Homeostasis and Transport
Terms in this set (24)
Membrane is "selectively permeable": only allows certain things to enter the cell
The lipids prevent too much water from entering or exiting the cell
Small, uncharged, molecules pass through easily (O2, CO2).
Concentration of molecules is equal inside the cell and outside of the cell;
This is how we achieve homeostasis
The cell is always moving towards finding its balance. Another term for balancing is..
Transport that does NOT require energy
Examples of Passive Transport
1) Diffusion 2) Osmosis 3) Facilitated Diffusion
Simplest type of transport; Movement of molecules from an area of high concentration(MORE)to an area of low concentration (LESS)
difference in concentration of molecules across a space
Movement of water across the cell membrane; goes from high to low concentration; Does not require energy;it is passive
having a lower solute concentration, and therefore a higher water concentration, relative to another solution.
Having a greater solute concentration, and therefore a lower water concentration, relative to another solution.
having an equal solute concentration and water concentration relative to another solution.
For molecules that can't pass through the membrane; Either too large or not lipid-soluble; Proteins in the membrane help push them through; From high to low concentration; The proteins will change their shape and this pushes the molecules through
Facilitated Diffusion through ion channels
Ion channels in the cell membrane act like gates in a fence; Allow sodium, calcium, potassium, and chloride to flow into cell; Useful in nerve and muscle cells
Sodium-Potassium Pump; Endocytosis; Exocytosis
From low to high concentration—AGAINST concentration gradient; Uses energy-Active; Sodium-potassium pump: in muscle cells uses energy ; Creates electrical impulses like in nerve cells
Cell membrane pumps
Push proteins and hormones "against" the concentration gradient; Key to survival of animal cells; Sodium potassium pump: Animals must have more sodium outside and potassium inside to allow for energy production in cells (push 3 Na+ out and 2 K+ in); Can move small and large molecules using this method
large molecules like food into the cell
Large molecules out of the cell
Opposite of endocytosis, cell releases large amounts of material through the membrane; Removes waste from the cell; Important to maintaining homeostasis in cells
Transports process Maintains Homeostasis
Cells of animals live in a salty or "saline" solution; This allows them to survive in a variety of different environments; Cells must maintain fluid levels or they die; Most animals will have a kidney type organism to manage these levels in the body
Kidneys help maintain homeostasis
Filter the blood of animals through osmosis and diffusion; Prevent dehydration and maintain fluid levels; Prevent toxins from building up in the blood; Eliminate swelling in the body