cell transport Flashcards
how do you calculate percentage change in mass after osmosis?
change in mass/start mass x 100
solute+solvent=?? [1]
solution
osmosis [2]
movement of water molecules from a dilute to concentrated solution
what can osmosis only happen through? [1]
a partially permeated membrane
how is the small intestine adapted for absorsion of nutrition? [4]
- many villi and many microvilli- increases the surface area
- thin walls of the villus- short diffusion distance
-good blood supply- maintains the concentration gradient
-many mitochondria- for respiration to release energy for active transport.
how are root cells adapted for absorpsion of sustances from the soil? [3]
projection (bit that juts out) makes a larger surface area which means better absorbtion
hypotonic solution [1]
one which is more dilute than the cell
isotonic solution [1]
one which is the same concentration as the cell
hypertonic solution [1]
one which is more concentrated than the cell
what will happen to cells if put in a hypotonic solution? [2]
animal cell bursts, plant cell turgid (firm)
what will happen to cells if put in an isotonic solution? [2]
animal cell normal, plant cell flacid (limp)
what will happen to cells if put in a hypertonic solution? [2]
animal cell shrivels, plant cell plasmolysed (shrunk)
What name is given to the process by which water moves across a membrane? [1]
osmosis
suggest three factors that can affect the rate of diffusion
-concentration gradient
-surface area
-wall thickness
active transport needs _____ to take place
energy
describe the difference between magnification and resolution.
magnification- the increase in size of an object when viewed through a microscope,
resolution-the ability of a microscope to distinguish between two separate objects that are close together.
describe the advantages and disadvantages of using a light and electron microscope.
light- cheaper and small but low magnification and resolution
electron- big and expensive high magnification and resolution
cell membrane function
controls what goes in and out of the cell
Nucleus function
Contains the cell’s genetic material (DNA) which controls the cells activity
Mitochondria function
powerhouse of the cell, where aerobic respiration occurs, releasing energy
Cytoplasm function
where chemical reactions happen, contains enzymes
Ribosome function
makes proteins
Vacuole function
stores food, nutrients and waste products
cell wall function
provides strength and structure, protects the the cell
Chloroplast function
Where photosynthesis takes place
what are the differences between animal and plant cells
-Plant cells have cell walls, animal cells only have a cell membrane
-Plant cells contain chloroplast, animals cells don’t
-Plant cells have vacuoles, animals cells don’t
-Plant cells have a rectangular shape while animal cells have a circular shape
Why do animals have specialised cells?
to carry out specific functions
compare the structure of a specialised and generalised animal cell.
generalised cells have a more simple structure whereas specialised cells have a more complex structure
how is a sperm adapted to its function
-Have a long tail so they can swim to find an egg
-Contain many mitochondria to release energy for movement
-Enzymes in the head of the sperm help it break into into the egg
-Nucleus contains half the DNA code required to make a person
how is a nerve cell adapted to its function
-extremely elongated
-many branches at both ends to connect to other nerve cells
why does surface area affect the rate of diffusion.
As the surface area of the membrane increases, the rate of diffusion also increases because there is more space for molecules to diffuse
active transport
the movement of substances against their concentration gradient (low to high)
