transport in cells

what is diffusion
the net movement of particles or gases or liquids from an area of high concentration to an area of lower concentration.
1 of 29
what is the concentration gradient
a measurement of how a concentration of a substance changes from one place to another
2 of 29
how does diffusion occur
it is a passive process meaning it requires no additional energy and happens naturally
3 of 29
do we get oxygen in our blood
when we breath in we take in air which is relatively high in oxygen. when in the individual alveoli in our lungs, the air is one tiny membrane away from our blood which has a lower concentration of oxygen than the air. therefore the oxygen naturally
4 of 29
continue
diffuses from inside the alveoli into our blood. because the blood in our body is always moving, the highconcentration oxygen blood is transported away and new low concentration blood replaces it.
5 of 29
how does oxygen get from the cappilaries to the cells that need it
blood travels through tiny capillaries. the cells near the capillaries have low concentration of oxygen as they are constantly using ther oxygen in respiration. to the oxygen moves down the concentrationgradient from the blood to the cells.
6 of 29
how does carbon dioxide travel from your cells to your lungs
carbon dioxide is produced during respiration in the tissues and organs so is therefore in higher concentration than the blood (as the blood has just unloaded its carbon dioxide in the lungs and picked up oxygen) so it diffuses down the concentration
7 of 29
continue
gradient. the blood then transports it to the lungs where it diffuses from an area of high conc to an area of low conc in the alveoli, where you then breathe it out
8 of 29
what are the adaptations of the lungs to maximise gas exchange
thin linings (one cell thick) to have a short diffusion distance // large surface area to give the particles more opportunity to diffuse // righ blood supply to always maintain steep concentration gradient
9 of 29
continue
the air sacs are moist so that gases can dissolve before diffusing // they are also well ventilated providing a regular supply of fresh air.
10 of 29
how does diffusion occur in the small intestine
if you have eaten a sugary meal, the glucose in high concentration in your small intestine diffuses into the blood through villi
11 of 29
what are the adaptations the small intestine has made to maintain diffusion
Good blood supply meaning there will always be a steep concentration gradient / Thin walls meaning there is a short diffusion distance / - Folds called villi and micro villi means there is a large surface area
12 of 29
what is the size of organisms determined by
the maximum distance that substances can diffuse quickly
13 of 29
how do insects breathe if they have no lungs
spiracles which are air tubes which run through their body in which the high concentration oxygen diffuses to the low concentration oxygen in the cells
14 of 29
what is the advantage smaller organisms have over larger organsisms
they have a greater surface area to volume ratio meaning if their cells are roughly the same size as ours they have more surface area for oxygen to diffuse than us. this also means they dont need exchange surfaces such as alveoli or transport
15 of 29
continue
systems such as blood for us
16 of 29
how have fish's gills adapted to maintain gas exchange
large surface area meaning there is allot of opportunity for the oxygen to diffuse / Thin walls meaning there is less distance for oxygen to travel / rich blood supply and ventilated with water meaning high concentration gradient
17 of 29
how have leaves adapted to maintain gas exchange
Leaves - spongy mesophyll contains air spaces to facilitate gas exchange (increases surface area)
18 of 29
what are the factors that affect the rate of diffusion and why
.
19 of 29
what is osmosis
the net diffusion of water from an area of high concentration of water to to an area of lower concentration of water across a partially permeable membrane
20 of 29
what is a partially permeable membrane
a membrane which allows only substances of a certain size through
21 of 29
give an example of osmosis
when it rains water is present in a high concentration in the soil around plant. the concentration of water inside the plant is lower, mostly if it hasnt rained in a while so the water moves to the plant cells across the partially permeable membrane
22 of 29
why will water constantly be "pulled up" by the roots
because the previously pulled up water will be carried up to the leaves where most of it will evaporate from tiny holes called stomata (transipiration)
23 of 29
what hapens if you plce a cell in a solution of the same concentration of water and solute
water can move in and out of the cell. it is in a isotonic solution. the cell becomes flaccid.
24 of 29
what happens when you place a cell in a solution with high concentration of solute
water moves out the cell. the cytoplasm pulls away from the cell membrane so the cell is plasmolysed. it is said to be in a hypertoni solution
25 of 29
what happens when you place a cell in a solution with low concentration solute
water moves into the cell. this causes the cell to become turgid. it is said to be in a hypotonic solution
26 of 29
what is active transport
Active transport is the net movement of particles from an area of low concentration to an area of higher concentration using energy
27 of 29
give an example of active transport in plants
plants need to take up mineral ions which exist in very low concentrations in the soil but high concentration in the plant.
28 of 29
give an example of active transport in animals
if your last meal didnt have much sugar, then active transport is done to move sugars from low concentrations in your small intestine to high concentrations in your blood
29 of 29

Other cards in this set

Card 2

Front

what is the concentration gradient

Back

a measurement of how a concentration of a substance changes from one place to another

Card 3

Front

how does diffusion occur

Back

Preview of the front of card 3

Card 4

Front

do we get oxygen in our blood

Back

Preview of the front of card 4

Card 5

Front

continue

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all transport in cells resources »