon dioxide is reduced into glucose, and water
is oxidized into oxygen.
What is the structure of chloroplast? - Answer 1. Thylakoid membranes:
- Light reactions
- Separates the lumen (interior) from the stroma
2. The stroma:
- Calvin cycle (dark reactions)
3. Circular genome (its own):
- Complete with T&T (transcription & translation)
- ex. D1 protein
Describe the photosynthetic electron transport (the light reactions). - Answer 1. Photos
come from the stroma into the lumen via photosystem II.
2. As electrons flow, protons are being moved from stroma into lumen to produce electron
gradient. The electron flow relates to free energy. The pH lumen is much larger than the pH of
the stroma.
2. NADP+ is reduced into NADPH that then goes into the Calvin cycle.
3. Protons go back to the stroma via ATP synthase, and so ATP is produced for the Calvin cycle.
What are supermolecular complexes? - Answer Multiple molecules held together by
covalent bonds. Examples include photosystem I & II, Cytochrome complex, Photosystem I , and
ATP synthase.
Describe how photosystem I & II work together. - Answer
What drives photosynthesis? - Answer P680+, the strongest oxidant known in biology. A
photon is added to P680 to make P680*, then an electron is removed to make P680+. An
electron from water splitting/oxidation is added, and P680* becomes P680 again to be reused.
, What if PSII is damaged? - Answer It is constantly being damaged and repaired. Damage can
be caused by exposure to light, so the damaged D1 protein is removed, inactivating the PSII. A
new D1 protein is inserted with cofactors such as P680, and PSII is active again.
What is the Calvin cycle? - Answer Also known falsely as the dark reactions, it includes
carbon fixation of organic molecules to create bigger organic molecules. It is typically defined by
3 full turns/cycles.
What is rubisco? - Answer An enzyme that incorporates carbon dioxide into an already
existing organic molecule.
What are the Calvin cycle steps? - Answer 1. Fixation:
- 3 carbon dioxide molecules go in with rubisco
- Becomes 6 3-Phosphoglycerate (PGA)
2. Reduction:
- PGA reduced by ATP from light reactions
- Becomes 6 1-3-Bisphosphoglycerate
- Becomes 6 Glyceraldehyde-3-phosphate (G3P)
- From 3 turns, 1 extra G3P is produced
- Makes gluclose and related molecules
3. Regeneration:
- 5 G3P is reduced by ATP
- Becomes 3 ribulose-1,5-bisphophate (RuBP)
- Ready for more carbon dioxide
What are the parts of the mitochondria? - Answer 1. Outer mitochondrial membrane.
2. Inner mitochondrial membrane (ETC).
3. Intermembrane space.
4. Matrix (Citric Acid Cycle/Krebs Cycle)
What is oxidative phosphorylation? - Answer Includes the electron transport chain and 4
super-molecular complexes. The goal of oxidative phosphorylation is to turn free energy from
NADH into ATP.
How does oxidative phosphorylation work? - Answer 1. Complex I has a binding site for
NADPH and takes the proton while pushing the NAD+ back into the matrix.
2. The electron from NADPH goes down the chain until it meets with oxygen to make water.
