miércoles, 20 de abril de 2011

Cell Membrane

Fluid Mosaic Model
fluid mixed composition of phospholipid
Adhesion Proteins
proteins that are embedded in the plasma membrane


Communication Proteins
allow substances to move from one cell to another
Receptor Proteins
combine with extracellular substances
Recognition Proteins
recognize what can enter or not enter the cell
Passive Transporters
have channels in their interior, no needs input of energy
Active Transporters
transporters that need input of energy and move against the core gradient

Concentration Gradient
is a difference in the number per unit volume of molecules
Diffusion
is the name for the net movement of like molecules or ions
Electric Gradient
is simply a difference in electric charge between adjoining regions
Pressure Gradient
pressure exerted per unit volume between two adjoining regions
Osmosis
is the diffusion of water across a selesctively permeable membrane
Hypotonic Solution
is the solution with fewer solutes
Hypertonic Solution
solution with more than one solutes
Isotonic Solution
solution that show no net osmotic movement
Hydrostatic Pressure
turger pressure
Osmotic Pressure
measure of the tendency of water to follow its water concentration
Endocytasis
a small patch of plasma membrane inside the cytoplasm
Exocytasis
a vesicles moves to the cell surface
Phagocytosis
cell eating. Is a common endocytic pathway

sábado, 9 de abril de 2011

Cell Structure and Function

Nucleoid
region of the cytoplasmthat is not enclosed in a membrenous sac.

Lipid Bilayer
a continous, oily boundary that prevents the free passage of water soluble substance across it
Wavelenght
distance from the peak of one way to the peak behind it
Electron Microscope
uses magnetic lenses to bend and diffract beams of electrons
Transmision Electron Microscope
electron pass through a specimen and are used to make images of its internal details
Scanning Electron Microscope
direct a beam of electrons back and forth across a surface of a specimen
Organelles
start out life with a nucleus and other membrane bounded sacs
Secretory Pathway
move polypeptide changes from one ribosome through ER and golgi body
Endocytic Pathway
move ions and molecules into the cytoplasm
Vesicles
tiny sacs
Peroxisomes
hold enzymes that digest fatty acids, amino acids, and hydrogen peroxide
Cell Junctions
molecular structure were a cell sends or receives signals of materials
Basal body
barrel shaped structure that produces and organizes microtubules
Pseudopods
false feet
Nuclear envelope
a double membrane system
Chromatin
a cell collection of DNA
Chromosome
a double-standed DNA molecule and its associated proteins