Bio 151 Chapter 5

Membrane structure

Membrane structure

phospholipids arranged in a bilayer

cellular membranes

phospholipid bilayer, transmembrane proteins, interior protein network, cell surface markers

phospholipid bilayer

provides barrier matrix for proteins

transmembrane proteins

carries, channels, and receptors

interior protein network

determines shape of cell and anchors certain proteins to specific cites

cell surface markers

“self” recognition or glycoproteins, and tissue regulation or glycolipid

protein key functions

transporters, enzymes, cell surface receptors, cell surface identity markers, cell to cell adhesion proteins, attachments to the cytoskeleton, proteins that affect membrane structure

transporters

allow only certain molecules to enter or leave the cell

enzymes

cells cary out chemical reactions to the inferior surface using enzymes attached to the membrane

cell surface receptors

sensitivity detector

cell surface identity markers

carry cell surface markers that identify them to there cells

cell to cell adhesion proteins

forming temporary interactions

attachments to the cytoskeleton

anchored to the cytoskeleton by linking proteins

passive transport

high concentration to low concentration

osmosis

net diffusion of water across a membrane toward a higher solute concentration

aqueous solution

mixture of substances in water

osmosis concentration

hypertonic and hypotonic solution

hypertonic solution

higher solute

hypotonic solution

Lower solute

isotonic

same osmosis concentration

maintaining osmosis balance

extrusion, isosmotic regulation, and turgor

extrusion

where water is ejected through vacuoles

isosmotic regulation

keeping cells isotonic with their environment

turgor

plant cells use it ti push the cell membrane against the cell walls and keep the cell rigid

bulk transport

endocytosis and exocytosis

endocytosis

movement of substance into cells. 3 types: phagocytosis, pinocytosis, and receptor mediated endocytosis

phagocytosis

cell takes in particle matter

pinocytosis

cell takes in only fluid

receptor mediated endocytosis

specific molecules are taken in affect after they bind to receptor

exocytosis

movement of substances out of cell

active transport

enables a cell to take a additional molecules of a substance that is already present in cytoplasm

uniporters

move one molecule at a time

symporters

move 2 molecules in the same direction

antiporters

move 2 molecules in opposite direction