Biology exam final-8.3

What direction do particles move during diffusion?

From an area of higher concentration to an area of lower concentration.

Facilitated Diffusion

The movement of molecules through channel proteins

Osmosis

Diffusion of water through a selectively permeable membrane

Isotonic

when the concentration of two solutions is the same

Hypertonic

when comparing two solutions, the solution with the greater concentration of solutes

Molecular Transport

Small molecules and ions are carried across membranes by proteins in the membrane that act like pumps

Bulk Transport

Larger molecules and even solid clumps of material can be transported by movements of the cell membrane

What is endocytosis?

The process of taking material into the cell.

How does endocytosis occur?

By means of infoldings, or pockets, of the cell membrane.

What is phagocytosis?

A type of endocytosis in which extensions of cytoplasm surround a particle.

What is formed during phagocytosis?

A food vacuole.

Pinocystosis

tiny pockets form along the cell membrane, fill with liquid and pinch off to form vacuoles

What is exocytosis?

A process where a vesicle or vacuole fuses with the cell membrane.

What happens during exocytosis?

The contents of the vesicle or vacuole are forced out of the cell.

Passive Transport

transport of molecules across cell membrane

what does passive transport require?

no effort and energy

Passive Transport is necessary for...

maintaining homeostasis (internal balance)

What are the 3 types of passive transport

diffusion, facilitative diffusion, osmosis

What does diffusion do in any solution?

solute particles move constantly and can diffuse across cell membrane

Equilibrium

is reached when concentration of solute particles is the same on both sides of the membrane

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

Homeostasis

Relatively constant internal physical and chemical conditions that organisms maintain

Facilitated Diffusion is only

small uncharged molecules can move through lipid bilayer

In FDiffusion

Ions and large molecules cannont simply diffuse across a membrane

In FDiffusion channel proteins...

help ions and large molecules pass through cell membrane.

Lipid Bilayer

hydrophobic, therefore water cannot easily diffuse through cell membrane

Water molecules pass

through aquaporin

Water Molecules

(not solute particles) pass from an area of high concentration to low concentration.

Isotonic solution

both sies of a semipermeable membrane have same concentration solute

Hypertonic solution

1 side of membrane has lower concentration of solute than the other

Active Transport

The movement of materials against a gradient concentration

Active T requires

Energy

In active Transport, 1)

small molecules of ions are carried by protein pumps

In Active Transport, 2)

Larger molecules or materials are gonna be carried by endo/extocytocis

In Molecular Transport,

Our body has CA, K, and NA ion pumps

In MTransport

cells use energy to the concentration of substances in particular location, for Ex: Why want a buildup of calcium in our bones?

Bulk Transport is a type of transport that

depends on size and shape of the material

Give an example of Phagocytosis

1: White blood cells engulf foreign materials and destroy them

2: Amoeba

In Exocytosis the contents are

forced out of the cell ex: contractile vacuole