Cell structure and organisation Flashcards
which 5 organelles are found in prokaryotic cells
cell wall cell membrane plasmids flagella cytoplasm
what is the function of the: upper epidermis palisade mesophyll spongy mesophyll xylem phloem stomata
upper epidermis- produces waxy cuticle to prevent water loss
palisade mesophyll- packed with chloroplasts at the top of the leaf for photosynthesis
spongy mesophyll- lots of space for reactants to pass through, big air spaces to increase surface area for diffusion
xylem- transports water and minerals around the plant
phloem- transports glucose
stomata- stops water from escaping and allows carbon dioxide in and out of leaf, surrounded by guard cells
what does the muscular tissue epithelial tissue glandular tissue do
contracts to bring movement
covers most parts of the body
produces substances like enzymes and hormones
what is osmosis
the movement of water from a high water concentration to a low water concentration through a partially permeable membrane
what does it mean when a cell is isotonic?
how does this affect animal and plant cells?
concentration of solutes in solution outside cell is the same inside the cell
animal cell- normal
plant cell- flaccid (soft)
what does it mean when a cell is hypotonic?
how does this affect animal and plant cells?
concentration of solutes in the cell is higher than outside
animal cell- bursts
plant cell- turgid (normal)
what does it mean when a cell is hypertonic?
how does this affect animal and plant cells?
concentration of solutes outside the cell is higher than inside the cell
animal cell- shrivelled
plant cell- plasmolysed (shrinks)
what is diffusion
the spreading of particles from a high to low concentration through a partially permeable membrane until equilibrium is reached
what increases the diffusion rate
a greater difference in concentration
what is active transport
when particles move from a low to high concentration causing particles to move against the concentration gradient.
what helps active transport give 2 examples
carrier proteins allow proteins to move from a high to low concentration.
minerals being absorbed from the soil by root hair cells.
sugar absorbed from kinkey tubes into blood
