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A TOUR OF THE CELL. CHAPTER 6. THE CELL THEORY. All living things are composed of cells and cell products or that the organism is unicellular. All true life is cellular. All cells come from preexisting cells through some type of cell division, usually mitotic. 2 Main Types of Cells.
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A TOUR OF THE CELL CHAPTER 6
THE CELL THEORY • All living things are composed of cells and cell products or that the organism is unicellular. • All true life is cellular. • All cells come from preexisting cells through some type of cell division, usually mitotic.
2 Main Types of Cells PROKARYOTIC vs. EUKARYOTIC • ProkaryotesEukaryotes • 1. No Nuclear Membrane 1. Nuclear Membrane • 2. Circular of DNA 2. Linear DNA, Many • 3. No Membrane-Bound 3. Membrane Bound Organelles • Organelles • 4. No Histones 4. Histones • 5. Unique Ribosomes 5. Ribosomes Different • 6. No Endoplasmic Reticulum 6. Endoplasmic Reticulum • 7. 2 to 10 μm 7. 10 to 100 μm • Kingdoms Archaebacteria 8. Other Kingdoms: Protista, • and Eubacteria Plantae, Fungi, Animalia
SIMILARITIES Prokaryotes and Eukaryotes • Ribosomes (therefore, make proteins) • Cell membrane • Cytoplasm • All 8 of the characteristics of living things • Cells, Evolve, Homeostasis, Energy, DNA, Respond to environment, Grow and Develop, Reproduce • Can have cilia/flagella; therefore, have some sort of cytoskeleton
Animal Cell No Cell Wall No Central Vacuole No Plastids Centrioles Lysosomes 2 Types of (many) Eukaryotes PLANT CELLS vs. ANIMAL CELLS • Plant Cell • Cell Wall • Central Vacuole • Plastids • No Centrioles • (No Lysosomes) Similarities – All other major organelles, ribosomes, cell membrane, cytoplasm, cytoskeleton, etc.
ANIMAL CELL ELECTRON MICROGRAPH Nucleus Membrane Cytoplasm Endoplasmic Reticulum
PLANT CELL ELECTRON MICROGRAPH Wall Nucleus Vacuole
ENDOMEMBRANE SYSTEM • Nuclear Envelope • Endoplasmic Reticulum • Golgi Apparatus • Lysosomes • Vacuoles • Plasma Membrane
NUCLEUS – only eukaryotes • Average 5 μm in diameter (lgst organelle) • Nuclear Envelope (part of endomembrane system) • Nuclear pores • Nucleus contains?? • Function
Nuclear Pore NUCLEUSELECTRON MICROGRAPH Chromatin Nucleolus Nucleus Nuclear Envelope
ROUGH and SMOOTH ER STRUCTURE • Membrane Network • Sacs (AKA cisternae) • reservoir for liquids • Cisternal Space (AKA lumen) • Internal cavity of the ER (away from cytosol)
ROUGH ER FUNCTIONS • Contain Ribosomes; therefore??? • Ship the products to Golgi
ROUGH ER . Ribosomes Paired Membranes
SMOOTH ER FUNCTIONS • Lipid Synthesis • Carbohydrate Metabolism • Detoxification • Ca+ Storage • Ship products to Golgi
Smooth ER Mitochondria - No Ribosomes SMOOTH ER
GOLGI APPARATUS • Flattened Membranous Sacs • cis face - Forming Face – vesicles fuse from ER • trans face - Maturing Face – vesicle pinch off to other parts of cell • Functions???
cis – from ER trans – to rest of cell
GOLGI COMPLEX Golgi
LYSOSOME • Membrane Bound Sac that contains?? • Functions • Digestion of food • Recycle cell parts • Programmed cell destruction • Human Disease due to mutations in lysosomes • Storage Diseases • Arthritis • Aging • Tay-Sachs
VACUOLE • Types • Food Vacuoles – contain carbs, lipids • Contractile Vacuoles – pump excess water out(usually freshwater protists) • Central Vacuole – lg vacuole (only plants) for storage • Surrounded by “tonoplast,” a membrane (see pic in 2 slides) • Functions • Storage • Cell Growth • Sequester Dangerous Metabolites • Pigments • Protection From Predators
VACUOLES Contractile Vacuole Contractile Vacuole Food Vacuole
PLANT CELL VACUOLE Tonoplast Tonoplast – membrane surrounding central vacuole in plant cells
PLASMA MEMBRANE • Structure • Phospholipid bi-layer with imbedded proteins, carbs, cholesterol • Only proteins and phospholipids in all membrane-bound organelles and plasma membrane • Functions • Movement of materials across the membrane • Creates enclosed unique environments • Different pH, compositions, etc. • Provides surface for the attachment of enzymes • Involved in many cell-to-cell interactions
how animal cells are connected…. tight junctions desmosomes gap junction via connexons
MITOCHONDRIA • Structure • Inner and Outer Membranes • Intermembrane Space • Matrix • Cristae • Function? You do NOT need to know cell respirations steps yet
MITOCHONDRIA Mitochondria Matrix Cristae
PEROXISOMES • Surrounded by membrane • Functions • Make peroxides combining extra H and O from fatty acids or other molecules needed for CR in mitochondria • Breakdown H2O2 (peroxide) to H2O b/c H2O2 is toxic to cells • Such as Catalase from your enzyme lab with yeast
PLASTIDS – plants and many plant-like organisms • Serve many different functions • Several different types • Proplastids - Small, often colorless, membrane sacs that can divide and can mature into functional plastids. • Chromoplast - Do not contain chlorophyll, are yellow, red, or orange. Provide color in fruit and some flowers. • Leucoplast - Colorless plastids, involved in food storage. • Amyloplast – contains amylose (a starch)
PLASTIDS - CHLOROPLAST • Structure • Double membrane bound with a third complex network of membranes, the thylakoids on the inside • Contain chlorophyll and other photosynthetic pigments • Function • Site of photosynthesis You do NOT need to know photosynthesis steps yet
CHLOROPLAST Stroma Grana Thylakoids
MICROTUBULES • Structure • Composed of 13 chains of a globular protein, tubulin. • 25 nm • Functions • Cell Shape • Flagella, cilia (cell motility) • Spindle fibers in cell division • Organelle movements
MICROFILAMENTS • Structure • 2 intertwined strands of actin polymers. • 7-10 nm • Functions • Cytoplasm streaming • Muscle contraction • Pseudopods (Cell motility) • Cleavage furrows in cell division • Cell shape changes and maintenance
INTERMEDIATE FILAMENTS • Structure • Super coiled fibrous proteins • 8-12 nm • Function • Anchors for nucleus and some organelles • Cell Shape • All of these are used for “cell motility” (AKA movement) and structure of the cell • Some actually serve as a highway for vesicles to follow to/from cell membrane
MICROTUBULES AND MICROFILAMENTS