General Ideas
What organelle allows Cellular Respiration to happen?
Mitochondria
Where does glycolysis take place?
In the cytoplasm.
What is made during the Krebs cycle?
Per one glucose (two turns of the cycle):
2 ATP
6 NADH
2 FADH₂
4 CO₂
What stage of cellular respiration requires O₂?
The Electron Transport Chain.
What is the purpose of the electron transport chain?
To create a proton gradient that powers ATP synthase to make large amounts of ATP.
A proton is a single hydrogen ion while the protein is a biomolecule that has different jobs in living things.
Where does the Krebs cycle take place?
In the mitochondrial matrix.
How is CoA used?
Coenzyme A attaches to pyruvate, forming acetyl-CoA, which allows carbon atoms from glucose to enter the Krebs cycle.
What stage of cellular respiration makes H₂O?
The Electron Transport Chain.
In addition to electron transport, what do NAD⁺ and FAD transport?
They also transport hydrogen ions (H⁺).
What is the purpose of cellular respiration?
To convert the chemical energy stored in glucose into ATP, the usable energy currency of the cell.
Why can’t we do very high-intensity exercise for long periods?
High-intensity activity outpaces oxygen delivery. Cells switch to fermentation, which makes far less ATP and leads to fatigue.
What is released as citric acid is broken down?
CO₂
High-energy electron carriers NADH and FADH2
What is made during the Electron Transport Chain?
~26–28 ATP
H₂O
What are the two types of fermentation?
Lactic acid fermentation
Alcoholic fermentation
What are the three stages of cellular respiration?
Glycolysis
Krebs Cycle (Citric Acid Cycle)
Electron Transport Chain (ETC)
What organisms do aerobic cellular respiration using mitochondria?
Animals
Plants
Fungi
Where do the 6 carbon atoms that make citric acid come from?
2 carbons from acetyl-CoA
4 carbons from oxaloacetate (OAA)
Why do we call O₂ the final electron acceptor?
Oxygen accepts electrons at the end of the ETC and combines with hydrogen ions to form water, preventing the system from backing up.
How are photosynthesis and cellular respiration different?
Photosynthesis stores energy, respiration releases energy
Photosynthesis uses CO₂ and H₂O, respiration produces them
Photosynthesis requires light, respiration does not
What is made during glycolysis?
2 pyruvate
2 ATP (net gain)
2 NADH
How are pyruvate and glucose related?
Glucose (6 carbons) is split during glycolysis into two 3-carbon pyruvate molecules.
Why could you argue that the Krebs cycle starts and ends with OAA?
Because oxaloacetate is regenerated at the end of the cycle. If OAA isn’t present, the cycle stops.
How are photosynthesis and cellular respiration similar?
Both use electron transport chains
Both rely on redox reactions
Both make ATP
Both involve membranes and gradients
What is passing through ATP synthase to drive ATP production?
Hydrogen ions (protons) moving down their concentration gradient.