NOTES 1:2 Looking Inside Cells

How Do the Parts of a Cell Work? Each cell structure has a different function within the cell. Cell wall Cytoplasm Chloroplasts Ask: What does this image show? Answer: Most students should recognize the image as a typical cell. Ask: How do you think this cell is like your body? Answer: My body has an outer covering and different parts inside that do different things. Have a volunteer read the statement at the top of the slide aloud. Explain to students that, just like their bodies, all cells contain smaller structures that carry out specific functions inside the cell. Tell students that this is a picture of a typical plant cell. Plant cells have two structures that surround the cell. These two structures are the cell wall and the cell membrane. Explain that animal cells do not have a cell wall, but do have a cell membrane. The cell wall is a rigid layer that protects and supports plant cells. The cell membrane acts like a screen that controls which substances pass into and out of the cell. Point out that the diagram shows many cell structures, not just the cell wall and cell membrane. Tell students that they will learn about the other structures in this presentation. Ask: Where is the cell wall in the diagram? Click to reveal the label and pointer for cell wall. Ask: Where is the cell membrane in the diagram? Click to reveal the label and pointer for cell membrane. Ask: Where is the cytoplasm in the diagram? Click to reveal the label and pointer for cytoplasm. Tell students that the cytoplasm is the fluid that fills the region between the cell membrane and the nucleus. Tell students that plant cells are green because they contain chlorophyll. Ask: Where are the green structures in this plant-cell diagram? Answer: Have a student point out the green chloroplasts. Click to reveal the label for chloroplasts. Explain that chloroplasts contain chlorophyll for capturing energy from the sun. Chloroplasts use this energy to make food for the cell. Cell membrane

How Do the Parts of a Cell Work? The nucleus acts as a cell’s control center, directing all of the cell’s activities. Endoplasmic reticulum Nucleolus Nucleus Ribosomes Tell students to look at the diagram of the animal cell. Ask: How is this diagram similar to the previous one? Answer: Both have a membrane surrounding them. Both have structures within the cell. Tell students that this is an animal cell. Explain that animal cells do not have a cell wall, so the only structure surrounding the animal cell is the cell membrane. Click to reveal the label for cell membrane. Ask: What is the function of your brain? Answer: It helps control what my body does. Explain that the cell has a “brain,” too. It is the nucleus. Click to reveal the label for nucleus. Explain that within the nucleus is chromatin, strands of material that contain information for directing a cell’s functions. Click to reveal the label for the nucleolus. Tell students that the nucleolus is where ribosomes are made. Ask students to guess where the ribosomes are on the diagram. Click to review the label and pointer for ribosomes. Explain that ribosomes are small grain-shaped organelles that produce proteins. Click to reveal the label for endoplasmic reticulum. Explain that the endoplasmic reticulum, or ER, is a network of membranes that produces many substances. Ribosomes frequently dot parts of the ER, as they do in this diagram. Click to reveal the label for mitochondria. Tell students that these organelles are called mitochondria. Ask: What do you think the mitochondria look like? Answers will vary: They look like sausages. Explain that mitochondria are called the “powerhouses” of the cell, because they convert energy stored in food to energy the cell can use to live and function. Review the nucleus, nucleolus, ribosomes, ER, and mitochondria and their functions in the cell. Mitochondria Cell membrane

How Do the Parts of a Cell Work? Lysosomes Golgi apparatus Tell students that now they are going to learn about three more organelles: the Golgi apparatus, lysosomes, and vacuoles. Have a volunteer indicate the label for Golgi apparatus. Click to point to the Golgi apparatus in the cell. Explain that the Golgi apparatus looks like flattened sacs and tubes, and that its function is to receive, package, and distribute proteins and other newly formed materials from the ER. Have a volunteer indicate the label for lysosomes. Click to point to lysosomes in the cell. Explain that lysosomes are saclike organelles that break down large food particles into smaller ones. Have a volunteer indicate the label for vacuole. Click to point to the vacuole in the cell. Explain that the vacuole is a sac used for storing water, food, or other materials needed by the cell. Point out that there may be one or more vacuoles in a cell. Vacuole

Cell Wall A rigid layer that surrounds the cells of plants. Helps protect and support the cell made of cellulose

Cell Membrane Controls what gets in and out of the cell “window screen” Controls what gets in and out of the cell In plants – just inside the cell wall In animals – outer boundary of the cell

Cell Membrane Color the cell membrane

Organelles Tiny Cell structures that carry out specific functions within the cell

Nucleus – the largest organelle “Brain of the cell” Directs the cell’s activities Surrounded by a membrane called the nuclear envelope - materials pass in and out through pores in the nuclear envelope.

Answer 1st question on pg. 14 What does the nuclear envelope do and where is it? It allows materials to pass through pores – surrounds the nucleus

More on the nucleus Chromatin thin strands of material that fill the nucleus contains info for directing a cell’s activities Chromatin forms DNA – write this…

Even more on the nucleus Nucleolus small round structure in nucleus make ribosomes Ribosomes produce proteins

Cytoplasm Thick, clear, gel like fluid Moves organelles within the cell

Organelles in the Cytoplasm Mitochondria “powerhouse” Converts energy stored in food into energy the cell can use

Challenge Question pg. 14 In what types of cells would you expect to find a lot of mitochondria? Muscle Cells

Endoplasmic Reticulum https://www.youtube.com/watch?v=8NPzLBSBzPI Endoplasmic Reticulum “conveyor belt” Maze of passageways Carries proteins from one part of the cell to another. (write that!!!) Show Lucy Ball video https://www.youtube.com/watch?v=8NPzLBSBzPI

Ribosomes “protein factories” Some are attached, or “dot part of the ER”, others float in the cytoplasm Place where proteins are made ER Ribosomes

Answer question on pg. 15 What do ribosomes do? Make proteins ER

Color the cell parts that you’ve learned so far in the diagram and the matching parts of the key

Comparing Plant and Animal Cells Have students study the two diagrams showing a typical plant cell on the left and a typical animal cell on the right. Ask a volunteer to name each of the organelles shown in the diagrams. Tell students to look at the chart. Go through the chart by asking if each of the organelles is found in plant cells or animal cells. For example: Ask: Are cell walls found in plant cells, animal cells, or both? Answer: plant cells only Click once to reveal a blue “X” next to plant cells and a red “-” next to animal cells. Continue by asking the same question about each organelle, and clicking to reveal either a blue “X” or a red “-” next to plant cells and animal cells. After going through the entire chart, ask the following questions. Ask: Which organelles are found only in plant cells? Answer: cell walls and chloroplasts Ask: Which organelle is usually found only in animal cells? Answer: lysosomes

Golgi Apparatus “Cell warehouse” Looks like flattened sacs and tubes Receives proteins from ER, packages and sends them throughout the cell, or outside the cell

Golgi Apparatus – define it… The Golgi apparatus is an organelle that and materials made in the ER

Golgi Apparatus – define it… The Golgi apparatus is an organelle that packages and distributes materials made in the ER

Vacuoles Large water filled sacs in cytoplasm “Storage” Large water filled sacs in cytoplasm Store food, H2O, and waste in cells Largest in plant cells – (write this!!!)

Nucleus Cell membrane Golgi apparatus Cell wall Mitochondria

Chloroplasts Green structures in plant cells Captures energy in sunlight and changes it to a form of energy cells can use in making food. photosynthesis occurs here (write that!!!)

Look at figure 5 – answer the question. In which part of a plant would you NOT expect to find cells with chloroplasts? Roots, flowers, or seeds

Lysosomes Recycling organelle Contain chemicals that break down large food particles into smaller ones. Also break down old cell parts

How do Cells Work Together in an Organism?

Cells in multicellular organisms are often very different from one another and perform different functions specialized cells are found only in multicellular organisms

Read the paragraph about specialized cells Read the paragraph about specialized cells. Underline the phrases or sentences that describe the main ideas about specialized cells. They perform specific functions that benefit the entire organism. One type of cell does one kind of job, while other types of cells do other jobs.

How Do Cells Work Together? 1 4 3 Point out to students that cells have specific jobs. Each cell shown in the chart is specialized for a particular function, and each specialized cell tends to have a distinctive appearance. Tell students that this appearance often reflects the cell’s function. Read each function aloud, and then ask students to guess which specialized cell is being described. Click once to reveal the four answers. 2

Cell Organization

Cells Working Together In multicellular organisms, cells are organized into tissues, organs, and organ systems.

Cells Working Together In multicellular organisms, cells are organized into tissues, organs, and organ systems.

Cell Organization “The Building Blocks” Cell - the basic unit of life Tissue - similar cells working together Ex. Blood, muscle, bone Organ – a group of tissues working Ex. Heart – made of blood, nerve, and muscle tissue Organ System – several organs working together Ex. Heart and blood vessels make circulatory system Organism – Organ systems functioning to keep organism alive Ex. Roots, stems, and leaves help keep plant alive

Amazing Facts about cells 50,000 of the cells in your body will die and be replaced with new cells, all while you have been reading this sentence! In 1 square inch of skin there lies 4 yards of nerve fibers, 1300 nerve cells, 100 sweat glands, 3 million cells, and 3 yards of blood vessels.

More Amazing Facts about cells The average adult is made up of 100 trillion cells. We give birth to 100 billion red blood cells every day and about two million red blood cells every second.

simple microscope (only one lens) compound microscope cork simple microscope (only one lens) drops of lake water, scrapings from teeth and gums, and water from rain gutters