AP Biology Unit 2 Test Flashcards
Role of oxygen
- Pull electrons down the electron transport chain
- Oxidative phosphorylation would stop entirely resulting in no ATP production
Ins and outs of glycolysis (including specific ATP numbers)
- Ins: Glucose 2 NAD+ (empty electron taxi) 2 ATP 4 ADP+4P
- Outs: 2 pyruvate 2 NADH (full electron taxi) 2 ADP+2P 4 ATP total
2 ATP net gain
Purpose/function of the Kreb’s cycle (citric acid cycle)
- Produce electron carriers to be used in oxidative phosphorylation
- Total of 4 ATP is made so far
Path of electrons during the entire cellular respiration process
- Downhill route most electrons follow in cellular respiration: Glucose –> NADH –> ETC –> Oxygen
Location of all stages of cellular respiration
- Occurs in the mitochondria
- Glycolysis: Cytoplasm
- Krebs Cycle: Matrix
- Electron Transport Chain: Inner membrane
Chemiosmosis/generation of proton gradient: what it is, how it happens, why it is important
- Building of proton gradient that causes the diffusion of hydrogen ions across the biological membrane via ATP synthase
- Occurs in oxidative phosphorylation
Function/purpose of fermentation pathways
- Mechanism of oxidizing organic fuel and generating ATP without oxygen
- Basically glycolysis happening over and over
- Without highly electronegative oxygen to pull electrons down the chain there will not be oxidative phosphorylation
- No oxidative phosphorylation means no large yield of ATP
- Glucose — pyruvate produces a small amount of ATP with a limited supply of NAD+
Why is glycolysis considered to be one of the first metabolic pathways to evolve?
- No oxygen means slow gain or reproduction
- Earth’s atmosphere is anaerobic so it is an ancient pathway
- Only harvesting a small percent of energy stored in glucose
- First cells were prokaryotes (no organelles); glycolysis occurred in the cytoplasm
Absorption/reflection of light and how this relates to pigments and the perceived color of things
- Pigment is the natural coloring matter of an animal or plant
- Absorbs visible light and reflects others in the mesophyll of a leaf
- Important because it absorbs the light needed to begin photosynthesis when light strikes a photon
Purpose and ins/outs of light-dependent reactions
- Photosystems absorb light and transfers electrons (oxidation reduction)
- Generates oxygen
- Ins:
H2O (electron donor) — O2
ADP+P — ATP
NADP+ (sunlight) — NADH
Purpose/function of cyclic electron flow
- Electrons are cycled so more ATP can be made but no NADH
- Calvin cycle consumes more ATP than NADPH
- If ATP is low, cyclic flow occurs (reverts back to photosystem I)
- Temporarily stops making NADPH so ATP can catch up its supply
Location of all stages of photosynthesis
- Occurs in the chloroplast
- Light Reactions: Thylakoid membrane
- Calvin Cycle: Stroma
Relationship between light-dependent reactions and Calvin cycle
- Light reactions (photosystems) produce NADPH, ATP, and oxygen
- Oxygen is released as a waste product but the NADPH and ATP enter the Calvin cycle
- It produces a simple sugar molecule
Purpose/function of Calvin cycle (light-independent reactions)
- Makes molecules of sugar
The problem of photorespiration and plant adaptations to deal with it
- Metabolic pathway that consumes oxygen, releases CO2, and generates no ATP and sugar
- Decreases photosynthetic output by siphoning material from the Calvin cycle
- CAM pathway helps with problems with dehydration
- During the night, the plant opens stomata and stores CO2 as malate
- During the day time, the plant closes the stomata and uses malate (easily converted to CO2) to undergo the Calvin cycle
