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
Relationship between photosynthesis and cellular respiration
- Reverse processes
- Photosynthesis is the process of turning energy from the sun and carbon dioxide and water into oxygen and sugar
- Cellular respiration is the process of turning oxygen and the food that you eat into the energy
Three stages of cell communication/signal transduction pathways and generally what happens in each
- Reception: Target cells detection of a signal molecule coming from outside the cell
- Transduction: Binding of the signal molecule initiates the process; converts to a form to bring cellular response
- Response: Transduced signal finally triggers a specific cellular response
What begins the process of transduction?
- Signal molecule signals the receptor
- Activates the protein kinase I
Know the testosterone example
- Hormone travels through the blood and enters cells all over the body
- In the cytoplasm of target cells, nay the cells that contain receptor for testosterone activate it
- Active form of the receptor protein enters the nucleus and turns on specific genes that control male sex characteristics
- Bound protein stimulates the transcription of the gene into mRNA
- mRNA is translated into a specific protein
Understand the role of kinases and phosphatases in transduction pathways
- Cascades of molecular interactions relay signals from the receptors to target molecules in the cells
- Protein kinase: Enzyme that transfer phosphate groups from ATP to protein
- Protein phosphatase: Enzyme remove phosphate groups from proteins oftener ever sing the effect of a protein kinase
Sequence of events in the cell cycle and mitosis and general happenings of each
Interphase: Part of the cell that is not dividing
- G1: Cell is doing its job
- S: Copying DNA
- G2: Duplicating organelles
Mitosis: Cell division
- Prophase: Chromatin is condensing and the mitotic spindle begins to form but the nucleus is in tact
- Prometaphase: Chromosomes consisting of identical sister chromatids appear, nucleus envelope fragments, and the spindle attach to the chromosomes
- Metaphase: Spindle is complete and the chromosomes are all aligned at the metaphase plate
- Anaphase: Chromatids of each chromosomes have separated and the daughter chromosomes are moving to the poles of the cell
- Telophase: Daughter nuclei are formed and cytokinesis begins
- Cytokinesis: Division of the cytoplasm
Difference between plant and animal cell mitosis (specifically cytokinesis)
- In animal cells, cytokinesis occurs by the process of cleavage producing two separate cells with its own nucleus
- In plant cells, there is no cleavage furrow. A cell plate is formed by vesicles moving to the middle of the cell resulting in two daughter cells and the formation of a new cell wall
Function/role of cyclin-dependent kinases (Cdks)
- Regulatory protein whose concentration fluctuates cyclically that is only active when attached to a particular protein
- Checkpoints in G1 and G2 in the cell cycle control system
