Biology Membrane test
What is a concentration gradient?
A measurement to the concentration on each side of the membrane.
What supplies the energy for active transport?
ATP, Mitochondria
What allows a cell to stockpile substances in greater concentrations than can occur outside the cell?
Active transport
What is exocytosis?
Big things leaving the cell.
What are the major differences between facilitated diffusion and active transport?
Facilitated diffusion does not require energy because it moves with the gradient while active transport moves against the gradient causing energy use.
What is an example of passive transport?
Facilitated diffusion.
What is solubility?
How solutes dissolve in water.
Are ion channels specific? Examples?
Ion channels are specific. Some only allow calcium ions.
Explain facilitated diffusion resect to the concentration gradient?
It goes from high to low concentration so it requires no energy.
Explain how diffusion takes place in accordance with the concentration gradient
It moves from high to low concentration so requires no energy.
Describe how a drop of dye illustrates the process of diffusion.
It moves from high to low concentration therefor coloring the water.
What happens to algal cells when they are n a isotonic solution and solutes are added to the solutions?
It shrinks
List the types of molecules that enter the cell by by means of facilitated diffusion?
Macromolecules, Sugar, Proteins, Lipids, Amino acids.
How does the sodium-potassium pump work?
Potassium gets pumped into the cell and sodium comes out of the cell.
What happens to a plat cell in a hypertonic environment?
The cell will lose most of its water causing it to wither up causing plant death. The vacuole loses turgor pressure.
Diffusion definition and example
The spreading molecules from high to low concentration. Example is dye in water
How do sugar molecules enter and leave the cell?
They are macromolecules so they go through protein holes. FACILITATED DIFFUSION.
How do carrier proteins work in ficilated diffusion?
They creat a doorway for the ions. They bond and drag molecules. There is no energy required.
Explain a specific example of how cells are transported across cell membranes.
They travel through proteins such as the sodium potassium pump.
What is endocytosis?
When the cell takes in big things
What is the end result of diffusion?
a solution that has reached equilibrium. The solution is equal and so is the movement.
Which of the following does not require expenditure of energy?
diffusion
What is dynamic equilibrium and when is it reached?
it is when water is being sent in and out of the cell but no change, it is reached when the solution is isotonic.
Why does the addition of a solute with polar molecules to one side of the membrane result in the diffusion of water?
it uses diffusion to stay balanced after the polar molecules enter or leave the cell
What types of materials are expelled from cells during exocytosis?
large molecules such as enzymes, proteins, and hormones.
What types of molecules enter the cell through active transport?
molecules too big for diffusion. Ions moving from hight to low concentration.
Define phagocytosis and pinocotyces and give and example of each
phagocytosis- cellular eating pinocotyces-Cellular drinking
Be able to tell cell tones based of of pictures.
shrunken-hyper, same-isotonic, big- hypotonic
What is osmosis?
the diffusion of water across the membrane.
What helps nerve impulses occur?
the sodium potassium pump.
What happens to a plant cell when it is a hypotonic solution?
the walls bulge and it is under great pressure. The vacuole bulges so there is more turgor pressure.
List the types of molecules that get through with simple diffusion?
water, oxygen, carbon dioxide
