Q&A Hero

Q: Most enzymatic reactions in the body are one step processes.

Q: Enzymes in a metabolic pathway act antagonistically to produce a final product.

Q: An enzyme-catalyzed reaction in the body at 50 C will proceed at a faster rate than at 37 C.

Q: The phosphatase found in bone would have a pH optimum that is ______________ than the pH optimum of the phosphatase found in the prostate gland. A. higher B. lower C. the same as

Q: The enzyme with the lowest pH optimum is A. acid phosphatase. B. lipase. C. monoamine oxidase. D. pepsin.

Q: In an enzymatic reaction, when temperature is increased past the point of "optimal temperature," the enzyme starts to A. increase its catalytic activity. B. reduce its catalytic activity. C. increase its allosteric properties. D. increase product formation.

Q: Coenzymes are organic molecules that are required for proper function of some enzymes.

Q: A deficiency of dietary copper could limit the activity of some enzymes.

Q: The pH optimum for enzymes secreted by the stomach is higher than the pH optimum for enzymes secreted by the pancreas.

Q: The pH optima for all digestive enzymes are approximately equal to the pH of blood.

Q: Isomers are different forms of an enzyme.

Q: Isoenzymes bind different substrates and catalyze different chemical reactions.

Q: Abnormally high concentration of the BB form of creatine phosphokinase is associated with a myocardial infarction.

Q: The MM isoenzyme of creatine phosphokinase is found in diseased skeletal muscle.

Q: Enzymes which remove hydrogen atoms from their substrates are referred to as A. dehydrogenases. B. hydrolases. C. catalases. D. peroxidases.

Q: The breakdown of hydrogen peroxide is catalyzed by A. aldolase. B. amylase. C. catalase. D. kinase.

Q: Addition of phosphate groups to a particular molecule is catalyzed by A. transaminases. B. phosphatases. C. isomerases. D. kinases.

Q: Hydrolysis reactions are catalyzed by A. dehydrogenases. B. hydrolases. C. isomerases. D. synthases.

Q: Dehydration synthesis reactions are catalyzed by A. dehydrogenases. B. hydrolases. C. isomerases. D. synthases.

Q: Pancreatic amylase catalyzes the breakdown of oligosaccarides to disaccharides with the addition of water. What classification of enzymes would amylase be in? A. dehydrogenase B. isomerase C. synthase D. hydrolase

Q: Which of the following does NOT affect the activity of an enzyme? A. the organ the enzyme is in B. concentration of enzyme and substrate molecules C. concentration of cofactors and coenzymes D. pH and temperature

Q: In general, decreased body temperature causes the rate of enzymatic reactions to decrease.

Q: Pyruvate dehydrogenase catalyzes the removal of hydrogen from pyruvic acid.

Q: The conversion of glucose to galactose is catalyzed by an isomerase.

Q: The model that explains how an enzyme and substrate fit together is the A. enzyme-substrate model. B. lock-and-key model. C. conformational model. D. None apply.

Q: The model that describes how an enzyme can adjust its shape to fit the shape of the substrate is the A. lock-and-key model. B. enzyme-substrate model. C. induced-fit model. D. conformational model.

Q: An enzyme elevated in the plasma of men with prostate cancer is A. alkaline phosphatase. B. catalase. C. creatine kinase. D. acid phosphatase.

Q: The level of protein structure primarily involved in determining enzyme activity is the A. primary structure. B. secondary structure. C. tertiary structure. D. quaternary structure.

Q: When an enzyme catalyzes a chemical reaction A. the enzyme binds to the substrate's active site. B. the enzyme's active site binds the product. C. amino acids in the substrate allow for interaction with the product. D. amino acids in the enzyme's active site interact with substrate molecules.

Q: Elevated plasma aldolase could be indicative of A. muscular dystrophy. B. pancreatitis. C. pernicious anemia. D. prostate cancer.

Q: Elevated plasma amylase could indicate A. osteitis deformans. B. a myocardial infarct. C. obstructive jaundice. D. a perforated peptic ulcer.

Q: Reactant molecules of enzyme action are called A. substrates. B. allosteric inhibitors. C. cofactors. D. products.

Q: Enzymes ______________ the rate of a specific chemical reaction. A. decrease increase C. have no effect on

Q: The rate at which a chemical reaction can be increased is by either ______________ the temperature or ______________ the activation energy. A. increasing, increasing B. increasing, decreasing C. decreasing, decreasing D. decreasing, increasing

Q: The vitalist concept was defeated because of fermentation experiments involving A. yeast. B. bacteria. C. amoebae. D. paramecia.

Q: Which of the following statements about enzymes is NOT true? A. Enzymes increase chemical reaction rates. B. Enzymes are consumed during a chemical reaction. C. Enzymes decrease the free energy of activation of specific reactions. D. Enzymes have unique pH and temperature optima.

Q: The process that yeast uses to make alcohol from glucose is A. fermentation. B. aerobic respiration. C. photosynthesis. D. catalysis.

Q: Biological catalysts A. decrease reaction rates. B. alter a reaction product. C. remain unchanged at the end of the reaction. D. All apply.

Q: Enzymes are specific for a given substrate.

Q: The substrate binds to the ______________ of the enzyme. A. allosteric site B. acidic site C. neutral site D. active site

Q: In some instances RNA can act as an enzyme.

Q: During a chemical reaction, a catalyst increases the rate at which the reaction occurs.

Q: Catalysts increase reaction rates by lowering the activation energy of a reaction.

Q: Ribozymes are RNA molecules that act as A. hormones. B. cofactors. C. enzymes. D. inhibitors.

Q: How are the phospholipids arranged to form the plasma membrane? A. single layer with hydrophilic heads outward B. double layer with hydrophobic tails facing inward toward each other C. double layer with hydrophilic heads facing inward toward each other D. double layer with phospholipids on the outside and proteins on the inside

Q: Large hydrophilic molecules can readily move unaided into and out of cells.

Q: Phagocytosis is a bulk transport process in which the plasma membrane extends as pseudopods around a particle of organic matter.

Q: Neutrophils and macrophages move through the extracellular matrix by amoeboid movement.

Q: Pseudopods can be used for both amoeboid movement and phagocytosis.

Q: Particulate matter is nonspecifically taken into cells by the process of A. exocytosis. B. phagocytosis. C. pinocytosis. D. receptor-mediated endocytosis.

Q: Phagocytosis is important for A. body defense against foreign organic matter. B. promoting inflammation. C. removal of old and dying cells. D. All apply.

Q: Most enzymes are lipids.

Q: Which of the following is NOT a characteristic of a catalyst? A. is not changed itself at the end of the reaction B. does not change the nature of the reaction C. can change the final result of the reaction D. increases the rate of the reaction

Q: The plasma membrane is referred to as a mosaic because of the presence of A. stationary proteins in a uniform arrangement. B. carbohydrates in changing patterns. C. phospholipids that are in constant motion. D. moving proteins in a random arrangement.

Q: The flexibility of a cell's membrane is determined by the ratio of _____________ to ___________. A. protein, carbohydrate B. cholesterol, protein C. phospholipids, protein D. cholesterol, phospholipids

Q: Which of the following is NOT a function of membrane proteins? A. transport B. energy production C. structural support D. receptors

Q: The cell is the basic structural and functional unit in the body.

Q: The _____________ is the liquid portion of the cell between the plasma membrane and nucleus. A. cytoskeleton B. peroxisome C. cytosol D. phospholipids

Q: The plasma membrane is a static, uniform structure that protects the cells and controls the passageway of materials into and out of the cell.

Q: Carbohydrates are primarily associated with the outer surface of the cell membrane.

Q: The hydrophobic center of the plasma membrane will restrict the movement of water and fat-soluble substances through the membrane.

Q: The body cells that contain plasma membranes with highest cholesterol content are the muscle cells.

Q: Proteins located on the surface of the plasma membrane can act as ___________ for hormones. A. receptors B. enzymes C. neurotransmitters D. pseudopods

Q: Proteins that are partially embedded on one side of the plasma membrane are A. integral proteins. B. transport proteins. C. peripheral proteins. D. fluid proteins.

Q: This organ contains cells that are haploid: A. the testis B. the liver C. the lung D. the heart

Q: This process is also known as reduction division: A. cell division B. meiosis C. mitosis D. genetic translation

Q: Crossing over occurs during A. anaphase I of meiosis. B. metaphase of mitosis. C. prophase I of meiosis. D. metaphase II of meiosis.

Q: Crossing over is important for A. increasing genetic variability. B. preventing mutations. C. limiting genetic recombination. D. maintaining chromosome structure.

Q: Genes that have been silenced are passed to daughter cells during mitosis and meiosis in a process called A. apoptosis. B. necrosis. C. hypertrophy. D. epigenetic inheritance.

Q: Gene silencing may be accomplished by A. removal of the gene. B. methylation of cytosine bases in DNA. C. crossing over. D. genetic recombination.

Q: In epigenetic inheritance A. both homologous chromosomes are inactivated. B. one set of the homologous chromosomes are silenced. C. one allele of a homologous pair is expressed. D. None apply.

Q: Match the statement to the correct part of the cell life cycle.1. 4. The centromeres split, separating sister chromotidsinterphase 2. 1. Chromatin is present in the nucleusmetaphase 3. 3. Spindle fibers attach to the centromeres of the chromosomesprophase 4. 5. The nucleolus reappearsanaphase 5. 2. Chromosomes line up along the equator of the celltelophase

Q: Meiosis is only observed in the _____________ and ___________. A. skin, finger nails B. ovaries, breasts C. testes, skin D. ovaries, testes

Q: Growth due to an increase in cell number is called A. hypertrophy. B. hyperplasia. C. atrophy. D. dystrophy.

Q: Growth due to increased cell size is called A. hypertrophy. B. hyperplasia. C. atrophy. D. dystrophy.

Q: Chromosomes move to opposite poles in A. anaphase. B. metaphase. C. prophase. D. telophase.

Q: Centrosomes replicate during A. anaphase. B. cytokinesis. C. interphase. D. telophase.

Q: The pericentriolar material is believed to be responsible for A. cytoskeletal organization. B. centriole replication. C. kinetochore formation. D. centrosome formation.

Q: Cellular senescence may be prevented by A. increased DNA polymerase activity. B. increased telomerase activity. C. increased RNA polymerase activity. D. increased synthase activity.

Q: Telomeres serve to A. increase apoptosis. B. cap the ends of DNA and protect it from damage. C. break DNA and cause it to degrade. D. cause replication of genes.