Metabolic pathwayIn plants and algae, which of the following is a by-product of photosynthesis? Epithelial tissue is found: A on the outer surface of the body. B lining the gastrointestinal tract. C lining the lungs.
MCB Exam 2 Practice Flashcards | Quizlet
In plants and algae, which of the following is a by-product of photosynthesis? Epithelial tissue is found: A on the outer surface of the body. B lining the gastrointestinal tract. C lining the lungs. D lining the blood vessels. E All of these choices are correct. A cellular response to a signal can be terminated by: A depletion of the signal that activates the receptor.
B inactivation of intracellular signal-transduction proteins. C automatic inactivation of proteins in the signal pathway over time. D depletion of a second messenger. Defects in cell signaling can lead to a cancerous cell due to: A overproduction of signals that trigger cell division. B overproduction of a receptor that triggers cell division. C a defective receptor that stays in the activated state and triggers cell division continuously.
D a defective signal-transduction protein that stays in the activated state and triggers cell division continuously. The reducing agent during the Calvin cycle is: Which of the following statements about cadherins and integrins are true? A They are found on the surfaces of most animal cells.
B They are transmembrane proteins that attach to cytoskeletal elements inside the cell. C They are highly diverse, and highly specific for what their extracellular domain will attach to. D They are found in embryonic cells.
E All of the above are correct. Which of the following is the most precise description of the role of enzymes in catalyzing biochemical reactions? A Enzymes provide the necessary activation energy to overcome the transition state. B Enzymes stabilize the transition state and decrease its free energy.
C Enzymes cut hard-to-break bonds allowing the reaction to proceed. A catabolic B anabolic C glycolytic D phosphorylation E carboxylation. Which of the following would you predict for an allosteric enzyme?
A An increase in the concentration of substrate molecules could activate the enzyme. B A downstream product later in the pathway could inactivate the enzyme. C An allosteric inhibitor could cause a conformational change in the enzyme decreasing its activity. D All of the above. Three critical amino acids in the active site of an enzyme are leucine, tryptophan, and alanine.
Which of the following characteristics would you predict the substrate to possess in order to bind the active site of this enzyme? You may use the figure on page 1 to answer this question. A relatively hydrophobic B hydrophilic, with a negative charge C hydrophilic, with a positive charge D hydrophilic, but without a charge.
Which of the following types of cellular activities can be a response to cell signaling? A Cell division is triggered. B Gene expression patterns are changed.
C Enzyme activity patterns are changed. D Cell signals are released to communicate with other cells. Which of the following processes is NOT part of the communication at a neuromuscular junction? A The neuron releases a neurotransmitter to signal contraction by the muscle cell. B A cell-surface receptor on the muscle cell is activated by acetylcholine binding. C Upon activation, the acetylcholine receptor on the neuron undergoes a conformational change to activate an ion channel in the muscle cell.
D An opened ligand-gated ion channel allows sodium ions to rush across the plasma membrane to the inside of the muscle cell. E A sudden influx of sodium ions across the plasma membrane drastically reduces the membrane potential and activates the contractile machinery of the muscle cell. A are used by epithelial cells to move substances along cell surfaces. B move through coordinated activity of cytoskeletal structures. C are used by sperm cells for motion. Autotrophs typically obtain their carbon from: A water; carbon dioxide B carbon dioxide; glucose C oxygen; water D glucose; oxygen E carbon dioxide; oxygen.
B carbon dioxide; glucose. A power ATP synthase. B provide a source of hydrogen ions needed for carbohydrate in the Calvin cycle. C provide a source of hydrogen ions to combine with molecular oxygen to make water. E None of the above. In human cells such as muscle tissue, the product of anaerobic respiration is: Cancer can be characterized by: A a mass of rapidly dividing cells called a tumor.
B metastasized tumor cells that leave the tumor and invade distant parts of the body. C cells that express a type of intermediate filament that is inappropriate for that area of the body. D cells with an enhanced ability to adhere to proteins in the basal lamina. Most of the ATP produced during cellular respiration is generated through: D reduction of FAD.
E oxidation of pyruvate. In a thylakoid membrane, absorbed light energy is passed from one chlorophyll molecule to another until: A it is dissipated as heat. B it is released as fluorescence. C it is passed to a reaction center. D it is converted to ATP. E it is converted to triose phosphate. Mammalian steroid hormones are signaling molecules that function in which of the following types of cell signaling? The extracellular matrix in animals: A is located exclusively in connective tissue.
B is formed by many types of cells, primarily fibroblasts, on their cell surfaces. C is a meshwork of insoluble fibrous proteins, primarily collagens, that assemble in a double helix. D differs from one tissue to the next, essential for maintaining the integrity of the tissue it surrounds. E is attached to cells by Gap junctions. Which one of the following is a characteristic of integrins in metastatic cells? A These integrins give the cells a stronger attachment to the extracellular matrix, especially that of the basal lamina.
B These integrins allow the cells to cross the capillary basal lamina. C These integrins allow the cells to cross the layer of capillary endothelial cells. D These integrins can be targeted by an anticancer therapy that specifically targets the metastatic cells.
The phosphorylation of glucose during glycolysis serves to: A destabilize the molecule, making it easier to cleave.
B trap imported glucose inside the cell. C reduce a biological cofactor, storing energy for later. Which one of the following statements about integrins is correct? A Integrins indirectly connect microfilaments with the extracellular matrix. B The integrins in animal cells are identical to the integrins in plant cells. C There is a single type of integrin, capable of binding to multiple types of extracellular matrix proteins. D Integrins are the primary cell adhesion molecule in a desmosome.
E Adjacent integrins create channels referred to as gap junctions. A least potential energy B most kinetic energy C least kinetic energy D most potential energy E same amount of energy as electrons closest to the nucleus. D most potential energy. Which product s of the Calvin cycle is are exported from the chloroplast for use by the plant cell?