I. Cellular Biology
Cells are made of molecules combined with other molecules. They are considered the basic unit of life because atoms and molecules are not considered alive. This is relevant to biology class is about studying life and living organisms and cells are alive.
II. How big is it?
Cells are smaller than small insects and cells cannot be seen without a microscope. Viruses are smaller than cells and viruses need a higher amount of magnification. The smallest cells are magnified around 20 micrometers. The smallest viruses are magnified around 20 nanometers.
Metric system:
III. Levels of Organization
Biological systems are organized by the size of the unit from smallest to largest.
- Atom - Smallest unit of an element that still retains the elements properties.
- Molecules - A combination of molecules
- Cell - The smallest unit that can live and reproduce on its own or part of a multi-celled organism.
- Tissue - Contains certain types and proportions of cells performing a task.
- Organ - Contains two or more tissues interacting in a certain task.
- Organ system - Interacts physically, chemically, or both.
- Multi-celled organism - Organized in as tissues, organs, and organ systems.
- Population - A group of single-celled or multi-celled individuals (same species) in a specified area.
- Community - All populations of species occupying a specified area.
- Ecosystem - A community interacting with its physical environment. Has inputs and outputs of energy and materials.
- Biosphere - Encompasses all regions of Earth's waters, crust, and atmosphere holding organisms.
IV. Types of Cells
There are many similarities with Prokayrotic and Eukaryotic cells. The two types of cells have ribosomes, a cell membrane, both have a cytoplasm, and both have a cell wall (not including animal cells). There are also differences with Prokaryotic and Eukaryotic cells. Eukaryotic cells are found in animal and plants while Prokayrotic cells are found in bacteria. Prokaryotic cells have no nucleus, but Prokaryotic cells have a nucleoid. Eukaryotic cells to contain a nucleus. Also, Eukaryotic cells contain enzymes. Prokaryotic cells do not.
V. Compare and Contrast Prokaryotic v. Eukaryotic
Prokaryotic Similarities Eukaryotic
|
|
|
VI. Visualizing Cells
We are using a compound microscope to visualize cells.
|
|
IX. Prokaryotic Cell
Bacterial cells at x40, drawing below.
Bacterial cells at x100, drawing below.
Bacterial cells at x400, drawing below.