Module 2 - Cell Structure

Question 1

What are stains?

Answer 1

Coloured chemicals that bind to molecules in or on the specimen, making it easier to see

Question 2

Name an all purpose stain

Answer 2

Methylene blue

Question 3

What is differential staining?

Answer 3

A stain that binds to specific structures, staining each structure differently so they can be easily identified with a single stain

Question 4

Give examples of some differential stains

Answer 4

1. Acetic orcein binds to DNA and stains chromosomes dark red
2. Eosin stains cytoplasm; Sudan red stains lipids
3. Iodine (in potassium iodide solution stains cellulose in plant cell walls yellow or starch granules blue/black

Question 5

What is the formula for magnification

Answer 5

M = I/A

Question 6

How do you prepare a specimen

Answer 6

1) Dehydrate it
2) embed it in wax to prevent distortion during slicing
3) using a special instrument make small slices called sections

Question 7

What is the Resolution of Light Microscope?

Answer 7

0.2 um

Question 8

What is the magnification of the SEM?

Answer 8

200,000 X

Question 9

What is the Magnification, Resolution and how is the image shown for a TEM?

Answer 9

resolution : 0.0002 um
Magnification: 1 mil
The electrons are absorbed and reflected and the image is 2D

Question 10

How is the image shown using SEM?

Answer 10

The image is 3D and the electrons bounce off the surface of the specimen

Question 11

Which two microscopes use dead specimens?

Answer 11

TEM and SEM

Question 12

What is the magnification for Light Microscope?

Answer 12

1500 X

Question 13

MAKING SLIDES

Answer 13

• Thin slice of specimen
• place specimen onto slide using tweezers
• Using a mounted needle, put cover slip onto slide over specimen (this prevents air bubbles)
• Close Microscope with clips

Question 14

What are the similarities of Prokaryotes and Eukaryotes

Answer 14

• Both have plasma membrane
• Both have a cytoplasm
• Both have ribosomes for protein synthesis
• Both have DNA and RNA

Question 15

What are differences of Prokaryotes to Eukaryotes?

Answer 15

• smaller
• no nucleus
• free floating DNA
• No membrane bound organelles
• Flagella
• Pili (adhere host)
• Waxy capsule surrounding cell wall
• Cell wall

Question 16

outline the process of Secreting Proteins

Answer 16

1) Gene codes protein (transcribes RNA)
2) Copied, pass out nuclear E pores
3) Ribosomes translate/ assemble protein
4) pass into RER
5) vesicles pinched off pass through microtubules to GA
6) vesicles fuse w// GA, proteins modified for release
7) vesicles pinched and pass into Plasma M
8) vesicles fuse w// PM
9) Protein released outside