MONTGOMERY COUNTY COMMUNITY COLLEGE BIO 140 CHAPTER 4 Functional Anatomy of Prokaryotic and Eukaryotic Cells I. PROKARYOTES A. Structure Of The Cell: Chemical Composition And Function 1. Cell Wall a. composition Peptidoglycan Two organic compounds and 1) rigidity/shape 2) chemically resistant 3) 4) 5) 2. Glycoccalyx (capsule) a. composition a complex polysaccharide 1) 2) 3) c. slime layer similar to capsule but more diffuse d. examples of organisms with glycoccalyx P:\sci\je\Review-Chapter 4 1
3. Cell Membrane (Plasma Membrane) a. composition phospholipids and proteins 1) encloses the cytoplasm 2) ATP 3) semi-permeable: allows transport of molecules in and out of the cell 4) Bacterial Transport Mechanisms 1. Passive Transport with the concentration gradient 2) Facilitated Transport with the concentration gradient 3) Activated Transport against the concentration gradient 4) Group Translocation 4. Genome (chromosome (DNA) not a true nucleus sine the DNA is not enclosed in a nuclear membrane double stranded (ds) circular, one large molecule a. composition DNA nucleotides A-T and G-C The Brain of the cell P:\sci\je\Review-Chapter 4 2
5. RNA a. composition RNA nucleotides A-U and G-C 1) mrna 2) rrna 3) trna 6. Ribosomes a. composition protein 7. Flagella a. composition protein and sometimes carbohydrates 8. Fimbriae a. composition protein 9. Plasmids a. composition DNA nucleotides, double-stranded, circular consist of 4 or 5 total genes extra chromosomal code for P:\sci\je\Review-Chapter 4 3
10. Pili a. composition protein 1) attach to other bacteria 2) conjugate and transfer genetic material ( ) from one cell to another 11. Endospores Most resistant form of microbial life a. composition all components of a Gram positive bacterial cell surrounded by a very thick outer protein coat (spore coat) P:\sci\je\Review-Chapter 4 4
GRAM REACTION PEPTIDOGLYCAN LAYER RETAIN CRYSTAL VIOLET DYE AND STAIN DARK VIOLET OR PURPLE THICK (MULTI-LAYERED) CAN BE DECOLORIZED TO ACCEPT COUNTERSTAIN (SAFRANIN) STAINS PINK THIN (SINGLE-LAYERED) TEICHOIC ACIDS PRESENT IN MANY ABSENT PERIPLASMIC SPACE ABSENT PRESENT OUTER MEMBRANE ABSENT PRESENT LIPOPOLYSACCHARIDE (LPS) CONTENT NONE HIGH LIPID AND LIPOPROTEIN CONTENT LOW (Except AFB s) HIGH (LPS) TOXINS PRODUCED EXOTOXINS PRIMARILY ENDOTOXINS (LPS) RESISTANCE TO PHYSICAL DISRUPTION HIGH LOW RESISTANCE TO DRYING HIGH LOW CELL WALL DISRUPTION BY LYSOZYME HIGH LOW OUTER MEMBRANE SUSCEPTIBILITY TO PENICILLIN HIGH LOW P:\sci\je\Review-Chapter 4 5
DIAGRAM OF THE MAJOR PROKARYOTIC CELL COMPONENTS P:\sci\je\Review-Chapter 4 6
B. Characteristics Of Prokaryotes 1. Division Binary Fission a. b. 2. Generation Time The length of time required for cells to replicate. Example: E. coli S. aureus 3. Differences between gram positive and Gram negative bacteria. Refer to chart. II. EUKARYOTES A. Structure Of The Cell: Chemical Composition And Function 1. Cell Wall a. composition polysaccharides (if present) 1) 2) 2. Gycoccalyx (capsule) a. composition polysaccharides 1) 2) P:\sci\je\Review-Chapter 4 7
3. Cell Membrane Often outermost layer of cell a. composition phospholipids and proteins Transportation 1) 2) 3) Other Functions 1) 2) 4. Genome (chromosome) DNA double stranded, linear a. composition 5. RNA a. composition 6. Ribosomes a. composition proteins and rrna 7. Flagella Cilia Pseudopods a. function P:\sci\je\Review-Chapter 4 8
8. Adherence structures (See text) a. Fungi b. Protozoa c. Helminths 9. Resistant/Resting Cells a. Fungi b. Protozoa c. Helminths 10. Organelles a. Mitochondria contain DNA, 70S ribosomes, enzymes and reproduce by binary fission Function b. ER (Endoplasmic Reticulum) Function c. Golgi Complex Function P:\sci\je\Review-Chapter 4 9
DIAGRAM OF THE MAIN STRUCTURAL COMPONENTS OF A EUKARYOTIC CELL P:\sci\je\Review-Chapter 4 10
B. Characteristics Of Eukaryotes 1. Division a. Mitosis b. Meiosis 2. Generation Time see prokaryote Bigger than prokaryote; therefore takes longer than a bacteria (usually) Example: Protozoa III. THE ENDOSYMBIOTIC THEORY 1981 DR. MARGULIS (BOSTON) P:\sci\je\Review-Chapter 4 11
WORKSHEET (To be completed by the student) Compare and Contrast Prokaryotes and Eukaryotes 1. Cell Size 2. Cell Wall 3. Cell Membrane 4. DNA 5. Ribosomes 6. Generation Time 7. Organelles 8. Reproduction 9. Gycocalyx 10. ATP Storage P:\sci\je\Review-Chapter 4 12