Principles of diffucion, osmosis, active transport Flashcards
What is a concentration gradient?
A concentration gradient is the difference in the concentration of a substance between two areas. Molecules move from an area of high concentration to an area of low concentration.
What is the key difference between passive and active transport?
Passive transport does not require energy (ATP) as molecules move from an area of high to low concentration. Active transport requires energy (ATP) to move molecules against their concentration gradient, from low to high concentration.
What is simple diffusion?
Simple diffusion is the movement of molecules from an area of high concentration to an area of low concentration, without the need for energy or a membrane protein.
Which types of molecules typically undergo simple diffusion?
Small, non-polar molecules such as oxygen and carbon dioxide can diffuse directly across cell membranes.
What is facilitated diffusion?
Facilitated diffusion is the passive movement of molecules across a membrane with the help of a protein channel or carrier, without the use of energy.
What type of molecules typically undergo facilitated diffusion?
Larger or polar molecules, such as glucose or ions, require facilitated diffusion to pass through the cell membrane.
What is osmosis?
Osmosis is the diffusion of water molecules across a selectively permeable membrane from an area of low solute concentration to an area of high solute concentration.
Why is osmosis important for cells?
Osmosis helps maintain the balance of water and solutes in and out of the cell, which is essential for proper cell function.
What is active transport?
Active transport is the movement of molecules or ions across a membrane from an area of low concentration to an area of high concentration, using energy (ATP) and transport proteins.
Why does active transport require energy?
Active transport requires energy because it moves molecules against their concentration gradient, from an area of low concentration to an area of high concentration.
Give an example of passive transport.
An example of passive transport is the diffusion of oxygen from the lungs into the blood.
Give an example of facilitated diffusion.
An example of facilitated diffusion is the movement of glucose into cells via a glucose transporter protein.
Give an example of osmosis.
An example of osmosis is water moving into plant cells from the soil through the root cell membrane.
Give an example of active transport.
An example of active transport is the sodium-potassium pump, which moves sodium ions out of a cell and potassium ions into the cell against their concentration gradients.
