1. Introduction to Cells

2. The Discovery of Cells Cells are too small to see! So how
were they discovered?
In 1665 Robert Hooke, an English
scientist, used a crude microscope
to look at the cells of a piece of cork.
Anton van Leeuwenhoek, from
, studied pond water
and called what he saw
“animalcules”.

4. Cell Theory
It took over 150 years for scientists to understand the importance of this discovery and to develop the concept of Cell Theory.
All living things are made of one or more cells
Cells are the basic units in organisms
All cells arise from existing cells

5. Levels of Organization

6. Looking at Cells A cells shape and size reflects the cell’s function.
Cell Size
The larger the cell the harder it is for the cell to exchange nutrients and waste. These substances must move farther to reach where they need to go.
Cell Shape
Larger cells often have shapes to reduce the cells surface area-to-volume ratio
How does a cell’s size affect
the cell’s function?

7. Cell Features
Cell membrane: the cell’s outer boundary, acts as a barrier. Cytoplasm: includes the fluid inside the cell and many of the structures like ribosomes. Ribosomes: structure that assembles the 20 amino acids of which proteins are made.

8. Prokaryotic Cells
Include bacteria and archaea. They do not have a nucleus, mitochondria, or any other membrane-bound organelles. Evolved before Eukaryotes.

9. Eukaryotic Cells
Eukaryotic cells have a more complex organization with a nucleus and membrane-bound organelles. They are also bigger than prokaryotes. The nucleus is where genetic material is stored.

10. Introduction to Cells: Review
List the three parts of the cell theory.
Describe the importance of a cell’s surface area-to-volume ratio.
Compare the structure of a eukaryotic cell with that of a prokaryotic cell.

11. Inside the Eukaryotic Cell
Framework Direction of Cellular Activity Protein Processing Storage and Maintenance Energy Production

12. The Framework of the Cell
Much like we have bones, a cell has a web of protein fibers called the cytoskeleton. The cytoskeleton helps the cell: -move -keep its shape -organize its parts

13. Directing Cellular Activity
Almost all cellular activity depends on the proteins that the cell makes. Instructions for making proteins are stored in DNA. What type of Biomolecule is DNA?

14. Directing Cellular Activity
Nucleus
DNA is stored in the nucleus. DNA instructions are copied as RNA messages which leave the nucleus which go to …..

15. Directing Cellular Activity
…the Ribosomes…. In the cytoplasm, ribosomes use the RNA message to assemble proteins. They are the factories of proteins!

16. Protein Processing
Some proteins are exported outside the cell. There are two main organelles responsible for this:
Endoplasmic Reticulum (ER) two types, smooth ER and rough ER. Ribosomes are attached to the rough
ER.
Golgi Apparatus
This organelle helps make and
Package materials to be
Transported out of the cell

20. Storage and Maintenance
Vesicles are small membrane enclosed sacs that store and transport materials within a cell. There are several kinds of vesicles.
Lysosomes
These vesicles contain enzymes
that Break down food for the
cell and Also digest
old organelles. They
are made In the
Golgi Apparatus.
Vacuoles
There are many kinds of vacuoles.
Some store water , nutrients, and
wastes.
First pic is animal cell, second is plant. Plants have larger vacuoles for water storage.

21. Energy Production
Cells need a constant source of energy.

22. Chloroplasts
Chloroplasts are organelles that use light energy to make sugar from carbon dioxide and water. Found in plants and plant-like protists (seaweed)

23. Mitochondria
Mitochondria are organelles that use energy from organic compounds to make ATP. What kind of biomolecule is ATP? Why do muscle cells have a lot of mitochondria?

24. Inside the Eukaryotic Cell: Review
1.Where is DNA stored in a Eukaryotic Cell? 2.What do ribosomes make and what two places will you find them in a cell? 3. Compare the role of mitochondria and chloroplasts.