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BIOL 3340 . Chapter 3. Chapter 4 . Microbial Cell Structure Eucaryotes. Eucaryotic Cell Structure. membrane-delimited nuclei membrane-bound organelles that perform specific functions more structurally complex than procaryotic cell generally larger than procaryotic cell.
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BIOL 3340 Chapter 3
Chapter 4 Microbial Cell Structure Eucaryotes
Eucaryotic Cell Structure • membrane-delimited nuclei • membrane-bound organelles that perform specific functions • more structurally complex than procaryotic cell • generally larger than procaryotic cell
Eucaryotic Membranes • Includes: animal & plant cells, fungi & protists (protozoa & algae). • Have a true nucleus with DNA • DNA is enclosed in a membrane-bound nucleus • membrane-enclosed cell organelles
…Eucaryotic Membranes • the fluid mosaic model is based on eucaryotic membranes • They are enriched with lipids and proteins • They participate in a variety of cell processes such as cell movement and transduction
Cytoplasm • Many organelles of eucaryotic cells lie in the cytoplasmic matrix • The cytoplasmic matrix -vast network of interconnected filaments. • Filaments that form the cytoskeleton: microfilaments, microtubules, and intermediate filaments. • plays role in both cell shape and cell movement
..Cytoplasmic Matrix • Viscous aqueous suspension of proteins, nucleic acid, dissolved organic compounds, mineral salts • Network of protein fibers similar to the eukaryotic cytoskeleton. Cytoplasmic Inclusion Bodies: • granules of organic or inorganic material that are stockpiled by the cell for future use. • some are enclosed by a single-layered membrane
Microfilaments • minute protein filaments, 4 to 7 nm in diameter • scattered within cytoplasmic matrix or organized into networks and parallel arrays • composed of actin protein • involved in cell motion and shape changes
Microtubules • shaped like thin cylinders ~ 25 nm in diameter • composed of a- and b-tubulin • help maintain cell shape • involved with microfilaments in cell movements • participate in intracellular transport processes
…The Endoplasmic Reticulum • irregular network of branching and fusing membranous tubules and flattened sacs (cisternae – s.,cisterna). • rough ER • ribosomes attached • synthesis of secreted proteins by ER-associated ribosomes • smooth ER • devoid of ribosomes • synthesis of lipids by ER-associated enzymes
…The Endoplasmic Reticulum • The ribosomes -sites of synthesis of some proteins that it transports • transports proteins, lipids, and other materials within cell. • Ribosomes in the eukaryotic cytoplasm are larger than prokaryotic ribosomes • Ribosomes are also found within mitochondria and chloroplasts; the ribosomes of these organelles are very similar in structure & size to prokaryotic ribosomes
Mitochondria • site where ATP is generated by electron transport and oxidative phosphorylation
Chloroplasts • site of photosynthetic reactions
Nucleus Nucleus: • membrane-bound structure that houses genetic material of eucaryotic cell Chromatin • dense fibrous material within nucleus • contains DNA • condenses to form chromosomes during cell division
…Nucleus Nuclear envelope: • double membrane structure that delimits nucleus • penetrated by nuclear pores • pores allow materials to be transported into or out of nucleus Nucleolus: • important in ribosome synthesis
Other cell inclusions • Golgi bodies-involved in modification, packaging, and secretion of materials • Lysosomes- membrane-bound vesicles found in most eucaryotes • involved in intracellular digestion • Vacuoles-transport system
Reproduction Eucaryotes: • asexual reproduction • transverse fission • budding • spore production • sexual reproduction • involves union of compatible nuclei followed by formation of sexual spores
Bibliography • http://en.wikipedia.org/wiki/Scientific_method • https://files.kennesaw.edu/faculty/jhendrix/bio3340/home.html • Lecture PowerPoints Prescott’s Principles of Microbiology-Mc Graw Hill Co. • http://images.search.yahoo.com/search/images;_ylt=A0geu_aaKX5JiBkAeUBXNyoA?ei=UTF-8&p=rough%20endoplasmic%20reticulum&fr2=tab-web&fr=yfp-t-501-s