Movement in and out of cells Flashcards
Define particles, kinetic energy, and concentration gradient
Particles: the smallest pieces of which a substance is made; particles can be molecules, atoms, or ions
Kinetic energy: the energy of moving objects
The concentration gradient is the difference in concentration of a substance between two areas. The greater the concentration gradient, the faster the rate of diffusion.
What is a solute and solvent?
Solute: a substance that has dissolved in a liquid
Solvent: the liquid that the solute has been dissolved in
3 functions of water
1) when we swallow food, some of it dissolved in water in the alimentary canal, where it can be acted on by enzymes which as also dissolved.
2) the kidneys excrete urea dissolved in water to form urine
3) substances are transported around the body dissolved in the water in blood plasma
Dialysis tubing
A type of membrane that has pores and holes that are very small. it is partially permeable.
Define turgid and turgor pressure
turgid: a description of a plant cell that is tight and firm
turgor pressure: the pressure of the water pushing outwards on a cell wall
Define Flaccid and plasmolysed
Flaccid: a description of a plant cell that is soft
plasmolysed:a description of a cell in which the cell membrane tears away from the cell wall
Describe active transport
The movement of molecules or ions through a cell membrane from a region of lower concentration to a region of higher concentration using energy from respiration
Give an example of active transport in plants
Root hair cells take in nitrate ions from the soil. the concentration of nitrate ions inside the root hair cell is usually higher than their concentration gradient in the soil. the diffusion gradient for the nitrate ions is out of the root hair, and into the soil. but the root hair cells are still able to take in nitrate ions in, using active transport
Carrier proteins definition
Protein molecules in a cell membrane that can use energy to change shape and move ions or molecules into or out of a cell
when does diffusion stop?
at equillibrium
describe active transport and salt glands
many marine animals have salt glands that use active transport t push out salt. otherwise there would be too much salt in the organism causing more water to flow in by osmosis
3 Explain how oxygen in the capillaries reaches the cells in the eye.
diffusion (across cell
membranes) ;
down concentration gradient /
AW ;
passive process / (uses) kinetic
energy / random movement of
molecules ;
through a thin capillary wall ;
State two ways a plant uses water other than for transpiration.
for support ;
in photosynthesis / to make
sugar ;
for transport ;
chemical reactions take place in solution/ solvent
What is dialysis tubing??
Dialysis tubing is a type of semi-permeable membrane made from materials like cellulose or synthetic polymers, used to simulate the function of a cell membrane in laboratory settings or medical devices. It allows certain small molecules (like water, salts, and waste products) to pass through while blocking larger molecules (like proteins or blood cells).
