Cell Membrane and Cell Transport

Homeostasis

• Maintaining a stable internal environment

• Adapting to external environmental changes

• Increasing metabolic rate during exercise

• Storing energy in the form of fat

concentration

• the amount of a substance dissolved (solute) in another substance (solvent)

• the total volume of a solution

• the temperature at which a solution boils

• the pressure exerted by a gas in a solution

active transport

• a type of transport that moves molecules against the concentration gradient (from low to high concentration), which requires energy in the form of ATP

• a passive process that allows molecules to move from high to low concentration without energy

• a method of transporting water across cell membranes using energy

• a type of transport that only occurs in plant cells during photosynthesis

phospholipid

• A type of carbohydrate that provides energy to cells.

• The type of lipid that makes up the majority of the cell membrane. Consists of a polar (hydrophilic) head and two nonpolar (hydrophobic) tails.

• A protein that helps in the transport of molecules across the cell membrane.

• A nucleic acid that stores genetic information.

selectively permeable

• Describes the cell membrane; it selects what it will allow in or out

• Refers to the ability of a cell to divide and replicate

• Indicates that all substances can freely pass through the membrane

• Describes the process of active transport in cells

facilitated diffusion

• a type of active transport that requires energy

• a type of passive transport where larger, polar molecules are moved down the concentration gradient using membrane proteins

• a process that moves small, nonpolar molecules against their concentration gradient

• a method of transporting ions through the cell membrane using ATP

What is the cell membrane (AKA, the plasma membrane)?

• A structure made of a single phospholipid layer

• Made of two phospholipid layers, called the phospholipid bilayer

• A rigid structure that protects the cell

• A component that only allows water to pass through

hypertonic

• There is more water inside the cell than outside, which leads to water leaving the cell, causing the cell to shrink/shrivel

• The concentration of solutes is equal inside and outside the cell, leading to no net movement of water

• There is more water outside the cell than inside, causing the cell to swell

• The cell remains unchanged as water moves in and out at an equal rate

concentration gradient

• the difference in concentration between two areas, such as between the inside and outside of the cell

• the process of moving substances against their concentration gradient

• the equal distribution of molecules in a solution

• the rate at which molecules move from one area to another

diffusion

• a type of active transport that moves large, polar molecules against the concentration gradient

• a type of passive transport that moves small, nonpolar molecules down the concentration gradient (from high to low concentration)

• a process that requires energy to move molecules from low to high concentration

• a method of cellular communication between adjacent cells