Honors Bio 1C: Diffusion, Osmosis, and the Membrane

Updated version

Homeostasis

the process of maintaining a stable internal environment in cells and organisms despite changes in external conditions.

Response to the Environment

the ability of an organism to adjust its processes in reaction to external stimuli.

Primary Structure

Peptide bonds link amino acids in a specific sequence to form a polypeptide chain.

Secondary Structure

the folding or coiling of a polypeptide chain due to hydrogen bonding between the amino acids

Tertiary Structure

the three-dimensional shape of a polypeptide formed by interactions between the side chains of amino acids, including hydrogen bonds, ionic bonds, and disulfide bridges.

Quatenary Structure

the structure formed when two or more polypeptide chains aggregate together to form a functional protein, stabilized by various interactions.

Denaturation 

the process in which a protein loses its native structure due to external stressors, leading to a loss of function.

Polar molecules

Charged ends ex. Water and Phosphate heads

Nonpolar molecules

Have no charge ex. lipds,oils and Phosphate tails

Triglycerides

Long-term energy storage

Waxes

Waterproof coatings (on leaves, skin, feathers)

Steroids

Ring-shaped lipids used as hormones

Solute

the substance being dissolved

Solvent

the substance doing the dissolving

Hypertonic

Water moves out of the cell - cell shrinks

Hypotonic

Water moves into the cell - cell swells

Isotonic

water moves equally in + out - cell stays normal

Diffusion

Molecules move directly through membrane

Osmosis

Diffusion of water through a semipermeable membrane

Facilitated Diffusion

Uses a channel or carrier protein to help larger or charged molecules cross

Protein pumps

Uses ATP to push ions across the membrane

Endocytosis

Cell brings material into a vesicle

Exocytosis

Cell releases material from vesicles

Cytolysis

Cell bursts from too much water

Crenation

cell shrivels from water loss