Download Starch: Amylose vs. Amylopectin

Starch: Amylose vs. Amylopectin
Lab Manual 1.Microscopes and
Plant Cells Lab
1.25.12
Pre-Lab Quiz
1. Say your oculars have a 10x magnification. If you
are looking at a specimen using the 40x objective,
what is your total magnification?
2. What is the name of the moveable structure to
which the objectives are attached?
3. What do the leucoplasts found in potatoes store?
4. What is the special name for these storage
structures?
5. How do some plants cope with the build up of
toxic substances?
The Compound Microscope
• Always carry microscopes with 2 hands:
one at the base, one at the arm
• Demo of microscope parts
• Always make sure you’re on the lowest
objective when mounting or removing
slides
• Wipe up spills immediately so you don’t
destroy the lenses
Outline for today’s lab:
• The letter E
• Cork cells- cell wall
• Onion- cell wall, nucleus, nucleoli, cytoplasm,
vacuoles... Add IKI if necessary
• Elodea leaf- cell wall, cytoplasm, nucleus,
chloroplasts, vacuole (tonoplast)... Add NaCl if you
want to see plasmolysis.
• Potato tuber- leucoplasts (amyloplasts), intercellular
spaces
• Red pepper- chromoplasts
• Zebrina- raphides
• Begonia- druses
The “e” Exercise: Dissecting vs.
Compound Microscope
“Depth of Field”
How thick of a slice can I get in focus at once?
y
y
z
z
x
Lower magnification
x
Higher magnification
Representative Plant Cell
Cork cell walls
100x
Onion and IKI
IKI (Lugol’s solution) should turn black in the presence of starches. It should help
you distinguish between some of the different cellular compartments.
Elodea and Plasmolysis
Waterweed (Elodea densa) a submersed South American aquarium plant that is naturalized in
ponds, streams and lakes throughout North America. The cartoon cell to the left shows a living
photosynthetic cell. Because most of the cell is occupied by a water-filled, large central vacuole,
the chloroplasts are displaced around the periphery of the cell, just inside the cell wall and
membrane. The cell on the right has shrunken away from the cell wall (plasmolysis) due to
water loss caused by disruption of its osmotic balance.
Potato tuber
Red Pepper
Different Plastids in Plants
Precursor of all plastids
Chloroplasts not yet
exposed to light
Site of photosynthesis
Monoterpene
synthesis; precursor to
other plastids
Synthesize and store
pigments
Starch storage
Fat storage
Protein-modifying
compounds
Zebrina Raphides
Begonia
Begonia Druses
Begin lab exercises!