Home
Flashcards
Preview
Lipids, Membranes, and the First Cells
Home
Get App
Take Quiz
Create
What kind of diffusion do membrane proteins perform?
Facilitated diffusion and Active Trasport
What are lipids?
Carbon containing compounds that are largely non-polar and hydrophobic
What are hydrocarbons?
molecules that contain only hydrogen and carbon
What is the major hydrocarbon component in a lipid?
Fatty Acid
What is a fatty acid?
Hydrocarbon chain bonded to a carboxyl group.
Three types of lipids found in cells?
Fats
Steroids
Phospholipids
What is a Fat?
three fatty acids linked to a glycerol
What is a steroid?
family of lipids distinguished by a four-ring structure
What is a Phospholipid?
Glycerol linked to a phosphate group and either 2 chains of isoprene or fatty acids
What does amphipathic mean?
Containing both hydrophobic and hydrophillic parts
How do Phosopholipid bilayers form (lipid bilayers)?
Two sheets of phospholipid molecules align where the non-polar tails face each other and the polar head are facing the surrounding solution.
They form spontaneously with no outside input of energy
How do phosholipid bilayers have selective permeability?
small and nonpolar molecules move across the bilayer quickly
Charged or large polar substances move across slowly, if at all
Unsaturated Lipid?
has a double bond between two carbons in a hydrocarbon chain
Saturated lipids
hydrocarbons without double bonds
Membrane fluidity decreases with temperature beacause...
molecules in the bilayer move more slowly
Decreased membrane fluidity causes...
decreases permeability
what is a solute?
Small ions and molecules in a solution
Hypertonic solution?
Solute concentration higher outside the cell, so water moves out of the cell
Hypotonic solution?
Solute concentration higher inside the cell, so water moves into the cell
Isotonic solution?
Solute concentration are equal inside and outside the cell.
Integral proteins that span the membrane are?
Transmembrane proteins
Function of transmembrane proteins?
transport of selected ions and molecules across the plasma membrane
Transmembrane proteins that transport molecules are called?
Transport proteins
Three types of transport proteins?
Channels
Carrier Proteins
Pumps
Channel proteins are responsible for what type of diffusion
Facilitated diffusion
What is facilitated diffusion?
The passive transport (no energy used) of substances that would not otherwise cross the membrane
Two methods facilitated diffusion can occur?
Channels
Carrier Proteins
Active Transport
Transport of molecules or ions against a electrochemical gradient - requires ATP.
What do pumps create?
A chemical and electrical gradient across the membrane
Three mechanisms of membrane transport?
Diffusion
Facilitated diffusion
Active Transport
Author
silverblade760
ID
11317
Card Set
Lipids, Membranes, and the First Cells
Description
BIOL 203
Updated
2010-03-20T04:55:51Z
Home
Flashcards
Preview