AP Biology Unit 2

Compartmentalization

Separation of cellular processes into distinct areas.

Prokaryote

Single-celled organisms without a nucleus.

Eukaryote

Organisms with complex cells containing a nucleus.

Organelles

Specialized structures within a cell performing specific functions.

Ribosomes

Molecular machines synthesizing proteins from amino acids.

Endoplasmic reticulum (ER)

Network for protein and lipid synthesis; includes rough and smooth.

Golgi complex

Modifies, sorts, and packages proteins for secretion.

Mitochondria

Powerhouse of the cell; site of ATP production.

Lysosomes

Organelles containing hydrolytic enzymes for digestion.

Hydrolytic enzymes

Enzymes that break down biomolecules in lysosomes.

Vacuole

Storage organelle for nutrients, waste, and water.

Chloroplasts

Organelles for photosynthesis in plant cells.

Cell wall

Rigid outer layer providing structure to plant cells.

Phospholipid Bilayer

Double layer of phospholipids forming cell membranes.

Selective permeability

Membrane property allowing certain substances to pass.

Fluid mosaic model

Describes cell membrane structure as flexible and dynamic.

Hypotonic

Solution with lower solute concentration than the cell.

Isotonic

Solution with equal solute concentration to the cell.

Hypertonic

Solution with higher solute concentration than the cell.

Passive transport

Movement of molecules across membranes without energy.

Active transport

Energy-requiring process moving molecules against concentration gradient.

Turgor pressure

Pressure from water in vacuoles against cell walls.

Osmosis

Diffusion of water across a selectively permeable membrane.

Homeostasis

Maintenance of stable internal conditions in organisms.

Osmoregulation

Regulation of water balance in cells and organisms.

Water potential

Potential energy of water in a system.

Solute potential

Effect of solute concentration on water potential.

Pressure potential

Physical pressure on water in a plant cell.

Diffusion

Movement of molecules from high to low concentration.

Facilitated Diffusion

Passive transport aided by membrane proteins.

SA:V ratio

Surface area to volume ratio affecting cell efficiency.

Embedded proteins

Proteins integrated within the phospholipid bilayer.

Glycoproteins

Proteins with carbohydrate chains attached for cell recognition.

Glycolipids

Lipids with carbohydrate chains contributing to membrane structure.

Exocytosis

Process of vesicles fusing with membranes to release contents.

Endocytosis

Process of taking substances into the cell via vesicles.

Aquaporins

Channel proteins facilitating water transport across membranes.

Endosymbiosis

Theory explaining origin of mitochondria and chloroplasts.

Na/K pump

Active transport mechanism maintaining sodium and potassium gradients.

Secondary Active Transport

Transport relying on the gradient created by primary active transport.