Diffusion, Osmosis and Active transport Flashcards
Cell Biology - Cell structure and division
what is Diffusion?
the spreading out of particles from an area of higher concentration to an area of lower concentration
where does diffusion happen?
in solutions and gases
what is the concentration gradient?
the difference in concentration, the bigger the difference, the faster the diffusion rate
what do molecules do?
- they flow through the membrane from where there’s a higher concentration to lower concentration
- they move both ways but if there are more particles on one side of the membrane theres a movement from that side
what is osmosis?
the movement of water molecules
what is a partially permeable membrane?
one with very small holes in it, tiny molecules can pass through it but not big ones
what do water molecules do during osmosis?
pass both ways through the membrane
what is the overall movement of water molecules?
they move from the less concentrated solution to the more concentrated solution, this means the more concentrated solution gets more dilute
what is active transport?
the process of moving molecules across a cellular membrane through the use of cellular energy
how do root hairs take in minerals using active transport?
- AT allows the plant to absorb minerals from a very dilute solution in the soil
- it moves the minerals against the concentration gradient
- active transport needs energy from respiration to make it work
why can’t root hair cells take in minerals using diffusion?
because the minerals are in very low concentration
why do we need active transport to stop us starving?
- active transport moves the nutrients from a lower concentration to a higher concentration in the blood
- meaning glucose can be taken into the blood against the concentration gradient, it is then transported to cells where it is used for respiration
