Bio Chapter 7
n/a
n/a
Fichier Détails
Cartes-fiches | 37 |
---|---|
Langue | English |
Catégorie | Biologie |
Niveau | Université |
Crée / Actualisé | 14.09.2014 / 14.09.2014 |
Lien de web |
https://card2brain.ch/box/bio_chapter_7
|
Intégrer |
<iframe src="https://card2brain.ch/box/bio_chapter_7/embed" width="780" height="150" scrolling="no" frameborder="0"></iframe>
|
selective permeability
allows some substances to cress more easily than others
amphilipathic
has hydrophobic and hydrophillic regions
Fluid Mosaic Model
the membrane is a fluid structure with a "mosiac" of various proteins embedded in or on the phospholipid bilayer
Integral Proteins
penetrate the hydrophobic part of the lipid bilayer
Transmembrane Protein
A protein that spans the whole membrane
Peripheral Proteins
Proteins not embedded in the lipid bilayer, but bonded loosely to the surface, usually to other proteins
The 6 Functions of Cell Membrane Proteins
1. Transport: channels and proteins
2. Enzymatic Activity: enzymes in the membrane
3. Signal Transduction: has a receptor to relay messages to the inside of the cell
4. Cell-Cell Recognition
5: Intercellular Joining: membrane proteins hook together
6: Attachment to Cytoskeleton and Extracellular Matrix
Glycolipids
a membrane carbohydrate- carbohydrate bonded to membrane lipids
Glycoproteins
type of membrane carbohydrates- carbohydrates covalently bonded to proteins
Channel Proteins
Function as a hydrophillic channel that molecules/ions use to cross the membrane
Aquaporins
Channels specifically for water
Carrier Proteins
hold and change shape in a way that allows a substance to cross the membrane
Diffusion
The movement of molecules of any substance so they spread evenly in available space
Concentration Gradient
The region along which the density of a chemical substance increases or decreases
Passive Transport
Diffusion of a substance across a biological membrane, with no energy required
Osmosis
The diffusion of free water across a selective permeable membrane
Tonicity
Ability of a surrounding solution to cause a cell to gain or lose water
Isotonic
Concentrations inside and outside the cell are equal- no net movement of water
Hypertonic
Solute is more concentrated outside the cell- movement of water out of the cell
Hypotonic
Solute is less concentrated outside of cell- cell gains water
Osmoregualtion
controls of solute concentration and H2O balance
Turgor Pressure
The pressure exerted by cell walls on a cell in hypotonic solution after so much water is absorbed
Turgid
State of cell where it is full of water and firm- the normal state
Flacid
the state in a cell with cell walls in isotonic solution- water isn't entering so the cell is limp
Plasmolysis
A cell in hypertonic solution loses water and the membrane pulls away from the cell wall
Facilitated Diffusion
Passive Diffusion of molecules and ions with the help of proteins
Gated Channels
Channel proteins open and close in response to stimuli
Active Transport
The movement of a solute across a membrane against its gradient which requires energy expenditure
Sodium Potassium Pump
exchanges Na+ for K+
Membrane Potential
The voltage across a membrane
Electrochemical Gradient
The combination of the ions concentration and the membrane potential that effect an ion's movement. An ion diffuses down its ELECTROCHEMICAL gradient, not it's concentration gradient
Electogenic Pump
A transport protein that generates voltage across the membrane
Proton Pump
Actively transports H+ out of a cell
Cotransport
The indirect driving of active transport of other solutes by the ATP transport of a specific solute
Exocytosis
The cell secretes large biological molecules by the fusion of vesicles with the plasma membrane
Endocytosis
Cells take in biological molecules by forming new vesicles in the plasma membrane
Ligands
Any molecule that binds to a specific receptor site on another molecule