organisation cells and microscopy- 01
magnification
conversion values for cm, mm, nm,µm
organelle
cells
definitions
formula
actual size- size of object in real life
magnification= how much the image has been zoomed
image size- size of image
image size= actual size x magnifcation
magnification= image size / actual size
actual size= image size / magnification
prokaryotes
eukaryotes
DNA in nucleas
simple structure
plant cells and animal cells
no membrane bound organelles
naked DNA
membrane bound organelles
no seperate organelles e.g. nucleas
cell membrane
cell wall
cytoplasm
mitochondira
nucleus
vacuole
ribsome
chloroplast
very small organelles
structure not seen under light microscope
perform protein synthesis
apperence: solid on light microscope
function to synthesize proteins
function is to contain DNA- controls cell activities including cell division
appearance: jelly like fluid
function is that it is the site of many reactions e.g. protein synthesis
appearance: thin layer of lipid molecules
function: controls what can enter/ leave the cell- partially permeable
small oval/ rounded organelles
double membrane
site of respiration
energy release from glucose
very strong
function: supports the shape of cell
appearance: fibrous layer made from cellulose
store of cell sap in plants
appearance:Vacuoles have a simple structure: they are surrounded by a thin membrane and filled with fluid and any molecules they take in
function: site of photosynthesis
appearance: small rounded organelles- contains chlorophyll
10 mm = 1 cm
1,000 mm = 1m
1,000 µm = 1 mm
100 cm = 1 m
100 nm = 1 µm
required practical 1
Use a dropping pipette to put one drop of water onto a microscope slide.
Use the mounted needle and forceps to peel off a thin layer of epidermal tissue from the inner surface of the onion.
There may be some liquid around the edge of the coverslip. Use a piece of blue roll to soak this liquid up.
Use forceps to put this thin layer onto the drop of water that you have placed on the microscope slide.
Put the slide on the microscope stage. Draw a large, labelled diagram of one cell, viewed under high power. Record the magnification next to your drawing.
Make sure that the layer of onion cells is flat on the slide.
Put two drops of iodine solution onto the onion tissue.
Carefully lower a coverslip onto the slide. Do this by: placing one edge of the coverslip onto the slide
using the forceps or mounted needle to lower the other edge onto the slide