Lehninger Principles of Biochemistry 7th Edition Nelson Test Bank question and answers

  Nucleoid - Correct Answers: The region in a bacterial cell where the DNA is located, not enclosed by a membrane. Eukaryotes - Correct Answers: Organisms with cells containing a true nucleus enclosed by a nuclear envelope. Nuclear envelope - Correct Answers: The double membrane structure that encloses the nucleus in eukaryotic cells. Cell dimensions - Correct Answers: Living cells usually have lengths and diameters in the range of 0.1 μm to 100 μm. Archaea - Correct Answers: A group of single-celled microorganisms found growing in extreme environments. Chemoheterotroph - Correct Answers: An organism that requires organic molecules for growth and energy. Organelles - Correct Answers: Specialized subunits within a cell, such as mitochondria, endoplasmic reticulum, and peroxisomes. Noncovalent interaction - Correct Answers: Interactions like hydrogen bonds, hydrophobic interactions, ionic interactions, and van der Waals interactions that maintain macromolecular structure. Carbon - Correct Answers: One of the four most abundant elements in living organisms. Tetrahedral - Correct Answers: The geometry formed by the four covalent bonds around carbon in methane (CH4). Proteome - Correct Answers: The catalog of all proteins functioning in a cell. Chemoautotrophs - Correct Answers: Organisms that use inorganic compounds as energy sources and CO2 as a carbon source. Stereospecificity - Correct Answers: The property of a reaction or process to produce a specific stereoisomer. Dynamic steady state - Correct Answers: A state in which a system is in a constant state of change but maintains a stable overall condition. Exothermic - Correct Answers: A chemical reaction that releases heat energy. Adenosine triphosphate (ATP) - Correct Answers: The major carrier of chemical energy in all cells. Enzymes - Correct Answers: Biological catalysts that enhance the rate of a reaction by decreasing the activation energy. Anabolic - Correct Answers: Energy-requiring metabolic pathways that yield complex molecules from simpler precursors. Deoxyribonucleic acid (DNA) - Correct Answers: The molecule that carries hereditary information in cells. Three-dimensional structure - Correct Answers: The primary determinant of a protein's function, formed by the sequence of amino acids in the protein. Oparin's theory - Correct Answers: A theory for the origin of life suggesting that the prebiotic atmosphere contained methane, ammonia, and water. Homologues - Correct Answers: Genes or gene products that share detectable sequence similarity and usually have the same function. Living organisms - Correct Answers: Described as an open system, maintaining a more-or-less constant composition, in equilibrium with their surroundings, existing in a dynamic steady-state, and having efficient mechanisms to convert chemical energy from one form into another. Plasma membrane - Correct Answers: A physical barrier separating the inside of the cell from its surroundings, composed of lipid and protein molecules. Prokaryotes - Correct Answers: Organisms lacking a true nucleus, such as bacteria. Facultative anaerobe - Correct Answers: An organism that does not require oxygen to live but will not die if exposed to oxygen. Energy sources - Correct Answers: Phototrophs can use carbon dioxide as a carbon source, and chemotrophs can use carbon dioxide as an energy source. Bacterial and archaeal cells - Correct Answers: Both consist of a thin bilayer of lipid molecules penetrated by proteins, with group-specific specializations in their cell envelope and a layer of peptidoglycan. Centrifugation - Correct Answers: A useful method for fractionating cellular organelles. Carbon - Correct Answers: Used in living organisms due to its ability to make four bonds, form double bonds, and create more preferred geometries when bonding. Jacques Monod's statement - Correct Answers: Suggesting that the principles of E. coli apply to all living organisms. Racemic mixture - Correct Answers: A mixture of equal amounts of two enantiomers, which can be separated to test each for biological activity. Living organisms - Correct Answers: Able to produce particular chiral forms of different biomolecules while laboratory chemical synthesis usually produces a racemic mixture. Mutation in DNA - Correct Answers: Can be harmful or beneficial to an organism, arising from an unrepaired mistake in DNA replication or incorrectly repaired damage to one of the DNA strands. Stanley Miller's experiment - Correct Answers: Subjecting a gaseous mixture mimicking the prebiotic atmosphere on Earth to electrical sparks, resulting in the formation of amino acids, aldehydes, and ribonucleotides. RNA world hypothesis - Correct Answers: Suggesting that RNA molecules participate in biologically significant reactions, serve as an information-carrying molecule, and catalyze peptide bond formation. Oxygen-producing bacteria - Correct Answers: Led to the eventual predominance of aerobic organisms on earth, welcoming oxygen as a preferable choice for metabolic reactions. Endosymbiotic association - Correct Answers: Explaining the evolution of eukaryotic cells capable of carrying out photosynthesis and/or aerobic metabolism through the engulfing of an aerobic bacterium by a eukaryotic cell. Cell dimensions - Correct Answers: Limited on the lower end by the minimum number of biomolecules necessary for function and on the upper end by the rate of diffusion of solutes such as oxygen. Three domains of life - Correct Answers: Archaea, Bacteria, and Eukarya, each with distinct characteristics. Membrane lipids in archaea - Correct Answers: Contain ether-linked alkyl acids, while eukaryotic membrane lipids consist of glycerol ester-linked to three fatty acids. Fatty acids - Correct Answers: Longer chains have higher melting points and lower solubility in water, and those with more double bonds have higher melting points. Trans fats - Correct Answers: Associated with increased inflammatory response in the body, raising of LDL cholesterol, and increased risk of heart disease. Waxes - Correct Answers: Used for energy storage, lubrication, structure, insulation, and waterproofing. Triacylglycerols - Correct Answers: Contain a glycerol backbone and three fatty acids, and are used for energy storage. Lipids floating on water - Correct Answers: Due to their nonpolar nature, while water is polar. Triacylglycerols vs. polysaccharides - Correct Answers: The carbon atoms of triacylglycerols are more reduced, and since they are hydrophobic, excess water does not need to be stored along with them. Partial hydrogenation - Correct Answers: Converts liquid forms of vegetable oils to solid forms and increases their shelf lives. Waxes - Correct Answers: Esters of one long-chain fatty acid and one long-chain alcohol, used for energy storage, lubrication, structure, insulation, and waterproofing. Platelet-activating factor - Correct Answers: Much more water-soluble than most other glycerophospholipids due to its ether-linked alkyl chain at the C-1 of glycerol. Membrane lipids in archaea vs. eukarya - Correct Answers: Archaeal membrane lipids have alkyl acids that are ether-linked to glycerol at both ends, while eukaryotic membrane lipids consist of glycerol that is ester-linked to three fatty acids. Membrane lipids - Correct Answers: Modified to determine blood type in humans and make up 70% to 80% of the total membrane lipids in a vascular plant. Fatty acids - Correct Answers: Longer chains have higher melting points, lower solubility in water, and those with more double bonds have higher melting points. Trans fats - Correct Answers: Associated with increased inflammatory response in the body, raising of LDL cholesterol, and increased risk of heart disease. Waxes - Correct Answers: Used for energy storage, lubrication, structure, insulation, and waterproofing. Triacylglycerols - Correct Answers: Contain a glycerol backbone and three fatty acids, and are used for energy storage. Lipids floating on water - Correct Answers: Due to their nonpolar nature, while water is polar. Triacylglycerols vs. polysaccharides - Correct Answers: The carbon atoms of triacylglycerols are more reduced, and since they are hydrophobic, excess water does not need to be stored along with them. Partial hydrogenation - Correct Answers: Converts liquid forms of vegetable oils to solid forms and increases their shelf lives. Waxes - Correct Answers: Esters of one long-chain fatty acid and one long-chain alcohol, used for energy storage, lubrication, structure, insulation, and waterproofing. Platelet-activating factor - Correct Answers: Much more water-soluble than most other glycerophospholipids due to its ether-linked alkyl chain at the C-1 of glycerol. Membrane lipids in archaea vs. eukarya - Correct Answers: Archaeal membrane lipids have alkyl acids that are ether-linked to glycerol at both ends, while eukaryotic membrane lipids consist of glycerol that is ester-linked to three fatty acids. Membrane lipids - Correct Answers: Modified to determine blood type in humans and make up 70% to 80% of the total membrane lipids in a vascular plant. Fatty acids - Correct Answers: Longer chains have higher melting points, lower solubility in water, and those with more double bonds have higher melting points. Trans fats - Correct Answers: Associated with increased inflammatory response in the body, raising of LDL cholesterol, and increased risk of heart disease. Waxes - Correct Answers: Used for energy storage, lubrication, structure, insulation, and waterproofing. Triacylglycerols - Correct Answers: Contain a glycerol backbone and three fatty acids, and are used for energy storage. Lipids floating on water - Correct Answers: Due to their nonpolar nature, while water is polar. Triacylglycerols vs. polysaccharides - Correct Answers: The carbon atoms of triacylglycerols are more reduced, and since they are hydrophobic, excess water does not need to be stored along with them. Partial hydrogenation - Correct Answers: Converts liquid forms of vegetable oils to solid forms and increases their shelf lives.