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Vanders Physiology 3
Chapter 3: Cellular Structure, Proteins, and Metabolism
| Question | Answer |
|---|---|
| Cell containing a membrane-enclosed nucleus with genetic material; plant and animal cells | Eukaryotic Cell |
| Maxim that an increase in reactant concentration causes a chemical reaction to proceed in direction of product formation; the opposite occurs with decreased reactant concentration | Law of Mass Action |
| Energy necessary to disrupt existing chemical bonds during a chemical reaction | Activation Energy |
| Formation of glucose by the liver or kidneys from pyruvate, lactate, glycerol, or amino acids | Gluconeogenesis |
| A class of breakdown products formed from the deamination of amino acids | Keto Acid |
| Three-nucleotide sequence in TRNA able to base-pair with complementary codon in MRNA during protein synthesis | Anticodon |
| Membrane-bound cell organelle containing digestive enzymes in a highly acid solution that break down bacteria, large molecules that have entered cell, and damaged components of cell | Lysosome |
| Three-nucleotide sequence in MRNA that signifies end of protein coding sequence | "Stop Signal" |
| Strength with which ligand binds to its binding site | Affinity |
| Enzyme that catalyzes the reaction CO2+H2O=H2CO3 | Carbonic Anhydrase |
| One of a series of enzymes that couples energy to ATP formation during oxidative phosphorylation | Cytochrome |
| Ionized form of lactic acid | Lactate |
| Rod-shaped or oval cytoplasmic organelle that produces most of cell's ATP;site of krebs cycle and oxidative phosphorylation enzymes | Mitochondrion |
| Reactant in enzyme-mediated reaction | Substrate |
| Sequence of enzyme-mediated chemical reactions by which molecules are synthesized and broken down in cells | Metabolic Pathway |
| Ligand that, by acting at an allosteric regulatory site, alters properties of other binding sites on a protein and thus regulates its functional activity | Modulator Molecule |
| Cytoplasmic particle that mediates linking together of amino acids to form proteins; attached to endoplasmic reticulum as bound ribosome, or suspended in cytoplasm as free ribosome | Ribosome |
| Cell junction in which extracellular surfaces of the plasma membrane of two adjacent cells are joined together; extends around epithelial cell and restricts molecule diffusion through space between cells | Tight Junction |
| Reaction in which an amino acid amino group (-NH2) is transferred to a ketoacid the ketoacid thus becoming an amino acid | Transanimation |
| Formation of RNA containing, in linear sequence of its nucleotides, the genetic information of a specific gene; first stage of protein synthesis | Transcription |
| In presence of oxygen | Aerobic |
| Region of cell cytoplasm in which microtubule formation and elongation occur, particularly during cell division | Centrosome |
| Organic cofactor; generally serves as a carrier that transfers atoms or small molecular fragments from one reaction to another; is not consumed in the reaction and can be reused | Coenzyme |
| Proteins required for ribosomal assembly and the establishment of an initiation complex that allows new protein synthesis to begin | Initiation Factors |
| Protein and nuclear RNA complex that removes introns and links exons together during gene transcription | Spliceosome |
| During protein synthesis, assembly of amino acids in correct order according to genetic instructions in MRNA; occurs on ribosomes | Translation |
| A protein that spans the plasma membrane and contains both hydrophilic and hydrophobic regions; often acts as a receptor or an ion channel | Transmembrane Protein |
| Amino acid that cannot be formed by the body at all (or at rate adequate to meet metabolic requirements) and must be obtained from diet | Essential Amino Acid |
| Mitochondrial metabolic pathway that utilizes fragments derived from carbohydrate, protein, and fat breakdown and produces carbon dioxide, hydrogen, and small amounts of ATP; also called TRI carboxylic acid cycle or citric acid cycle | Krebs Cycle |
| An enzyme capable of breaking peptide bonds in a protein | Protease |
| Any enzyme that phosphorylates other proteins by transferring to them a phosphate group from ATP | Protein Kinase |
| A complex of proteins capable of denaturing (unfolding) other proteins and assisting in protein degradation | Proteasome |
| Small intracellular peptide that attaches and directs them to proteasomes | Ubiquitin |
| Region of enzyme to which substrate binds | Active Site |
| Opening in nuclear envelope through which molecular messengers pass between nucleus and cytoplasm | Nuclear Pore |
| Particular steroid molecule; precursor of steroid hormones and bile salts and a component of plasma membranes | Cholesterol |
| Major nitrogenous waste product of protein breakdown and amino acid catabolizm | Urea |
| Organic molecule that is required in trace-amounts for normal health and growth, but it is not manufactured in the body and must be supplied by diet; classified as water-soluble (Vit C & B complex) and fat soluble (Vit A, D, E, and K) | Vitamin |
| Maxim that an increase in reactant concentration causes a chemical reaction to proceed in direction of product formation; the opposite occurs with decreased reactant concentration | Law of Mass Action |
| Double membrane surrounding cell nucleus | Nuclear Envelope |
| Large membrane-bound organelle that contains cell's DNA; (neural) cluster of neuron cell bodies in CNS | Nucleus |
| Tubular cytoplasmic filament compsed of the protein tubulin; provides internal support for cells and allows change in cell shape and organelle movement in cell | Microtuble |
| Intracellular fluid that surrounds cell organelles and nucleus | Cytosol |
| State when rates of forward and reverse components of a chemical reaction are equal, and no net change in reactant or product concentration occurs | Chemical Equiliibrium |
| H2O2; Chemical produced by phagosome and highly destructive to macromolecules | Hydrogen Peroxide |
| Protein embedded in membrane lipid layer; may span entire membrane or be located at only one side | Integral Membrane Protein |
| Any molecule or ion that binds to protein surface by noncovalent bonds | Ligand |
| Rod-like cytoplasmic actin filament that forms major component of cytoskeleton | Microfilament |
| Small cytoplasmic body having nine fused sets of microtubules; participates in nuclear and cell division | Centriole |
| DNA region containing code words for a part of the amino acid sequence of a protein | Exon |
| Region of cell interior outside the nucleus | Cytoplasm |
| Substance that accelerates chemical reactions but does not itself undergo any net chemical change during the reaction | Catalyst |
| Combination of DNA and nuclear proteins; principal component of chromosomes | Chromatin |
| Protein whose biding site characteristics are subject to allosteric modulation | Allosteric Protein |
| A series of metal-containing proteins within mitochondria that participate in the flow of electrons from proteins to molecular oxygen; they are key compnents of the energy-producing processes in all cells | Electron Transport Chain |
| Junction that holds two cells together; consists of plasma membranes of adjacent cells linked by fibers, yet separated by a 20-NM extracellular space filled with a cementing substance | Desmosome |
| Cell membrane structure consists of proteins embedded in bimolecular lipid that has the physical properties of a fluid, allowing membrane proteins to move laterally within it | Fluid-Mosaic Model |
| Actin-comtaining filament associated with desmosomes | Intermediate Filament |
| Region of protein to which a specific ligand binds | Binding Site |
| Factor in the environment that increases mutation rate | Mutagen |
| Cellular synthesis of organic molecules | Anabolism |
| Ability of similar molecules to combine with the same binding site or receptor | Competition |
| Protein catalyst that accelerates specific chemical reactions but does not itself undergo net chemical change during the reation | Enzyme |
| Nuclear complexes of several histones and their associated coils of DNA | Nucleosome |
| Class of proteins that participate in the packaging of DNA within the nucleus; strands of DNA form coils around the histones | Histones |
| Any change in badse sequence of DNA that changes genetic information | Mutation |
| Hydrophilic proteins associated with cytoplasmic surface of cell membrane | Peripheral Membrane Protein |
| Cell organelle that destroys certain toxic products by oxidative reactions | Peroxisome |
| Rate at which enzyme converts reactant to product; may be measure of the properties of enzyme's active site as altered by allosteric or covalent modulation; affects rate of enzyme-mediated reaction | Enzyme Activity |
| A group of transcription factors and accessory proteins that associate with promoter regions of specific genes; the complex is required for gene transcription to commence | Preinitation Complex |
| Cells such as bacteria that do not contain their genetic information within a membrane-enclosed nucleus | Procaryotic Cells |
| Chemical reactions that occur in a living organism | Metabolism |
| Cell organelle consisting of flattened membranous sacs; usually near nucleus; processes newly synthesized proteins for secretion or distribution to other organelles | Golgi Apparatus |
| Lipid subclass similar to triglyceride except that a phosphate group (-PO4 2-) and small nitrogen-containing molecule are attached to third hydroxyl group of glycerol; major component of cell membranes | Phospholipid |
| Specific nucleotide sequence at beginning of gene that controls the initiation of gene transcription; determines which of the paired strands of DNA is transcribed into RNA | Promoter |
| Highly coiled, condensed form of chomatin formed in cell nucleus during mitosis and meiosis | Chromosome |
| Densely staining nuclear region containing portions of DNA that code for ribosomal proteins | Nucleolus |
| Transmembrane protein in plasma membrane; binds to specific proteins in extracellular matrix and on adjacent cells to help organize cells into tissues | Integrin |
| Cytoplasmic filamentous network associated with cell shape and movement | Cytoskeleton |
| Membrane that forms outer surface of cell and separates cell's contents from extracellular fluid | Plasma Membrane |
| Site on protein that interacts with modulator molecule; alters functional site properties | Regulatory Site |
| Metabolic intermediate that transfers acetyl groups to krebs cycle and various synthetic pathways | Acetyl Coenzyme A (Aceyle COA) |
| In the absence of oxygen | Anaerobic |
| Anion formed when pyruvic acid loses a hydrogen ion | Pyruvate |
| Protein channels linking cytosol of adjacent cells; allows ions and small molecules to flow between cytosols of the connected cells | Gap Junction |
| Substance required for normal or optimal body function but synthesized by the body either not at all or in amounts inadequate to prevent disease | Essential Nutrient |
| Highly branched polysaccaride composed of glucose subunits; major carbohydrate storage form in body | Glycogen |
| Globular contractile protein to which myosin crossbridges bind; located in muscle thin filaments and in microfilaments of cytoskeleton | Actin |
| Three-carbon molecule that combines with fatty acids to from triglyceride; also called glycerol 3-phosphate | Alpha-Glycerol Phosphate |
| Control of protein binding site properties by modulator molecules that bind to regions of the protein other than the binding site altered by them | Allosteric Modulation |
| Fluid in cells; cytosol plus fluid in cell organelles, including nucleus | Intracellular Fluid |
| Regions of noncoding nucleotides in a gene | Intron |
| Process by which energy derived from reaction between hydrogen and oxygen to form water is transferred to ATP during its formation | Oxidative Phosphorylation |
| Three-base sequence in MRNA that determines the position of a specific amino acid during protein synthesis or designates the end of the coded sequence of a protein | Codon |
| Series of reactions that generate hydrogen atoms (for oxidative phosphorylation) from breakdown of fatty acids to acetyl COA | Beta Oxidation |
| The proposed mechanism by which ATP is formed during oxidative phosphorylation, the hypothesis proposes that the movement of protons across mitochondrial inner membranes is coupled with ATP production | Chemiosmotic Hypothesis |
| Ribonucleic acid that transfers genetic information for a protein's amino acid sequence from DNA to ribosome | Messenger RNA (MRNA) |
| Enzyme that removes phosphate from protein | Phosphoprotein Phosphatase |
| Chemical reaction that releases large quantities of energy and results in almost all the reactant molecules being converted to product | Irreversible Reaction |
| Addition of phosphate group to an organic molecule | Phosphorylation |
| An RNA molecule transcribed from a gene before nitron removal and splicing | Primary RNA Transcript |
| Alteration of a protein's shape, and therefore its function by the covalent binding of various chemical groups to it | Covalent Modulation |
| Metabolic pathway that breaks down glucose to two molecules of pyruvate (aerobically) or two molucules of lactate (anaerobically) | Glycolysis |
| Type of RNA used in ribosome assembly; becomes part of ribosome | Ribosomal RNA (RRNA) |
| Unit of hereditary information; portion of DNA containing information required to determine a protein's amino acid sequence | Gene |
| Cellular breakdown of organic molecules | Catabolism |
| Enzyme that forms RNA by joining together appropriate nucleotides after they have base-paired to DNA | RNA Polymerase |
| Membrane-bound vesicle produced by golgi apparatus; contains protein to be secreted by cell | Secretory Vesicle |
| Organic or inorganic substance that binds to a specific region of an enzyme and is necessary for the enzyme's activity | Cofactor |
| Chemical reaction in which energy release is small enough for reverse reaction to occur readily | Reversible Reaction |
| Initial portion of newly synthesized protein (if protein is destined for secretion) | Signal Sequence |
| Energy necessary to disrupt existing chemical bonds during a chemical reaction | Activation Energy |
| Formation of glucose by the liver or kidneys from pyruvate, lactate glycerol, or amino acids | Gluconeogenesis |
| A class of breakdown products fromed from the deamination of amino acids | Keto Acid |
| Three-nucleotide sequence in TRNA able to base-pair with complementary codon in MRNA during protein syntbesis | Anticodon |
| Membrane-bound cell organelle containing digestive enzymes in a highly acid solution that break down bacteria, large molecules that have entered cell, and damaged components of cell | Lysosome |
| Harilike projections from specialized epithelial cells; sweep back and forth in a synchronized way to propel material along epithelial surface | Cilia |
| Inhibition of a metabolic pathway by final product's action upon allosteric site on an enzyme (usually the rate-limiting enzyme) in the pathway | End-Product Ihibition |
| Membrane-bound compartment, nonmembranous particle, or filament that performs specialized functions in cell | Cell Organelle |
| Type of RNA; different TRNAs combine with different amino acids and with codon on MRNA specific for that amino acid, thus arranging amino acids in sequence to form specific protein | Transfer RNA (TRNA) |
| Complete set of an organism's genes | Genome |
| Fuzzy coating on extracellular surface of plasma membrane; consists of short, branched carbohydrate chains | Glycocalyx |
| Interaction between functional binding sites in a multimeric protein | Cooperativity |
| Amount of heat required to change the temperature of 1 L water by 1 ºC; calorie used in nutrition; also called calorie and large calorie | Kilocalorie (KCAL) |
| Cell specialized for triglyceride synthesis and storage; fat cell | Adipocyte |
| Direct transfer of phosphate group from metabolic intermediate to ADP to form ATP | Substrate-Level Phosphorylation |
| One of a class of proteins that act as gene switches, regulating the transcription of a particular gene by activating or repressing the initiation process | Transcription Factor |
| Tissue composed largely of fat-storing cells | Adipose Tissue |
| Reaction in which an amino group (-NH2) from an amino acid is replaced by oxygen to form a keto acid | Oxidative Deamination |
| Intracellular vesicles and tubular elements between golgi apparatus and plasma membrane; sorts and distributes vesicles during endo- and exocytosis | Endosome |
| Slowest reaction in metabolic pathway; catalyzed by rate-limiting enzyme | Rate-Limiting Reaction |
| Binding site on allosteric protein that, when activated, carries out protein's physiological function; also called active site | Functional Site |
| Occupation of all available binding sites by their ligand | Saturation |
| The major protein component of microtubules | Tubulin |
| Unit of heat-energy measurement; amount of heat needed to raise temperature of 1 G of water 1 ºC | Calorie (CAL) |