Glycolysis
What molecule begins glycolysis?
What is another name for the Krebs Cycle?
Citric Acid Cycle
What integral membrane protein (protein embedded into the membrane) is used to make energy in the ETC?
ATP Synthase
What conditions warrant fermentation?
An anaerobic environment (no oxygen present).
What are the three steps of cellular respiration in order?
1. Glycolysis
2. Krebs Cycle
3. Electron Transport Chain
Where does glycolysis take place in a cell?
The cytosol (cytoplasm)
Where does the Krebs Cycle occur?
Mitochondrial Matrix (the space inside the mitochondria)
Where does the ETC chain take place in cellular respiration?
The Mitochondrial Cristae (inner membrane of the mitochondria)
What two molecules can be produced as a result of the 2 types of fermentation?
What are the two types of cellular respiration?
Aerobic respiration (with oxygen) and Anaerobic respiration (without oxygen)
What 3 molecules are made in glycolysis and where do they go?
2 pyruvate molecules (to the Krebs Cycle), 2 ATP (energy used by the cell), 2 NADH (used in ETC)
What 4 molecules do you get at the end of Krebs Cycle?
2 ATP, 6 NADH, 2 FADH2, 4 CO2
What is the job/purpose of the molecules NADH and FADH2 in the ETC?
NADH and FADH2 are electron carriers. They replenish the ETC with electrons so that it can power ATP Synthase to make energy.
What are the two types of fermentation? What type can humans NOT go through?
Where is carbon dioxide given off as a waste product in cellular respiration?
Krebs Cycle
How many ATP are produced in glycolysis? What is the net amount of ATP/available to use in other biochemical processes?
Glycolysis produces 4 ATP molecules. However, since 2 ATP molecules are required to start glycolysis, there is only a NET 2 ATP produced.
How many times does 1 glucose molecule turn the Krebs Cycle?
2 times. 1 glucose molecule = 2 Krebs Cycle turns.
What is the job of oxygen in the ETC? Why is oxygen's role in the ETC crucial?
Oxygen is the FINAL electron acceptor in the ETC. Without it, the electrons in the ETC could not flow forward and ATP Synthase would not be powered. Organisms could not make energy.
What types of organisms go through fermentation?
ALL organisms can go through fermentation. Mammals use fermentation as a last resort to make energy, whereas, unicellular organisms like yeast use fermentation to make energy all the time.
What is one chemical you learned about that can prevent electrons from being passed onto the final electron acceptor (oxygen) in the ETC? Which eventually leads to death...
Cyanide! (Chicago cyanide murders case study)
Explain why glycolysis does not require oxygen, and why it would be bad if it did.
Glycolysis produces a small amount of ATP (~2ATP). If oxygen is not present, glycolysis will repeat itself (through fermentation). This allows the body to continue to make ATP even without O2. If glycolysis did require oxygen, the body would have no way to make energy without oxygen.
What is the intermediate molecule between pyruvate and the Krebs Cycle? What happens if pyruvate cannot be made into this molecule?
Acetyl CoA. If Acetyl CoA cannot be made, the Krebs Cycle cannot turn and therefore, cannot make the electron carriers necessary to power the ETC. Cells will resort to fermentation.
What is the role of chemiosmosis in the Electron Transport Chain? Explain.
Chemiosmosis is the creation of a concentration gradient of H+ ions via the lost energy from electrons traveling down the ETC. This concentration gradient is used to power ATP Synthase through diffusion.
Explain the process of fermentation.
NADH is produced in glycolysis. This NADH is then turned back into NAD+, which is recycled at the end of glycolysis (fed back to the start of glycolysis) to produce 2 ATP.
Explain how water and oxygen are used in the electron transport chains in cellular respiration and in photosynthesis.
H2O is used as an electron donor in photosynthesis; it is split into electrons and O2. O2 is an electron acceptor in cellular respiration; it accepts electrons at the end of the ETC and turns into H2O