🔋 ATP & Energy
What is ATP used for?
Chemical energy for all cellular processes
What is the correct equation for photosynthesis?
6 CO₂ + 6 H₂O + Light → C₆H₁₂O₆ + 6 O₂
What is the purpose of aerobic cellular respiration?
To break down glucose in the presence of oxygen to produce ATP
What is anerobic cellular respiration?
Anaerobic cellular respiration is a type of respiration that occurs when oxygen is NOT present.
What are the main reactants of photosynthesis?
Carbon dioxide (CO₂) and water (H₂O)
What does ATP become after it is used for energy?
ADP
Where in the chloroplast does the light-dependent reaction occur?
Thylakoid
What is the correct chemical equation for aerobic cellular respiration?
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP
How much ATP is produced from anaerobic respiration?
Glycolysis - Produces 2 ATP
Fermentation - Produces 0 ATP
TOTAL ATP - 2 ATP
What are the products of cellular respiration?
Carbon dioxide (CO₂), water (H₂O), and ATP
How is ADP cycled to become ATP?
When a phosphate is added to an ADP molecule to charge up and become ATP.
Why are pigments like chlorophyll important in photosynthesis?
They absorb light energy, especially from the blue and red parts of the spectrum, which powers the light-dependent reactions of photosynthesis.
Why is the electron transport chain important in aerobic respiration?
It produces most of the ATP by using electrons to power ATP synthesis
What are the two main types of fermentation?
Lactic acid fermentation and alcoholic fermentation
How is glucose utilized in cellular respiration after being produced in photosynthesis?
Glucose is the reactant needed in order to be broken down in the process of glycolysis, where it is converted into pyruvate, releasing energy that is further used to produce ATP in the later stages of cellular respiration
How does ATP function like a rechargeable battery in the cell?
It releases energy when a phosphate is removed and can be recharged by adding a phosphate back
What are the two main stages of photosynthesis, and what happens during each?
The light-dependent reactions (in the thylakoid) capture sunlight and make energy-carrying molecules, and the light-independent reactions (in the stroma) use that energy to build glucose.
Where do the three stages of aerobic respiration occur in the cell?
Glycolysis occurs in the cytoplasm, the Krebs cycle occurs in the mitochondria's matrix, and the electron transport chain occurs across the inner mitochondrial membrane.
What is the purpose of fermentation in cells?
The second step in anaerobic fermentation to recycle NAD⁺ so glycolysis can continue making ATP when oxygen isn’t available
Compare the products of aerobic cellular respiration and anaerobic fermentation. How do these differences impact energy yield?
Aerobic respiration produces 36–38 ATP, carbon dioxide, and water, while anaerobic fermentation produces only 2 ATP per glucose molecule, along with either lactic acid (in muscles) or ethanol (in yeast). The lower ATP yield in anaerobic fermentation limits energy production but allows cells to continue producing ATP in the absence of oxygen.
How is ATP connected to both the photosynthesis and cellular respiration equations, and what does this reveal about the role of energy in living systems?
ATP is a product of cellular respiration, where glucose is broken down to release energy (C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP). In photosynthesis, energy from sunlight is used to build glucose (6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂), storing potential energy. This shows that photosynthesis stores energy in glucose, and cellular respiration releases it as ATP for the cell’s use.
How is energy converted during photosynthesis?
Light energy from the sun is converted into chemical energy during the light-dependent reactions. That energy is then used to build glucose during the light-independent reactions, storing the energy in the bonds of the glucose molecule.
[Light Energy --> Chemical Energy (ATP) --> Chemical Energy (Glucose)]
Explain the entire process of aerobic cellular respiration, including the main energy carriers produced at each step and their role in ATP synthesis.
In glycolysis (in the cytoplasm), glucose is split into two pyruvate molecules, producing 2 ATP and 2 NADH. In the Krebs cycle (in the mitochondria matrix), each pyruvate is further broken down, releasing 2 ATP, 6 NADH, and 2 FADH₂. In the electron transport chain (on the inner mitochondrial membrane), NADH and FADH₂ donate electrons to create a proton gradient, which drives ATP synthesis via ATP synthase, producing approximately 34 ATP. The final electron acceptor is oxygen, which combines with electrons and protons to form water.
Compare lactic acid and alcoholic fermentation by listing one organism that performs each and the products each create.
Lactic acid: Human muscle cells --> lactic acid
Alcoholic: Yeast --> ethanol and carbon dioxide
Explain the role of oxygen in cellular respiration and how it is involved in the electron transport chain.
Oxygen acts as the final electron acceptor in the electron transport chain. It combines with electrons and protons to form water, which allows the chain to continue, maintaining the proton gradient needed for ATP synthesis.