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Chapter 4, part B. Functional Anatomy of Prokaryotic and Eukaryotic Cells. Plasma Membrane. Functions for membranes Selective permeability allows passage of some molecules Movement through the membrane Active - requires energy Passive - no energy involved Enzymes for ATP production
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Chapter 4, part B Functional Anatomy of Prokaryotic and Eukaryotic Cells
Plasma Membrane • Functions for membranes • Selective permeability allows passage of some molecules • Movement through the membrane • Active - requires energy • Passive - no energy involved • Enzymes for ATP production • Photosynthetic pigments on foldings called chromatophores or thylakoids
Plasma Membrane • Damage to the membrane by alcohols, quaternary ammonium (detergents) and polymyxin antibiotics causes leakage of cell contents.
Movement Across Membranes Passive Transport Diffusion and Osmosis • Simple diffusion: Movement of a solute from an area of high concentration to an area of low concentration. • Facilitative diffusion: Solute combines with a transporter protein in the membrane.
Movement Across Membranes Figure 4.17
Movement Across Membranes • Osmosis • Movement of water across a selectively permeable membrane from an area of high water concentration to an area of lower water. • Osmotic pressure • The pressure needed to stop the movement of water across the membrane. Figure 4.18a
Movement Across Membranes • Active transport of substances requires a transporter protein and ATP. • Group translocation of substances requires a transporter protein and PEP.
Cytoplasm • Cytoplasm is the substance inside the plasma membrane Figure 4.6a, b
Nuclear Area • Nuclear area (nucleoid) Figure 4.6a, b
Ribosomes Figure 4.6a
Ribosomes 50S and 30S subunits making a 70S ribosome Composed of RNA and protein Figure 4.19
Inclusions • Phosphate reserves • Energy reserves • Energy reserves • Energy reserves • Ribulose 1,5-diphosphate carboxylase for CO2 fixation • Protein covered cylinders • Iron oxide (destroys H2O2) • Metachromatic granules (volutin) • Polysaccharide granules • Lipid inclusions • Sulfur granules • Carboxysomes • Gas vacuoles • Magnetosomes
Endospores • Resting cells • Resistant to desiccation, heat, chemicals • Bacillus, Clostridium • Sporulation: Endospore formation • Germination: Return to vegetative state
Eukaryotic Cells • Comparing Prokaryotic and Eukaryotic Cells • Prokaryote comes from the Greek words for pre-nucleus. • Eukaryote comes from the Greek words for true nucleus.
Flagella and Cilia Figure 4.23a, b
Eukaryotic Flagella • Microtubules • Tubulin • 9 pairs + 2 arrangements Figure 4.23c
Cell Wall • Cell wall • Plants, algae, fungi • Carbohydrates • Cellulose, chitin, glucan, mannan • Glycocalyx • Carbohydrates extending from animal plasma membrane • Bonded to proteins and lipids in membrane
Plasma Membrane • Phospholipid bilayer • Peripheral proteins • Integral proteins • Transmembrane proteins • Sterols • Glycocalyx carbohydrates
Plasma Membrane • Selective permeability allows passage of some molecules • Simple diffusion • Facilitative diffusion • Osmosis • Active transport • Endocytosis • Phagocytosis: Pseudopods extend and engulf particles • Pinocytosis: Membrane folds inward bringing in fluid and dissolved substances
Eukaryotic Cell • Cytoplasm Substance inside plasma membrane and outside nucleus • Cytosol Fluid portion of cytoplasm • Cytoskeleton Microfilaments, intermediate filaments, microtubules • Cytoplasmic streaming Movement of cytoplasm throughout cells
Organelles • Membrane-bound: • Nucleus Contains chromosomes • ER Transport network • Golgi complex Membrane formation and secretion • Lysosome Digestive enzymes • Vacuole Brings food into cells and provides support • Mitochondrion Cellular respiration • Chloroplast Photosynthesis • Peroxisome Oxidation of fatty acids; destroys H2O2
Eukaryotic Cell • Not membrane-bound: • Ribosome Protein synthesis • Centrosome Consists of protein fibers and centrioles • Centriole Mitotic spindle formation
Nucleus Figure 4.24
Endoplasmic Reticulum Figure 4.25
Ribosomes • 80S • Membrane-bound Attached to ER • Free In cytoplasm • 70S • In chloroplasts and mitochondria
Golgi Complex Figure 4.26
Lysosomes Figure 4.22b
Vacuoles Figure 4.22b
Mitochondrion Figure 4.27
Chloroplast Figure 4.28
Endosymbiotic Theory http://www.sumanasinc.com/webcontent/anisamples/nonmajorsbiology/organelles.html Figure 10.2