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I = Image size
A = Actual size of image M = Magnification 1m=1000mm 1mm=1000µm 1µm = 1000nm |
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Number of Micrometers ÷
Number of Graticule Division |
= 1 Graticule Division
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Graticule Divisions x
Magnification Factor |
= Measurement (µm)
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How many times bigger the image of a specimen observed is in compared to the actual size of the specimen.
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A light microscope has two types of lens:
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An eyepiece lens.
A series of objective lenses. |
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Total
Magnification: |
Eyepiece Lens Magnification x Objective Lens Magnification
= Total Magnification |
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The ability to distinguish between two separate points.
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Resolution of a light microscope is limited by the wavelength of light.
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Electron microscopes have a higher resolution and magnification as electrons have a much smaller wavelength than visible light.
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Electron Microscope
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Light Microscope
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Large and installations = Can't move.
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Small and easy to carry.
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Vacuum Needed.
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No Vacuum Needed.
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Complicated sample
preparation. |
Easy sample preparation.
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Over X 500 000
Magnification. |
Up to X 2000 Magnification.
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Resolution = 0.5nm
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Resolution = 200nm
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Specimens = Dead
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Specimens = Dead/Living
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Images obtained from a light microscope, these are used for specimens above 200 nm.
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Images obtained from electron microscopes, both scanning and transmission, these are used for specimens above 0.5 nm
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Controls exchange of material between the internal and external cell environment.
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Used to enclose/protect/support.
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Fully permeable = Lets anything through.
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Gives instruction.
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Contains the cells DNA
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Contains nuclear envelope = separates nucleus from cytoplasm.
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Site where ribosomes are made.
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Powerhouse of the cell.
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Site of aerobic respiration.
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Produces ATP.
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Has 70s Ribosomes & Circular DNA.
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Contain DNA.
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Can't live on their own.
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Where photosynthesis happens.
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Built of 2 subunits.
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Do ont have a membrane.
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Ones found in cytosol = always attached to ER
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Ones found freely in cytoplasm or as part of the Rough endoplasmic reticulum in Eukaryotic cells.
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Is a complex of ribosomal RNA & Proteins.
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Site of translation.
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60s & 40s subunits.
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Found in Eukaryotic Cells
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In cytoplasm
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50s & 30s subunits.
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Ribosomes in Prokaryotes.
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In Mitochondria & Chloroplast.
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Has 2 Types
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Rough endoplasmic reticulum (RER):
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Round sacs transport substances.
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Processes proteins.
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Smooth endoplasmic reticulum (ER):
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Involved in the production/processing/storage of lipids/carbohydrates/steroids.
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Site where substances needed by the cell are made.
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Has no ribosomes.
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Synthesises specific functions:
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Hormones & enzymes.
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Modifies proteins and packages them into vesicles or lysosomes.
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Controls exchange.
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Around vacuole in plants.
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Regulates osmotic properties.
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Used to keep plants stiff.
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Where pigment (petal colour) is found.
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Cleaners of the cell.
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Single membrane.
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Contains concentrated mixtures of digestive enzymes:
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Hydrolytic enzymes
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Attached to the vacuole of cells.
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Discharged/removed from cell.
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Involved in making the cilia.
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Not found in flowering plants & fungi.
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Involved in movement of components within the cell.
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Guid & direct organelles.
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Important for transport/communication/signalling between cells.
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Controls movement & created paths between cells.
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Adenosine Triphosphate is a nucleotide.
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Provides energy to cells.
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It is produces in mitochondria & chloroplasts.
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This energy
is required: |
In anabolic reactions.
Active Transport. In animals. |
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ATP from respiration = used to transfer energy in all energy-requiring prosesses in the cells.
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Bacteria are a type of prokaryote.
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Unicellular
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100s/1000s of times smaller than eukaryotic cells.
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Genetic material is not packaged within a membrane-bound nucleus and is usually circular.
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Non-cellular structures.
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They have:
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A protein coat called a ‘capsid’
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A nucleic acid core (their genomes are either DNA or RNA, can be single or double-stranded)
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Cheatography n. The art of mapping complex subjects into clear, instantly navigable reference guides.
