Question | Answer |
cell containing a membrane-enclosed nucleus with genetic material; plant and animal cells | Eukaryotic cell |
Cells such as bacteria that do not contain their genetic info w/in a membrane-enclosed nucleus | Prokaryotic cell |
Membrane that forms outer surface of cell and separates cell's contents from extracellular fluid | Plasma membrane |
membrane bound compartment, along with some particles and filaments that perform specialized functions in cell | Cell Organelles |
large membrane bound organelle that contains cell's DNA; primary function is the storage & transmission of the genetic info to the next generation of cells | Nucleus |
region of cell interior outside of nucleus | Cytoplasm |
Intracellular fluid that surrounds cell organelles and nucleus | Cytosol |
performs a variety of functions, but most universal is to provide a selective barrier to the passage of molecules | Membranes |
major component of cell membranes; this lipid is a Amphipathic molecule | Phospholipids |
protein embedded in membrane lipid layer; may span entire membrane or be located at only one side | Integral membrane protein |
hydrophilic proteins associated w/ cytoplasmic surface in the interior of the membrane | Peripheral membrane proteins |
integral protein that spans the plasma membrane; often acts as a receptor or ion channel | Transmembrane protein |
transmembrane protein in plasma membrane; binds to specific proteins in extracellular matrix and on adjacent cells to help organize cells into tissues | Integrins |
junction that holds two cells together; consists of plasma membranes junction of adjacent cells linked by fibers. hold adjacent cells firmly together in areas that are subject to considerable stretching, such as skin | Desmosomes |
membrane junction in which extracellular surfaces of the plasma membrane of 2 adjacent cells are joined together so that no extracellular space remains between them and restricts molecule diffusion through space between cells | Tight junctions |
membrane junction that creates protein channels linking cytosol of adjacent cells; allows ions and small molecules to flow between cytosols of the connected cells | Gap junctions |
Double membrane surrounding cell nucleus | Nuclear envelope |
opening in nuclear envelope through which molecular messengers pass between nucleus and cytoplasm | Nuclear pores |
particular steroid (lipid) molecule which makes up 25% of cell membranes | Cholesterol |
fine network of threads made up of DNA & nuclear proteins; principal component of chromosomes | Chromatin |
highly coiled, condensed form of chromatin formed in cell nucleus during mitosis and meiosis forming rod like bodies | Chromosomes |
densely staining nuclear region containing portions of DNA that code for ribosomal proteins | Nucleolus |
cells which has no nucleus or organelles | Red blood cells |
cells which have multiple nuclei | Skeletal muscle cells |
protein factories of a cell; site of protein synthesis from amino acids, may be either free in cytosol or attached to endoplasmic reticulum | Ribosomes |
cell organelle that consists of interconnected network of membrane-bound branch tubules & flattened sacs; 2 types, rough; with ribosomes attached to synthesize protein, smooth; (no ribosomes attached) synthesizes lipids & detoxifies certain molecules | Endoplasmic reticulum |
cell organelle consisting of flattened membranous sacs; usually near nucleus; processes newly synthesized proteins for secretion or distribution to other organelles | Golgi apparatus |
membrane bound vesicle produced by Golgi apparatus; contain protein to be secreted by cell | Secretory vesicle |
cellular taxis that sorts & distributes vesicles | Endosomes |
oval shaped body surrounded by "2" membranes; site of production of most ATP during cellular respiration | Mitochondria |
cell organelle containing digestive enzymes in a highly acidic solution that break down bacteria, debris from dead cells, & or damaged cell organelles | Lysosomes |
cell organelle that makes or disposes of hydrogen peroxide | Peroxisome |
cytoplasmic filametous network which maintains the cell shape and provide cell movements; includes 3 types of protein filaments; microfilaments(actin), intermediate filaments, microtubules (cilia) | Cytoskeleton |
hairlike extension on epithelial cells to propel material along epithelial surface | Cilia |
unit of hereditary information; portion of DNA containing information req'd to determine a protein's amino acid sequence | Gene (20-25K genes in humans) |
complete set of an organism's genes | Genome |
Gene code is Universal, there are "3" Stop Codes, BUT only "1" Start Code | Universal genetic code for Methionine; A-U-G; "Start Code" |
any change in base sequence of DNA that changes genetic information | Mutation (3 types) |
the process of transferring genetic information from DNA to RNA in the nucleus | Transcription |
the process that used the coded information in RNA to assemble a protein in the cytoplasm | Translation |
ribonucleic acid that transfers genetic information for a protein's amino acid sequence from DNA to ribosome | Messenger RNA |
enzyme that forms RNA by joining together appropriate nucleotides after they have base-paired to DNA | RNA polymerase |
specific sequence of DNA nucleotide at the beginning of gene that controls the initiation of gene Transcription; determines which of the paired strands of DNA is transcribed into RNA template strand | Promoter |
small intracellular peptide that attaches to proteins and directs them to proteasomes | Ubiquitin |
a complex of proteins capable of denaturing (unfolding) other proteins and assisting in protein degradation | Proteasome |
initial portion of newly synthesized protein (if protein is destined for secretion out of the cell) | Signal sequence |
any molecule or ion that binds to protein surface by non covalent bonds (reversible) | Ligand |
region of a protein to which a specific ligand binds | Binding site |
selectivity; ability of binding site to react with only one, or limited # of molecules | Chemical Specificity |
strength with which ligand binds to its binding site (can be high or low) | Affinity |
refers to the fraction of total binding sites that are occupied by ligands at any given time | Saturation |
ability of similar molecules to combine with the same binding site or receptor | Competition |
alteration of a protein's shape, and therefore its function, by the covalent binding of various chemical groups to it | Covalent modulation (ex: Stereo's on/off switch) |
addition of phosphate group to an organic molecule | Phosphorylation |
any enzyme that phosphorylates other proteins by transferring to them a phosphate group from ATP | Protein kinase (ex: turns stereo on) |
any enzyme that removes phosphate from protein | Phosphoprotein phosphatase (ex: turns stereo off) |
control of protein binding site preoperties by modulator molecules that bind to regions of the protein other than the binding site altered by them | Allosteric modulation (ex: stereo's volume) |
ligand that, by action at an allosteric regulatory site, alters properties of other binding sites on a protein and thus regulates its functional activity | Modulator molecule |
site on protein that interacts with modulator molecule; alters functional site properties | Regulatory site |
binding site on allosteric protein that when activated, carries out protein's physiological function; also called active site | Functional site |
chemical reactions that occur in living organisms | Metabolism |
the synthesis of organic molecules by cells | Anabolism |
the breakdown of organic molecules by cells | Catabolism |
chemical reaction in which energy release is small enough for reverse reaction to occur readily | Reversible reaction |
chemical reaction that releases large quantities of energy and results in almost all reactant molecules being converted to product | Irreversible reaction |
maxim that an increase in reactant concentration causes a chemical reaction to proceed in direction of product formation | Law of mass action |
protein molecule, acts as protein catalyst that accelerates specific chemical reactions but does not itself undergo net chemical change during reaction | Enzyme (~2000 different enzymes in a typical cell) |
substance that binds to a specific region of an enzyme & is necessary for the enzyme's activity | Cofactor |
sequence of enzyme-mediated chemical reactions by which molecules are synthesized and broken down in cells | Metabolic pathway |
metabolic pathway that breaks down glucose to 2 molecules of pyruvate(aerobically, with O2) or 2 molecules of lactate (anaerobically, lack of O2) | Glycolysis |
mitochondrial metabolic pathway that utilizes fragments derived from carbs, proteins, and fat breakdown, & produces CO2, H, & small amounts of ATP | Krebs Cycle |