transport in cells Flashcards
what is diffusion?
the movement of particles from an area of higher concentration to an area of lower concentration
What are examples of diffusion and n living organisms?
oxygen and carbon dioxide diffuse during gas exchange in lungs, gills, and plants leaves. urea diffuses from cells into the blood plasma for excretion by the kidney. digested food molecules from the small intestine diffuse into the blood.
What factors affect diffusion?
the differences in concentration (concentration gradient), temperature, surface area of membrane.
what is osmosis?
diffusion of water from a dilute solution to a concentrated solution though a partially permeable membrane.
what is active transport?
moves substances against a concentration gradient from an area of low concentration to high, this requires energy.
What does active transport allow to be absorbed?
mineral ions into plant root hairs, sugar molecules in the gut.
Why do people in the room smell perfume faster on a warmer day?
molecules of the fragrance are much more likely to evaporate faster from your skin when in hot climates.
