Transport in Cells Flashcards
(23 cards)
What types of particles move by diffusion?
gas and solute
What energy store does diffusion use?
kinetic
What molecules move into or out of our cells through diffusion?
oxygen, carbon dioxide, glucose and amino acids
What three factors affect the rate of diffusion?
temperature, concentration gradient, surface area
What is surface area?
The amount of surface the air is in contact with.
What is volume?
The amount of space that something takes up.
As something gets smaller, the SA to V ratio _________.
increases
What do plants need to absorb from the soil?
water and nutrients
What two features of a bean root enable efficient absorption?
1) short diffusion path
2) increased surface area
How many alveoli are in the lungs?
about 150 million
What two factors ensure the diffusion of gases occurs at an efficient rate?
ventilation and circulation
What substances need to be absorbed into the small intestine?
amino acids, glucose, fatty acids and glycerol
What structures line the inside of the small intestine?
villi
What to villi do and why is it so important?
Increase surface area, without them diffusion of substances from gut to bloodstream would occur too slowly.
Active transport is the movement of substances from a (1) concentration to a (2) concentration.
1) low
2) high
What is absorbed by the ciliated epithelial cell from the small intestine?
glucose
What enables the absorption of nutrients and glucose?
active transport
Why is it necessary to absorb some food molecules by active transport?
We need to move things against a concentration gradient.
One substance that plants absorb by active transport?
mineral ions
Does temperature affect gaseous exchange?
no
What is osmosis?
The diffusion of water from an area of high concentration to an area of low concentration.
What type of membrane does osmosis occur across?
A partially permeable membrane.
Does osmosis require an input of energy?
no
