The Types of Cells

1. The Types of Cells

2. Two Basic Types of Cells • All living things fall into one of two categories of cells: • Prokaryotes (bacteria, simple cells) • (E. coli, Salmonella, Streptococcus, etc.) • Eukaryotes

3. Prokaryotes • Found everywhere (most numerous organisms on Earth) • Earliest forms of life • Unicellular • NO membrane-bound organelles • 99% are helpful… https://www.youtube.com/watch?v=eksagPy5tmQ • Food production • Digestion • Water purification • Decomposers • Oil spills Meningitis Pneumonia Staph aureus Gonorrhoeae

4. D. Shapes of Bacteria Shapes Prefixes 1. 1. = pair = sphere 2. 2. = rod = chain 3. 3. =spiral = bunch Images from: http://biology.clc.uc.edu/courses/bio106/bacteria.htm

5. Coccus (Spherical) Streptococcus Strep Throat

6. Bacillus (Rod) Escherichia coli(E. coli)

7. Bacillus anthracis Death from anthrax is due to oxygen depletion

8. Spirillum (Spiral) Cholera Intestinal infection caused by ingestion of contaminated food or water.

9. Prokaryotic Cell Structure

10. Prokaryotic Cell Structure • Nucleoid – the “nuclear” region of a prokaryotic cell where the DNA attaches to the plasma membrane

11. Prokaryotic Cell Structure • Plasmid – Circular DNA containing a few genes to help bacteria survive under some conditions.

12. Prokaryotic Cell Structure • Flagella – long, whiplike protein extensions that rotate like propellers, allowing cells to move (“swim”) through water or other fluids

13. Eukaryotic Cells • More complex than prokaryotes • Have many parts (organelles) that each have their own function • Advantageous, as each organelle can specialize and become more efficient • Compartmentalization

14. Eukaryotic Organelles • Nucleus: genetic control center • Contains chromosomes • Chromatin: Chromosomes attached to protein • Surrounded by a nuclear membrane • Main difference b/w prokaryotes & eukaryotes • Nucleolus: Area within the nucleus where RNA is synthesized • Appears most dense/darkest • Produces ribosomes

15. Nuclear Envelope Nucleus Nucleolus Animal cell Plant Cell Chromatin

16. Eukaryotic Organelles • Nuclear Envelope: Double membrane with thousands of nuclear pores • Surrounds the nucleus • Controls flow into and out of the nucleus

17. Eukaryotic Organelles • Endoplasmic Reticulum (ER): A system of membranous tubes & channels • Located just outside the nucleus • Two parts: • Smooth: No ribosomes • Functions: • Synthesis & transport of lipids • Detoxifies substances • Rough: Coated in ribosomes • Function: Protein synthesis & transport

19. RoughER Smooth ER Rough ER Smooth ER Animal cell Plant Cell

20. Eukaryotic Organelles • Ribosomes: Small bodies of RNA floating in the nucleus or attached to rough ER • Site of protein synthesis • Tiny, round objects • Found in both prokaryotic and eukaryotic cells

21. Animal cell Plant Cell Ribosomes

22. Eukaryotic Organelles • Golgi Apparatus: Stack of flattened membranous sacs/tubes • Located near the ER • Can break off sections to move around cell • Functions: • Sorts and modifies proteins • Packages materials in vesicles for use within the cell or export out of the cell

23. Animal Cell Plant Cell Golgi Apparatus

24. Eukaryotic Organelles • Mitochondrion: “power plant” of cell • Double-membraned organelle • Membranes separated by matrix • Cristae: folds of inner membrane • Major site of ATP synthesis

25. Animal cell Plant Cell

26. Eukaryotic Organelles • Chloroplast: Double-membrane organelle in plant cells • Site of photosynthesis • Captures solar energy, converts it to chemical energy • Large stacks of membranes containing green pigment chlorophyll • NOT IN ANIMAL CELLS

27. Chloroplasts Animal cell Plant Cell

28. Eukaryotic Organelles • Vacuole: Vesicles in a cell that store water & food (among some other substances) • Plants: Central Vacuole. Takes up most of volume • Give cells their rigidity, store waste products • Present in animals, but much smaller

29. Plant Cell Animal cell Vacuole

30. Eukaryotic Organelles • Lysosome: Vesicle in animal cells (rarely plants) that contains enzymes to digest food, nutrients, organelles, etc. • Causes cell suicide (apoptosis) Animal Cell Lysosome

31. Eukaryotic Organelles • Centriole: Tubular structures involved in cell division/reproduction • Animals only, NOT in plants • Near nucleus • Cytoskeleton: Network of protein fibers that help shape the cell • Can hold organelles in place or move them around • Found in animal and plant cells

32. cytoskeleton centrioles Animal cell

33. Eukaryotic Organelles • Cytoplasm (Cytosol): Gel-like substance that fills the cell in which the organelles are bathed • Found in ALL cells • Plasma (Cell) Membrane: Surrounds all cells • Phospholipid Bilayer • Responsible for letting substances into & out of the cell • Not a source of protection!!!

34. Plant Cell Animal cell CellMembrane

35. Eukaryotic Organelles • Cell Wall: A rigid structure that surrounds plant & fungal cells • NOT found in animal cells • Found in prokaryotic cells (similarity) • Surrounds plasma membrane • Protects the cell and helps maintain its shape • Composed of cellulose

36. Cell wall: Along the perimeter. Plant Cell Animal cell

37. Eukaryotic Organelles • Cilia: Tiny hair-like structures surrounding the cell membrane • Used for movement of the cell or moving material along a cell/tissue • Flagella: Found in eukaryotic sperm cells • Found in bacteria • NOT in plants

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