B1 Cell Structure and Transport Flashcards
membrane bound organelles
organelles that have inner and outer membranes within it
magnification
however many times the size of an object/ image gets bigger
resolution
the minimum distance where two points can still be distinguished
diffusion
the net movement of particles from an area of high to low concentration
concentration gradient
the difference between the number of particles inside and outside a cell
active transport
the movement of particles from a low to high concentration
partially-permeable membrane
membranes of cells that let some types of substances through but not others
osmosis
1st definition - high and low
the net movement of water molecules across a partially-permeable membrane from an area of high to low concentration
osmosis
2nd definition - dilute and concentrate
The net movement of water molecules from a pure/ dilute solution to a concentrate solution across a partially-permeable membrane
solute
a substance that dissolves in a solution
isotonic solution
the concentration of solute is the same inside and outside of the cell
hypertonic solution
the concentration of the solute is higher outside the cell and lower inside
hypotonic solution
the concentration of the solute is lower outside the cell and higher
SA:V ratio
the ratio of an object’s surface area compared to its volume
what three organelles do plant cells have that animal cells don’t
permanent vacuole, cell wall, chloroplasts
cell membrane
controls what enters and exits the cell
cytoplasm
the site of anaerobic respiration
cell wall
provides strength and support for the cell - keeps it rigid
ribosomes
site of protein synthesis
nucleus
contains cell genetics and DNA and controls cell’s activities
permanent vacuole
stores cell sap and keeps the shape rigid
mitochondria
the site of aerobic respiration
chloroplasts
site of photosynthesis - contains chlorophyll
where is genetic material stored in a prokaryotic cell?
freely in the cell in plasmids
plasmids
circular DNA
T.E.M
Transmission Electron Microscope
S.E.M
Scanning Electron Microscope
what type of radiation do electron microscopes use?
electro-magnetic radiation
what disadvantages are there to using an electron microscope?
- can only view dead, non-living material;
- is large and static;
- is difficult to use and expensive
what disadvantages are there to using a light microscope
has a low magnification and resolution
what advantages are there to using an electron microscope?
high magnification and resolution
what advantages are there to using a light microscope?
- cheapy and easy to use;
- small and poratble;
- can view living, moving, dead, and non-living material
What is the formula for..
Total magnification
eyepiece lens x objective lens
What is the formula for…
Magnification
Image size / Actual size
- What is the maximum magnification of a light microscope?
x2’000
what is the maximum magnification of an electron microscope?
x2’000’000
what is the minimum resolution of a light microscope?
200nm
what the minimum resolution of an electron microscope?
0.25nm
`
what kind of process is diffusion?
a passive process
what is the movement of particles in relation to the concentration gradient during diffusion?
down the concentration gradient
which factors effect the rate of diffusion?
- temperature
- surface area
- concentration gradient
- distance of diffusion
Why does a higher temperature increase the rate of diffusion?
Because the particles have more kinetic energy and move faster - diffuse quicker
what kind of process is active transport?
an active process
what is the movement of particles in relation to the concentration gradient during active transport?
against the concentration gradient
what is an active process?
a process that requires energy
for active transport, energy is required via respiration
what is a passive process?
a process that doesn’t require energy from an external source
for diffusion, particles use their own energy to move
what happens to a cell if it is in a hypertonic solution?
the cell shrinks and loses water
what happens to a cell if it is in a hypotonic solution?
the cell swells up and bursts
what happens to an organism’s SA:V ratio as it gets larger
it decreases
what are the purposes of specialised exchange surfaces?
they increase surface area to volume ratio within an organism and increase the efficiency of diffusion
name two specialised exchange surfaces
- alveoli
- villi
why is a smaller surface area important for diffusion?
because particles travel a smaller distance
