Unit 1 - KA2 Transport across cell membranes Flashcards
What is the cell membrane made out of?
Proteins and phospholipids
What substances diffuse into cells?
-Oxygen
-Glucose
-Amino acids
What substances diffuse out of cells?
-Carbon dioxide
-Other waste products
What are the two types of passive transport?
Diffusion and osmosis
Passive transport occurs when…
…molecules move down a concentration gradient.
What is diffusion?
The movement of molecules from an area of high concentration to an area of lower concentration, down a concentration gradient, this requires no energy.
What is osmosis?
The movement of water molecules from a high water concentration to a lower water concentration through a selectively permeable membrane.
What is active transport?
Membrane proteins use energy (ATP) to move molecules and ions against the concentration gradient. Molecules move from a low concentration to a higher concentration.
What happens to an animal cell in low water concentration?
Cell shrinks
What happens to a animal cell in high water concentration?
Cell bursts
What happens to a plant cell in low water concentration?
Plasmolysed
What happens to a plant cell in high water concentration?
Turgid
