Transport In Cells Flashcards
Diffusion
Net movement of particles from area of high to low concentration
Active transport
Movement of particles from area of low to high concentration
Requires energy from respiration
Osmosis
Diffusion of water from an area of high concentration to an area of low concentration solution through partially permeable membrane
Passive process
Diffusion example
Oxygen into cells
Carbon dioxide and urea out of cells
Active transport example
Movement of mineral ions into root hair cells
Sugar molecules into blood
Factors that increase rate of diffusion
Higher concentration gradient
Higher temp
Higher surface area of the membrane
Surface area to volume ratio
The larger something is, the smaller the the surface area to volume ratio
Exchanging surfaces- villi in small intestine
Network of capillaries
Large surface area due to folding
Thin walls
Good blood supply to maintain concentration gradient
Single celled organisms
Large surface to volume ratio
Allows enough molecules to be transported across their cell membrane to meet their needs
Multicellular organism
Small surface area to volume ratio
Means they need specialised cells and organ system to allow enough molecules to be transported into and out of cells
Alveoli in lungs
Network of capillaries
Good blood supply to maintain concentration gradient
Membrane of alveoli- large surface area, moist, one cell thick
Root hair cells
Mitochondria to take on mineral ions by active transport
Large surface area helps efficient absorption of water and mineral ions
Fish gills
Made up of stacks of thin filaments with- large surface area to increase diffusion
Good blood supply to maintain concentration gradient
Leaves
Large surface area to exchange carbon dioxide and oxygen through stomata
Spongey mesophyll tissue to all gases to diffuse quickly to cells
