Cellular Respiration
What is the main job of cellular respiration?
To transfer energy from food molecules into ATP that cells can use.
What is the first stage of cellular respiration?
Glycolysis
How many ATP molecules are invested to get glycolysis started?
2
Fermentation occurs when oxygen is available or unavailable?
unavailable
What is the ultimate energy source for the energy stored in an orange?
Sunlight, captured by the orange tree through photosynthesis.
Which molecule is often called the cell’s energy currency?
ATP
Where does glycolysis take place?
cytoplasm
What is the net ATP yield of glycolysis?
2
Where does fermentation take place?
cytoplasm
Which gas is used up as a reactant during aerobic cellular respiration?
Does cellular respiration require light?
No
What is another name for the Krebs cycle?
The citric acid cycle.
About what happens to the portion of glucose energy that is not captured in ATP?
released as heat
What type of fermentation is associated with intense muscle activity in organisms when oxygen is limited?
Lactic acid fermentation.
Which gas produced by cellular respiration can enter the atmosphere?
carbon dioxide
Name two products of aerobic cellular respiration besides ATP.
Carbon dioxide
water
Where do the Krebs cycle reactions take place in the cell?
In the mitochondrial matrix.
Which carriers bring high-energy electrons to the electron transport chain?
NADH and FADH₂.
What two products are formed during alcoholic fermentation?
Ethyl alcohol (ethanol) and carbon dioxide.
Which macromolecules provide about 9 Calories per gram, compared with about 4 for carbohydrates and proteins?
lipids
Write the overall cellular respiration equation.
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy
Put these stages in order: electron transport chain, glycolysis, Krebs cycle.
Glycolysis → Krebs cycle → electron transport chain.
How does the electron transport chain help ATP synthase make ATP?
Electron energy helps build a hydrogen-ion gradient; hydrogen ions flow through ATP synthase, powering ATP formation from ADP and phosphate.
Why can fermentation be useful when oxygen is unavailable?
It allows glycolysis to continue by regenerating NAD⁺, though it yields much less ATP than the electron transport chain.
what type of fermentation can be used to make foods like yogurt, and often gives them a sour taste?
lactic acid fermentation