1. I. Introduction to Cells
Chapter 7-1

2. A. Discovering Cells Problem -- we can’t see cells with naked eye
First cells seen & recognized were in plants, not animals
The cell walls make them visible
Figure: 04-15
Title:
Common Structures in Animal and Plant Cells
Caption:
Common Structures in Animal and Plant Cells.

3. First description of cells
By Robert Hooke In 1665
He Named them for a monk’s cell
Referring to bare walls

4. Frog cartilage From pig embryo Further ID of cells
Description of cells from many organisms
T. Schwann in 1839
Frog cartilage
From pig embryo

5. B. Cell theory The smallest unit of life is a cell.
All life is either a cell, or is composed of cells.
Every cell comes from another cell.
Human beings cannot form cells from scratch in lab yet
apparently, nature made cells from simple molecules only once

6. 3 How many types of cells are in this picture? Figure: 04-00UN3c
Title:
Red and White Blood Cells
Caption:
(c) Human red and white blood cells inside a blood vessel. The large, dark ovals that can be seen in the background are flat cells that form the interior lining of the blood vessel. 3

7. A specialized nasal nerve cell
Figure: 04-01
Title:
Cells Can Specialize
Caption:
In more complex organisms, different cells carry out different functions. In the picture at left, you can see one type of cell,—a nerve cell, in this case located in the lining of the nose and surrounded by gray accessory cells. A closer look at one of these nerve cells, in the picture at right, shows a number of hair-like extensions, called cilia, protruding from it. When we smell muffins in the oven, gas molecules that waft off the muffins bind with the cilia, which sets in motion a nerve impulse to the brain about the muffins.
A specialized nasal nerve cell

9. C. 2 Cell Types Prokaryotes Eukaryotes Bacteria Plants Animals Fungi
& Others

10. 2. Differences between the 2 types
Location of the DNA
Eukaryotes = In the membrane bound nucleus
Prokaryotes = In the cytoplasm
Size
Eukaryotes are “large” visible at 100x
Prokaryotes are tiny Visible at 1000x

11. Organization Organelles Eukaryotes are often multicellular (like us)
Prokaryotes are all unicellular
Organelles
Eukaryotes have small membrane bound inner parts called organelles
Prokaryotes do not have membrane bound organelles

12. Metabolism Eukaryotes usually need oxygen
Prokaryotes can often live without oxygen

13. D. Cell Sizes Cells are tiny 85x 425x 2100x 0.1mm – 0.0001mm
Ex) Bacteria on the Tip of a Pin
Title:
Hidden Life
Caption:
Microscope enlargements of the tip of this pin show an abundance of life—in this case bacteria—thriving on an object that we normally think of as being devoid of living organisms.
85x
425x
2100x

14. Figure: UN
Title:
Little and Big
Caption:
The sizes of some selected objects in the natural world.

15. Why So Small? Volume increases much faster than surface area.
Surface Area = 4π r2
Volume = 4/3π r3
Limited surface = limited import of everything
Food