Bio Chapter 7

Selective permeability

is a property of cellular membranes that allows certain molecules to enter or exit the cell while restricting others, thus maintaining homeostasis.

Amphipathic

refers to molecules that have both hydrophilic and hydrophobic regions, enabling them to interact with both water and lipid environments.

Phospholipid

A type of lipid molecule that is a major component of cell membranes, consisting of a hydrophilic "head" and two hydrophobic "tails."

Phospholipid bilayer

a fundamental structure of cell membranes composed of two layers of phospholipids. The hydrophobic tails face inward, while the hydrophilic heads face outward, allowing for selective permeability.

Integral/peripheral protein

Integral proteins are embedded within the phospholipid bilayer, often extending across it, while peripheral proteins are located on the surface of the membrane and do not penetrate the lipid bilayer.

Glycolipids

Glycolipids are lipids with carbohydrate chains attached, found in cell membranes where they play roles in cell recognition and signaling.

Glycoproteins

molecules formed from the combination of carbohydrates and proteins, playing key roles in cell recognition and signaling.

Transport proteins

Transport proteins are proteins that facilitate the movement of ions and molecules across the cell membrane. They can be integral or peripheral, functioning in various transport mechanisms such as passive or active transport.

Aquaporins

specific channel proteins that facilitate the transport of water across cell membranes, allowing for rapid water movement.

Passive transport

The process by which molecules move across the cell membrane without the use of energy, typically following their concentration gradient.

Diffusion

Osmosis

Isotonic

Hypertonic

Hypotonic

Osmoregulation

Contractile vacuole

Turgor pressure

Plasmolysis

Facilitated diffusion

Ion channels/gated channels

Active transport

Sodium/potassium pump

Electrochemical gradient

Proton pump

Cotransport

Endocytosis

exocytosis

Recognize components of cell membranes (See diagram on p. 127)

Describe the role of cholesterol in the membrane.

For integral proteins, predict which types of amino acids (acidic/basic, polar, nonpolar) would be found

within the phospholipid bilayer.

Briefly describe the roles of different types of membrane proteins.

The role of carbohydrates on the extracellular side of the plasma membrane

For channel proteins, describe the chemical characteristics of the channel. Is it charged/polar or

nonpolar