BioTest2

24 July 2022
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160 test answers

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question
When do cells take on their unique characteristics?
answer
During Embryonic Development
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What is the most important transport within a cell?
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Microtubules and Intracellular Membranes
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What are the surface apendages that allow bacterium to stick the surface?
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Pili
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Where are proteins synthesized?
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Ribosomes
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Cell Membrane same as
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Plasma Membrane
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Which proteins are synthesized by bound ribosomes?
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Insulin, ER Protein, and Lysosomal Enzyme
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What is the pathway of Secretory Proteins?
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1. Endoplasmic Reticulum 2. Cis Golgi Cisternae 3. Medial Golgi Cisternae 4. Trans Golgi Cisternae 5. Plasma Membrane
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Mitochondria are found in
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both plant cells and animal cells
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In Animal cells but not Plant cells
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Lysosomes Centrosomes, with Centrioles Flagella
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In Plant Cells but not Animal Cells
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Chloroplasts Central Vacuole Cell Wall Plasmodesmata
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Which of the following statements about the combustion of glucose with oxygen to form water and carbon dioxide (C6H12O6 + 6 O2 → 6 CO2 + 6 H2O) is correct?
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The entropy of the products is greater than the entropy of the reactants.
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Which of these reactions requires a net input of energy from its surroundings?
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endergonic
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In cells, what is usually the immediate source of energy for an endergonic reaction?
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ATP
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The reaction ADP + P --> ATP is a(n) _____ reaction.
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endergonic
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The energy for an endergonic reaction comes from a(n) _____ reaction.
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exergonic
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What is the fate of the phosphate group that is removed when ATP is converted to ADP?
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It is acquired by a reactant in an endergonic reaction.
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What will happen to the rates of the forward and reverse reactions when a catalyst is added?
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Both forward and reverse rates increase.
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An enzyme is _____ when it loses its native conformation and its biological activity.
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denatured
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An enzyme is considered a _____ because it speeds up chemical reactions without being used up.
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catalyst
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An enzyme is considered _____ because of its ability to recognize the shape of a particular molecule.
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specific
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A _____, such as a vitamin, binds to an enzyme and plays a role in catalysis.
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cofactor
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When properly aligned, the enzyme and substrate form an enzyme-substrate (ES) _____.
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complex
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A substrate binds to an enzyme at the _____, where the reaction occurs.
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active site
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In a catalyzed reaction a reactant is often called a _____.
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substrate
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Choose the pair of terms that correctly completes this sentence: Catabolism is to anabolism as _______ is to _______.
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exergonic; endergonic
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Most cells cannot harness heat to perform work because
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temperature is usually uniform throughout a cell.
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Which of the following metabolic processes can occur without a net influx of energy from some other process?
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C6H12O6+6O2->6CO2+6H20
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If an enzyme in solution is saturated with substrate, the most effective way to obtain a faster yield of products is to
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add more of the enzyme.
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Some bacteria are metabolically active in hot springs because
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their enzymes have high optimal temperatures.
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Select the correct statement about chemical energy, a term used by biologists to refer to potential energy available for release in a chemical reaction.
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Light energy is converted to chemical energy during photosynthesis.
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Which of the following statements about the role of ATP in cell metabolism is true?
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The energy from the hydrolysis of ATP may be directly coupled to endergonic processes by the transfer of the phosphate group to another molecule.
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According to the first law of thermodynamics
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The amount of energy in the universe is constant. Chemical reactions do not create or destroy energy. Energy can change from one form to another. Both [The amount of energy in the universe is constant] and [Chemical reactions do not create or destroy energy].
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The second law of thermodynamics states that:
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Energy tends to become increasingly more disorganized.
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Which reaction is NOT an exergonic reaction?
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protein synthesis
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When ATP releases its energy, it forms
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both ADP and Pi
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During enzyme-catalyzed reactions, substrate is a synonym for
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reactant
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Enzymes increase the rate of a given reaction by lowering what kind of energy?
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activation
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Although it is too simple an explanation, the concept of a key fitting into a lock is descriptive of the
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matching of enzyme with substrate
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Which of the following is NOT true of enzyme behavior?
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Each enzyme can catalyze a wide variety of different reactions.
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An allosteric enzyme
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has an active site where substrate molecules bind and another site that binds with intermediate or end-product molecules
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Enzymatic reactions can be affected by
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pH salinity temperature cofactors
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The products of catabolic pathways are usually
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smaller and lower in energy
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Four of the five answers listed below apply to conditions where energy is released. Select the exception.
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synthesis of a fat molecule
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Four of the five answers listed below affect the rate of metabolic pathways. Select the exception.
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the free energy of the reactants and products
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Four of the five answers listed below are portions of a well-known theory. Select the exception.
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All cells have a nucleus.
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Four of the five answers listed below can be found in both prokaryotes and eukaryotes. Select the exception.
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vesicles
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Four of the five answers listed below are bound by membranes. Select the exception.
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ribosome
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Which of the following is(are) not components of all cells?
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cell wall
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Large cells work better if they
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are both flat/thin and have folded membranes
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Prokaryotic cells do NOT have
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Golgi bodies
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Both Bacteria and Archaea have
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cell walls cell membranes ribosomes both cell walls and ribosomes
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Which of the following are common in plants but not in animals?
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chloroplasts and central vacuoles
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An organelle found in the nucleus is a
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nucleolus
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Chromatin includes
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both DNA and protein
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Which of the following is NOT true concerning the nuclear envelope?
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DNA molecules are transported out through the pores.
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These organelles are sometimes referred to as rough or smooth, depending on the structure.
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endoplasmic reticula
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These structures are the primary cellular sites for the production of proteins.
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ribosomes
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These are the primary structures for the packaging of cellular secretions for export from the cell.
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Golgi bodies
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These contain enzymes and are the main organelles of intracellular digestion
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lysosomes
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Mitochondria convert the energy stored in ____ to usable energy for the cell.
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carbon compounds
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Plasmodesmata are
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cross-connections between cell walls
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Structural features that contain the protein actin and help to control the shapes of cells are
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microfilaments
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Organelles used to move chromosomes are the
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microtubules
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The organelle that is compared to a whip and aids a cell to move is a
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flagellum
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Amoeba move by using
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pseudopods
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part of an enzyme that binds to the substrate
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active site
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a permanent loss of protein structure
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denaturation
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universal energy currency
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adenosine triphosphate
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lowers the activation energy of a reaction
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catalyst
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binding of a regulatory molecule changes the shape of the enzyme
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allosteric enzyme
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rate of forward reaction equals rate of reverse reaction
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equilibrium
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an excess of end-product molecules alters the shape of the first enzyme in the pathway and shuts off that metabolic pathway
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feedback inhibition
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attaching a phosphate group by a high-energy bond
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phosphorylation
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contain enzymes for intracellular digestion
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lysosomes
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have microtubules in a 9 x 3 arrangement
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centrioles
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package cellular secretions for export
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Golgi bodies
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extract energy stored in carbohydrates; synthesize ATP; produce water and CO2
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mitochondria
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help distribute chromosomes to the new cells during cell division
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Microtubules
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synthesize subunits that will be assembled into two-part ribosomes in the cytoplasm
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Nucleoli
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a copy of the hereditary information delivered to the ribosomes
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RNA molecules
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store water, ions and organic compounds
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central vacuoles
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encode hereditary information
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DNA molecules
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convert light energy to chemical energy stored in the chemical bonds of glucose or starch
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chloroplasts
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What is the function of a bacterium's capsule?
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protection
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Where is a bacterial cell's DNA found?
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nucleoid region
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In a bacterium, where are proteins synthesized?
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ribosomes
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What name is given to the rigid structure, found outside the plasma membrane, that surrounds and supports the bacterial cell?
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cell wall
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The _____ is the bacterial structure that acts as a selective barrier, allowing nutrients to enter the cell and wastes to leave the cell.
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plasma membrane
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What is the function of the nucleus?
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It houses DNA.
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Mitosis refers to _____.
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producing new cells
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What is the function of the cell membrane?
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take in and release materials
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Which of the following clues would tell you if a cell is prokaryotic or eukaryotic?
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whether or not the cell is partitioned by internal membranes
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Which of the following correctly matches an organelle with its function?
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central vacuole ... storage nucleus ... cellular respiration mitochondrion ... photosynthesis lysosome ... movement ribosome ... manufacture of lipids
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Smooth ER
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Lipid Synthesis Calcium Ion Storage Poison Detoxification
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Rough ER
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Protein Synthesis
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Golgi Apparatus
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Protein Modification and Sorting Cisternal Maturation
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Lysosomes
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Macromolecule Digestion Autophagy
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Plant Cells Only
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Chloroplast Central Vacuole Cellulose Cell Wall
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Animal Cells Only
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Centriole
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Both Plant and Animal Cells
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Nucleus Plasma Membrane Endoplasmic Reticulum Golgi Apparatus Cytoskeleton Mitochondrion
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Strong, protective structure made from cellulose fibrils.
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Plant Cell Wall
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Regulates cytoplasm composition, creates internal pressure, and stores cell compounds
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Central Vacuole
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Makes sugar by converting light energy into chemical energy
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Chloroplast
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Produces chemical energy ATP that can power the cell
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Mitochondrion
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Modifies and packages proteins
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Golgi Apparatus
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Which statements are true for chloroplasts?
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They are the sites of reactions that convert solar energy into chemical energy. They contain the green pigment chlorophyll. They have membranous sacs called thylakoids that are surrounded by a fluid called stroma.
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Prokaryotic Only
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Nucleoid
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Eukaryotic Only
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Lysosome Mitochondria Nucleus
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Both Prokaryotic and Eukaryotic
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Ribosome Plasma Membrane Flagella
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Responsible for cell locomotion and the cell's structural characteristics.
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Microfilaments
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Serve as intracellular highways for transporting vesicles and organelles; they are also required for cellular locomotion via flagella and cilia.
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Microtubules
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Rope-like structures that anchor organelles and intercellular junctions called desmosomes. They are specialized for bearing tension.
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Intermediate filaments
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The cilia and flagella of eukaryotic cells are composed of _____.
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microtubules
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Which of these organelles carries out cellular respiration?
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mitochondrion
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The _____ is composed of DNA and protein.
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chromatin
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Ribosomal subunits are manufactured by the _____.
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nucleolus
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_____ are the sites of protein synthesis.
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Ribosomes
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Which of these manufactures cellular membranes by adding membrane proteins and phospholipids to its own membrane?
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rough endoplasmic reticulum
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The _____ is a selective barrier, regulating the passage of material into and out of the cell.
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plasma membrane
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Where is calcium stored?
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smooth endoplasmic reticulum
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Which of these are hollow rods that shape and support the cell?
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microtubules
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_____ is/are identical in structure to centrioles.
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Basal bodies
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Which of these organelles produces H2O2 as a by-product?
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peroxisome
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Which of these is exhibiting kinetic energy?
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a space station orbiting Earth a person sitting on a couch while watching TV an archer with a flexed bow a rock on a mountain ledge the high-energy phosphate bonds of a molecule of ATP
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"Conservation of energy" refers to the fact that _____.
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energy cannot be created or destroyed but can be converted from one form to another
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Chemical energy is a form of _____ energy.
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potential
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In your body, what process converts the chemical energy found in glucose into the chemical energy found in ATP?
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cellular respiration
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Which of these are by-products of cellular respiration?
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heat, carbon dioxide, and water
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The process of cellular respiration, which converts simple sugars such as glucose into CO2 and water, is an example of _____.
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a catabolic pathway
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Which of the following statements about the combustion of glucose with oxygen to form water and carbon dioxide (C6H12O6 + 6 O2 → 6 CO2 + 6 H2O) is correct?
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The entropy of the products is greater than the entropy of the reactants.
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Which part of the adenosine triphosphate molecule is released when it is hydrolyzed to provide energy for biological reactions?
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(gamma)phosphate (the terminal phosphate)
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A(n) _____ reaction occurs spontaneously
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exergonic
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Which of these reactions requires a net input of energy from its surroundings?
answer
endergonic
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In cells, what is usually the immediate source of energy for an endergonic reaction?
answer
ATP
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The reaction ADP + P --> ATP is a(n) _____ reaction.
answer
endergonic
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The energy for an endergonic reaction comes from a(n) _____ reaction.
answer
exergonic
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What is the fate of the phosphate group that is removed when ATP is converted to ADP?
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It is acquired by a reactant in an endergonic reaction
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Select the INCORRECT association.
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exergonic ... uphill enzyme ... protein potential energy ... positional energy exergonic ... spontaneous kinetic energy ... motion
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What is energy coupling?
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the use of energy released from an exergonic reaction to drive an endergonic reaction
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a_____ inhibitor has a structure that is so similar to a substrate that it can bond to the enzyme just like a substrate
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competitive
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a ______ inhibitor binds to a site on the enzyme that is not the active site
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noncompetitive
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Forms a covalent bond with an amino acid side group within the active site, which prevents the substrate from entering the active site or prevents catalytic activity
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Irreversible Inhibitor
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What the competitive inhibitor competes with the substrate for on the enzyme
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Active Site
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When the noncompetitive inhibitor is bonded to the enzyme, the shape of the _____ is distorted.
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enzyme
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Enzyme inhibitors disrupt normal interactions between an enzyme and its
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substrate
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You have added an irreversible inhibitor to a sample of enzyme and substrate. At this point, the reaction has stopped completely. What can you do to regain the activity of the enzyme?
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The enzyme is inactive at this point. New enzyme must be added to regain enzyme activity.
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You have an enzymatic reaction proceeding at the optimum pH and optimum temperature. You add a competitive inhibitor to the reaction and notice that the reaction slows down. What can you do to speed the reaction up again?
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Add more substrate; it will outcompete the inhibitor and increase the reaction rate.
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In general, enzymes are what kinds of molecules?
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proteins
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Enzymes work by _____.
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reducing EA
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An enzyme _____.
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is an organic catalyst
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What name is given to the reactants in an enzymatically catalyzed reaction?
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substrate
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As a result of its involvement in a reaction, an enzyme _____.
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is unchanged
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Enzymes are described as catalysts, which means that they _____.
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increase the rate of a reaction without being consumed by the reaction
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The binding of a compound to an enzyme is observed to slow down or stop the rate of the reaction catalyzed by the enzyme. Increasing the substrate concentration reduces the inhibitory effects of this compound. Which of the following could account for this observation?
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The compound is a competitive inhibitor.
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Which of the following is NOT a way in which an enzyme can speed up the reaction that it catalyzes?
answer
The active site can provide heat from the environment that raises the energy content of the substrate.
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If an enzyme in solution is saturated with substrate, the most effective way to obtain a faster yield of products is to
answer
add more of the enzyme.
question
Some bacteria are metabolically active in hot springs because
answer
their enzymes have high optimal temperatures.
question
Select the correct statement about chemical energy, a term used by biologists to refer to potential energy available for release in a chemical reaction.
answer
Light energy is converted to chemical energy during photosynthesis.
question
Which of the following statements about the role of ATP in cell metabolism is true?
answer
The energy from the hydrolysis of ATP may be directly coupled to endergonic processes by the transfer of the phosphate group to another molecule.
question
Which statement about the binding of enzymes and substrates is correct?
answer
When substrate molecules bind to the active site of the enzyme, the enzyme undergoes a slight change in shape.