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Cell Theory

Cell theory and cell organells for rrb

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Sainath Reddy Gali
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16 views10 pages

Cell Theory

Cell theory and cell organells for rrb

Uploaded by

Sainath Reddy Gali
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
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11/15/2015 The History of Cells & the Cell Theory Discovery of Cells. 1665- Englsh Scientist, Robert Hooke, discovered cells while looking at a’thin sice of cork. He described the cells as tiny boxes or a honeycomb He thought that cells only existed in piants and fungi 1673- Used a handmade microscope to observe pond scum & discovered single-celled organisms He called them “animalcules” ~ He also observed blood cals from fish, birds, frogs, dogs, and humans ‘Therefore, it was known that cells are found in animals as well as plants 150-200 Year Gap??? Between the Hooke/Leuwenhoek discoveries ‘and the mid 19" century, very few cell theory advancements were made, ‘This is probably due to the widely accepted, traditional belief in Spontaneous Generation. Examples: Mice from dirty dothes/corn husks “Maggots from rotting meat Development of Cell Theory 1838. English Botanist, Matthias Schleiden, ‘concluded that all plant parts are made of cells 1838- German physiologist, Theodor Schwann, who wasa clase friend of Schleiden, stated that all animal tissues are composed of cells. 11/15/2015 Development of Cell Theory 1858- Rudolf Virchow, Russian physician, after extensive study of cellular pathology, concluded that cells must arise from 3 Basic Components of the Cell Theory 1. All organisms are composed of one or more cells. = (Schleiden & Schwann)(1938-39) 2. The cell is the basic unit of if in all living things. '=(Schleiden & Schwann)(1838-39) 3. All calls are produced by the division of preexisting cells. ‘= (Virchow)(1858) Theory Aset of statements or principles devised to explain a group of facts or phenomena, especially ‘one that has been repeatedly tested or is widely accepted and can be used to make predictions about natural phenomena. Modern Cell Theory DN Madern Cell Theory consists ofthe 3 basic components (of cell theory, plus 4 additional statements: '= 4. The cell pass information from cell to cell during cell division using DNA. 1=5. Allces have basically the same chemical ‘composition and metabolic activities. 1=6, Allcells have basically the same chemical & physiological functions-(movemert, digestion, etc) Cell activity depends on the actwities of structures Within the cell. (organelles, nudieus, plasma 1 Disease/Health/Medical Research ‘and Cures(AIDS, Cancer, Vaccines, ‘Cloning, Stam Call Research, etc.) membrane) How Has The Cell Theory Been Used? Character of Cells All Cells have common A structures hou ca sted in the Cel Tory Cal Membrane in are the basis for things such as: = Ribosomes = Cells contain DNA ‘=Found in the nucleus Cells are independent units of life 11/15/2015 need a host cell to reproduce + A vitus is very small compared to a cell + Like cells, viruses contain nucleic acids 11/15/2015 Characteristics of Eukaryotes ws has a nucleus ‘= can be single or multicellular ‘= have many organelles, Performing complex functions} / |= specialized to perform 1 specific functions = larger than prokaryotic cells ‘= Animals, plants, fungi and protists are made of eukaryotic cells Animal and Plant Cells Summary of Differences Both Have: =o ae == =" Anucleus en Ribosomes that make protein Tae aa cate | chee near Rough and smooth endoplasmic eotars loom evaratn reticulum eames Beam ST Teasanes as eR Golgi bodies ‘no cpskeiein “aiways has acyiosialnion Mitochondria a Cytoplasm ‘erahaion bana went | ahidons eeaale seam ‘Vacuoles that store food, water Pe and waste products. ) a iE Animal Cells |Animal cells cont. Do not have a cell wall Gan not make their own food Do not have a large vacuole Have many lysosomes Do not have chlornnlasts ‘Are more round shaped —— Have centrioles Use mitochondria to release eneray Have many Golgi bodies Have more extensive cytoskeleton than plant cells 11/15/2015 Eukaryotic Cell Organelles and Function ‘Nucleus ‘Nickname: “The Control Center” ‘= Function: holds the DNA = Paris: ucistus: dark spot the mide ofthe ‘nucleus that helps mate ribosomes ‘Nucleus - largest organelle; control center of the cel; consists of: ‘= Muctoar envelope - couble membrane structure containing pores = Nucteoli synthesize ribosomes = Chromatin - threadlike material composed ‘of DNA (genes) & proteins Note: during cell division, chromatin condenses to form chromosomes 11/15/2015 ytoplasm Consists of: ytosol~ liquid potion Organelies ~ secielized cellar compartments Inclusions chemical substances |= Gycogen (muscle & wer cells) “+ Up droplets (rat cells) ‘+ Melanin granules (kin & hair els) = Function: Energy formation ‘Breaks down food to make ATP. ~~ ATE: isthe mar fa fr all cl actives that Featie energy = Mitochondria- double ‘membrane structures; site Of cellular respiration (ATP synthesis) = Contain their own DNA & RNA © Able to replicate themselves Ribosomes ‘= Function: makes proteins ‘= Found in all cells, prokaryctic and eukaryotic Ribosomes ~ dense particles of rRNA and protein ‘Free ribosomes — synthesize proteins that function within the cell ‘= Aitached nbosomes ~ synthesize proteins incorporated into cell membranes or exported outside the cell 11/15/2015 Cytoskeleton — network of rods that support the cell ‘= Microtubules - thick rods composed of ‘tubulin form cla, Nagel & centrioles Microfilaments thin filaments composed of actin Invaved in muscle contraction orm cleavage furrow dung cel distor Intermediate filaments - tough proten fibers attached to desmosomes Hm cece, WSsys = Centrioles - paired cylindrical bodies ‘composed of microtubules ‘= Organize spindle apparatus (cel division) Cellular extensions Miccovill: fingerike ‘projections of the plasma membrane: increase suface ‘ares for abserption Gilg short hair-like projections: propel Substances over surface of cel Flagelta: tong hair-like projections: propel the cell ‘= Function: The internal deiivery system of the cel Endoplasmic Reticulum = 2 Types: Rough ER: “Rough appearance because It has ribosomes Function: helps make proteins, that’s why it as nbocomes ‘Smooth ER: NO ribosomes function’ make fats or lip 11/15/2015 Endoplasmic reticulum (ER) - extensve membrane system Recto 1 Shes of pens carey, ad is 2 Seraged! sythesoed mobcuesand mates 3 Tansporotnateras wenn the SR “4 Dwautkaton of drs or tes ‘Bough ER ~ studded with rbosames; abundant in secretory cells Smooth ER - ‘ree of ribosomes ‘Symthesizs lipids and steroids Detoniies drugs/poisons (iver cals) Stores calcum lone (muscle cell) Golgi Apparutus ‘= AKA Gola) Body or Golgi complex ‘= Nickname: The shippers ‘= Eundion: packages, modifies, and transports materials to afferent location inside/outside ofthe cell = Appearance: stack of pancakes = Golgi apparatus - stack of fattened ‘membranous sacs 1» Packages proteins for secretion from the call (exocytosis) = Packages proteins for incorporation into plasma membrane = Forms lysosomes 11/15/2015 Lysosomes: circular (but bigger than ribosomes) ‘= Nickname: “Clean-up Crews” ‘= Function: to bresk down food into particles the rest ofthe cell can use and to destroy old cels Lysosomes ~ membrarous sacs of hydrolytic: enzymes; sites of intracellular digestion 1 Primary lysosome Fxmed by Goll apparatus and active enzymes + Secondary lysoseme ysosone fused with damaged egance ‘Spee ensymes stated “Tle cemict okted Peroxisomes - membranous sacs of oxidase & catalase enzymes; detoxify aleohal & neutralize dangerous free radicals Plant Cells rs) Have a call wall and cell membranes Have a large vacuole unlike the animal cell which ‘only has small vacuoles Have mitochondria to convert sugar to usable ‘energy for the cell Have a few lysosomes ‘Are more rectangular in shape Have chloroplasts to carry out photosynthesis 1s Make sugar to store solar ene-gy Cell Membrane cel walt ‘= Function: stores water ‘This is what makes lettuce cisp = When neste no water, he plant te 11/15/2015 Chloroplasts ‘= Function: traps energy from the sun to produce food for the plant cell ‘= Green in color because of chlorophyll, which isa green pigment Chloroplasts svete of Chioroplat (octal) provides support and protection to the cell membrane ‘= Found outside the cell membrane in plant cells 10

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