Cell Processes Flashcards
Which organelles do both plants and animals have?
Mitochondria
Vacuoles (vesicles)
List the components of the cytoskeleton from smallest to largest.
- Microfilaments
- Intermediate filaments
- Microtubules
Describe the progression of a signal sent to a cell’s extracellular matrix.
Collagen receives the signal, and it goes through the fibronectins, to the integrins, to the microfilaments.
List the three types of cell junctions and their functions.
- Tight: prevent leakage
- Anchoring: greater strength
- Gap: communicate
If anabolic metabolism is like construction, then catabolic metabolism is like…
Deconstruction
What is ‘G’ (free energy)?
The energy of a system that can be used to do work.
What is phosphorylation?
The removal of the terminal phosphate from ATP which releases energy.
What sorts of factors affect enzyme activity?
Temperature, pH, concentrations of substrate and of product, inhibitors, activators, and cofactors.
What is part of the endomembrane system?
The endoplasmic reticulum and the golgi apparatus.
Aerobic respiration reduces oxygen to water, and oxidizes…
Glucose to carbon dioxide.
What are the two phases of glycolysis?
Energy investment and energy payoff, in that order.
What occurs during energy investment of glycolysis?
Glucose is phosphorylated and converted to fructose. This fructose splits into G3P and DHAP. The hydrogen from glucose is used in the payoff phase.
What occurs during the payoff phase of glycolysis?
G3P is oxidized and NAD+ is reduced. Substrate-level phosphorylation converts 3-phosphoglycerate into PEP, and PEP into pyruvate.
True or false: glycolysis produces four ATPs.
False. It produces two.
What is added to oxaloacetate to produce citrate, and begin the Citric Acid Cycle?
Acetyl CoA
What is produced by the Citric Acid Cycle?
FADH(2)
CO(2)
NADH
Two ATPs
Where does oxidative phosphorylation occur?
In the cristae of the mitochondria.
What is the “fuel” in the “ATP mill” of chemiosmosis?
H+ flowing down a gradient.
What are the two processes of oxidative phosphorylation?
Electron transport chain
Chemiosmosis
True or false: If mitochondria are uncoupled, ATP synthesis is much slower.
True. When coupled, 26 ATPs are produced; when not, only 4.
What is fermentation?
The production of ATP without oxygen or the ETC. This does not completely oxidize pyruvate, so you end up with ethanol or lactate as byproducts.
What are carotenoids for?
Photoprotection for chlorophyll molecules. They absorb excess light.
Describe the progression of the evolution of the cell.
- Volcanoes and lightning produced lots of gases
- Non-living organic molecules
- Polymerization
- Membranes
- Protocells
- RNA
- Anaerobic metabolism
- Oxygen revolution
- Prokaryotes
- Eukaryotes
In the light reactions of photosynthesis, light first excites electrons, which are then passed to the P680 chlorophyll a pair. In which photosystem does this occur?
Photosystem II
The P680 pair passes electrons to the primary electron acceptor. They are then transferred to the ETC. What happens next?
The electrons are passed to Photosystem I and move from the ETC to the pigments of the photosystem to the P700 pair to the primary electron acceptor - and then through FD to a second ETC. This produces NADPH.
What is the purpose of the Calvin Cycle?
The production of sugar in plants.
What are the three steps of the Calvin Cycle?
- Carbon fixation to RuBP to produce sugars
- Reduction of sugars
- Regeneration of RuBP using ATP
What is photorespiration?
The use of oxygen in the Calvin Cycle instead of carbon dioxide, due to the closing of stoma for water conservation in C3 plants.
What is the benefit to C4 plants having mesophyll and bundle-sheath cells?
The light reactions and the Calvin cycle are separated, and photorespiration cannot occur.
What are the three stages of cell signalling?
Reception
Transduction
Response
