2.1 Cell Structure (spec) Flashcards
What are the advantages of a optical microscope?
Cheap
Easy
Portable
Study whole living species
What is the magnification of a optical microscope?
X1500 to X2000
What is the resolution of a optical microscope?
Limited
What is visible with a optical microscope?
Mitochondria
Chloroplasts
Bacteria
How does an optical microscope work?
Light is reflected from a mirror onto the specimen
What are the advantages of a laser scanning microscope?
Selective depth
Eliminates a background
What is the magnification of a laser scanning microscope?
X1000
What is the resolution of a laser scanning microscope?
High (with contrast)
What is visible with a laser scanning microscope?
Whole live specimens
Cells
Eyes (medical scanning)
How does a laser scanning microscope work?
Laser scans an object point by point and assembles on a computer screen
What are the advantages of a transmission electron microscope?
Magnifies to a high degree
Good resolution
What is the magnification of a transmission electron microscope?
X2 million
What is the resolution of a transmission electron microscope?
High
What are the disadvantages of a transmission electron microscope?
Expensive
Dead specimens only
Needs training
2D
Black and white
What is visible with a transmission electron microscope?
Cell wall
Ribosomes
Nucleus
Vacuole
Thin specimens
How does a transmission electron microscope work?
A beam of electron passes through a specimen stained with metal salts
What are the advantages of a scanning electron microscope?
3D images
Can colour on a software
Chemical analysis
What is the magnification of a scanning electron microscope?
X15 to X200,000
What is the resolution of a scanning electron microscope?
High 3D
What is visible with a scanning electron microscope?
Shape of cell structures
Atoms
Chemical bonds
What are the disadvantages of a scanning electron microscope?
Specimens must be coated with a fine film
Colour is false
Expensive
Large
Why do we stain specimens?
Provide contrast
More detail
See specific organisms
What is an all purpose stain?
Methylene blue
What is the job of the stain Acetin Orcerin?
Binds to DNA and stains chromosomes dark red
What is the job of the stain Eosin?
To stain the cytoplasm
What is the job of the stain sudan red?
To stain lipids
What is the job of the stain potassium iodide?
Turns cellulose cell walls yellow and starch dark blue/black
What is the formula for magnification?
magnification = image/actual
How do you measure a microscopic image to use the magnification formula?
Measure widest part of leaf
Multiply by 1000 to μm
Put into the formula