Unit 2.5 Honors Biology

Phospholipid

A lipid with a polar head and a non polar tail, these create the phospholipid bilayer

Hydrophilic

Water loving

Hydrophobic

Water fearing

Cholesterol

Helps maintain stability in fluidity in the membrane *waxy

Polar

Uneven distribution of electron density

Non-polar

Even distribution of electrons (no positive or negative poles

Extracellular

Outside of the cell

Cytoplasm

Jelly-like substance filling a cell, inside the cell/intracellular

Glycolipid

Help with cell recognition, signaling, and stability in the membrane (cell to cell)

Glycoprotein

Aid in cell recognition in the immune response

Selectively permeable

To choose what comes in and stays out of the cell

Integral protein

Proteins permanently embedded within the cell membrane, function-transport, cell signaling, structural support, and enzyme activity

Peripheral protein

Permanently embedded in the phospholipid bilayer function-cell adhesion, enzyme activity, transport, and cell structure

Cell-surface markers

Proteins that aid to cell-cell communication

Diffusion

The movement of molecules from a high to low concentration

Osmosis

The transport of water molecules through the membrane that does not require energy

Passive transport

Movement of molecules across the cell membrane that does not require energy

Concentration gradient

The region along which the density of a substance increases or decreases

Equilibrium

State of balance between opposing forces

Active transport

Moving something against its concentration gradient using energy (ATP)

Sodium potassium pump

The active transport where the sodium is pushed out of the cell and the potassium s pushed into the cell using ATP

Endocytosis

Movement of something into the cell using vesicles

Exocytosis

Release of substance out of the cell by vesicle fusion

Phagocytosis

“Cell eating”, cell absorbs/ surrounds large solid particles

Pinocytosis

“Cell drinking”, movement of liquids into the cell