Do Now

1. Do Now • What is an organelle? Name three examples of organelles? • What is the difference between a plant and animal cell?

2. Cell Structure and Functions

3. Recap • The human body is composed of atoms, molecules, cells, tissues, organs, and organ systems that have specific functions and interactions • Cells are the smallest unit of life that can function independently and perform all the necessary functions of life • Photosynthesis and cellular respiration are important processes by which energy is acquired and utilized by organisms

4. Goals and Objectives • 1. Students will understand that the cell is the smallest independent unit of life and that all living things, including themselves, are made up of cells. • 2. Students will understand that cells contain smaller units called organelles and will be able to explain the functions of some major organelles.

5. Nucleus • A membrane-enclosed organelle found in eukaryotic cells • Contains most of the cell’s genetic material • maintain the integrity of these genes and to control the activities of the cell by regulating gene expression • http://my.hrw.com/sh2/sh07_10/student/flash/visual_concepts/60051.htm

6. Nuclear Membrane • Surrounds the nucleus • Composed of two layers (double lipid bilayer) • Encloses the material in eukaryotic cells • Numerous openings for nuclear traffic • http://my.hrw.com/sh2/sh07_10/student/flash/visual_concepts/60055.htm

7. Nucleolus • Spherical shape • Visible when cell is not dividing • Contains RNA for protein manufacture

8. Centrioles • Paired cylindrical organelles near the nucleus • Composed of nine tubes, each with three tubules • Involved in cellular division • Lie at right angles to each other

9. Chloroplasts • An organelle found in plant cells • Contain green chlorophyll where photosynthesis takes place • http://my.hrw.com/sh2/sh07_10/student/flash/visual_concepts/60090.htm

10. Cytoskeleton • Composed of microtubules • Support cell and provides shape • Aids movement of material in and out of cell

11. Endoplasmic Reticulum • Tubular network fused to cellular membrane • Goes through cytoplasm onto cell membrane • Stores, separate, and serves as cell transport system • Smooth ER: lacks ribosomes • Rough ER: ribosomes embedded in surface • http://my.hrw.com/sh2/sh07_10/student/flash/visual_concepts/60061.htm

12. Golgi Apparatus • Protein “packaging plant” • A membrane structure found near the nucleus • Composed of numerous layers forming sacs • http://my.hrw.com/sh2/sh07_10/student/flash/visual_concepts/60062.htm

13. Lysosome • Contains digestive enzymes for breaking down proteins, lipids, and carbohydrates • Transports undigested material to cell membrane for removal • Vary in shape depending on process being carried out • Cell breaks down if lysosome explodes • http://my.hrw.com/sh2/sh07_10/student/flash/visual_concepts/60063.htm

14. Mitochondria • Second largest organelle with unique genetic structure. Known as the ‘power house’ of the cell • Is the cell organelle that is surrounded by two membranes and that is the site of cellular respiration, which produces ATP. • Energy-producing chemical reactions take place on cristae • Controls level of water and other materials in cell • Recycles and decomposes proteins, fats, and carbohydrates, and forms urea • http://my.hrw.com/sh2/sh07_10/student/flash/visual_concepts/60060.htm

15. Ribosomes • Each cell contains thousands of miniature 'protein factories‘ • Composes 25% of cell's mass • Stationary type: embedded in rough endoplasmic reticulum • Mobile type: injects proteins directly into cytoplasmhttp://my.hrw.com/sh2/sh07_10/student/flash/visual_concepts/60186.htm

16. Vacuoles • Membrane-bound sacs for storage, digestion, and waste removal • Contains water solution • Contractile vacuoles for water removal (in unicellular organisms) • http://my.hrw.com/sh2/sh07_10/student/flash/visual_concepts/60071.htm

17. Cell Wall • Most commonly found in plant cells • Extracellular structure surrounding plasma membrane • Primary cell wall: extremely elastic • Secondary cell wall: forms around primary cell wall after growth is complete • http://my.hrw.com/sh2/sh07_10/student/flash/visual_concepts/60068.htm

18. Plasma Membrane • Outer membrane of cell that controls cellular traffic • Contains proteins that span through the membrane and allow passage of materials • Proteins are surrounded by a phospholipid bi-layer

19. Exit Ticket • 1. (True or False) Some cells can survive with no nucleus. • 2. Which of these choices is not an organelle? • Endoplasmic Reticulum B. Mitochondria • C. Lung D. Lysosome • 3. Which of these organelles are involved in protein synthesis? • Lysosome B. Ribosome • Endoplasmic Reticulum D. None of the above • 4. (True or False) Plants have organelles that animals do not. • 5. All organelles are contained by the…

20. Answers • True, There are prokaryotic and eukaryotic cells. Prokaryotic cells have no organized nucleus. Eukaryotic cells have an organized nucleus and organelles. • A lung is not an organelle. A lung is an organ in your body. The other choices are all cell organelles. The endoplasmic reticulum is used to make proteins. Chloroplasts are found in plants and capture energy from the Sun. Mitochondria are the powerhouses of the cell, breaking down chemical bonds and releasing energy. • The endoplasmic reticulum is the cell organelle involved in protein synthesis. Ribosomes are also involved in making proteins but they are not considered to be cell organelles. • Plants have some organelles that are not found in animal-like cells. The main organelle that you will find in plant cells is the chloroplast. Chloroplasts are involved in the process of photosynthesis. • All of the organelles are found inside of the cell. If an object is inside of the cell, it is contained within the cell membrane. The nuclear envelope only surrounds the nucleus and thykaloids are a part of chloroplasts.