Cell Structure & Function

1. Cell Structure & Function http://koning.ecsu.ctstateu.edu/cell/cell.html

2. Definition of Cell A cell is the smallest unit that is capable of performing life functions.

3. Cell Theory: Importance of Cells • All living things are made up of cells 2) Cells are the smallest units in all living things 3) All cells come from existing cells through cell division

4. Examples of Cells Amoeba Proteus Plant Stem Bacteria Red Blood Cell Nerve Cell

5. Two Types of Cells Prokaryotic Eukaryotic

6. Prokaryotic • Single-celled organisms that DO NOT HAVE NUCLEUS • Nucleoid region • DNA/RNA floating freely inside cell (circular loop of DNA) • Do not have structures surrounded by membranes • Few internal structures • Ex: Bacteria

7. Parts of a Prokaryotic Cell • Nucleoid – Area where DNA or RNA is located. Not enclosed in a membrane like a nucleus. • Ribosomes – Small structures that use DNA or RNA instructions to produce proteins. • Pili – Hollow, hair-like structures that can be used to exchange genes. • Flagella – Spin to produce movement. • Cell membrane – Controls what leaves or enters the cell

8. Eukaryotic • Contain organelles surrounded by membranes • HAS A NUCLEUS • DNA in chains • Animals, plants, protists, fungus Plant Animal http://library.thinkquest.org/C004535/eukaryotic_cells.html

9. DIAGRAM ANSWERS Animal • Centrioles • Plasma Membrane • Peroxisomes • Mitochondria • Cytoskeleton • Lysosomes • Smooth Endoplasmic Reticulum 8) Golgi Apparatus 9) Vesicles 10) Ribosomes 11) Rough Endoplasmic Reticulum 12) Nucleus 13) Nucleolus 14) DNA

10. DIAGRAM ANSWERS Plant Cell • Smooth ER • Plasmodesmata • Mitochondria • Cell wall • Cell membrane • Cytoskeleton • Perioxisomes • Vacuole • Chloroplast • Ribosome • Rough ER • Golgi Apparatus • Vesicles • Nucleolus • Nucleus • DNA

11. Comparison of Eukaryotes and Prokaryotes

12. Cell Parts Organelles

13. Surrounding the Cell

14. Cell Membrane • Phospholipid double layer • Outer membrane of cell that controls movement in and out of the cell http://library.thinkquest.org/12413/structures.html

15. Cell Wall • Most commonly found in plant cells & bacteria • Supports & protects cells http://library.thinkquest.org/12413/structures.html

16. “Typical” Animal Cell http://web.jjay.cuny.edu/~acarpi/NSC/images/cell.gif

17. “Typical” Plant Cell http://waynesword.palomar.edu/images/plant3.gif

18. Inside the Cell

19. Nucleus • Contains genetic material - DNA • Directs cell activities • Separated from cytoplasm by nuclear membrane

20. Nuclear Membrane • Surrounds nucleus • Is made of two layers • Openings allow material to enter and leave nucleus http://library.thinkquest.org/12413/structures.html

21. Chromosomes • In the nucleus, DNA is packaged into structures called chromosomes • Made of DNA • Contain instructions for traits & characteristics http://library.thinkquest.org/12413/structures.html

22. Nucleolus • Inside nucleus, is a region called the nucleolus • Contains RNA to build proteins http://library.thinkquest.org/12413/structures.html

23. Organelles that build proteins • Ribosomes • Endoplasmic Reticulum • Golgi Apparatus

24. Ribosomes • Proteins are made (synthesized) on Ribosomes • Each cell contains thousands of ribosomes • Found floating throughout the cell or attached to the ER http://library.thinkquest.org/12413/structures.html

25. Endoplasmic Reticulum • Function: Produce proteins needed by the cell • Structure: huge membrane that is connected to the nuclear membrane. • There are two distinct regions of ER: • Smooth ER, which lacks ribosomes, breaks down toxins • Rough ER, with ribosomes studding its surface

26. Golgi Bodies • Protein 'packaging plant’ • Flattened membrane sacs with vesicles • Moves, sorts, packages, transports materials within cell • Move materials out of the cell • A typical path for a protein produced by the cell: • Rough ER → Golgi → Cell membrane → Released by cell

27. Organelles that Store, Clean up, and Support • Lysosomes • Vacuoles

28. Vacuoles • Membrane-bound sacs for storage • Vacuole contains water • LARGE vacuoles in plants • Help plants maintain shape • If empty: plants lose turgor pressure http://library.thinkquest.org/12413/structures.html

29. Lysosome • Digestive organelle for proteins, fats, and carbohydrates • Lysosomes break down old organelles • Cell breaks down if lysosome explodes http://library.thinkquest.org/12413/structures.html

30. Organelles that Capture and Release Energy: Mitochondria & Chloroplasts • All life requires energy • Organisms either can get their energy from sunlight via photosynthesis, or by eating other organisms via cell respiration • Photosynthesis occurs in chloroplasts. • Cell respiration occurs in mitochondria.

31. Mitochondria • Mitochondria are the power houses of the cell. • They convert the chemical energy stored in food into smaller molecules for the cell to use: What is the process??? http://library.thinkquest.org/12413/structures.html

32. Chloroplast • Usually found in plant cells • Contains green chlorophyll • FUNCTION: capture light energy and convert it to chemical energy http://library.thinkquest.org/12413/structures.html

33. Cytoplasm • Gel-like mixture • Surrounded by cell membrane • Contains hereditary material

34. Cell Specialization Not all cells are similar looking. Cells may have different sizes, structure, and function. Many cells have a specialized structure that enables them to better carry out their specific function.