Chapter 15: Transport Systems in Living Things Flashcards
(UNFINISHED) (13 cards)
What is the definition of diffusion?
Diffusion is the net movement of particles from a region of higher concentration to a region of lower concentration.
Explain how mineral salts (ions) enter the root hair cell from a soil solution that is fertile.
soil solution has a higher concentration of ions than the cell sap of the root hair cell. Hence, ions diffuse from soil solution into the cell.
Explain how gaseous exchange occurs on plants. (Oxygen and stomatas of leaves)
during photosynthesis, carbon dioxide is rapidly used up. Carbon dioxide concentration in the leaf becomes lower than that in the atmospheric air. therefore, carbon dioxide diffuses from the surrounding air through the stomata into the air spaces in the leaf.
Explain how gaseous exchange occurs in humans.
Blood entering the lungs has a lower concentration of oxygen but a higher concentration of carbon dioxide than the atmospheric air entering the alveoli in the lungs. Therefore, oxygen diffusers from the aveolar air into the blood capillaries, and carbon dioxide diffuses from the blood capillaries into the alveolus.
What is the definition of osmosis?
Osmosis is the net movement of water molecules from a solution of higher water potential to a solution of lower water potential through a partially permeable membrane
What is the relationship between the concentration of solid in the region and the water potential in the region?
The higher the concentration of solute in the region, the lower the water potential in the region.
What happens to a plant cell when in a solution with higher water potential?
The cell sap in the vacuole has a lower water potential than the outside solution. More water enters the cell via osmosis through the partially permeable membrane. Hence, the cell enlarges and becomes turgid due to the cell wall preventing the cell from bursting.
What happens to a plant cell when a solution with lower water potential?
The cell sap in the vacuole has a higher water potential than the outside solution. More water moves out of the cell via osmosis through the partially permeable membrane. Hence, the cytoplasm shrinks away from the cell wall, and the cell becomes flaccid and plasmolyses.
what happens to an animal cell when in a solution with higher water potential?
The cytoplasm of the cell has a lower water potential than the outside solution. Water enters the cell via osmosis through the partially permeable membrane. Hence, the cell enlarges and burst due to the absence of the cell wall, resulting in the bursting of the cell.
What happens to an animal cell when in a solution with lower water potential??
The cytoplasm of the cell has a higher water potential than the outside solution. More water leaves the cell via osmosis through the partially permeable membrane. Hence, the cell shrinks and becomes cremated, little spikes appearing on the cell surface membrane, and eventually becomes dehydrated.
What are the similarities between diffusion and osmosis?
Both are passive processes. Both involve the movement of substances down a concentration gradient.
What are the differences between diffusion and osmosis?
Diffusion can occur in any substances, gaseous or liquid while osmosis can only refer to water molecules. Diffusion does not require a membrane while osmosis takes place only across a partially permeable membrane.
What is active transport?
Active transport is the process in which energy is used to move the particles of a substance against a concentration gradient. Active transport can only occur in living cells because living cells can respire and release energy.
