* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download cell-intro-powerpoint-for-notes
Survey
Document related concepts
Signal transduction wikipedia , lookup
Cell membrane wikipedia , lookup
Extracellular matrix wikipedia , lookup
Tissue engineering wikipedia , lookup
Cell nucleus wikipedia , lookup
Cell growth wikipedia , lookup
Cell encapsulation wikipedia , lookup
Cellular differentiation wikipedia , lookup
Cytokinesis wikipedia , lookup
Cell culture wikipedia , lookup
Endomembrane system wikipedia , lookup
Transcript
• A cell is the basic unit of structure and function in all living things. • It needs water and nutrients to survive. • It is found in all living things: bacteria, plants, and animals. • It is NOT found in non-living things. 1665 Robert Hooke: Looked at a slice of cork through a microscope and discovered tiny boxes which he called “cells.” 1673 Anton von Leeuwenhoek: looked at pond scum through a microscope and discovered singlecelled organisms called protists. 1838 Matthias Schleiden: studied plants and concluded that all plant parts were made of cells. 1839 Theodor Schwann: studied animals and concluded that all animal tissues are made of cells. 1858 Rudolf Virchow: discovered that cells could only come from other cells. With all these discoveries, Schwann and Virchow came up with the cell theory: 1. All organisms are made of cells 2. The cell is the Basic unit of all living things 3. All cells Come from existing cells • Most cells are so tiny that you have to use a microscope to see them. • Because of the surface area-to-volume ratio: –Cells take in nutrients and get rid of wastes through their outside surface. –BUT the volume (space inside) grows faster than the surface area (the cell’s surface). –If the volume becomes too big, the cell cannot survive because…. • it can’t get enough nutrients in & • can’t get rid of wastes fast enough. Therefore, a cell only grows to a certain size. •If you blow into a balloon, the volume increases. •Eventually, the balloon’s surface cannot stretch anymore. •When this happens, the balloon cannot continue to exist and will pop. •Likewise, if a cell’s volume increases too much, the cell’s surface will not be able to get nutrients in or wastes out fast enough and it will die. • Some cells are big because they don’t need to take in nutrients or get rid of wastes. • Ie. Chicken egg is a cell The Cell Two Categories of Cells Prokaryotic Cells - A single celled organism that does not have a nucleus covering its DNA or membrane covered organelles. Example: Bacteria PRO rhymes with NO – no nucleus Eukaryotic Cells - an organism made up of cells (multi-cellular) that have a nucleus enclosed by a membrane. Example: Plants and Animals The Cell All Cells have 4 components (part; element; ingredient) in common Cell Membrane Organelles Cytoplasm DNA The Cell Plant Cell Animal Cell The Cell Cell Membrane – The cell membrane is the outermost part of the animal cell. It controls the flow of materials in and out of the cell and protects the cell from its environment. Organelles – The parts within the cell that perform specific functions. Organelles The Cell Cell Membrane The Cell Cytoplasm – The cytoplasm is a ‘jelly’ like substance the organelles float in inside the cell membrane. DNA – The genetic material that carries the information to build and maintain cells. DNA The Cell Cytoplasm The Cell Questions: What are 4 things that all cells have in common? What is the difference between Prokaryotic and Eukaryotic cells? What is one purpose of the cell membrane? Describe cytoplasm – what could you compare it to? Two Kinds of Cells: Prokaryotes: Bacteria and Archaea – textbook pages 64-65 Prokaryotes are single celled organisms that do not have a nucleus or “membrane-bound” organelles. Bacteria • most common prokaryote • smallest cells known • live almost everywhere • no membrane-covered organelles but they do have ribosomes • have a cell wall with the cell membrane just inside of it • DNA is this cell is a long, circular molecule shaped like a twisted rubber band Two Kinds of Cells: Prokaryotes: Bacteria and Archaea – textbook pages 64-65 Archaea: • Single-celled organism • Their ribosomes are different from those of bacteria • Three types of archaea: • Heat-loving – extremophile – live in very hot water, like in hot springs • Salt-loving – extremophile-live in areas that are extremely salty • Methane-making – live deep in ocean near volcanic vents Eukaryotic Cells • 10 times larger than most bacterial cells • Have a nucleus – one type of membranebound organelle • The nucleus holds the DNA • These cells have other organelles that each have a specific job • Most Eukaryotes are multicellular • Plants, animals, including humans are eukaryotes • Eukaryotes can be single celled like amoebas and yeast or multicellular like green algae and mushrooms • No nucleus • 2 types: bacteria & archebacteria • Smallest cells • Organelles: • DNA & ribosomes only • Use flagellum (tail) to move • Most prokaryotes are Unicellular (only 1 cell) • Have a nucleus Examples: • plants, animals, and humans • Largest cells (10x *DNA larger than bacteria •ribosomes, * cells!) cell membranes •cytoplasm • DNA in nucleus • Many organelles • Most eukaryotes are multi-cellular (made of more than 1 cell) BACTERIAL CELLS • Usually smaller than plant & animal cells • Have a cell wall, cell membrane, ribosomes, cytoplasm, & DNA. •Does NOT contain a nucleus so it is a PROKARYOTE