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Cellular Respiration and Metabolism - General Biology

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Terms in this set (20)

  • What is metabolism?

    Metabolism is the sum of all chemical reactions in a cell, including both catabolic and anabolic reactions.

  • Difference between catabolic and anabolic reactions

    Catabolic reactions break down molecules and release energy, while anabolic reactions build molecules and require energy.

  • What are exergonic and endergonic reactions?

    Exergonic reactions release energy; endergonic reactions require energy. They are often coupled in metabolism.

  • Role of enzymes in metabolism

    Enzymes speed up metabolic reactions by lowering activation energy and are specific to substrates.

  • Structure and function of ATP

    ATP has three phosphate groups with high-energy bonds; it stores and releases energy for cellular processes.

  • How are ATP and ADP related?

    ATP loses a phosphate group to become ADP, releasing energy; ADP can be phosphorylated back to ATP using energy.

  • What are redox reactions?

    Redox reactions involve the transfer of electrons; oxidation is loss of electrons, reduction is gain of electrons.

  • Role of electron carriers NAD+ and FAD

    NAD+ and FAD accept electrons (are reduced) to NADH and FADH2, transporting energy in cellular respiration.

  • Overall chemical equation for cellular respiration

    \(\mathrm{C_6H_{12}O_6 + 6 O_2 \rightarrow 6 CO_2 + 6 H_2O + \sim 36 ATP}\)

  • Where does glycolysis occur and what are its products?

    Glycolysis occurs in the cytoplasm; it converts glucose into 2 pyruvate, producing 2 ATP (net) and 2 NADH.

  • What happens during pyruvate oxidation?

    Pyruvate is transported into the mitochondria and converted to acetyl CoA, producing 2 NADH and releasing CO2.

  • Key features of the Citric Acid (Krebs) Cycle

    Occurs in mitochondrial matrix; acetyl CoA is broken down, producing 2 ATP, 6 NADH, 2 FADH2, and releasing CO2.

  • What is substrate-level phosphorylation?

    ATP synthesis where a phosphate group is directly transferred from a substrate to ADP, occurring in glycolysis and Krebs cycle.

  • Role of the Electron Transport Chain (ETC)

    ETC uses electrons from NADH and FADH2 to pump protons across the inner mitochondrial membrane, creating a gradient.

  • What is chemiosmosis?

    Protons flow back through ATP synthase, using proton motive force to synthesize ATP from ADP and phosphate.

  • Why is oxygen essential in cellular respiration?

    Oxygen is the final electron acceptor in the ETC, allowing electrons to flow and ATP production to continue.

  • Difference between aerobic and anaerobic respiration

    Aerobic respiration requires oxygen; anaerobic respiration (fermentation) does not and regenerates NAD+ for glycolysis.

  • Purpose of fermentation

    Fermentation regenerates NAD+ in the absence of oxygen, allowing glycolysis to continue producing ATP.

  • Types of fermentation and their products

    Alcohol fermentation produces ethanol and CO2 (used by yeast); lactic acid fermentation produces lactic acid (used by bacteria and muscles).

  • How is cellular respiration regulated?

    Feedback inhibition controls enzyme activity; high ATP levels inhibit enzymes, while low ATP levels activate them.