* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Cell - Clayton School District
Survey
Document related concepts
Cytoplasmic streaming wikipedia , lookup
Tissue engineering wikipedia , lookup
Signal transduction wikipedia , lookup
Cell membrane wikipedia , lookup
Extracellular matrix wikipedia , lookup
Cell encapsulation wikipedia , lookup
Cellular differentiation wikipedia , lookup
Cell culture wikipedia , lookup
Cell growth wikipedia , lookup
Cell nucleus wikipedia , lookup
Organ-on-a-chip wikipedia , lookup
Cytokinesis wikipedia , lookup
Transcript
Cell Theory & Cell Parts Proposed after hundreds of years of microscopy ◦ In 1665 Robert Hooke discovered cells in Cork (wood). Saw “little boxes” (cell walls). Coined the term “Cell”. Used a crude compound microscope ◦ In late 1680’s, Anton van Leeuwenhoek observed microorganisms in water from ponds and rainwater Lead to idea of single celled organisms 1831, Robert Brown discovered & named the nucleus of the cell. MJ. Schleiden- Plants are made of cells which are made up of nuclei and cell fluid. 1839-Theodore Schwann- Animals made up of small units. In 1858, Rudolph Virchow suggested ◦ “All cells come from cells” Cell Theory- cells are the basic unit of structure in every living thing. Either unicellular simple organims or multicellular complex organisms. Schwann, Schleiden, and, Virchow are credited with developing cell theory. ◦ In 1839 Schwann and Schleiden suggested that cells were the basic unit of life. ◦ In 1858, Virchow concluded that all cells come from pre-existing cells. Cell Theory states that 1. Cells and cell products are the units of structure and function in organisms 1. ALL cells arise from preexisting cell Once cell theory was developed, scientists began to study the structures and functions of cells more in depth Microscopes made of many lens components ◦ Lens improvements in microscope construction lead to Compound Light Microscopes ◦ Advances in staining techniques and slide preparation have made samples easier to see ◦ Electron Microscopes (1930s) can magnify objects by over 1,000,000x (0.5μm) Enough magnification to see structure of DNA and other organelles Prokaryotes No membrane enclosed organelles Singular circular chromosome No streaming in the cytoplasm Cell division without mitosis (binary fission) Simple flagella Small ribosomes No know cytoskelelton No cellulose in cell walls Proteins bound to DNA Eukaryotes Membrane enclosed organelles Multiple linear chromosomes, often in pairs Cell division by mitosis Complex flagella Large ribosomes Cellulose in cell walls DNA wrapped around protein Cell Wall, Cell membrane, flagella, Nucleoid, Plasmid, Cillia, cytoplasm, ribosomes Prokaryotes ◦ Simplest living cells, unicellular Bacteria ◦ On average 0.3 μm to 5μm ◦ Extremely adaptable Live in wide variety of environments Intestine, thermal ocean vents, ice cores everywhere ◦ No true nucleus, no organelles Unicellular ◦ Arrange in clusters Cell wall – surrounds cell ◦ Made up of lipids, carbs; no cellulose Plasma membrane – interior to cell wall No nucleus ◦ DNA in circular molecule ◦ Attached to plasma membrane in Nucleoid region Plasmids –small ring of extrachromosomal DNA May also have Ribosomes – ◦ Function in protein formation May have flagella for movement ◦ Whip like motion; propellers Three types: 1. Rod shaped – Bacilli 2. Sphere shaped – Cocci 3. Corkscrew shaped – Spirochette or spirilla Prokaryotes Various metabolisms ◦ All dependent on environmental level of O2 1. Aerobic – Need O2, cannot grow without 1. Anaerobic – Poisoned by SO4-) to extract energy 1. Facultative O2; use ions (NO3- or – Able to use both O2 or ions; Environment dependent Important function within ecosystems Decomposers Can have symbiotic relationship ◦ Interactions between two+ organisms Variety of ecosystems means variety of ways to obtain energy & carbon source Energy - light (Photo) or chemical (Chemo) Carbon – Inorganic (Autotroph) or organic (Heterotroph) Photoautotroph, Chemoautotroph Photoheterotroph, Chemoheterotroph Eukaryotes ◦ Complex, larger Protists, Fungi, Plants, Animals Protist - unicellular eukaryotes ◦ Average size - 10 – 50 μm ◦ Have nucleus & organelles Specific functions; Development of specializations ◦ Organelle - specialized structures within a living cell Smallest functioning part Cell Walls (plants), Chloroplast (plants), Central Vacuole (plants), Cell Membrane, Nucleus (Nuclear Envelope, Nucleolus, DNA (Chromatin)), Rough ER, Smooth ER, ribosomes (RNA and proteins), Golgi Apparatus, Mitochondria, Lysosomes, Cytoplasm ((Cytosol and organelles), Cytoskeleton (microtubules, filaments, microfilaments), Centriole (animals) “Control Center” of cell ◦ Houses DNA of the cell ◦ Double layer membrane DNA ◦ Molecule of hereditary ◦ Directs production of proteins, enzymes Anything that controls cell function/metabolism ◦ Most often in form of Chromatin Grainy thread-like, loose ◦ In cell division, becomes Chromosomes Tight, coiled, condensed DNA Needs to be copied/transported out of cell Molecule of heredity Large molecule ◦ Can’t leave nucleus – too large for nuclear pores ◦ Chromosomes cannot leave the nucleus Too large to fit through nuclear pores ◦ DNA is coded into message that can fit – RNA Ribonucleaic Acid versus DEOXYribonucleaic Acid Found inside the nucleus ◦ Dense, dark region Produces RNA – 3 types ◦ mRNA – messenger RNA Messenger of code from nucleus to ribosomes ◦ rRNA – Actual ribosome ◦ tRNA – Transfers individual Amino Acid to ribosome Uses complementary code of mRNA Location of protein synthesis Small bodies of protein/RNA Catalyze protein synthesis in cells Can be free floating in cytoplasm or bound to a membrane ◦ Bound to Endoplasmic Reticulum Cytoplasm Inside of P.M., outside of nucleus Thick, akin to toothpaste Consists of fluid - Cytosol ◦ Organized system of fluid (Cytosol) and fibers (Cytoskeleton) Fibers are scaffolding that connects organelles in cell Membrane tubes/channels through cytoplasm ◦ Weaves throughout – connecting organelles ◦ Transport materials to organelles Can have ribosomes embedded ◦ Rough Endoplasmic Reticulum …or not. ◦ Smooth Endoplasmic Reticulum Proteins synthesized on E.R. can enter the E.R. move to different parts of cell where needed Series of membrane bound sacs stacked together Looks like Smooth E.R. Function ◦ Modification – complete final structure of protein Attaching protein segments together Assembling 4o structure Packages proteins into vesicles for transport How does material move from ER to Golgi/out of cell? ◦ Intercellular Endo/Exocytosis Plasma Membrane Phospholipid bilayer; found in plant & animal Cell Wall Rigid wall surrounding P.M. of plant cells ◦ Made up of Cellulose, complex carbs & stiff fibers Lysosome – membrane-bound organelle containing digestive enzymes ◦ Made in G.A. Peroxisome – specific type of lysosome Vacuole In plant cells ◦ Very large – holds material 90% of plants volume – H2O, organic acids, digestive enzymes, salts, pigments Centrioles Paired bundles of microtubules ◦ Help organize DNA in cell reproduction Cillia & Flagella Membrane wrapped microtubule bundles ◦ Provide movement Chloroplasts Use light, water, CO2 to produce sugars ◦ Phtosynthesis light energy chemical energy (ATP) Mitochondria Double membrane organelle Control energy reactions in cell ◦ Cell Respiration ◦ ATP synthesis 10s to 1000s What is the distinction between unicellular and multicellular organisms? Unicellular organisms MUST address all of life’s needs in order to survive. What are the needs that unicellular organisms must be concerned with? Unicellular organisms must be able to: 1. Obtain nutrients 2. Expel wastes 3. Exchange gas regularly/ exchange gas produced by energy conversion reactions 4. Defend against “predators” 5. Reproduce 6. Respond to changes in environment ◦ ◦ Move to areas of high [O2] Move away from areas of intense heat Unicellular organisms team up for survival – form colonies Colonies – distinct group of microorganisms growing together Colonies ◦ Can be group of the same species (organism) ◦ Can be different species (biofilm) Cells in colony secrete chemicals to coordinate activities When in colonies, groups of cells secrete protective slime ◦ Proteins & Polysaccharides Helps control environment inside colony ◦ pH ◦ Concentration of food ◦ Water Each cell remains separate organism! Remove one cell from colony – the cell does not die When does a colony stop being unicellular and start being Multicellular – When specific cells stop doing everything and starts SPECALIZING on some things. Is specialization good or bad? Both - Leads to greater complexity But cells cannot survive alone – must cooperate. Volvox Eukaryotic algae-Chlamydomonas Lives in Fresh H2O Cells work together to function If one cell dies – colony lives Colony – sphere of cells Possess cells where each cell has: Nucleus 2 Flagella Vacuoles Light sensing structures Chloroplast However, some cells are specialized Reproductive cells Some cells larger/smaller ◦ Larger cells in rear for “swimming” Flagella beat in synchrony - coordination between cells Unicellular Colony ◦ Most cells VERY similar ◦ Structures and function Multicellular Organism ◦ Cellular specialization Book “Barely a multicellular organism” Remember – Answer is not as important as is understanding argument for both! Multicellular – Specialized cells dependent on each other to divide labor successfully for survival Atom Carbon Molecule C6H12O6 Macromolecule Starch Organelle Golgi Apparatus Cell Animal Cell/Plant Cell Tissue Group of same cells w/ common fcn Organ Group of diff. tissues w/common fcn Organ System Group of diff. organs w/ common fcn Organism Group of different organ systems working together for life ◦ Muscle tissue, Connective tissue ◦ Heart, bone, skin, brain, eye ◦ Circulatory, Immune, Nervous ◦ YOU