1. 7C42: A Closer Look at Cells

2. Background
Schleiden & Schwann discovered all living organisms are made of one or more cells.
Microbes are often made of just one cell.
What do you see in microscopic cells?

3. Typical Cell Scientists noticed structures inside cells.
Some structures are found in nearly all cells.
These are often in models of a typical cell.

4. Cell Membrane Cell membrane is the most common structure.
Membrane separates cell from environment.
Acts as barrier to control what goes in & out.

5. Cytoplasm: draw this 
Material enclosed by the membrane is called cytoplasm, which means “cell material”.
In the cytoplasm the cell breaks down nutrients from food and builds the new substances it needs to grow and to carry out its other functions.

6. Nucleus
Nucleus is the dark center found in the cells of most organisms except bacteria.
It is a small compartment within the cell separated by a nuclear membrane.
It contains the genetic information of the cell and directs its activities, including growth and reproduction.

7. Organelles
Organelles are “little organs” that help cells do many jobs.
Often surrounded by their own membranes.
Some of the jobs include obtaining and storing energy, helping cells move and divide, and making substances that are either used in the cell or transported to other parts of the body.

8. C42 Draw Cell Assignment, pC59
On separate paper Draw, Label, and Color Figure 1 on page C59 from your textbook.
Under that write Cell Membrane and then describe its function.
Next write Cytoplasm & describe its function.
Then write Nucleus and describe its function.
Why is Nucleus so important to most cells?
What organism does not contain a nucleus?

9. Cell Structure

10. Cellular Hierarchy Levels
From largest to smallest these include:
Body (organism)
Organ system (like digestive system)
Organ (stomach)
Tissue
Cell
Organelles
Macromolecule
Molecule/Atom

11. Studying Cells: AIDS
AIDS is a disease of one group of cells within the human body. Knowing how the cells work normally and what goes wrong in the cells of a person with AIDS helps scientists understand the disease and develop treatment.

12. Blood Red blood cells live for about 120 days.
New cells form as old ones die.
Knowing how they develop helped us make a drug that causes more red blood cells to form.
It is given to patients who need certain surgeries or to patients who have illnesses that reduce their numbers of red blood cells.
They make more cells & need less transfusions

13. Cell Biology Branch of Biology studies how cells work. Also:
What each part of the cell does, and how.
How do cells communicate, and their timing.
How can one human cell grow into an adult.
How a cell knows when to divide.

14. C42 Close Look at Cells Analysis
Do problems #1-4 on page C62 in the textbook
Match pictures to descriptions a, b, c, and d
Match pictures in #1 to cell types listed
Give one example of how the study of cells helps treat diseases. Explain in 1 paragraph.
Explain in 1 paragraph why membranes are so important to cells.