* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Structure of Eukaryotic Cells
Survey
Document related concepts
Microtubule wikipedia , lookup
Cell growth wikipedia , lookup
Cell culture wikipedia , lookup
Lipid bilayer wikipedia , lookup
Cell encapsulation wikipedia , lookup
Cellular differentiation wikipedia , lookup
Extracellular matrix wikipedia , lookup
Organ-on-a-chip wikipedia , lookup
Model lipid bilayer wikipedia , lookup
Cytokinesis wikipedia , lookup
Cell membrane wikipedia , lookup
Signal transduction wikipedia , lookup
Cell nucleus wikipedia , lookup
Transcript
Cell Structure and Function Chapter 4 Cell Theory 1) Every organism is composed of one or more cells 2) Cell is smallest unit having properties of life 3) Continuity of life arises from growth and division of single cells Structure of Cells All start out life with: Two types: – Plasma membrane – Prokaryotic – Region where DNA is stored – Eukaryotic – Cytoplasm – Know table 4.2 Animal Cell Features • • • • • • • • Plasma membrane Nucleus Ribosomes Endoplasmic reticulum Golgi body Vesicles Mitochondria Cytoskeleton nuclear enevelope nucleolus NUCLEUS DNA + nucleoplasm microfilaments vesicle microtubules lysosome components of cytoskeleton rough ER ribosomes (attached to rough ER and free in cytoplasm) smooth ER plasma membrane vesicle Golgi body mitochondrion pair of centrioles Fig. 4.8b, p. 57 Lipid Bilayer • Main component of cell membranes • Gives the membrane its fluid properties • Two layers of phospholipids Bacteria Cells are unable to endocytose Membrane Proteins • Transport proteins • Receptor proteins • Recognition proteins • Adhesion proteins oligosaccharide cholesterol groups phospholipid EXTRACELLULAR ENVIRONMENT (cytoskeletal proteins beneatch ADHESION the plasma PROTEIN membrane) open gated channel channel protein proten (open) gated channel proten (closed) (area of enlargment) TRANSPORT PROTEINS active transport protein RECEPTOR PROTEIN LIPID BILAYER RECOGNITION PROTEIN CYTOPLASM PLASMA MEMBRANE Fig. 4.4, p. 53 Functions of Nucleus • Keeps the DNA molecules of eukaryotic cells separated from metabolic machinery of cytoplasm • Makes it easier to organize DNA and to copy it before parent cells divide into daughter cells Components of Nucleus Nuclear envelope Nucleoplasm Nucleolus Chromosome Chromatin Nuclear Envelope • Two outer membranes (lipid bilayers) • Innermost surface has DNA attachment sites • Pores span bilayer Nucleolus • • • • Dense mass of material in nucleus May be one or more Cluster of DNA and proteins Materials from which ribosomal subunits are built • Subunits must pass through nuclear pores to reach cytoplasm Chromatin • Cell’s collection of DNA and associated proteins • Chromosome is one DNA molecule and its associated proteins • Appearance changes as cell divides Components of Cytomembrane System Endoplasmic reticulum Golgi bodies Vesicles Endoplasmic Reticulum • In animal cells, continuous with nuclear membrane • Extends throughout cytoplasm • Two regions - rough and smooth Ribosome Cisterns Rough ER • Ribosomes on surface give it a rough appearance • Some polypeptide chains enter rough ER and are folded and modified • Cells that specialize in secreting proteins have lots of rough ER Smooth ER • No ribosomes on surface • Lipids assembled inside tubules • Synthesizes steroids, such as estrogen and testosterone. • inactivates wastes, toxic chemicals and drugs Golgi Bodies • Put finishing touches on proteins and lipids that arrive from ER • Package finished material for shipment to final destinations outside the cell. • Material arrives and leaves in vesicles Vesicles • Membranous sacs that move through the cytoplasm • Lysosomes • Peroxisomes Mitochondria • ATP-producing powerhouses • Double-membrane system • Carry out the most efficient energy-releasing reactions • These reactions require oxygen Cytoskeleton • Present in all eukaryotic cells • Basis for cell shape and internal organization • Allows organelle movement within cells and, in some cases, cell motility Cytoskeletal Elements intermediate filament microtubule microfilament Mechanisms of Movement • Length of microtubules or microfilaments can change • Parallel rows of microtubules or microfilaments actively slide in a specific direction • Microtubules or microfilaments can shunt organelles to different parts of cell