Transport Across the Cell Membrane Flashcards
Active Process
A process that involves the expediture of energy
Active Transport
The use of energy to move substances, usually ions, across a cell membrane against the concentration gradent
Carrier-mediated transport
Transport of ions or molecules across a cell membrane by special carrier proteins
Carrier Protein
A protein the carries substances from one side of the cell membrane to another
Channel Protein
A protein the allows ions, water and small molecules to pass through the cell membrane
Concentration
A measure of the number of particles in a given volume
Concentration Gradient
A difference in concentration of a solution, often between the inside and outside of a cell; also called diffusion gradient
Semipermeable membrane
Membrane that permits the passage of liquid and gases but not large molecules
Diffusion / Net diffusion
The movement of particles of liquid or a gas so that they are distributed evenly over the available space; movement of high concentration to low concentration, distributed evenly
Endocytosis
The process by which a cell take in materials by enfolding and enclosing them; includes phagocytosis and pinocytosis
Exocytosis
The process whereby the contents of the vesicles of cells are pushed out through the cell membrane
Facilitated Diffusion
The process whereby proteins allow the movement of substances through the cell membrane along the concentration gradient
Facilitated Transport
Proteins in the cell membrane allow molecules to be transported across the membrane
Fluid mosaic model
the currently accepted model of the cell membrane structure
Osmosis
The diffusion of water molecules through a semipermeable membrane from a high area of higher water concentration to an area of lover water concentration
Osmotic pressure
The pressure due to differences in concentration on either side of a semipermeable membrane; the ability to attract water
Passive Process
a process the occurs without any input of energy
Passive Transport
The transport of substances across the cell membrane without energy input
Phagocytosis
The process by which a cell surrounds, and takes in, solid particels
Pinocytosis
The process by which a cell surrounds, and takes in, liquids
Simple Diffusion
The process of substances moving along the concentration gradient in a solution or across a semipermeable membrane, without the use of membrane protiens
Vesicular transport / Bulk transport
The transport of materials into or out of a cell in membrane-bound sacs
