Looking Inside Cells

1. Looking Inside Cells Cells and Heredity Lesson 2 chapter 1

2. Enter the Cell • The tiny structures inside cells are known as organelles. • The cell wall is found in plant cells, which is a rigid layer of nonliving material that surrounds plant cells and some other organisms. • A plant’s cell wall helps to protect a support the cell.

3. Cell Membrane • All cells have cell membranes. • The cell membrane controls what substances come into and out of a cell. • Everything the cell needs, from food to oxygen enters through the cell membrane. • Harmful waste products leave through the cell membrane. For a cell to survive, the cell membrane must allow these materials to pass in and out.

4. The Nucleus • The nucleus acts as the “brain” of the cell. • You can think of the nucleus as the cell’s control center, directing all the cell’s activities. • The nucleus is surrounded by a membrane called the nuclear envelope. Just like mailing envelope protects letters inside, the nuclear membrane protects the nucleus. • Inside the nucleus you will find chromatin, which directs or tells the nucleus how to function. Chromatin contains genetic material. • The nucleolus, is where ribosome's are made, where proteins are produced.

5. Organelles in the Cytoplasm • As you leave the nucleus, you will find the cytoplasm, which is located between the cell membrane and the nucleus. • Many cell organelles are found here. • The mitochondria are known as the “powerhouses” of cells because they convert energy in food to energy the cell can use to carry out functions.

6. Organelles • The endoplasmic reticulum contains passageways that carries proteins and other materials from one part of the cell to another. • Attached to some surfaces of the endoplasmic reticulum are small, grain like bodies called ribosome's. • Ribosome's function as factories to produce proteins.

7. Organelles • The Golgi Bodies receive proteins and other newly formed materials from the endoplasmic reticulum, package them, and distribute them to other parts of the cell. • Chloroplasts capture energy from the sunlight and use it to produce food for the cell. (found in plant cells) This makes leaves green. • Vacuoles are the storage areas of cells. They store food and other materials needed by the cell.

8. Organelles • Lysosomes are small, round structures containing chemicals that break down certain materials in the cell. • Lysosomes also break down large old cell parts and release the substances so they can be used again. • Lysosomes are like a cell’s cleanup crew.

9. Specialized Cells • Plants and animals contain may cells. • In many celled organisms cells are often organized into tissues, organs, and organ systems. • An organ such as your heart is made up of tissues that function together. • An organ system is a group of organs that work together to perform a major function. EX: circulatory system.

10. Bacterial Cells • While a bacterial cell does have a cell wall and a cell membrane, it does not contain a nucleus. • The bacterial cell’s genetic material, which looks like a thick, tangles string, is found in the cytoplasm.