Identify Cellular Respiration Components - Biology

1. In $\mathrm{C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O}$, identify the product gases.

   Carbon dioxide ($6\ \mathrm{CO_2}$). Carbon dioxide gas is produced as waste during respiration.

2. Identify the product that contains the carbon atoms originally found in glucose.

   Carbon dioxide ($\mathrm{CO_2}$). Glucose carbons are oxidized and released as $\mathrm{CO_2}$ waste.

3. What is the product released as gas during pyruvate oxidation per pyruvate?

   $1\ \mathrm{CO_2}$. One carbon is removed from each 3-carbon pyruvate as $\mathrm{CO_2}$.

4. How many FADH$_2$ are produced by the citric acid cycle per glucose?

   $2$ FADH$_2$ per glucose. Two acetyl-CoA from glucose each produce 1 FADH$_2$ molecule.

5. Identify the products formed when NADH is oxidized in the electron transport chain.

   NAD$^+$ and electrons (energy released). NADH loses electrons and hydrogen, returning to oxidized NAD$^+$ form.

6. Identify the reactant that provides most of the carbon atoms in cellular respiration.

   Glucose ($\mathrm{C_6H_{12}O_6}$). Glucose's 6 carbon atoms are released as $\mathrm{CO_2}$ during respiration.

7. In $\mathrm{C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O}$, identify the reactant gases.

   Oxygen ($6\ \mathrm{O_2}$). Oxygen gas is consumed as a reactant in cellular respiration.

8. Identify the stage that produces acetyl-CoA as its key product.

   Pyruvate oxidation (link reaction). Pyruvate is converted to acetyl-CoA during the link reaction.

9. How many FADH$_2$ are produced by the citric acid cycle per acetyl-CoA?

   $1$ FADH$_2$ per acetyl-CoA. One FADH$_2$ is produced per acetyl-CoA during the cycle.

10. Identify the two products of lactic acid fermentation from pyruvate reduction.

    Lactate and NAD$^+$. Pyruvate is reduced to lactate while NADH is oxidized to NAD$^+$.

11. Identify the immediate reactant molecule that enters the citric acid cycle after pyruvate oxidation.

    Acetyl-CoA. Pyruvate is converted to acetyl-CoA before entering the citric acid cycle.

12. Identify the molecule that is a reactant in respiration but a product in photosynthesis.

    Glucose ($\mathrm{C_6H_{12}O_6}$). These processes have opposite reactants and products for glucose.

13. What is the main carbon-containing product of pyruvate oxidation (link reaction) per pyruvate?

    Acetyl-CoA (plus $\mathrm{CO_2}$ released). Pyruvate loses one carbon as $\mathrm{CO_2}$, forming 2-carbon acetyl-CoA.

14. Which molecule is regenerated as a product of fermentation to allow glycolysis to continue?

    NAD$^+$. NAD$^+$ regeneration allows glycolysis to continue producing ATP.

15. Which reactant is required for aerobic respiration but not required for fermentation?

    Oxygen ($\mathrm{O_2}$). Aerobic respiration requires oxygen; fermentation occurs without oxygen.

16. Identify the stage that uses oxygen directly as a reactant.

    Electron transport chain (oxidative phosphorylation). Oxygen serves as the final electron acceptor in aerobic respiration.

17. Identify the molecule that is a product in respiration but a reactant in photosynthesis.

    Carbon dioxide ($\mathrm{CO_2}$). These processes have opposite reactants and products for $\mathrm{CO_2}$.

18. Which three outputs are the main products of aerobic cellular respiration?

    Carbon dioxide, water, and ATP ($\mathrm{CO_2}$, $\mathrm{H_2O}$, ATP). Carbon dioxide and water are waste products; ATP stores captured energy.

19. Identify the correct side of the arrow for products in a chemical equation.

    Right side of $\rightarrow$. Products are substances formed as a result of the reaction.

20. What is the net NADH product of glycolysis per glucose?

    $2$ NADH. Two NADH molecules are formed during glucose oxidation in glycolysis.

21. Identify the stage that produces the most $\mathrm{CO_2}$ per glucose molecule.

    Citric acid cycle ($4\ \mathrm{CO_2}$ per glucose). The citric acid cycle produces most $\mathrm{CO_2}$ per glucose molecule.

22. Identify the reactant that serves as the final electron acceptor in aerobic respiration.

    Oxygen ($\mathrm{O_2}$). Oxygen accepts electrons at the end of the electron transport chain.

23. Identify the correct side of the arrow for reactants in a chemical equation.

    Left side of $\rightarrow$. Reactants are starting materials that get consumed in the reaction.

24. Which molecule is the immediate reactant reduced to lactate during lactic acid fermentation?

    Pyruvate. Pyruvate accepts electrons from NADH to become lactate.

25. Identify the total number of $\mathrm{CO_2}$ produced per glucose in aerobic respiration.

    $6\ \mathrm{CO_2}$ per glucose. All 6 glucose carbons are eventually released as $\mathrm{CO_2}$ molecules.

26. How many $\mathrm{CO_2}$ molecules are produced by the citric acid cycle per acetyl-CoA?

    $2\ \mathrm{CO_2}$ per acetyl-CoA. Both carbons from acetyl-CoA are released as $\mathrm{CO_2}$ waste.

27. Identify the two main reactants needed for oxidative phosphorylation to make ATP.

    NADH/FADH$_2$ and $\mathrm{O_2}$ (with ADP + $\mathrm{P_i}$). Electron carriers provide electrons; oxygen is the final acceptor.

28. Which molecule is reduced to form water during aerobic respiration?

    Oxygen ($\mathrm{O_2}$) is reduced to $\mathrm{H_2O}$. Oxygen accepts electrons and hydrogen ions to form water molecules.

29. In aerobic respiration, which molecule is the final product of energy capture for cell work?

    ATP. ATP stores energy in phosphate bonds for cellular work.

30. Identify the product formed when oxygen accepts electrons and hydrogen ions at the end.

    Water ($\mathrm{H_2O}$). Forms when oxygen accepts electrons and combines with hydrogen ions.

31. Which stage directly produces water as a product: electron transport chain or glycolysis?

    Electron transport chain (oxidative phosphorylation). Water forms when oxygen accepts electrons at the transport chain end.

32. Which two substances are the main reactants of aerobic cellular respiration?

    Glucose and oxygen ($\mathrm{C_6H_{12}O_6}$ and $\mathrm{O_2}$). Glucose provides carbon and energy; oxygen serves as the final electron acceptor.

33. Which molecule is oxidized during cellular respiration to release energy?

    Glucose ($\mathrm{C_6H_{12}O_6}$). Glucose loses electrons (is oxidized) to release stored chemical energy.

34. How many $\mathrm{CO_2}$ molecules are produced by the citric acid cycle per glucose?

    $4\ \mathrm{CO_2}$ per glucose. Two acetyl-CoA from glucose each release 2 $\mathrm{CO_2}$ molecules.

35. How many NADH are produced by the citric acid cycle per acetyl-CoA?

    $3$ NADH per acetyl-CoA. Three NADH are generated per acetyl-CoA during the cycle.

36. Identify the stage that produces pyruvate as its main carbon product.

    Glycolysis. Glycolysis breaks glucose into two 3-carbon pyruvate molecules.

37. Identify the two products of alcoholic fermentation from pyruvate (overall end products).

    Ethanol and $\mathrm{CO_2}$ (and NAD$^+$ regenerated). Pyruvate loses $\mathrm{CO_2}$ then is reduced to ethanol by NADH.

38. What is the net ATP product of glycolysis per glucose under typical textbook accounting?

    Net $2$ ATP. Glycolysis produces 4 ATP but uses 2 ATP, giving net gain of 2.

39. Identify the coefficient of carbon dioxide in $\mathrm{C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O}$.

    $6$. The coefficient shows 6 carbon dioxide molecules are produced.

40. What are the main reduced electron carriers produced by the citric acid cycle?

    NADH and FADH$_2$. These carry electrons to the electron transport chain for ATP production.

41. What is the direct ATP-equivalent product made in the citric acid cycle per glucose?

    $2$ ATP (or GTP) per glucose. Two acetyl-CoA from glucose each produce 1 ATP equivalent.

42. What is the main carbon-containing product of glycolysis from one glucose molecule?

    Two pyruvate ($2\ \mathrm{C_3H_3O_3^-}$). One glucose splits into two 3-carbon pyruvate molecules.

43. Identify the products formed when FADH$_2$ is oxidized in the electron transport chain.

    FAD and electrons (energy released). FADH$_2$ loses electrons and hydrogen, returning to oxidized FAD form.

44. What is the direct ATP-equivalent product made in the citric acid cycle per acetyl-CoA?

    $1$ ATP (or GTP) per acetyl-CoA. Direct phosphorylation produces 1 ATP (or equivalent GTP) per cycle.

45. Identify the coefficient of oxygen in $\mathrm{C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O}$.

    $6$. The coefficient shows 6 oxygen molecules are needed per glucose.

46. How many NADH are produced by the citric acid cycle per glucose?

    $6$ NADH per glucose. Two acetyl-CoA from glucose each produce 3 NADH molecules.

47. Identify the coefficient of water in $\mathrm{C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O}$.

    $6$. The coefficient shows 6 water molecules are formed per glucose.

48. Identify the immediate reactants used by ATP synthase to form ATP.

    ADP and inorganic phosphate ($\mathrm{P_i}$). ATP synthase combines these to form ATP using proton gradient energy.

49. What is the overall balanced equation for aerobic cellular respiration (using formulas)?

    $\mathrm{C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + ATP}$. Shows glucose and oxygen converted to carbon dioxide, water, and energy (ATP).

50. How many NADH are produced during pyruvate oxidation per glucose?

    $2$ NADH per glucose. Two pyruvates from one glucose each produce one NADH during oxidation.

51. Identify the total number of $\mathrm{H_2O}$ molecules formed per glucose in the overall equation.

    $6\ \mathrm{H_2O}$ per glucose. Water molecules form when oxygen accepts electrons and hydrogen ions.

52. Which process produces $\mathrm{CO_2}$ as a waste product: glycolysis or citric acid cycle?

    Citric acid cycle. The citric acid cycle releases carbon atoms as $\mathrm{CO_2}$ waste.

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