| A | B |
|---|
| plasma membrane | selectively permeable barrier |
| passive transport | movement across cell membranes, driven by concentration gradients |
| active transport | movement across cell membranes, driven by ATP decomposition, may involve pumps (carrier proteins) |
| diffusion | movement of molecules down a concentration gradient |
| protein channels | responsible for movement of molecules or ions, some are selective |
| osmosis | diffusion of a solvent through a selectively permeable membrane from an area of lesser osmolarity to greater osmolarity |
| cell swelling or shrinking | caused by the presence of impermeable solutes inside or outside of a cell |
| equilibrium | acheived when net osmosis ceases, solute concentration is even on both sides of the cell membrane |
| hypertonic | solutions that cause a net loss of water from cells |
| hypotonic | solutions causing net water gain |
| isotonic | solutions causing neither gain nor loss of water |
| facilitated diffusion | passive movement solute across a membrane by their combination with a membrane carrier protein |
| filtration | occurs when a filtrate is forced across a membrane by hydrostatic pressure, nonselective, limited by pore size |
| ATP | molecule that drives active transport |
| Active Transport Pumps | move substances against a concentration gradient |
| vesicular transport | an active transport mechanism, exocytosis and endocytosis |
| resting membrane potential | a voltage across a cell membrane in a nonreacting cell membrane |
| membrane potential | charge separation that occurs in a reacting cell membrane |
| sodium ion | found in high amounts extracellularly and low levels intercellularly |
| potassium | found in high concentration in the cell and low concentration outside |
| sodium-potassium pump | responsible for a charge separation that generates and action potential on a cell membrane |
| gene | DNA segment that provides instructions for the synthesis of one polypeptide chain |
| polypeptide chains | all proteins including enzymes and other structural molecules |
| three-base sequence (triplet) | codes for one amino acid |
| DNA template | codes for all three varieties of RNA |
| ribosomal RNA | protein synthesis site |
| messenger RNA | carries instructions for making a protein from the nucleus to the ribosome |
| transfer RNA | ferries amino acids to the ribosomes and recognizes codons on the mRNA strand calling for its amino acid |
| transcription | synthesizes mRNA |
| translation | reading of mRNA by tRNA and peptide bonding of amino acids into a protein |
| peptide bond | joins amino acids into polypeptide chains (proteins) |
| ribosomes | coordinate translation |
| dysplasia | change in cell size, shape, or arrangement due to chronic irritation or inflammation |
| hypertrophy | growth of an organ or tissue due to an increase in the size of its cells, muscle gets bigger |
| liposomes | hollow microscopic sacs formed of phospholipids that can be filled with drugs, genetic material etc. |
| necrosis | cell death due to injury or disease |
| mitochondria | site of ATP synthesis; powerhouse of the cell |
| ribosomes | sites of protein synthesis |
| rough endoplasmic reticulum | membranous system of sacs covered with ribosomes that package proteins |
| smooth endoplasmic reticulum | membranous system of sacs free of ribosomes that packages lipids |
| lysosomes | sites of intracellular digestion, contains acid hydrolases |
| cilia | short cell processes that create a unidirectional current that propels substances along the cell surfaces |
| flagella | like cilium, but longer; sperm cells in humans have them |
