Chapter 7 - Cell Membrane Flashcards
What is ur Fluid Mosaic Model?
A model of what we think a cell membrane looks like.
What is the cell membrane made up of?
Phospholipid bilayer
What does amphipathic mean?
Hint: phospholipids
Has hydrophobic and hydrophilic properties.
How is a cell membrane held together?
They are held together by hydrophobic and hydrophilic reactions.
What are integral proteins?
It is a membrane protein that penetrate the hydrophobic interior if the lipid bilayer.
What is a peripheral protein?
They are proteins that aren’t embedded in the lipid bilayer at all; they are appendages loosely Bond to the surface of the membrane, often to expose parts of integral proteins.
What are glycolipids?
They are membrane carbohydrates that are usually short; some are covalently bonded to lipids.
What are glycoproteins?
They are membrane carbohydrates that are usually short; most of these carbohydrates are covalently bonded to proteins.
Do cell membranes move? How fast?
Yes they move, they have a lateral movement and they move 10 to the 7th power times per second.
Lipids on a cell membrane have…
Hydrophilic heads - stays on the outside of the membrane
Hydrophobic - tails will stay on the inside of the membrane
What happens to a membrane when there are unsaturated fats?
It makes the membrane more fluid by linking the tails so that the tails can’t pack like they should.
When are cell membranes more fluid? What about in lower temperature?
At high temperatures
It will remain fluid at lower temperatures if there is a lot of phospholipids with unsaturated hydrocarbon tails.
What function does cholesterol have for the membrane?
It is like a fluid buffer.
At higher temperature labor makes the membrane less fluid to help the cell from getting destroyed.
At lower temperatures it hinders solidification by disrupting the packing of the tails within the membrane.
What is an integral protein?
Proteins that penetrate the hydrophobic interior of the membrane.
They have hydrophilic and hydrophobic portions
What are peripheral proteins?
They are proteins that are not embedded in the lipid bilayer at all; they are appendages loosely bound to the surface of the membrane. Hey
What are the functions of proteins?
Transport Enzymatic activity Signal transduction Cell-cell recognition Intercellular joining Attachment to the cytoskeleton and extra cellular matrix (ECM)
What are glycoproteins?
Short branch chained carbohydrates of <15 sugar Monomers
They are covalently bonded to proteins.
What are glycolipids?
Short branch chained carbohydrates of <15 sugar Monomers
Glycolipids are covalently bonded to lipids
How is blood types distinguished?
Variations of the carbohydrate part of glycoproteins on the surface of red blood cells.
What is a fluid mosaic model?
A model of what we think a cell membrane looks like.
What are the 5 different types of membrane transport?
Diffusion Osmosis Facilitated diffusion Active transport Bulk transport
What is diffusion?
When something moves from high concentration to low concentration.
Equilibrium can be reached (where there is the same number of molecules on one side and the other side)
What is osmosis?
Diffusion of water through a semipermeable membrane
Isotonic - solutes in a solution; the outside is the same as the concentration on the inside.
Hypertonic - solutes in a solution greater outside (will pull water out)
Hypotonic - solutes in a solution less outside (will pull water in)
What is facilitated diffusion?
Going towards equilibrium
Will work through membranes to get to equilibrium
What is active transport?
To pump a solute across a membrane against its gradient
This pump also requires ATP
What is the sodium-potassium pump?
Pump sodium and potassium through to help make energy.
Potassium will be on one side of the membrane while sodium will be on the other side.
What is the proton pump?
Actively transports protons out of the cell.
The pumping of H+ transfers positive charge from the cytoplasm to the extracellular solution.
By generating voltage across membranes, electromagnetic pumps help store energy that can be tapped for cellular work.
What is the cotransport?
When hydrogen pumps out of proton pump it will pump hydrogen back through the cotransport bringing sucrose with it.
What is the bulk transport?
When a molecule hits a membrane it will wrap around molecule until it closes off into the cell
What is endocytosis?
Part of the bulk transport where a molecule goes from the outside to the inside.
What is exocytosis?
Part of bulk transport where a molecule goes from the inside to the outside.
