Cells

1. Cells

3. Henrietta Lacks Read pages 31 to 33 Questions 1. What is Henrietta in the hospital for? 2. They ask Henrietta to sign something for permission to do anything. Is there anything wrong with this in your opinion? 3. What do you think they are going to with her cells.

4. Why are cells important? 1. You are made of cells!! 2. If you can understand your cells, you can understand your body. 3. All diseases/illness originates at a cellular level. 4. If you’re an athlete, your cells have to work together to make you run/jump. If you feed your cells right, and practice right, maybe you can become a better athlete. THIS HAPPENS IN YOUR CELLS!

5. Today, if you could pile all HeLa cells ever grown onto a scale, they'd weigh more than 50 million metric tons — more than 100 Empire State Buildings. People have made millions and millions of dollars off of these cells. Henrietta and her family have never received any compensation.

6. Who helped in cell Theory Development? • Schleiden- all plants are made of cells • Schwann – all animals are made of cells • Virchow – new cells come only from existing cells

7. And then the Cell Theory • All living things are composed of cells • The cell is the basic unit of life • New cells come from preexisting cells

8. How are cells organized into organisms? Atoms  molecules  organelles  cells tissues  organs  organ systems  organisms

9. So…How big are cells? • Cells are small because they are able to function better at a smaller size • The larger the cell, the smaller the surface area to volume ratio. It takes longer to get food and gases to the inside of a large cell • The average cells range in size from 2 micrometers to 200 micrometers

11. What are two main groups of Cells? • Prokaryotic – has no nucleus or membrane organelles ( this does not include organelles that don’t have a membrane) • Eukaryotic- cell has a nucleus and membrane bound organelles

12. What are the key structural features? • Cell membrane ( plasma membrane) – surrounds all cells and controls what enters and leaves • Cell wall – For some cells this provides added support. Plants, fungi, bacteria • Cytoplasm ( cytosol) – jelly like fluid that everything floats around in.Moves by a process called cyclosis • http://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artnov00/dwelodea.html

13. What are the key organelles and how do they function • Nucleus – contains DNA, controls the cell • Mitochondria – Makes energy in the form of ATP • Endoplasmic Reticulum – transports proteins and fats • Ribosomes – Site of protein synthesis

14. What are the key structural features? • Lysosomes – digests food and old organelles • Chloroplast – converts light energy into food • Chromatin- the material eukaryote chromosomes are composed. It consists of protein, RNA, and DNA.

15. More organelles • Golgi apparatus – packages protein to leave the cell • Vacuoles – storage of water and food • Cilia /flagella – short hair-like structures that allow movement. Some eukaryotic and prokaryotic cells have flagella • Cytoskeleton – thread that run through the cytoplasm and give support and/or motion

17. Prokaryotic vs Eukaryotic

18. Eukaryotic Cell DNA in nucleus Ribosomes may be free or bound to ER May have cell wall of cellulose (Plants) Cell Membrane Cytoplasm No pili differences between prokaryotic and eukaryotic cells Prokaryotic cell • DNA is free floating • NO nucleus! • Ribosomes are all free • Cell wall ( peptidoglycan) • Cell Membrane • Cytoplasm • Pili ( look like cilia)

20. What’s the difference between a cell wall and a cell membrane?

21. Compare prokaryotic and eukaryotic cells using your notes.

22. What do prokaryotic and eukaryotic cells both have? Why do you think this is?

23. Plant Cell wall of cellulose Plasma membrane Chloroplastsand other plastids Large vacuole No centrioles Animal No cell wall Plasma membrane No plastids Vacuoles are small when present centrioles Differences between Plant and Animal Cells

25. Cell Specialization

26. Unicellular – One Cell • A unicellular organism is a living thing that is just one cell. • There are different types of unicellular organism, including: • bacteria • protozoa • unicellular fungi

27. Multicellular – many cells • A multicellular organism is a living thing that consists of more than one cell. • Examples: • Eukaryotes (plants & animals) • Multicellular fungi

28. Multicellular Organisms • Have three characteristics: 1. Can be seen with the naked eye. 2. Are specialized 3. Able to communicate

29. All cells within an organism start out the same way as stem cells. • The DNA inside each cell is identical. • The DNA tells every cell what type of cell to become and makes special proteins to the job it is told to do.

30. Types of Specialized Cells Sperm Cells • Function: to reach female egg cells and fertilize it. • Special Structures: • Long flagella for swimming

31. Specialized Cells Continued Skin Cells • Function: Provides our bodies protection from outside pathogens, allows for sensation, and thermoregulation • Special Structures: • Never stop dividing • Forms many layers

32. Specialized Cells Continued Red Blood Cells • Function: to carry oxygen • Special Structures: • Large surface area for oxygen to pass through • Contains hemoglobin which joins with the oxygen • Does not contain a nucleus

33. Specialized Cells Continued White Blood Cells • Function: to protect the body against disease and foreign invaders. • There are different types of white bloods cells that are specialized for different immune responses. • Special Structures: • Lack hemoglobin but have a nucleus • Have granules that contain enzymes that damage or digest pathogens and release inflammatory mediators into the bloodstream

34. Specialized Cells Continued Muscle Cells (There are 3 types: cardiac, smooth, and skeletal) • Function: enables body parts to move, exert forces, or change shape • Special Structures: • Are long and thin in structure to allow for contracting and extending • Branching pattern increases strength • High concentration of mitochondria to supply energy required to change shape.

35. Specialized Cells Continued Nerve Cells • Function: to carry nerve impulses to different parts of the body. • Special Structures: • Long connections at each end • Can carry electrical signals

36. Basic compound light microscope Magnifies about 400x’s Can be used for living or dead specimens Light shines up through the base Dissecting microscopes are like light microscopes but you get a 3-D image Used for whole specimens and large specimen Magnificant is poor VIEWING CELLS - The light microscope

37. Transition electron microscopes ( TEM) Shoot a beam of electrons through the specimen to make a picture Magnifies Scanning electron microscopes ( SEM) Shoot a beam of electrons across the surface giving a 3-D picture Magnifies The Electron Microscopes Both SEM and TEM can only be used for dead specimens

39. TEM

40. SEM

41. Cell Variety and Specialization • In organisms cells are often specifically shaped and sized for their function • The may need to support, to transport, to transmit a signal or to pick up information from the surrounding • Cells can become specialized as different genes are turned on/off in different kinds of cells.