Lesson2- Cell Transport

Passive Transport

Movement of substances across the cell membrane. Requires no energy from the cell

Diffusion

Movement of molecules from HIGH

concentration to LOW concentration

Concentration Gradient

the difference

between concentrations in space.

Equilibrium

same concentration across the

gradient.

OSMOSIS

Process by which WATER

molecules diffuse across a

membrane from high to low

concentrations

isotonic

has the same concentration of solutes (like salt) as the inside of the cell. There is no net movement of water in or out, keeping the cell stable.

Hypotonic

has a lower concentration of solutes than the inside of the cell. When a cell is placed in a _______ solution, water moves into the cell to balance the concentration.

Hypertonic

has a higher concentration of solutes than the inside of the cell. When a cell is placed in a ________ solution, water moves out of the cell to balance the concentration gradient, causing the cell to shrink.

Contractile Vacuoles

It is how cells deal with osmosis in Animal cells where they collects water and expels it from the cell.

Turgor Pressure

It is how cells deal with osmosis in plant cells where water pressure is exerted against the cell wall.

Plasmolysis

loss of turgor pressure.

► Plants wilt

Cytolysis

cells burst due to hypotonic solution cell is in

Facilitated Diffusion

Needs a carrier protein. Refers to a process where specific molecules pass through a cell membrane with the help of transport proteins.

Ion Channels

Transport ions such as Na, K, Ca and Cl

Can’t pass through membrane w/ochannel

Active Transport

Moving molecules from a LOW concentration to a higher

concentration .

Moving molecules from a LOW concentration to a higher concentration.

Endocytosis

process of

ingesting macromolecules and

nutrients that are too large to pass

through membrane

Pinocytosis

Transport of other fluids

Phagocytosis

Transport of large particles or whole cells.

may fuse with lysosomes to destroy ingested bacteria or viruses.

Exocytosis

process by which materials are released from the inside of the cell.

Release toxins and waste products.

Membranes

organize the chemical activities of cells.

outer plasma membrane

forms a boundary between a living cell and its

surroundings

● Exhibits selective permeability

laterally

Most protein and phospholipid molecules can

move ____________.

Phospholipids

are the major structural component of membranes.

Integral proteins

span the membrane

Peripheral proteins

are on one side or the other of

the membrane

Glycoproteins

are short chain carbohydrates that are attached on the proteins.

Glycolipids

are short chain carbohydrates that are attached on the lipids.

Cell-cell recognition proteins

identify type of cell and identify a cell as “self” versus foreign.

Integrins

• strengthen the membrane.

• Cytoskeleton attaches to them on the cytoplasmic side of the membrane.

Intercellular junction proteins

help like cells stick together to form tissues.

Enzymes

are biological molecules, typically proteins, that act as catalysts to accelerate chemical reactions within living organisms.

Signal transduction proteins

bind hormones and other substances on

the outside of the cell

Carbohydrates

They are always on the cells' exterior surface and are

bound either to proteins (forming glycoproteins) or to

lipids (forming glycolipids)

Cholesterol

makes it possible for the cell membrane to maintain its fluidity across a wide range of temperatures.

saturated fatty acids

has greater interactions among themselves making the cell membrane stiffer.

unsaturated fatty acids

make themembrane becomes less tightly packed resulting to the increase of the cell membrane fluidity.

• Steepness of concentration gradient

• Temperature

• Molecular Size

Factors Affecting Diffusion Rate

Nonpolar, hydrophobic molecules

substances that diffuse directly through the lipid bilayer.

Polar, hydrophilic substances

cannot pass directly through the lipid bilayer.

aquaporins

Water travels in/out of the cell through________.

Bulk Flow

Vesicles are used to transport large

particles across the PM.