* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download cells - RIScienceTeachers
Survey
Document related concepts
Tissue engineering wikipedia , lookup
Biochemical switches in the cell cycle wikipedia , lookup
Cytoplasmic streaming wikipedia , lookup
Extracellular matrix wikipedia , lookup
Cell encapsulation wikipedia , lookup
Cell culture wikipedia , lookup
Cellular differentiation wikipedia , lookup
Cell growth wikipedia , lookup
Signal transduction wikipedia , lookup
Cell membrane wikipedia , lookup
Organ-on-a-chip wikipedia , lookup
Cell nucleus wikipedia , lookup
Cytokinesis wikipedia , lookup
Transcript
Cell Theory • All living things are composed of cells • Cells are the basic unit of structure and function in living things • All cells come from preexisting cells by way of: binary fission (prokaryotes) mitosis (eukaryotes) CELLS Prokaryote Eukaryote • 0.1-10 um • 10-100 um • No Nucleus • True Nucleus • Simple cellular structure • Complex organelle structure • 70s ribosomes • 80s ribosomes Prokaryotic Cells • Believed to be the first cells to evolve. • Lack a membrane bound nucleus and organelles. • Genetic material is naked in the cytoplasm • Ribosomes are only organelle. • Http.micro.magnet.fsu.edu/cells.html Eukaryote Cell Structure Cells vary greatly in size and shape Basic structure • Cell membrane: the outer boundary • Nucleus: the control center • Cytoplasm: the space in between membrane and nucleus Overview of an animal cell Overview of a plant cell NUCLEUS see fig 7.6 • Found only Eukaryotes • Nuclear envelope: double membrane with pores • Nucleolus: RNA & proteins - makes ribosomes • Chromosomes: (condensed chromatin) – DNA: (contains genetic information) – Histones: proteins that organize the DNA & provides structure for chromosomes NUCLEUS The nucleus and its envelope CYTOPLASM • Cytoplasm - area between nuclear membrane and cell membrane • Cytoplasmic organelles - tiny structures that perform a specific function within the cell MITOCHONDRIA • Double membrane -outer for protection -inner folded to increase surface area • Function: produces ATP from glucose • Contains DNA and 70S ribosomes MITOCHONDRIA CHLOROPLAST • Double membrane for protection • Third membrane turns radiant energy into chemical energy (glucose). The site of Photosynthesis • Contain DNA and 70S ribosomes CHLOROPLAST RIBOSOME • One of the smallest organelles • Can be "free" in the cytoplasm or attached to ER • Composed of RNA and protein • Function: Synthesize proteins • Eukaryotic – 80S / Prokaryotic – 70S RIBOSOME: functions in protein synthesis Ribosome Http://cellbio.utmb.edu/cellbio/ribosome.htm ENDOMEMBRANE SYSTEM System of interrelated membranes: some membranes are directly connected some are functionally connected. • • • • • • • Nucleus (nuclear envelope) Rough Endoplasmic Reticulum Smooth Endoplasmic Reticulum Golgi Apparatus Lysosome Vacuole Cell membrane aka plasma membrane Rough Endoplasmic Reticulum • complex network of sacs • Ribosomes are attached to the surface • Functions in protein synthesis and the modification of proteins destined for export • Modifies and Transports material throughout the inside of the cell Rough Endoplasmic Reticulum • Network of continuous sacs, studded with ribosomes. • Manufactures, processes, and transports proteins for export from cell. • Continuous with nuclear envelope. • Http://micro.magnet.fsu.edu/cels/animal/endoplasmi creticulum.html Rough Endoplasmic Reticulum Http://cellbio.utmb.edu/cellbio/ribosome.htm Smooth Endoplasmic Reticulum • Similar in appearance to rough ER, but without the ribosomes. • Involved in: • The production of lipids • Carbohydrate metabolism • Detoxification of drugs and poisons. • Modifies and Transports material throughout the inside of the cell • Http://micro.magnet.fsu.edu/cells/animals/endoplasmicreticulum.html GOLGI APPARATUS • Flattened membranous structure • Function: – Modify or “package” proteins for storage in the cell or secretion outside of the cell • Can be associated with the cell membrane Golgi Apparatus LYSOSOMES • Small membrane bound structures containing digestive enzymes & acids. • Produced by the Golgi • Function: breakdown of cellular material that has outlived its usefulness • Also involved in the breakdown (digestion) of lipids, carbohydrates, and proteins into small molecules that the rest of the cell can use. • Cell breaks down if lysosome explodes • NOT FOUND IN PLANTS The formation and functions of lysosomes Lysosome VACUOLES • Saclike structures • Function: store various materials, such as water, salts, proteins, carbohydrates • An example is the central vacuole in plants that provides structural support Central Vacuole CYTOSKELETON • The supporting structure that gives Eukaryotic cells their shape and internal organization. • Composed of: – Microtubules & Microfiliments MICROTUBULES AND MICROFILAMENTS MICROFILIMENTS Thin protein threads (actin) that run from one side of cell to the other Functions: • Provides a flexible framework that supports the cell • Allow movement of the cytoplasm (cytoplasmic streaming). Assembly and disassembly of microfiliments allows cells, such as amoebas, to crawl along surfaces. MICROFILIMENTS Provide the structure for the cytoskeleton MICROTUBULES Hollow tubes made of protein (tubulin) Functions: 1) Maintain cell shape 2) Involved in cell division (mitotic spindle) 3) Structure that makeup Centrioles, which help to organize cell division see fig. 7.6 4) Involved in cell movement (cilia and undulipodia) see fig. 7.11 (9+2 pattern in cilia) CENTRIOLES Centrioles: act as “anchors” for the mitotic spindle during cell division found only in animal cells not found in plant cells CILIA • Cilia: short hair-like projections that allow movement of a cell or material near a cell CILIA on a PARAMECIUM UNDULIPODIA • Extra cellular projections • Involved in cell propulsion • Eukaryotic Undulipodia-composed of 9 pairs of microtubules around a central pair CILIA & UNDULIPODIA (FLAGELLA) CELL SPECIALIZATION • Some cells are designed to perform a particular function • They may have more or less of a particular organelle based on their special needs i.e. • pancreatic cells- lots of rough ER and Golgi THE END