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

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.

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.

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.

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.

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.

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.

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.

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.

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.