Unit I - The Cell PDF

Unit I- The Cell copyright cmassengale 1 Learning Outcomes: 1. Demonstrate an understanding of the following: ❖ Cell theory ❖ Cell Structure & Functions ❖ Prokaryotic and eukaryotic cells ❖ Cell Types ❖ Cell Modifications ❖ Cell Cycle, Mitosis and Meiosis ❖ Transport mechanism in Cells 2. C...

Unit I- The Cell copyright cmassengale 1 Learning Outcomes: 1. Demonstrate an understanding of the following: ❖ Cell theory ❖ Cell Structure & Functions ❖ Prokaryotic and eukaryotic cells ❖ Cell Types ❖ Cell Modifications ❖ Cell Cycle, Mitosis and Meiosis ❖ Transport mechanism in Cells 2. Construct a three-dimensional (3D) model of plant, animal or bacterial cell using recyclable materials 3. Construct a cell membrane (3D fluid mosaic) model from indigenous or recyclable materials. copyright cmassengale 2  Module 1- The Foundation of Life In this module, you will be able to: Trace the events that led to the inventions of the first microscope Relate the inventions of the first microscope with the discovery of the cell. Determine the events that led to the cell theory. Explain the postulates of the cell theory. Describe how the cell theory disproved the belief of spontaneous generations. copyright cmassengale 3 The Cell is the basic unit of life. All living things are made up of one or more cells. a. Unicellular organisms (prokaryotes) – are made up of only cell such as bacteria, and protozoa. b. Multicellular organisms (eukaryotes) – are made up of many cells such as plants and animals. Multicellular organisms are macroscopic, which means they can be seen by the unaided eye. copyright cmassengale 4 Unicellular organisms are mostly microscopic, which means they are so small that you cannot see them with your unaided eye. You have to you use a microscope to see them. The microscope is an instrument used to view objects that cannot be seen by the unaided eye. It can magnify the size of very small objects. copyright cmassengale 5  What Are the Main Characteristics of organisms? 1. Made of CELLS 2. Require ENERGY (food) 3. REPRODUCE (species) 4. Maintain HOMEOSTASIS 5. ORGANIZED 6. RESPOND to environment 7. GROW and DEVELOP 8. EXCHANGE materials with surroundings (water, wastes, gases) copyright cmassengale 6  LEVELS OF ORGANIZATION Nonliving Levels: 1.ATOM (element) 2.MOLECULE (compounds like carbohydrates & proteins) 3.ORGANELLES (nucleus, ER, Golgi …) copyright cmassengale 7  LEVELS OF ORGANIZATION Living Levels: 1.CELL (makes up ALL organisms) 2.TISSUE (cells working together 3.ORGAN (heart, brain, stomach …) 4.ORGAN SYSTEMS (respiratory, circulatory …) 5.ORGANISM copyright cmassengale 8  LEVELS OF ORGANIZATION Living Levels continued: 1.POPULATION (one species in an area) 2.COMMUNITY (several populations in an area 3.ECOSYSTEM (forest, prairie …) 4.BIOME (Tundra, Tropical Rain forest…) 5.BIOSPHERE (all living and nonliving things on Earth) copyright cmassengale 9 History of Cells & the Cell Theory Cell Specialization copyright cmassengale 10 The Inventions of the Microscope and Discovery of the Cell Before the microscope was invented, the romans had already invented and experimented with glasses during the first century. One these glass samples involved a piece that had thick middle and thin edges. They discovered that small become larger when viewed through this glass sample. copyright cmassengale 11 This became the earliest form of lens. (The word lens is derived form the Latin word lentil, because it closely resemble the shape of the lentil bean). These lenses were not fully utilized until the 13th century, when they were finally used in eyeglass production. These lenses can magnify objects only at 6x – 10x. copyright cmassengale 12 Around the late 16th century, The first compound microscope was invented by Zachariaz Janseen. It is believed that Zacharias probably had help from his father, Hans, because he was still young at that time.. They made this microscope by placing several lenses together, and discovered that objects were further enlarge upon viewing. copyright cmassengale 13  First to View Cells In 1665, Robert Hooke used a microscope that he built to examine a thin slice of cork (dead plant cell walls) He was able to see and A 17th century compound microscope, from an engraving in Robert observe small boxes or Hooke's Micrographia. compartments cellula because they reminded him of the “little rooms” in the monastery, which were reported in his famous publication micrographia. copyright cmassengale 14  First to View Cells Hooke is responsible for naming cells Hooke called them “CELLS” because they looked like the small rooms that monks lived in called Cells copyright cmassengale 15 Robert Hooke was the first to name the cell (1665) 2  Anton van Leeuwenhoek In 1673, Leeuwenhoek (a Dutch microscope maker), created a microscope with a much higher magnification than the microscope that Hooke used. He used this microscope to observe specimens such as bacteria, blood cells and protist , which he called animalcules. He was also the first scientist to observe sperm cells and egg cells of both animals and plants. copyright cmassengale 17  Beginning of the Cell Theory In 1838, a German botanist named Matthias Schleiden concluded that all plants were made of cells Schleiden is a cofounder of the cell theory copyright cmassengale 18 The Cell Theory A century passed before several improvements on the microscope were made. These latest microscopes were used by Matthias Jakob Schleiden and Theodore Schwann. Schleiden was a professor of botany at the University of Jena, Germany. Schwann was a professor of physiology at the University of Louvain, Belgium copyright cmassengale 19  Beginning of the Cell Theory In 1839, a German zoologist named Theodore Schwann concluded that all animals were made of cells Schwann also cofounded the cell theory copyright cmassengale 20  Schleiden published his research in 1838, which was based on several years of studying different types of plants under the microscope. Schwann published his research a year later, based on his study of several slides of animal cells. Their researches became the basis of the first two postulates of the cell theory: 1. All organisms are made up of cells. 2. The basic unit of life is the cell copyright cmassengale 21 Beginning of the Cell Theory In 1855, a German medical doctor named Rudolph Virchow observed, under the microscope, cells dividing He reasoned that all cells come from other pre-existing cells by cell division copyright cmassengale 22  The last postulates was eventually proven by Rudolf Ludwig Karl Virchow in 1858. Virchow upon studying how cells played a roe in body diseases at that time, noticed that the existence of disease in the organs and tissues come from affected cells. From this, he stated Omnis cellula e cellula, which means that all cells arise from pre existing cells. It was believed, however that this discovery was initially made by Robert Remak, a Jewish scientist in 1855, when he tried to prove the idea of cell division by hardening the cell membrane. copyright cmassengale 23  CELL THEORY All living things are made of cells Cells are the basic unit of structure and function in an organism (basic unit of life) Cells come from the reproduction of existing cells (cell division) copyright cmassengale 24 The Theory of Spontaneous Generation copyright cmassengale 25 copyright cmassengale 26 copyright cmassengale 27 copyright cmassengale 28 copyright cmassengale 29 THANK YOU FOR LISTENING copyright cmassengale 30  Module 2- Cell Size and Types Cells, the basic units of organisms, can only be observed under microscope Three Basic types of cells include: Animal Cell Plant Cell Bacterial Cell copyright cmassengale 31  Number of Cells Although ALL living things are made of cells, organisms may be: Unicellular – composed of one cell Multicellular- composed of many cells that may organize into tissues, etc. copyright cmassengale 32  CELL SIZE Typical cells range from 5 – 50 micrometers (microns) in diameter copyright cmassengale 33  Which Cell Type is Larger? Plant cell > _____________ _________ Animal cell > ___________ bacteria copyright cmassengale 34  How Big is a Micron ( µ ) ? 1 cm = 10,000 microns 1” = 25,000 microns copyright cmassengale 35  Multicellular Organisms Cells in multicellular organisms often specialize (take on different shapes & functions) copyright cmassengale 36  Cell Specialization Cells in a multi- cellular organism become specialized by turning different genes on and off This is known as DIFFERENTIATION copyright cmassengale 37  Specialized Animal Cells Muscle cells Red blood cells Cheek cells copyright cmassengale 38  Specialized Plant cells Guard Cells Pollen Xylem cells copyright cmassengale 39 Organization Levels of Life Atoms to Organisms copyright cmassengale 40  Nonliving Levels ATOMS → MOLECULES → ORGANELLES copyright cmassengale 41  Living Levels → CELLS – life TISSUES – Similar cells → starts here working together copyright cmassengale 42  More Living Levels ORGAN ORGANS → → ORGANISM SYSTEMS Different tissues Different organs working together working together copyright cmassengale 43 Simple or Complex Cells copyright cmassengale 44 Prokaryotes – The first Cells Cells that lack a nucleus or membrane-bound organelles Includes bacteria Simplest type of cell Single, circular chromosome copyright cmassengale 45  Prokaryotes Nucleoid region (center) contains the DNA Surrounded by cell membrane & cell wall (peptidoglycan) Contain ribosomes (no membrane) in their cytoplasm to make proteins copyright cmassengale 46  Eukaryotes Cells that HAVE a nucleus and membrane- bound organelles Includes protists, fungi, plants, and animals More complex type of cells copyright cmassengale 47  Eukaryotic Cell Contain 3 basic cell structures: Nucleus Cell Membrane Cytoplasm with organelles copyright cmassengale 48  Two Main Types of Eukaryotic Cells Plant Cell Animal Cell copyright cmassengale 49 Organelles copyright cmassengale 50  Organelles Very small (Microscopic) Perform various functions for a cell Found in the cytoplasm May or may not be membrane- bound copyright cmassengale 51  Animal Cell Organelles Ribosome (attached) Nucleolus Ribosome (free) Nucleus Cell Membrane Nuclear envelope Mitochondrion Rough Smooth endoplasmic endoplasmic reticulum reticulum Centrioles Golgi apparatus copyright cmassengale 52 Plant Cell Organelles copyright cmassengale 53  Cell or Plasma Membrane Composed of double layer of phospholipids and proteins Surrounds outside of ALL cells Controls what enters or leaves the cell Living layer Outside of cell Carbohydrate chains Proteins Cell membrane Inside of cell Protein (cytoplasm) channelcopyright cmassengale Lipid bilayer 54  Phospholipids Heads contain glycerol & phosphate and are hydrophilic (attract water) Tails are made of fatty acids and are hydrophobic (repel water) Make up a bilayer where tails point inward toward each other Can move laterally to allow small molecules (O2, CO2, & H2O to enter) copyright cmassengale 55  The Cell Membrane is Fluid Molecules in cell membranes are constantly moving and changing copyright cmassengale 56  Cell Membrane Proteins Proteins help move large molecules or aid in cell recognition Peripheral proteins are attached on the surface (inner or outer) Integral proteins are embedded completely through the membrane copyright cmassengale 57  GLYCOPROTEINS Recognize “self” Glycoproteins have carbohydrate tails to act as markers for cell recognition copyright cmassengale 58  Cell Membrane in Plants Cell membrane Lies immediately against the cell wall in plant cells Pushes out against the cell wall to maintain cell shape copyright cmassengale 59  Cell Wall Cell wall Nonliving layer Found in plants, fungi, & bacteria Made of cellulose in plants Made of peptidoglycan in bacteria Made of chitin in Fungi copyright cmassengale 60  Cell Wall Supports and protects cell Found outside of the cell membrane copyright cmassengale 61  Cytoplasm of a Cell cytoplasm Jelly-like substance enclosed by cell membrane Provides a medium for chemical reactions to take place copyright cmassengale 62  More on Cytoplasm cytoplasm Contains organelles to carry out specific jobs Found in ALL cells copyright cmassengale 63 The Control Organelle - Nucleus Controls the normal activities of the cell Contains the DNA in chromosomes Bounded by a nuclear envelope (membrane) with pores Usually the largest organelle copyright cmassengale 64  More on the Nucleus Nucleus Each cell has fixed number of chromosomes that carry genes Genes control cell characteristics copyright cmassengale 65  Nuclear Envelope Double membrane surrounding nucleus Also called nuclear membrane Contains nuclear pores for materials to enter & leave nucleus Connected to the rough ER Nuclear pores copyright cmassengale 66  Inside the Nucleus - The genetic material (DNA) is found DNA is spread out DNA is condensed & And appears as wrapped around proteins CHROMATIN forming in non-dividing cells as CHROMOSOMES in dividing cells copyright cmassengale 67  What Does DNA do? DNA is the hereditary material of the cell Genes that make up the DNA molecule code for different proteins copyright cmassengale 68  Nucleolus Inside nucleus Cell may have 1 to 3 nucleoli Disappears when cell divides Makes ribosomes that make proteins copyright cmassengale 69  Cytoskeleton Helps cell maintain cell shape Also help move organelles around Made of proteins Microfilaments are threadlike & made of ACTIN Microtubules are tubelike & made of TUBULIN copyright cmassengale 70  Cytoskeleton MICROTUBULES MICROFILAMENTS copyright cmassengale 71 Centrioles Found only in animal cells Paired structures near nucleus Made of bundle of microtubules Appear during cell division forming mitotic spindle Help to pull chromosome pairs apart to opposite ends of the cell copyright cmassengale 72 Centrioles & the Mitotic Spindle Made of MICROTUBULES (Tubulin) copyright cmassengale 73  Mitochondrion (plural = mitochondria) “Powerhouse” of the cell Generate cellular energy (ATP) More active cells like muscle cells have MORE mitochondria Both plants & animal cells have mitochondria Site of CELLULAR RESPIRATION (burning glucose) copyright cmassengale 74 MITOCHONDRIA Surrounded by a DOUBLE membrane Has its own DNA Folded inner membrane called CRISTAE (increases surface area for more chemical Reactions) Interior called MATRIX copyright cmassengale 75 Interesting Fact --- Mitochondria Come from cytoplasm in the EGG cell during fertilization Therefore … You inherit your mitochondria from your mother! copyright cmassengale 76  Cell Powerhouse Mitochondrion ( mitochondria ) Rod shape copyright cmassengale 77 What do mitochondria do? “Power plant” of the cell Burns glucose to release energy (ATP) Stores energy as ATP copyright cmassengale 78  Endoplasmic Reticulum - ER Network of hollow membrane tubules Connects to nuclear envelope & cell membrane Functions in Synthesis of cell products & Transport Two kinds of ER ---ROUGH & SMOOTH copyright cmassengale 79 Rough Endoplasmic Reticulum (Rough ER) Has ribosomes on its surface Makes membrane proteins and proteins for EXPORT out of cell copyright cmassengale 80 Rough Endoplasmic Reticulum (Rough ER) Proteins are made by ribosomes on ER surface They are then threaded into the interior of the Rough ER to be modified and transported copyright cmassengale 81  Smooth Endoplasmic Reticulum Smooth ER lacks ribosomes on its surface Is attached to the ends of rough ER Makes cell products that are USED INSIDE the cell copyright cmassengale 82 Functions of the Smooth ER Makes membrane lipids (steroids) Regulates calcium (muscle cells) Destroys toxic substances (Liver) copyright cmassengale 83  Endomembrane System Includes nuclear membrane connected to ER connected to cell membrane (transport) copyright cmassengale 84  Ribosomes Made of PROTEINS and rRNA “Protein factories” for cell Join amino acids to make proteins Process called protein synthesis → copyright cmassengale 85 Ribosomes Can be attached to Rough ER OR Be free (unattached) in the cytoplasm copyright cmassengale 86  Golgi Bodies Stacks of flattened sacs Have a shipping side CIS (trans face) and receiving side (cis face) Receive proteins made by ER Transport vesicles with modified proteins pinch TRANS off the ends Transport vesicle copyright cmassengale 87  Golgi Bodies Look like a stack of pancakes Modify, sort, & package molecules from ER for storage OR transport out of cell copyright cmassengale 88  Golgi copyright cmassengale 89  Golgi Animation Materials are transported from Rough ER to Golgi to the cell membrane by VESICLES copyright cmassengale 90  Lysosomes Contain digestive enzymes Break down food, bacteria, and worn out cell parts for cells Programmed for cell death (AUTOLYSIS) Lyse (break open) & release enzymes to break down & recycle cell parts) copyright cmassengale 91  Lysosome Digestion Cells take in food by phagocytosis Lysosomes digest the food & get rid of wastes copyright cmassengale 92  Cilia & Flagella Made of protein tubes called microtubules Microtubules arranged (9 + 2 arrangement) Function in moving cells, in moving fluids, or in small particles across the cell surface copyright cmassengale 93  Cilia & Flagella Cilia are shorter and more numerous on cells Flagella are longer and fewer (usually 1-3) on cells copyright cmassengale 94 Cell Movement with Cilia & Flagella copyright cmassengale 95 Cilia Moving Away Dust Particles from the Lungs Respiratory System copyright cmassengale 96  Vacuoles Fluid filled sacks for storage Small or absent in animal cells Plant cells have a large Central Vacuole No vacuoles in bacterial cells copyright cmassengale 97  Vacuoles In plants, they store Cell Sap Includes storage of sugars, proteins, minerals, lipids, wastes, salts, water, and enzymes copyright cmassengale 98  Contractile Vacuole Found in unicellular protists like paramecia Regulate water intake by pumping out excess (homeostasis) Keeps the cell from lysing (bursting) Contractile vacuole animation copyright cmassengale 99  Chloroplasts Found only in producers (organisms containing chlorophyll) Use energy from sunlight to make own food (glucose) Energy from sun stored in the Chemical Bonds of Sugars copyright cmassengale 100  Chloroplasts Surrounded by DOUBLE membrane Outer membrane smooth Inner membrane modified into sacs called Thylakoids Thylakoids in stacks called Grana & interconnected Stroma – gel like material surrounding thylakoids copyright cmassengale 101  Chloroplasts Contains its own DNA Contains enzymes & pigments for Photosynthesis Never in animal or bacterial cells Photosynthesis – food making process copyright cmassengale 102  Cell Size Question: Are the cells in an elephant bigger, smaller, or about the same size as those in a mouse? copyright cmassengale 103  Factors Affecting Cell Size Surface area (plasma membrane surface) is determined by multiplying length times width (L x W) Volume of a cell is determined by multiplying length times width times height (L x W x H) Therefore, Volume increases FASTER than the surface area copyright cmassengale 104  Cell Size When the surface area is no longer great enough to get rid of all the wastes and to get in enough food and water, then the cell must divide Therefore, the cells of an organism are close in size copyright cmassengale 105  Cell Size Question: Are the cells in an elephant bigger, smaller, or about the same size as those in a mouse? About the same size, but … The elephant has MANY MORE cells than a mouse! copyright cmassengale 106 copyright cmassengale 107