Cell Transport Flashcards

Active transport

Energy-requiring process that moves material across a cell membrane against a concentration difference

Amphipathic

having both a hydrophilic region and a hydrophobic region - phospholipids have a hydrophilic head and hydrophobic tail

Carrier protein

a protein that transports substances across a cell membrane in active transport - helps polar molecules cross the membrane

Concentration gradient

A region along which the density of a chemical substance increases or decreases.

Crenate

when a cell shrinks due to water loss - blood cells

Diffusion

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

Exocytosis

Process by which a cell releases large amounts of material

Faciliated diffusion

Passive movement of molecules down its concentration gradient via a transport protein

Flaccid

plants in an isotonic solution

Fluid Mosaic Model

model that describes the arrangement and movement of the molecules that make up a cell membrane

Gated ion channels

ion channels that open or close in response to stimuli

Glycolipids

Membrane carbohydrates that are covalently bonded to lipids.

Glycoproteins

Membrane carbohydrates that are covalently bonded to proteins.

Hypertonic

The solution with the higher concentration of solutes

Hypotonic

The solution with the lower concentration of solutes

Integral proteins

proteins that pass through the membrane

Ion channels

A transmembrane protein channel that allows a specific ion to diffuse across the membrane down its concentration or electrochemical gradient. - passive

Isotonic

when the concentration of two solutions is the same

Ligands

A molecule that binds specifically to a receptor site of another molecule.

Osmoregulation

the control of solute concentrations and water balance

Osmosis

Diffusion of water through a selectively permeable membrane

passive transport

the movement of substances across a cell membrane without the use of energy by the cell - with the concentration gradient

Peripheral proteins

proteins that do not pass through the membrane

Phagocytosis

Form of endosytosis - “cellular eating”

cell engulfs particle by extending cytoplasm (pseudopodia) around it and packing it in a large vacuole.

contents of vacuole are digested when it fuses w/ a lysosome.

Pinocytosis

“Cellular drinking”

a cell creates a vesicle around a droplet of extracellular fluid

Plasmolysis

This happens when a cell shrinks inside its cell wall while the cell wall remains intact. - collapse

Proton Pump

pushes H+ ions across the membrane

lyse

when a human cell bursts

Selective Permeability

A property of a plasma membrane that allows some substances to cross more easily than others.

Tonicity

the ability of a surrounding solution to cause a cell to gain or lose water

Turgid

(adj.) swollen, bloated, filled to excess; overdecorated or excessive in language - plant cells like to be turgid

Contransport

a single ATP-powered pump that transports a specific solute