Grade 9 Bio - Cellular Transport

Simple Diffusion

The movement of molecules from an area of higher concentration to an area of lower concentration.

Facilitated Diffusion

The transport of molecules that cannot diffuse through the cell membrane on their own, using the help of a membrane protein.

Osmosis

The process by which water diffuses across a membrane.

What type(s) of substances do(es) simple diffusion bring in and/or out of the cell?

Small and nonpolar molecules

What type(s) of substances do(es) facilitated diffusion bring in and/or out of the cell?

Big, polar, and charged molecules

What type(s) of substances do(es) osmosis bring in and/or out of the cell?

Water

Water wants to move to areas where it can ___________ things

dissolve

Hypotonic Solution

A lower concentration of solute molecules.

Hypertonic Solution

A higher concentration of solute molecules

Isotonic Solution

An equal concentration of solute molecules.

Passive Transport

The movement of substances across the cell membrane without the input of energy (ATP).

What type(s) of protein are(is) used for osmosis

Channel protein (aquaporin)

What type(s) of protein are(is) used for facilitated diffusion?

Carrier/channel proteins

What type(s) of protein are(is) used for simple diffusion?

Proteins are not used for simple diffusion.

Concentration Gradient

The difference in the concentration of molecules across a space.

Equilibrium

when the concentration of the molecules of a substance is the same throughout the space.

True or False: The molecules continue moving after equilibrium is reached, but will not change in concentration

True

What molecules can easily diffuse across a cell membrane?

Very small molecules and hydrophobic molecules.

True or False: Water moves from an area of low concentration of water to an area of high concentration

False

Water will diffuse _____ from a hypotonic area

away

Water will diffuse _____ a hypertonic area

into

Water will diffuse __ ___ ___ _______ in an isotonic area.

in and out equally

What is this an image of?

A cell in a hypotonic solution

Is there more or less solute inside the cell?

More

Is there more or less solute in the substance surrounding the cell?

Less

What is this an image of?

A cell in a hypertonic solution

Is there more or less solute inside the cell?

Less

Is there more or less solute in the substance surrounding the cell?

More

Turgor Pressure

the force within the cell that pushes the plasma membrane against the cell wall

What type of cell has turgor pressure?

Plant cells

How does a cell lose its turgor pressure?

by losing water

Plasmolysis

water leaves the cell through osmosis and the cell shrinks

True or False: Cytolysis causes a loss of turgor pressure.

False

Cytolysis

water diffuses into the cells too quickly, causing them to swell and eventually burst

What type of solution does cytolysis occur in?

A hypotonic solution

Ion channels

small protein passageways in the cell membrane that allow ions to pass through.

True or False: Ions are not soluble in lipids, so they cannot cross the membrane on their own

True

Are all ion channels always open?

No

Active Transport

the movement of molecules that requires energy

True or False: Active transport moves molecules against their concentration gradient

True

Solute(Protein) Pumps

proteins within the cell membrane that use energy to move molecules against the concentration gradient.

Bulk transport

the process used to move macromolecules, food particles and large quantities of small molecules through the cell membrane inside vesicles (small vacuoles)

What are the two types of bulk transport?

Endocytosis and exocytosis

Endocytosis

cell membrane folds around something and forms a pouch. The pouch then pinches off and becomes a vesicle in the cytoplasm.

What are the two types of endocytosis?

Phagocytosis and Pinocytosis

Phagocytosis

“cell eating”; the vesicle contains large particles or cells.

Pinocytosis

“cell drinking”; the vesicle contains solutes or fluids.

Exocytosis

vesicles made by the cell fuse with the cell membrane, releasing their contents outside the cell.

What is this an image of?

Endocytosis

What is this an image of?

Exocytosis