Movement across the cell membrane

aquaporin

"water-hole". The channel through which water diffuses through in a cell membrane

hypertonic

(of a solution) having a higher osmotic pressure than a comparison solution. Cells shrink in hypertonic solutions.

hypotonic

(of a solution) having a lower osmotic pressure than a comparison solution. Cells swell in a hypotonic solution.

channel protein

A membrane protein, specifically a transport protein, that has a hydrophilic channel that certain molecules or atomic ions use as a tunnel.

endocytosis

A process in which a cell engulfs extracellular material through an inward folding of its plasma membrane.

carrier protein

A protein found in membranes, which is capable of carrying a specific molecule or ion through the membrane by active transport.

channel proteins

A protein pore that spans a membrane, through which very small ions and water soluble molecules may pass.

plasma membrane

A selectively-permeable phospholipid bilayer forming the boundary of the cells

phagocytosis

A type of endocytosis in which a cell engulfs large particles or whole cells. Also known as "cell eating"

pinocytosis

A type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes. also known as "cell drinking"

Cells in a hypotonic solution

An animal cell swells until pressure bursts it, resulting in cell death. This does not happen to plant cells because they have a cell wall. (the plant cell will expand but will not burst). What kind of solution are the both cells placed in?

turgor

Condition of being distended or swollen; normal fullness

Fluid Mosaic Model

Describes the following properties of the cell membrane: 1. cell membrane is fluid, flexible and moves. 2. cell membrane is composed of proteins, lipids and carbohydrates.

osmosis

Diffusion of water through a selectively permeable membrane

exocytosis

Process by which a cell releases large amounts of material A process in which a cell releases substances to the extracellular environment by fusing a vesicular membrane with the plasma membrane, separating the membrane at the point of fusion and allowing the substance to be released.

ion pump

Proteins move ions across a membrane (hydrogen, sodium or potassium); requires ATP

Plasma membrane (cell membrane)

Regulates what enters and leaves the cell and separates the internal environment of the cell from the external environment

passive transport

Requires NO energy, Movement of molecules from high to low concentration, Moves with the concentration gradient

Osmosis

The diffusion WATER across a selectively permeable membrane.

CONCENTRATION GRADIENT

The gradient in molecular concentration (the difference in concentrations) that allows diffusion to occur

facilitated diffusion

The movement of molecules across a semi permeable membrane from an area of high concentration to an area of low concentration and which is aided by carrier protein molecules or protein channels. No metabolic energy ois required.

Diffusion

The movement of molecules from an area of high concentration to area of low concentration.

osmosis

The movement of water molecules from a region of higher water potential to a region of lower water potential across a partially permeable membrane.

diffusion

The net movement of molecules from an area of high concentration to an area of low cencentration.

Plant cells in a hypertonic solution

The plant cell shrinks inside its cell wall while the cell wall remains intact. What kind of solution is the plant cell placed in?

exocytosis

The process of removing materials from the cell by fusing vesicles containing the material with the plasma membrane (cell surface membrane).

endocytosis

The process of taking materials into a cell by surrounding them with part of the plasma membrane, which then pinches off to form a vesicle inside the cell. This is an active process requiring ATP

selectively permeable

a property of cell membranes that allows some substances to pass through, while others cannot

Sodium- Potassium pump

a protein that uses ATP to actively transport sodium ions out of a cell and potassium ions into the cell

cell wall

a structure that surrounds a cell to provide structural support.

concentration gradient

A difference in the concentration of a substance across a distance. When something diffuses, it travels with the concentration gradient.

Concentration gradient

A difference in the concentration of solutes on one side of the cell membrane compared to the other side.

isotonic

Having the same solute concentration as another solution.

transmembrane protein

Integral proteins that span the membrane.

Phospholipid

Makes up the cell membrane; has 1 head (hydrophilic) and 2 tails (hydrophobic)

Hydrophilic

Means "water lovings" Describes the heads (circle portion) of the phospholipids

Hydrophobic

Means water fearing. Describes the tails of the phospholipids

glycolipids

Membrane carbohydrates that are covalently bonded to lipids.

glycoproteins

Membrane carbohydrates that are covalently bonded to proteins.

diffusion

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

facilitated diffusion

Movement of specific molecules across cell membranes through protein channels

active transport

Movement of substances across a semi permeable membrane from an area of low concentration to an area of high concentration. Requires the use of energy in the form of ATP and either carrier protein or protein channels.

Active transport

Movement of substances across the cell membrane that require extra energy.

Non-Polar Tail

Part of the phospholipid that is not attracted to water.

fluid mosaic model

Structural model of the plasma membrane where molecules are free to move sideways within a lipid bilayer.

Bilayer

The cell membrane is made of two layers of lipid molecules.

Selectively permeable

The term to describe a cell membrane that allows some substances to pass, but not others

Facilitated diffusion

The type of cell transport in which large molecules (like glucose) move across the membrane with help from proteins.

Hypertonic solution

The type of solution that causes water molecules to leave the cell, and cell shrivels up and dies.

Hypotonic solution

The type of solution that causes water molecules to move into the cell and the cell swells

Isotonic solution

The type of solution when the same amount of water molecules enter and leave the cell.

Carbohydrates

This component of the cell membrane allows different cells in your body to identify each other.

Channel protein

This component of the cell membrane allows the transport of specific substances across a cell membrane.

Protein

This component of the cell membrane are channels that transports substances.

plasmolysis

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

Passive transport

When substances move across the membrane without using extra energy (naturally happens).

active transport

moving stuff across the cell membrane with ATP (energy), typically against the concentration gradient

Polar Head

part of the phospholipid that is attracted to water.

carrier proteins

proteins change shape as it carries out facilitated diffusion