Cell membranes cells, and organelles

The two classifications of cells

1) Sex cells - sperm and ooctyes

2) somatic cells- all other cells

Plasma membrane

Separates the interior of the cell from the outside environment

Diffusion

The movement of particles from an area of higher concentration to lower concentration

Factors that influence diffusion

Distance, molecule size, temperature, gradient, size, electrical forces

Osmosis

The net diffusion of water across a membrane

Isotonic solutions

There is no osmotic flow in or out of the cell (cells keeps normal size)

Hypertonic solution

Net osmotic flow out of the cell (the cell shrinks)

Hypotonic solution

Net osmotic flow moves in the cell (cell bursts)

Active transport

A high energy bond provides the energy needed to move ions or molecules across a membrane with the use of ATP

Tight junctions

A cell junction that occurs when cells that are joined near the top surfaces, by collars of tightly fused membranes

Desmosomes

A cell junction that hold adjacent cells together

Gap junctions

A cell junction that occurs when adjacent from each other and contain a channel between them

Nucleus

An organelle that controls the cell and stores DNA

Mitochondria

An organelle that produces ATP

Endoplasmic reticulum

An organelle that builds and transports proteins and lipids

Golgi apparatus

Modify, sorts, and ships proteins

Ribosomes

An organelle that makes proteins

Cilia

Long slender cell extensions of the plasma membrane that line the respiratory track

Microvilli

Small finger like self extensions of the plasma membrane that increase surface area and help with absorption and secretion