lab 5

Lipid bilayer

two rows of phospholipid molecules, heads face outward and tails face inward.

Phospholipid

Main molecule that makes up the lipid bilayer.

Phosphate group head

a phosphate group, polar and hydrophilic.

Fatty acid tails

two fatty acid chains, nonpolar and hydrophobic.

Hydrophilic

Water-loving

Hydrophobic

Water-fearing

Cholesterol

Rigid ring lipid; randomly distributed through hydrophobic region; gives the plasma membrane structural strength.

Transmembrane proteins

Extend through lipid bilayer; may serve as a transport protein or channel across the bilayer.

Peripheral protein

Does not extend across the lipid bilayer; may serve as an anchor point for the cytoskeleton.

Carbohydrate chains

Extend from the outer surface; attached to protein or phospholipid; function as a signal, coating, or receptor.

Extracellular environment

Outside of the cell; aqueous/watery.

Cytoplasm

Inside of the cell; aqueous/watery; contains organelles.

secondary active transport

Occurs down the gradient and does not use ATP

primary Active Transport

Occurs against the gradient and requires energy

SIMPLE DIFFUSION

Driven by the concentration or pressure gradient, May occur through different media, May or may not involve the semipermeable membrane

simple diffusion example

gas exchange in lungs, a dye spreading through the liquid

FACILITATED DIFFUSION

Solute particles move driven by the concentration gradient
Involves carrier proteins (transporters) in the cell membrane

FACILITATED DIFFUSION example

Glucose transport across the cell membranes through Glucose transporter

OSMOSIS

Solvent moves down the concentration Involves semipermeable membrane

blue dye

methylene

pink dye

potassium permanganate

hypotonic solution

lower solute concentration, higher solvent concentration,

hypertonic solution

higher solute concentration, lower solvent concentration

selectively permeable membrane

solvent passes through

isotonic solution

equal solute and solvent concentration

Hypertonic

More solute outside the cell; water moves out of the cell, so it shrinks, This is called crenation.

Hypotonic

Less solute outside the cell; water moves into the cell, so it swells and lyse, This is called hemolysis.

Isotonic

Equal solute inside and outside the cell; water moves evenly, so the cell stays the same.

primary active transport

by using ATP it moves the substance against the chemical or electrical gradient.

secondary active transport

no ATP so it moves the substance against the gradient and is driven by the primary active transport

Receptor-mediated Transport

Involves membrane surface receptors to internalize the substance

Phagocytosis

Cells engulf solid particles or bacteria etc.

Pinocytosis

Cells engulf liquid substance