Cork CellThe word cell comes from theLatin cella, a small room.
The Cell Theory Robert Brown (1831) Described the nucleus of the cell Matthias Schleiden (1838) All plants are composed of cells. Theodor Schwann (1838) All animals are composed of cells Rudolph Virchow (1850s) Cells reproduce
The Cell Theory All organisms are composed of cells. Cells are the basic units of structure and function in organisms. Cells come only from pre-existing cells because cells are self- reproducing.
Microscopy Today Electron Microscopes are scientific instruments that use a beam of highly energetic electrons to examine objects on a very fine scale.
Microscopy Today Topography: shows the surface features of an object or "how it looks", its texture; and materials properties (hardness, reflectivity...etc.) Morphology: shows shape and size of the particles making up the object; and materials properties (ductility, strength, reactivity...etc.)
Two Basic Typesof Cell Structure Prokaryotic Eukaryotic
Two Basic Types of Cell Structure Prokaryotic “pro” = before, “kary”= nut (nucleus) NO nucleus or NO organelles Genetic material (DNA) is naked in the cytoplasm Cell division is called binary fission
Two Basic Types of Cell Structure Prokaryotic Believed to be the first cells to evolve. Ribosomes are the only organelle.
Two Basic Types of Cell StructureProkaryotic • Kingdom Monera • Kingdom Archaea
Two Basic Typesof Cell Structure Prokaryotic Eukaryotic
Two Basic Typesof Cell StructureEukaryotic Nucleus containing DNA “Eu” - true Organelles (membrane bound) with specialized functions Cell division: mitosis and meiosis
Two Basic Typesof Cell StructureEukaryotic• Kingdom Protista• Kingdom Fungi• Kingdom Plantae• Kingdom Animalia
Differences between Prokaryotic & Eukaryotic cellsBacterial cells also contain flagellum, plasmid and capsule. Feature Prokaryote Eukaryote Size Small about 0.5 Up to 40 micrometers micrometers Genetic Circular DNA (in DNA in form of linear material cytoplasm) chromosomes ( in nucleus) Many organelles: Few present, none •Double membranes e.g.:Organelles nucleus, mitochondria & membrane bound chloroplasts •Single membrane e.g.: GA, ER & lysosomes •Fungi: rigid, formed from Rigid formed from polysaccharide, chitin. Cell walls glycoproteins (mainly •Plant: rigid, formed from polysaccharides. E.g.: murein) cellulose. •Animals no cell wallRibosome’s 70s 80s
Figure 7-5 Plant and Animal Cells Section 7-2 Animal Cell Cytoplasm Nucleolus Ribosome Nucleus s Cell MembraneGo toSection:
Eukaryotic Cell Organelles and Function2. Ribosomes Function: makes proteins Found in all cells, prokaryotic and eukaryotic
Eukaryotic Cell Organelles and Function3. Endoplasmic Reticulum (ER) Nickname: “Roads” Function: The internal delivery system of the cell
Figure 7-5 Plant and Animal Cells Section 7-2 Animal Cell Cytoplasm Nucleolus Ribosomes Nucleus Cell Membrane Smooth Rough Endoplasm Endoplasmi ic c Reticulum ReticulumGo toSection:
Endoplasmic Reticulum Rough ER: Rough appearance because of ribosomes Function: helps make proteins, that’s why it has ribosomes
Endoplasmic ReticulumSmooth ER:• similar in appearance with RER but NOribosomes•Function: functions depending on thespecific cell type including lipid andsteroid hormone synthesis ,breakdown of lipid-soluble toxins inliver cells, and control of calciumrelease in muscle cell contraction.
Eukaryotic Cell Organelles and Function4. Golgi Complex Nickname: The shippers Function: packages, modifies, and transports materials to different location inside/outside of the cell Appearance: stack of pancakes
Eukaryotic Cell Organelles and FunctionGolgi Complex Modifies proteins and lipids made by the ER and prepares them for export from the cell
Eukaryotic Cell Organelles and Function5. Lysosomes: circular, but bigger than ribosomes Nickname: “Clean-up Crews” Function: to break down food into particles the rest of the cell can use and to destroy old cells
Eukaryotic Cell Organelles and Function Single membrane bound structure. Contains digestive enzymes that break down cellular waste and debris and nutrients for use by the cell. Http://micro.magnet.fsu.edu/cells/animals/lysoso me/html
Eukaryotic Cell Organelles and Function6. Mitochondria Nickname: “The Powerhouse” Function: Energy formation Breaks down food to make ATP ATP: is the major fuel for all cell activities that require energy
Eukaryotic Cell Organelles and Function7. Plasma Membrane • Another name: Cell Membrane; “traffic enforcer” • Function: hold the cell together. It keeps all of the pieces, like the organelles and the CYTOPLASM inside; regulates the entrance and exit of materials in and out the cell.
Plasma MembraneFluid Mosaic Model of Plasma Membrane
Fluid Mosaic Model of the Plasma Membrane The membrane is seen as a bilayer of phospholipids in which protein molecules are embedded.Lipid bilayer a. Phospholipids : polar head and nonpolar tail b. Cholesterol: makes membrane a bit more rigid c. Proteins: provide means of transportation through membrane and receptor proteins d. Carbohydrates: recognition patterns for cells and organisms (“self” markers to avoid immune system attack)
8. Cytoskeleton-composed offilaments andmicrotubulesthat maintain thecell shape andassist movementof its part
Eukaryotic Cell Organelles and Function9. Cilia and flagella External appendages from the cell membrane that aid in locomotion of the cell. Cilia also help to move substance past the membrane.
Cilia and Flagella • The most common examples of ciliated cells are those that line the trachea, or wind pipe of animals. • The cilia move mucus containing dirt and other inhaled particles up the windpipe and into the esophagus where they can be coughed up or
Cilia and FlagellaParamecium sp.This unicellular organism sweeps food into itsmouth by using cilia.
Cilia and FlagellaSperm cell has a tail or "flagellum"which executes the lashingmovements to propel the sperm.
Eukaryotic Cell Organelles and Function10. Centrioles Found only in animal cells. Self-replicating Made of bundles of microtubules. Help in organizing cell division.
11. Cytosol/Cytoplasm• The cytosol is the "soup"within which all the other cellorganelles reside and where mostof the cellular metabolism occurs .* Though mostly water, the cytosol is full of proteins that control cell metabolism including signal transduction pathways, glycolysis, and transcription factors.
Eukaryotic Cell Organelles and Function11. Huge vacuoles Function: store water, waste products, food, and other cellular materials. It may take up most of the cells volume. When there is no water, the plant wilts
Eukaryotic Cell Organelles and Function9. Cell Wall Function: provides support and protection to the cell membrane; gives rigidity to the cell structure. Found outside the cell membrane in plant cells.
Plant Cell Cytoplasm Vacuole Smooth ER Ribosomes ChloroplastsCell MembraneCell Wall Nucleolus Golgi Bodies Nucleus Mitochondria Rough ER
Cell Structure Reflects CellFunction Muscle cells: contain numerous mitochondria providing energy needed for muscle contraction (action).
Cell Structure Reflects CellFunction Cells of renal tubule lining are cube- shaped (helps with their function of absorption/secretion)
Cell Structure Reflects CellFunction Nerve cells: are long and thin to carry impulses over distance.
Cell Structure Reflects CellFunction Columnar epithelium with cilia on the free surface lines of the respiratory tract, fallopian tubes and uterus. The cilia beat rhythmically to transport particles.
Cell Structure Reflects CellFunction Sperm cell has a tail or "flagellum" which executes the lashing movements to propel the sperm.
Cell Structure Reflects CellFunction Red blood cells contain hemoglobin which permits them to transport oxygen (and carbon dioxide).