Cellular Respiration
What process turns glucose into two molecules of pyruvate and produces a small net gain of ATP in the cytoplasm?
Glycolysis
What organelle is primarily responsible for photosynthesis?
Chloroplast
What is another name commonly used for anaerobic respiration in cells?
Fermentation
Write the balanced chemical equation for photosynthesis using chemical formulas (reactants → products).
Photosynthesis chemical equation (balanced): 6CO2+6H2O+light→C6H12O6+6O2
Where in the cell does glycolysis occur?
Cytoplasm
Name the three main stages of aerobic cellular respiration in order.
Glycolysis, Krebs Cycle, Electron Transport Chain
Give the overall chemical equation for photosynthesis in words.
Carbon dioxide + water + light energy -----> glucose + oxygen
Where in the cell does anaerobic respiration (fermentation) take place?
Cytoplasm
Write the balanced chemical equation for aerobic cellular respiration using chemical formulas (reactants → products).
Aerobic cellular respiration chemical equation (balanced): C6H12O6+6O2→6CO2+6H2O+ATP (energy)
In which mitochondrial compartment does the Krebs (citric acid) cycle occur?
Mitochondrial Matrix
What electron carrying molecules are produced in glycolysis and the Krebs cycle and then power the Electron Transport Chain?
NADH and FADH2
Identify the location (within the chloroplast) of the light-dependent reactions and name two major inputs to those reactions.
Thylakoid membrane, Major inputs are light and water, ADP, and NADP+
What are the products of anaerobic respiration in eukaryotic muscle cells and in yeast (a common prokaryote example used in labs)?
In eukaryotic cells the products are lactic acid and 2 ATP. In yeast cells or prokaryotic cells the products are CO2 and ethanol (alcohol).
Provide the chemical equation (in words or formulas) that summarizes glycolysis from glucose to pyruvate (include ATP net yield).
Glucose (C6H12O6)→2 Pyruvate (3C each)+2 ATP (net)+2 NADH
Where (specific mitochondrial structure) does the Electron Transport Chain take place?
Inner membrane of the mitochondria
What are the inputs to the Krebs cycle that result in CO2 being released?
Pyruvate
Identify the location (within the chloroplast) of the light-independent reactions (Calvin cycle) and list two outputs of the light-independent reactions.
Light-independent reactions (Calvin cycle) occur in the stroma of the chloroplast; outputs include G3P (a 3 carbon sugar) which is used to make glucose and ADP + Pi and NADP+ that are returned to light-dependent reactions. Some outputs (like ADP and NADP+) do not leave the chloroplast.
List at least two factors that could influence the rate of anaerobic respiration you might have observed in a fermentation lab.
Factors: sugar (glucose) concentration, temperature, pH, amount of yeast cells
Write the simplified chemical equation for fermentation in yeast (alcoholic fermentation).
Alcoholic fermentation (yeast): Pyruvate→Ethanol+CO2 Pyruvate→Ethanol+CO2
Name the parts of the mitochondrion that are relevant to cellular respiration (at least three distinct structures).
Mitochondria parts: Intermembrane space, inner membrane, cristae, matrix
Define aerobic respiration and explain why oxygen is essential for the Electron Transport Chain.
Aerobic respiration is the process of producing ATP using oxygen as the final electron acceptor in the Electron Transport Chain; oxygen accepts electrons and protons to form water, allowing the ETC to continue and produce a large amount of ATP.
Explain how the light-dependent and light-independent reactions depend on each other (give specific molecules that link them).
Light-dependent reactions produce ATP and NADPH which the Calvin cycle (light-independent reactions) uses to fix CO2 into sugars; the Calvin cycle returns ADP, Pi, and NADP+ to be reused in the light-dependent reactions.
Explain why organisms use fermentation instead of aerobic respiration under certain conditions; include the role of NADH and NAD+.
Without oxygen, the Electron Transport Chain cannot accept electrons, so NADH must be oxidized back to NAD+ via fermentation pathways (lactic acid or alcohol fermentation) so glycolysis can continue producing ATP. Fermentation yields far less ATP per glucose than aerobic respiration but allows short-term ATP production.
Compare the chemical equations for photosynthesis and aerobic respiration and explain how the products of one are the inputs of the other.
Photosynthesis stores energy by converting CO2 and H2O into glucose and O2; aerobic respiration reverses this process, breaking glucose back down into CO2 and H2O and releasing energy as ATP. The products of photosynthesis (glucose, O2) are reactants for cellular respiration.
For both chloroplasts and mitochondria, name the specific locations where ATP is produced and explain briefly how ATP generation differs between the two organelles.
In chloroplasts, ATP is made by ATP synthase in the thylakoid membrane during light-dependent reactions using a proton gradient across the thylakoid membrane; in mitochondria, ATP is made by ATP synthase in the inner mitochondrial membrane (cristae) using a proton gradient across the inner membrane created by the ETC.
The main difference: chloroplasts use light energy to drive proton pumping while mitochondria use energy from chemical electron carriers.