Movement Into and Out of Cells Flashcards
What is diffusion?
Diffusion is the net movement of particles down the concentration gradient (from high to low concentration) as a result of their random movement.
Where does the energy for diffusion come from?
The energy for diffusion comes from the kinetic energy of the random movement of molecules and ions.
Why is diffusion important for living organisms?
Diffusion is essential as it allows molecules like glucose and oxygen, needed for respiration, to reach the places they are required.
What are the factors influencing diffusion?
Factors include the concentration gradient, temperature, surface area to volume ratio, and distance.
What is osmosis?
Osmosis is the net movement of water molecules from a region of higher water potential (dilute solution) to a region of lower water potential (concentrated solution) through a partially permeable membrane.
What is the condition of a cell if the concentration of solute inside is lower than outside?
The cell shrinks (flaccid or hypertonic).
What happens to an animal cell in a hypotonic solution?
The cell may burst (cell lysis) because it absorbs too much water and lacks a cell wall.
What happens to a plant cell in a hypotonic solution?
The plant cell becomes turgid as the vacuole fills up, and the cell wall withstands the increased turgor pressure.
What is active transport?
Active transport is the movement of particles through a cell membrane from a lower concentration to a higher concentration (against the concentration gradient), using energy from respiration.
How does active transport use carrier proteins?
Carrier proteins in the cell membrane pick up specific molecules and move them through the membrane against their concentration gradient.
What is phagocytosis?
Phagocytosis is the process where the cell surface membrane flows around and engulfs large particles, often used by white blood cells to capture pathogens.
What is the role of dialysis tubing in osmosis experiments?
Dialysis tubing acts as a non-living, partially permeable membrane that allows smaller molecules like glucose and water to pass through but blocks larger molecules like sucrose.
Why is active transport important for root hair cells?
Active transport helps root hair cells optimize nutrient uptake, such as absorbing ions from the soil.
What are the factors that influence diffusion?
Surface area, temperature, concentration gradient, and distance influence diffusion.
Why is the cell membrane described as partially permeable?
It allows small molecules like water to pass through but blocks larger molecules like proteins.
