Cell Membrane Flashcards
Cell Membrane
A gateway for nutrients to enter and wastes to leave the cell
Integral membrane proteins
- Span the lipid bilayer
- Proteins are hydrophilic/hydrophobic when they interact with hydrophilic/hydrophobic portion of the membrane
What are 2 structural types of the Fluid Mosaic Model?
Integral membrane proteins, Peripheral membrane proteins
Peripheral membrane proteins
Attached to the outside of the membrane
Channel protein
Allows particular molecules or ions to cross the plasma membrane
Carrier protein
Selectively interacts with specific molecules or ions so it can cross the plasma membrane
Ex. sodium ions
Cell recognition protein
Recognizes a certain substance and starts a response
Ex. immunity recognition
Receptor Protein
Has a specific shape that certain molecules can bind to and start a response
Ex. human growth hormone binding receptors
Enzymatic protein
Catalyzes specific reactions: making ATP
Glycoproteins
Proteins which have an attached carbohydrate chain
Glycolipids
Phospholipids whose hydrophilic head have an attached carbohydrate chain
What is the function of glycoproteins and glycolipids?
The carbohydrate chains allow tissues and cells of embryo to sort themselves out
Where are glycoproteins and glycolipids found?
The extracellular side of the membrane
How do the glycoprotein and glycolipid chains vary?
- Number of sugars
- Number of branching patterns
- Sequence of sugars
What happens after the DEVELOPMENT of the embryo?
It develops its own glycoproteins and glycolipids
What do the embryo’s glycoproteins and glycolipids do?
They help the immune system to identify which cells are invaders and which belong to the body
Why are blood types unique?
Due to unique glycoproteins on red blood cells
Cholesterol
is a lipid steroid found within the animal lipid bilayer
-serves as a temperature-stability buffer
At higher temps : impedes phospholipid fluidity
At lower temps: interferes with solidification of membranes
Some molecules can enter, while others of the same size cannot
Selectively premeable
Diffusion
Particles moving from an area of greater concentration towards the are of lesser concentration
-does not require energy
What is the rate of diffusion affected by?
- Concentration gradient - the difference in []
- Size/shape of molecules
- Temperature
- State
