Bio Chapter 5

What is the plasma membrane made of?

Two layers of amphipatic phospholipids

What is the fluid-mosaic model?

A model that depicts the plasma membrane as a mosaic of components

What are membrane proteins?

proteins found in the cell membrane that perform various functions for the cell

What is membrane cholesterol?

cholesterol that maintains an optimal fluidity of the membrane in animal cells.

When and how does membrane cholesterol increase fluidity?

At low temperatures by preventing fatty acid tails from packing together

When and how does membrane cholesterol decrease fluidity

At high temperatures by restricting the movement of membrane components

Glcosylation

covalently attaching a carbohydrate chain to a protein or lipid

Glycolipid

lipid with a carbohydrate chain

Glycoprotein

protein with a carbohydrate chain

What can easily pass through the semipermeable plasma membrane?

small, hydrophobic (non polar) molecules

What can easily pass through the semipermeable plasma membrane?

Gases

Can water pass through the membrane? Why or why not?

yes, although hydrophilic (polar) it is small enough to pass through

What is in the plasma membrane?

Phospholipids embedded with proteins, glycoprotiens, glycolipids and cholesterol

Concentration gradient

A difference in concentration between two areas

Chemical gradient

Concentration of solute is higher on one side than the other

Passive transport

molecules move from high to low concentration

Active transport

molecules move from high to low concentration using energy (ATP) and transport protiens

Electrochemical gradient

A difference in both solute and charge across a gradient

What 3 properties determine how easily a molecule can pass through the plasma membrane?

Size, polarity, charge

Receptor protiens

proteins used for cell recognition

Transport proteins

proteins used to transport molecules

Anchor proteins

Anchored in the cell membrane

Three types of passive transport

Simple diffusion, facilitated diffusion, Osmosis,

Simple diffusion

The net movement of molecules form high to low concentration until equilibrium is achieved

Facilitated diffusion

Membrane transport proteins assist the movement of molecules from high to low concentration

Osmosis

The diffusion of solvent molecules across a semipermeable membrane from a dilute solution (more water) into a more concentrated solution (more solute) (movement of water)

Tonicity

the relative difference in concentration between 2 solutions

what does a solution contain?

A solute disolved in a solvent

Outside the cell is a hypotonic solution

A solution with lower solute concentration, water moves into the cell through osmosis

Outside the cell is a hypertonic solution

A solution with higher solute concentration, water moves out of the cell through osmosis

Isotonic

A solution with equal solute concentration, no net movement of water

Bulk transport

Movement of large bulky molecules across the plasma membrane using a vesicle

Exocytosis

Transport of molecules out of the cell through a vesicle

Endocytosis

Transport of molecules into the cell through a vesicle