BIOCHEM Ashley Q's

• what does photosynthesis convert light energy into?

  chemical energy
• The synthesis of proteins using amino acids is best described as:

  An anabolic reaction
• According to the first law of thermodynamics, the quantity of energy is constant in the universe.
• A cell that was not able to do work would be....?

  dead
• Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics?

  The decrease in entropy is associated with growth of an organism. As a consequence of growth, organisms cause a greater increase in entropy in their environment than the decrease in entropy associated with their increased complexity.
• What is the charge on a molecule of ADP?

  -3
• According to the second law of thermodynamics...?

  Each energy transfer increases the level of disorder of a system
• The breakdown of a polysaccharide into monosaccharides is best described as:

  a catabolic reaction.
• What does ATP stand for?

  Adenosine triphosphate
• What is the charge on a molecule of ATP?

  -4
• Which of the following is a product of aerobic respiration in a yeast cell?

  ATP.
• For each glucose molecule that is oxidised in aerobic respiration approximately how many molecules of ATP are produced?

  32.
• Which kind of metabolic poison would most directly interfere with glycolysis?

  an agent that closely mimics the structure of glucose but is not metabolized
• How does a noncompetitive inhibitor decrease the rate of an enzyme-catalyzed reaction?

  by binding to an allosteric site, thus changing the shape of the active site of the enzyme
• Which of the following statements about an enzyme is true:

  it can often contain a cofactor.
• In the wild bears are able to keep warm during the winter because of which of the following?

  Uncoupling proteins
• At a temperature above the optimal temperature for a particular reaction which of the following is true?

  The enzyme could become denatured
• Which of the following is a product of anaerobic respiration in a yeast cell?

  Ethanol
• For each glucose molecule that is metabolised via aerobic respiration how many molecules of ATP are produced?

  32
• At a temperature above the optimal temperature for a particular reaction.....

  the enzyme will start to lose its shape.
• Where do the Calvin cycle reactions in photosynthesis take place?

  the stroma
• The reducing power for Calvin cycle reactions is provided by which of the following molecules?

  NADPH
• Chloroplast ATP synthase is present in which membrane?

  the thylakoid membrane
• Where in a plant cell does the Calvin cycle take place?

  stroma of the chloroplast
• How is photosynthesis similar in C4 plants and CAM plants?

  In both cases, rubisco is not used to fix carbon initially.
• Which are the substrates of Rubisco?

  Ribulose bisphosphate and CO2 or O2
• Which is probably the most abundant enzyme in the world?

  rubisco
• The light-dependent reactions of photosynthesis resemble aerobic respiration as both:

  Require electron transport systems to synthesise ATP
• The molecules that link the light-dependent and Calvin cycle reactions are:

  ATP and NADPH.
• Even though plants cells carry out photosynthesis, they still use their mitochondria for oxidation of pyruvate. Under what conditions will plant cell mitochondria be active in this process?

  In all cells, with or without light
• What is the name of a solution that has a higher solute concentration than the inside of a cell?

  hypertonic.
• Which of the following plays a role in the depolarising phase of an action potential in a nerve cell?

  a Na+ ion channel.
• Which of the following is true about a neuron at rest?

  Na+ and Cl- ions are mostly outside the cell, while K+ ions are mostly inside the cell
• A sodium-potassium pump does which of the following?

  moves three sodium ions out of a cell and two potassium ions into a cell using energy from ATP hydrolysis
• Which of the following would be the least permeable across a lipid bilayer?

  H+
• If a plant cell were placed in a hypotonic solution which of the following would best describe the cell?

  it would be turgid.
• Which of the following would move most easily across a lipid bilayer?

  O2
• The transient change in membrane potential that occurs during a nerve impulse can be best described as what?

  An action potential
• Water can move across the plasma membrane via which of the following?

  Through both dimple diffusion and facilitated diffusion
• At resting potential, what is the status of different membrance proteins?

  Na+ and K+ channels are mostly closed, the Na+/K+ transporter pumps ions in and out of the cell