1. UNIT 3: CELLS STANDARD: SL74

2. UNIT 3: CELLS S7L2. Students will describe the structure and function of cells, tissues, organs, and organ systems. – a. Explain that cells take in nutrients in order to grow and divide and to make needed materials. – b. Relate cell structures (cell membrane, nucleus, cytoplasm, chloroplasts, mitochondria) to basic cell functions. – c. Explain that cells are organized into tissues, tissues into organs, organs into systems, and systems into organisms.

3. EQ: What do we need to know about cells? Cells take in nutrients to grow, divide, and make needed materials. Cells are the basic units of structure and function in living things. Organelles are tiny cell structures that carry out a specific function within the cell. – Nucleus – Cell membrane – Mitochondria – Chloroplasts – Cytoplasm

4. Animal vs. Plant Cells

5. What makes up a cell? MOLECULES: Water – 90% Protein – 5% Carbohydrate – 1.5% Nucleic Acid – 1.5% Lipid – 1% Other – 1% ELEMENTS: Oxygen – 63% Carbon – 20% Hydrogen – 10% Other – 4% Nitrogen – 3%

6. CELL THEORY 1.All living things are composed of cells 2.Cells are the basic units of structure and function in living things 3.All cells are produced from other cells

7. Cell Organelles: THE BIG 5 Nucleus – The control center of the cell that directs the cells activities.

8. Cell Organelles: THE BIG 5 Cell membrane – The outer layer of the cell that controls the movement of dissolved molecules into and out of the cell

9. Cell Organelles: THE BIG 5 Cytoplasm – The large, fluid-filled space in the cell. It is a gel-like substance that surrounds and supports the organelles outside the nucleus.

10. Cell Organelles: THE BIG 5 Mitochondria – Rod-shaped, convert chemical energy in food molecules to energy the cell can use to carry out functions.

11. Cell Organelles: THE BIG 5 Chloroplasts – Found in plant cells, captures energy from sunlight and uses it to produce food during photosynthesis. Chlorophyll is a pigment in chloroplasts that absorbs the energy in sunlight. Chlorophyll gives plants their green color.

12. Cell Organelles Cell wall – Found in plant cells, a rigid layer of nonliving material that surrounds the cells of plants and some other organisms. It provides strength & support to the cell.

13. Enzymes Are Important! – Enzymes are proteins that form part of the cell membrane and make up many of the organelles within the cell. – Enzymes are important because they speed up chemical reactions. – For example, enzymes in your saliva speed up the digestion of food by breaking down starches into sugars in your mouth.

14. PHOTOSYNTHESIS – The process in which some organisms use water along with sunlight & carbon dioxide to make their own food – Plants change carbon dioxide from the air and water into food in the form of sugars (glucose) where energy is stored – During this chemical reaction, oxygen is released

15. CELLULAR RESPIRATION – The process by which cells break down simple food molecules to release the energy they contain – Cells change oxygen and glucose (sugar) into carbon dioxide and water – During this chemical reaction, energy is released – PHOTOSYNTHESIS & CELLULAR RESPIRATION ARE…

16. ...OPPOSITE PROCESSES…A CYCLE!

17. FERMENTATION – The process by which cells break down molecules to release energy without using oxygen – One type occurs in muscle cells after strenuous activity Lactic acid fermentation – Another type occurs in yeast Alcoholic fermentation

18. The Cell in its Environment – Selectively Permeable: some substances can pass through the cell membrane while others can not. – Diffusion: moving from an area of HIGH concentration to an area of LOW concentration – Homeostasis: The maintenance of stable internal conditions no matter what is going on outside the cell

19. The Cell in its Environment – Osmosis: diffusion of water molecules through a selectively permeable membrane – Active Transport: movement of material through the cell membrane USING cell energy – Passive Transport: movement of material through the cell membrane NOT USING cell energy

20. Endocytosis vs. Exocytosis – Endocytosis : How a cell takes IN material by forming a pocket called a vesicle around the particle and pulling the material into the cell. – Exocytosis: How a cell removes material in a similar way. Materials EXIT the cell.

21. MITOSIS…Time to Grow! – The process in which body cells divide into two new cells, one copy of the DNA is distributed into each daughter cell.

22. MEIOSIS…Reproduction – The process that occurs in the formation of sex cells (sperm & egg) by which the number of chromosomes is reduced by half.

23. Cell Tissue Organ Organ System Organism

24. Cell The smallest unit of a living thing that can perform the functions of life; has an orderly structure and contains genetic material (example – animal cell).

25. Cell Organization Cells are often organized into tissues, organs, organ systems, and organisms. – Tissue: a group of similar cells that work together to perform a specific function Ex: Your brain is made mostly of nervous tissue, which consists of nerve cells.

26. Tissue A group of similar cells that work together to do one job (example – muscle).

27. Cell Organization Cells are often organized into tissues, organs, organ systems, and organisms. – Organ: is made up of different kinds of tissues that function together Ex: Your brain is made mostly of nervous tissues that function together.

28. Organ A structure made up of two or more different types of tissues that work together (example – heart).

29. Cell Organization Cells are often organized into tissues, organs, organ systems, and organisms. – Organ System: a group of organs that work together to perform a major function. Ex: Your brain is part of your nervous system, which is an organ system that directs body activities and processes.

30. Organ System A group of organs working together to perform a certain function (example – cardiovascular system).

31. Cell Organization Cells are often organized into tissues, organs, organ systems, and organisms. – Organisms: a group of organ systems working Ex: A human is an organism made up of several organ systems (nervous system, skeletal system, respiratory system, etc.)

32. Organism Any living thing that uses energy, is made of cells, reproduces, responds, grows, and develops (example – human).