topic 1 cellss Flashcards
what is osmosis
the movement of water from a high water concentration to an area of low water concentration across a partially permeable membrane
what is a partially permeable membrane
-one with small holes in it- only tiny molecules can pass through them
how do water molecules pass both ways in osmosis
because water molecules move about randomly all the time
dilute sugar solutions contain a high conc of what …
water
concentrated solutuions contain a … conc of water
low
in osmosis the high conc of water moves in the direction where there is …
a low concentration of water
the cytoplasm of cells is …
concentrated- it contains a low concentration of water
if we placed an animal cell in water what would happen
water will move from by osmosis from outside of the cell to inside the cell
what would happen if we placed an animal cell in a very concentrated solution
water will move out of the cell by osmosis and the cell will shrink
what happens if we place a plant cell in water
water will move into the cell by osmosis and the cell will expand
in plant cells what prevents the plant cell from bursting
its cell wall
as the cell wall prevents the plant cell from bursting, what happens to the plant cell
it becomes swollen- turgid
what happens if we place a plant cell in a concentrated solution
water moves out of the plant cell
when water moves out of the cell what happens to the plant cell-
it shrinks and become flaccid
what is active transport
the movement of particles from an area of low concentration to an area of high concentration (against a concentration gradient)
what does active transport require
energy from respiration
describe the difference between diffusion and active tansport
diffusion- particles move down a conc gradient
- active transport- particles move against the conc gradient
- active transport requires energy
what does active transport allow plant to do
absorb minerals from a very dilute solution against a concentration gradient
where does active transport happen in humans and why
in the gut- taking in glucose from the gut and from the kidney tubules
where is active transport used in the gut
where there is a lower concentration of nutrients in the gut but a higher concentration of nutrients in the blood
when do amino acids and glucose in the gut diffuse naturally in the blood
when there is a higher concentration of glucose and amino acids in the gut
what does active transport allow nutrients to do
allows nutrients to be taken in the blood despite the fact that the concentration gradient is thw wrong way
describe the conc of ions in the soil
the concentration of the ions in the soil is lower than concentration of the root hair cells
why do plants need magnesium
to make chlorophyll in the leaves
