cell structure and transport Flashcards
light microscopes
use beam of light
can magnify up to 2000 times
can view living objects
relatively cheap
electron microscopes
use beam of electrons
can magnify objects up to 2,000,000 times
cant view living objects
very expensive
magnification calculation
image size/ real size
nucleus
controls cells activities and holds the dna
cytoplasm
liquid gel where chemical reactions take place
cell membrane
controls the movement of substances in and out the cell
mitochondria
where energy is transferred during aerobic respiration
ribosomes
where proteinsynthesis takes place
cell wall
keeps the cell rigid- made of cellulose
chloroplasts
contains chlorophyll for photosynthesis
permanent vacuole
helps support the plant
eukaryotic cell
multicellular
plants, fungi, protista
prokaryotic cell
single celled
bacteria
nerve cells
many dendrites to make connections
an axon to carry impulses from one place to another
nerve endings to pass impulses to other cells
many mitochondria to transfer the energy needed
sperm cells
a long tail that whips
large nucleus to contain genetic information
middle section full of mitochondria to transfer the energy needed by the tail to move
acrosome to store digestive enzymes for break down of the egg
muscle cells
special proteins that slide over each other
many mitochondria to transfer the energy needed for chemical reactions
a store of glycogen to be used in respiration to transfer energy
root hair cells
increase the surface area available for water to move into the cell.
large permanent vacuole to speed up movement of water by osmosis
many mitochondria to transfer energy needed for active transport
photosynthetic cells
chloroplasts containing chlorophyll to trap light
often found in continuous layers
have a large permanent vacuole that helps keep the cell rigid
xylem cells
xylem tissue supports the plant
xylem cell transports the water and mineral ions from the roots to the stem and leaves
xylem cells are living when their first formed
cells die leaving long hollow tubes
phloem cells
transports food made by photosynthesis
difcell walls between phloem cells break down to form sieve plates
phloem cells lose a lot of their structures
companion cells contain mitochondria for that transfer energy
diffusion
spreading out of particles across a concentration gradient
examples of diffusion
oxygen and glucose into the cells of the body from the blood stream
CO2 into actively photosynthesising plant cells
oxygen and CO2 in opposite directions in the lungs( gas exchange)
simple sugars and amino acids from the gut through cell membranes
osmosis
diffusion of water across a partially permeable membrane high to low concentration
isotonic
two solutions with the same concentration
hypertonic
solution that is more concentrated
hypotonic
solution that is more dilute
osmosis in plant cells
water moves into plant cells by osmosis- the vacuole swells- the cytoplasm is pressed against the cell wall- the cell becomes rigid- leaves and stem become rigid
active transport
movement of particles against the concentration gradient- this requires energy
