Scaling Up Flashcards
(30 cards)
what is diffusion?
the movement of particles from a higher concentration to a lower concentration. no energy
what does a high temperature in diffusion result in?
particles have more kinetic energy and can move faster
what does partially permeable mean?
not all substances are able to diffuse across the cell membrane
what is an example of diffusion in a leaf?
oxygen moves from air spaces between mesophyll cells to mitochondria in all cells
what is an example of diffusion in the lungs?
carbon dioxide moves from blood in capillaries to al veolar air space
what type of process is diffusion and osmosis
a passive process (doesn’t require energy)
what is osmosis
the net movement of water molecules across a partially permeable membrane from a higher water concentration to a lower water concentration. no energy
what does a concentrated solution of sugar mean
a low concentration of water molecules and a low water potential so water molecules move into the concentrated sugar solution
explain osmosis in animal cells
they dont have a supporting cell wall and if they are placed into a strong sugar solution, it will lose water by osmosis and become shrivelled up
explain osmosis in plant cells
they have a supporting cell wall and if placed in distilled water it gains water
what happens to the cell when water enters it by osmosis
it becomes rigid and firm so it can provide strength and support for the plant
what is active transport
movement of substances from a more dilute concentration to a more concentrated solution (requires energy)
why are magnesium ions needed in plants
to make chlorophyll
why are nitrate ions needed in plants
to make amino acids for protein synthesis
what does active transport do in animals
allows nutrients like glucose to be transported into the bloodstream from the small intestine
why do cells need to divide
growth and repair
what are the 3 parts of the cell cycle
interphase (growth), mitosis, cytokinesis (cytoplasm and cell membrane dividing)
explain the process of mitosis
DNA copied to produce duplicate chromosomes
cell fibres pull apart the duplicate chromosomes
new nucleus forms around chromosomes
cytoplasm and cell membranes divide (cytokinesis)
what is made after the process of mitosis
two genetically identical daughter cells
what are specialised cells
cells that have undergone cell differentiation and perform specific functions
give 5 examples of specialised animal cells
ciliated cell
nerve cell
redblood cell
sperm cell
egg cell
give 3 examples of specialised plant cells
root hair cell
xylem vessel
palisade mesophyll cell
why do root hair cells have a large surface area
to maximise absorption of water and minerals
why do palisade mesophyll cells contain many chloroplasts
to maximise photosynthesis
