Ch. 3 Structure and Function of the Cell

Common characteristics a cell has:

1. Plasma (cell) Membrane

2. Nucleus

3. Cytoplasm

4. Organelles

Organelles

“Little Organs”

• Preform specialized functions

Organelles functions

1. Basic unit of life

2. Protection and support

3. Movement

4. Communication

5. Cell metabolism and energy release

6. Inheritance

Plasma Membrane

Regulates what comes into and out of cells; communicates with other cells

Membrane potential

A charge difference inside and outside the cell, this helps regulate ion movement across the cell

Outside the cell

More positive charged than inside

Inside the cell

More negative charged than outside

Membrane is (?) lipids

45-50%

Membrane is (?) proteins

45-50%

Membrane is (?) carbs

4-8%

Carbs + Lipids

Glycolipids

Proteins + carbs

Glycoproteins

Glycocalyx

Glycolipids, glycoproteins, and carbs on membrane

Main lipid is a phospholipid

Lipid bilayer

Polar heads

Hydrophilic (water loving), exposed to water inside and outside of cell

Nonpolar tails

Hydrophobic (Water hating), faced to eachother in the interior of the membrane

Another lipid in membrane:

Cholesterol

Cholesterol

Determines fluid nature of membrane, which is important to is function

Membrane protein

The plasma membrane is very fluid

Fluid

Fluid-mosaic model

Fluid-mosaic model

Allows molecules to be distributed into and out of the cell, easy repair of damaged membranes, and enables membranes to fuse with eachother

Integral proteins

Extend deep into the membrane

Peripheral protein

Attached to either inside or outside of the membrane

• Usually bound to integral proteins