Cell Membrane Structure and Function

glycolipid

A carbohydrate-lipid moleule involved in cell to cell recognition

Transport proteins

A molecule that helps to move ions and other molecules across the cell membrane

glycoprotein

A peripheral protein with a carbohydrate portion whose main function is helping the cell recognize other cells, and cell to cell communication.

a home central heating and air conditioning unit

A typical analogy/illustration to a negative feedback system.

Selectively Permeable

Allows certain things to pass through and prevents other things from passing through.

Integral protein

Also known as a trans-membrane protein, which is located throughout the cell membrane. Functions in transporting materials.

Decides what can enter or leave the cell.

Cell(Plasma) Membrane

Fluid mosaic model

Describes the composition of the cell membrane; states that different parts of the membrane can float in a fluid-like space

Phospholipid bilayer

Double layer of lipids; heads face outward, tails are in the middle

Phospholipids

Lipids (fats) that make up the cell membrane. They have a polar head with two non-polar tails.

Homeostasis

Maintaining stable internal conditions

Cholesterol

Molecules found throughout the membrane; help to stabilize the phospholipids and keep them in position, and help to maintain the cell membrane's flexibility

Giving birth

One of the two examples of positive feedback system in human beings.

Proteins

Scattered throughout the cell(plasma) membrane and responsible for most of the specialized functions of the membrane.

Cell (Plasma) Membrane

The major structure of the cell that helps maintain homeostasis in the cell.

negative feedback system

The net effect of the response to the stimulus is to shut off the original stimulus or reduce the intensity. These are more common and require continuous adjusting.

positive feedback system

The stimulus increases in strength and pushes the variable farther from the original point. These are rare and do not require continuous adjustments.

Hydrophilic

Will mix with water; polar phospholipid heads

Hydrophobic

Will not mix with water; nonpolar phospholipids tails

Golgi Apparatus

packages, modifies, and ships proteins throughout the cell.