1. WHAT DO YOU ALREADY KNOW ABOUT CELLS?
Class Warm-Up
WHAT DO YOU ALREADY KNOW ABOUT CELLS?

2. Cell Structure and Function
Chapter 7.1 Life is Cellular

3. The Discovery of the Cell
Robert Hooke
1665
Englishman
Looked at a slice of cork
(plant material) under an
early microscope
Found the cork was made up of thousands of small chambers
He called these chambers “cells”

4. The Discovery of the Cell
Anton von Leeuwenhoek
1674 Holland, The Netherlands
Considered to be the “Father of Microbiology”
First to observe living microorganisms using
a microscope
Bacteria
Protists

5. Microscopes Over the Ages

6. Co-Founders of The Cell Theory
Matthias Schleiden, Botanist, 1837
All plants are made of cells.
Theodor Schwann, Physiologist, 1838
All animals are made of cells
Rudolf Virchow, 1858
All cells are made from the division
of existing cells

7. The Discovery of the Cell
The Cell Theory
All living things are made up of cells.
Cells are the basic units of structure and function in living things.
New cells are produced from existing cells.
Cells – the basic unit of life

8. Class Warm-Up
"an unbelievably great company of living animalcules, a-swimming more nimbly than any I had ever seen up to this time. The biggest sort. . . bent their body into curves in going forwards. . . Moreover, the other animalcules were in such enormous numbers, that all the water. . . seemed to be alive."
Which scientist that we discussed yesterday would have said this? How do you know?

9. Eukaryotic Prokaryotic
(Bacteria)
(Plant & Animal)
Cheek Cells
400x
Onion Cells
400x
400x
Elodea Cells
CLASS WARM Up Which Cells are prokaryotic and which are Eukaryotic? How do you Know? ‘

10. Compound Light Microscope
Use lenses to magnify the image of an object by focusing light
Cell structures as small as 1 millionth of a meter
Magnification up to 2,000x
Classroom microscopes go up to 400x
How Big? Animation

11. Exploring the Cell Why are chemical stains/dyes used in microscopy?
Most living cells are nearly transparent
Stains allow the cells to be seen under the microscope
Some reveal only certain compounds and structures within the cell
Fluorescent dyes
Different colors attached to different
molecules
Allows scientists to observe how
materials move throughout the cell

12. Dissecting Microscope
Also referred to as the stereo microscope
designed for low magnification observation of a sample, typically using light reflected from the surface of an object rather than transmitted through it.
3D images
used to study the surfaces of solid specimens or to carry out close work such as dissection, microsurgery, watch- making, and circuit board manufacture or inspection

13. Electron Microscopes 2 types: Transmission (TEM) and Scanning (SEM)
Used for viewing NON-LIVING cells and organisms only
Sends an electron beam through a vacuum to illuminate a specimen and produce a magnified image
Smaller cell structures as small as 1 billionth of a meter
DNA
Protein molecules
Viruses

14. SEM vs. TEM SEM (Scanning Electron Microscope) 3D images
up to 200,000x magnified
focuses the electron beam to a very small point on the sample and scans over the sample to produce an image
TEM (Transmission Electron Microscope)
sends an electron beam through a thin sample, projecting an image on a fluorescent screen
Cannot view the surface of specimens
Up to 50 million times magnified
Cool Electron Microscope Images

15. Types of Cells Prokaryotic Cells – cells that do not contain a nucleus
Eukaryotic Cells – cells that contain a nucleus A B
Nucleus – a large membrane-bound structure that contains genetic material (DNA) and controls many of the cell’s activities

16. Smaller and simpler cells
Prokaryotes
Eukaryotes
Both
No nucleus
Smaller and simpler cells
No membrane bound organelles
Most primitive form of life on Earth
Example: Bacteria
Nucleus
Larger and more complex cells
Have membrane bound organelles
Examples:
Plants
Animals
Fungi
Protists – single celled (unicellular) organisms
Cell membrane
DNA
Ribosomes
Cytoplasm
Cytoskeleton

17. WOW!!! One cell has 2 meters of DNA.
If all the DNA in your body was put end to end, it would reach to the sun and back over 600 times!
Your body has about trillion cells!
90% of those cells are bacteria cells!!
They can live as short as a day to as long as a year!

18. Formative Assessment Learning Goals
Explain the 3 parts of the cell theory.
Describe the differences, similarities and evolutionary links between prokaryotic and eukaryotic cells.

19. Which of the following statements are true?
All living things are made up of cells
Cells are the basic unit of structure and function
New cells are produced from existing cells
All of the above

20. What is a membrane bound structure that contains genetic material and controls many of the cell’s activities?
Prokaryote
Eukaryote
Nucleus
Cell membrane

21. Which of the following cells do not contain a nucleus?
Animal cell
Plant cell
Bacterial cell

22. Both prokaryotes and eukaryotes
have a nucleus
have DNA
have membrane bound organelles
are the same size

23. True or false? Eukaryotes are cells that do not have a nucleus.