Cells and Extracellular Environment

What is outside the plasma membrane?

solvents, substances dissolved in fluid

What is inside the plasma membrane?

solvents, proteins and ions

Types of passive transport

• simple diffusion

• facilitated diffusion

• osmosis

Types of active transport

ion pumps

lipid bilayer

controls what goes in and out

matrix metalloproteinases

form or regenerate tissues

What does insulin do in the cell?

respiration

What does insulin store in the cell?

glycogen and fat

insulin

lowers blood glucose

What does it mean if there is not enough insulin?

increased blood glucose

Na+/K+ Pump

• active transport

• against conc. gradient

• uses ATP

• 1 pump cycle

What is the Na+/K pump cycle

• 1 ATP

• 3 Na+ out

• 2 K+ in

resting membrane potential

70 mv more negative inside than outside the cell

action potential

allow neurons to fire and muscle to contract

paracrine/endocrine

signaling cells that move from one cell to another to cause a reaction

regulatory molecule

neurotransmitter, hormone, or paracrine regulator

polar

water soluble; membrane bound

nonpolar

lipid-soluble; cytosolic receptors

extracellular matrix

consists of collagen and elastin

plasma membrane

selectively permeable

passive transport

high to low concentration

active transport

low to high concentration

pumps

use ATP to power carrier proteins

aqueous solution

solvent, water, and solute

osmosis

diffusion of water

aquaporins

permit osmosis

osmotic pressure

pressure needed to stop osmosis

tonicity

the affect of a solution on the osmotic movement of water

hypotonic

lower solute conc.

hypertonic

high solute conc.

diffusion

does not use ATP

cell signaling

how cells communicate

What does a target cell use to respond?

receptor protein

second messengers

enter the extracellular fluid in response to the binding of regulatory molecules to their receptors

important second messengers

cAMP

g-proteins

3 proteins that shuttle between receptors, enzymes and ion channels