ATP & Energy
What molecule is the direct usable energy source for cells?
ATP
What organelle carries out photosynthesis
Chloroplast
Which reactions require light energy?
Light-dependent reactions
What is the main purpose of cellular respiration?
Produce ATP
Which type of respiration requires oxygen?
Aerobic respiration
What gas produced by photosynthesis is used in cellular respiration?
Oxygen
Name the 3 parts of ATP
Adenine, ribose, 3 phosphate groups
Name the two main reactants of photosynthesis
CO₂ and H₂O
Where do the LDR and LIR reactions take place?
Thylakoids
Stroma
Where does glycolysis occur?
Cytoplasm
What type of fermentation occurs in yeast, and what two major products are formed?
Alcoholic fermentation; ethanol and CO
What two products of photosynthesis become reactants for cellular respiration?
Glucose and oxygen
What happens when ATP loses its third phosphate? (Two part answer)
Energy is released and ATP becomes ADP
A plant takes in CO₂ and water while receiving sunlight. What two major products should be produced?
Glucose and O₂
What happens to water during the light-dependent reactions?
It is split, releasing oxygen
Put these in order: ETC, glycolysis, Krebs cycle.
Glycolysis → Krebs cycle → ETC
Human muscle cells temporarily lack enough oxygen during intense exercise. What process allows glycolysis to continue?
Lactic acid fermentation
Complete the relationship: Photosynthesis stores energy in ________, while cellular respiration releases that energy to make ________.
glucose; ATP
A cell contains large amounts of ADP and very little ATP. What does this suggest about the cell's energy situation?
ATP has been used for cell work and the cell needs to regenerate ATP
A plant receives plenty of water and CO₂ but is placed in darkness. Predict what happens to glucose production.
It decreases/stops because light energy is needed to drive photosynthesis
A chemical prevents the light-dependent reactions from producing ATP and NADPH. What process would be affected next?
Light-independent reactions/Calvin cycle
A poison stops the Krebs cycle. Which later stage of respiration would receive fewer high-energy electrons and be affected?
ETC
Compare aerobic respiration and fermentation in terms of oxygen, ATP production, and when a cell would use each.
Aerobic requires O₂ and makes much more ATP; fermentation occurs without O₂ and produces only 2 ATP from glycolysis, allowing glycolysis to continue
A sealed ecosystem contains plants and animals. Explain how one product released by the animals can be used by the plants.
Animals release CO₂ through respiration; plants use CO₂ for photosynthesis
A muscle cell suddenly needs more energy to contract. Would you expect more ATP → ADP or ADP → ATP reactions to occur immediately as the cell performs work?
ATP → ADP
Algae in a lake experience a large decrease in available CO₂. Predict how glucose production would change and explain why.
Glucose production decreases because CO₂ is a reactant/input of photosynthesis
Compare the major roles of the two stages of photosynthesis.
Light-dependent reactions capture light energy and produce energy-carrying molecules/O₂; light-independent reactions use that energy and CO₂ to build sugars
Oxygen suddenly becomes unavailable to an aerobic cell. Why will the ETC eventually stop producing large amounts of ATP?
Oxygen is the final electron acceptor, so without it the ETC cannot continue normally
Two cells receive the same amount of glucose. Cell A has oxygen; Cell B does not. Which produces more ATP and why?
Cell A because aerobic respiration uses the Krebs cycle and ETC and is much more efficient than fermentation
A student says, “Plants photosynthesize, so they do not perform cellular respiration.” Explain why this statement is incorrect.
Plants perform both; photosynthesis stores energy in glucose and cellular respiration releases energy from glucose to make ATP