1. Cells and Heredity – Chapter 1 Section2
Learning Targets:
1. I can describe different types of microscopes
2. I can describe prokaryotic and eukaryotic cells
3. I can compare and contrast plant and animal cells.

2. How Small Are Cells
Because cells are so small, a very small unit is used to measure them.
The micrometer is one millionth of a meter.
Cells vary in size from about 1 micrometer (bacteria) to about 1000 micrometers(plant/animal cells)
It would take about 17,000 bacterial cells lined up to reach across a dime

3. The Microscope is an Important Tool
The invention of the microscope led to the discovery of cells and the development of the cell theory
In light microscopes, lenses are used to bend light and make objects appear bigger than they are.
One important advantage of light microscopes is that scientists can observe living cells with them.
Two other types of microscopes are the scanning electron microscope (SEM) and the transmission electron microscope (TEM).
In an SEM, a cell sample is coated in a heavy metal, such as gold. A beam of electrons is run back and forth over the surface of the cell. This will produce a three dimensional image.
In a TEM, a cell is sliced extremely thin and electron pass through a section. This will produce a two dimensional image.

4. Microscopes

5. Cells Are Diverse
Every cell has a boundary that separates the inside from the outside. That boundary is called the cell membrane. It is a protective covering that any material coming in or out of the cell must pass through.
Inside the cell membrane is a gelatin like fluid called the cytoplasm.
In a eukaryotic cell the genetic material is in a structure called a nucleus.
The nucleus is often thought of as the brain of the cell. It controls and directs all of the activities of the cell.
An organelle is any part of the cell that is enclosed by membrane.
In a prokaryotic cell there is no separate compartment for the genetic material. Instead, it is in the cytoplasm.
There are no organelles in a prokaryotic cell.
Most unicellular organisms are prokaryotes
Almost all multi-cellular organisms are eukaryotes

6. Plants and Animals Have Eukaryotic Cells
All eukaryotic cells are divided into two main compartments.
The nucleus, the largest organelle is the compartment that stores all the instructions a cell needs to function
A cell wall is a tough outer covering that lies just outside the cell membrane.
The cell wall protects and supports the cell.
Having a cell wall is one important way in which plant cells differ from animal cells.

7. Plant and Animal Cell

8. Structures That Process Information
The information that the nucleus contains is translated by ribosomes.
Ribosomes use the information to gather the materials a cell needs to build proteins

9. Organelles That Provide Energy
An organelle is a structure in a cell that is enclosed by a membrane and that performs a specific function.
Chloroplasts are organelles n which the energy from sunlight is used to make sugar.
Animal cells do not contain chloroplasts
Mitochondria are the organelles that use oxygen to process food to manufacture energy in both plant and animal cells.
The endoplasmic reticulum is a series of twisting and winding membranes.
The endoplasmic reticulum processes materials it gets from ribosomes and uses them to manufacture proteins and parts of cell membrane.
The Golgi apparatus looks something like a stack of pancakes.
The Golgi apparatus takes the materials from the endoplasmic reticulum and finishes them.

10. Organelles for Storage, Recycling and Waste
Vacuoles are made of membrane and can hold waste, water, and other materials.
A plant cell has a large central vacuole in which water and materials can be stored
Animal cells do not have central vacuoles.
Lysosomes are vacuoles that contain chemicals that break down materials taken into the cells, as well as old cell parts.