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Exam 2 Review

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  • #24:Which of the following could be a cellular response to a signal received by a cell?
    Activation of a gene, Activation of a protein, Inactivation of a protein, Cellular division
  • #31: Tryosine kinase receptors phosphorylate the same amino acid residues as intracellular kinases.
    False
  • #10: TRUE vs FALSE: Molecule Y is an allosteric regulator of an enzyme, which means it binds to the active site of the molecule and prevents the enzyme’s ligand from binding, thereby inhibiting the enzyme’s activity.
    False
  • #6: Molecule D inhibits its own synthesis via a negative feedback pathway; which part of the pathway is it MOST LIKELY to interact with?
    Enzyme 1
  • #17: What is the oxygen released by photosynthesis a byproduct of?
    Splitting water
  • #9: TRUE vs FALSE: Fermentation is an anabolic and anaerobic process that does not need ATP
    False
  • #7: Chemical reactions that build large molecules from smaller molecules are------- reactions; an example of this type of reaction in a metabolic pathway is-------.
    Anabolic / photosynthesis
  • #27:Receptors for cellular communication signals are found in which part(s) of the cell?
    Plasma membrane and cytosol
  • #37: Consider this pathway: epinephrine → G protein-coupled receptor → G protein → adenylyl cyclase → cAMP. Identify the second messenger
    cAMP
  • #40: Protein phosphorylation is commonly involved with all of the following except
    activation of G protein-coupled receptors. (not phosphorylated, for example GDP is switched out for GTP and not phosphorylated to create GTP)
  • #38: Apoptosis involves all but which of the following?
    Lysis of the cell
  • #4: TRUE or FALSE: A cell at equilibrium is a dead cell.
    True
  • #22:TRUE vs FALSE: Most leaves look green because the major photosynthetic pigment, chlorophyll, absorbs green light
    False
  • #12: Why is glycolysis considered to be one of the first metabolic pathways to have evolved?
    It occurs in the cytosol, does not require oxygen and is found in most organisms
  • #33: Scaffolding proteins can increase the efficiency of signal transduction.
    True
  • #20: TRUE vs FALSE:The mitochondrial matrix in a mitochondrion is equivalent to the stroma of a chloroplast.
    True
  • #16: TRUE vs FALSE: The total amount of ATP made from one glucose molecule after cellular respiration is 16-18 ATP
    False
  • #5: The ΔG of an enzyme catalyzed reaction was measured in lab and was -20 kcal/mol. If you repeat the experiment with twice the amount of enzyme, what will the ΔG of the new reaction be?
    -20 kcal/mol
  • #14: In the Krebs Cycle, which occurs in the _____________________, the rest of the carbon from glucose is converted to ____________, and more _______ , which is made by __________________.
    mitochondrial matrix, CO2, ATP, substrate level phosphorylation
  • #18: Which part of the chlorophyll molecule is responsible for its location in the chloroplast?
    The hydrophobic tail
  • #29: Endocrine signaling, which involves hormones, is an example of long distance signaling
    True
  • #8: TRUE or FALSE; When a molecule is oxidized, the molecule gains an electron.
    False ( OIL- RIG: Oxidation Is Losing - Reduction Is Gaining)
  • #30: Which of the following statements about cell communication and signal transduction is TRUE?
    Plasma membrane receptors bind proteins and peptides, while cytoplasmic receptors bind molecules that can cross the plasma membrane
  • #15: Which of the following types of molecules can be used as an energy source in cellular respiration?
    Proteins, amino acids, Carbohydrates, Fats, fatty acids
  • #34: Binding of a signaling molecule to which type of receptor leads directly to a change in the distribution of substances on opposite sides of the membrane?
    ligand-gated ion channel
  • #3: Spontaneous chemical reactions have a [positive/negative] free energy. Enzymes increase the [rate/direction] of reactions by [increasing/decreasing] the energy of activation but [do/do not] change the ΔG of the reaction.
    negative, rate, decreasing, do not,
  • 2) Which of the following occurs in glycolysis?
    Glucose is converted to pyruvate
  • #35: The activation of receptor tyrosine kinases is characterized by
    dimerization and phosphorylation
  • #32: G-protein coupled receptors only activate one pathway
    True
  • #23: What is the correct order of the steps in signal transduction?
    Reception, transduction, response, reset
  • #1: What happens to the heat generated when a cell does work (chemical, transport, or mechanical)?
    It is lost to the environment
  • #25: Second messengers serve what function?
    Transduce (or amplify) a message received from another cell
  • #39: Which observation suggested to Sutherland the involvement of a second messenger in epinephrine’s effect on liver cells?
    Glycogen breakdown was observed only when epinephrine was administered to intact cells.
  • #36: Lipid-soluble signaling molecules, such as aldosterone, cross the membranes of all cells but affect only target cells because
    intracellular receptors are present only in target cells.
  • #21: Photosystems 1 and 2, which capture the photons of light from the sun, are located in which part of the chloroplast?
    Thylakoid membrane
  • #13: Fermentation is important in organisms because it
    Regenerates NAD+
  • #11: ATP is formed by chemiosmosis during which two processes?
    Oxidative Phosphorylation and the Light Reactions
  • #26: Direct communication between cells occurs by which of the following?
    Gap junctions between animal cells, Plasmodesmata between plant cells, Cell recognition molecules binding specific receptors on other cells
  • #19: What is the first step of photosynthesis?
    Absorb a photon of light
  • Extra ?... TRUE or FALSE: A reaction that has ΔG= 17 kcal/mol is a spontaneous reaction
    false
  • #28: The transduction step in cell communication is important for which reason?
    It is the step that amplifies the original signal and Different signals can be combined to fine tune the cell’s response