Chapter 7 The Cell Pages 171-187

How do we study cells? Microscopes Magnifies objects that are too small to see with the naked eye. Types: Simple 1 lens & uses light Can only see larger objects Compound 2/more lens & uses light Can magnify objects 1500 x Can only see outside cell Electron Uses stream of electrons Can magnify objects 500,000 x Allows to see inside cell Transmission Electron Microscope (TEM) – flat picture Scanning Electron Microscope (SEM) - 3D picture

Compound Microscope Parts Revolving Nose Piece: Moves desired objective lens into position Ocular: Magnifies the image Arm High Power Objective Lens: Contains the lens with high power magnification (40X) Low Power Objective Lens: Contains the lens with low power magnification (4 x)

Compound Microscope Parts Body Tube: Holds eye-piece in place Coarse Adjustment: Focuses the image under low power Stage: Holds the slide Fine Adjustment: Sharpens the image under high and low magnification Stage Clips: Holds the slide in position

Compound Microscope Parts Diaphragm: Regulates the amount of light that passes through the specimen Mirror/Light Source: Supplies light to object Inclination Joint: Tilts Microscope to Eye Level Base

-Base -Ocular -Arm -High Pwr -Base -Ocular -Arm -High Pwr. Objective Lens -Diaphragm -Stage Clips -Inclination Joint -Mirror/Light Source -Revolving Nose Piece -Low Objective Lens -Coarse Adjustment -Stage -Fine Adjustment -Body Tube 9. 1. 3. 10. 2. 11. 4. 12. 5. 13. 6. 7. 14. 8.

Answers Body Tube Revolving Nose Piece High Power Objective Lens Stage Clip Stage Diaphragm Mirror/Light Source Base Ocular Arm Low Power Objective Lens Coarse Adjustment Fine Adjustment Inclination Joint

Match the Microscope Part to its Function: Part Function Body Tube High Power Objective Lens Diaphragm Coarse Adjustment Low Power Objective Lens Stage Clips Ocular Revolving Nosepiece Mirror/Light Arm Inclination Joint Base Fine Adjustment Stage To raise & lower the stage, for major focus change Magnifies things 10 x Lens used to scan large areas of specimen Where slides are placed To make minor focusing adjustments To change objective lenses Lens used to magnify the object as much as possible The source of light To keep the scope level and securely standing For the purpose of carrying the microscope To hold the slide in place To adjust the amount of light entering from the bottom Tilts microscope to eye level Holds eye-piece in place

Answers D K G A E N M H B I L J F C

Find the Magnification What is the magnification of an onion cell when looking at it through the low power magnification lens that has a 4 x magnification? What is the magnification of an elodea leaf cell when looking at it through a lens with the magnification of 10x? What lens are you using when the cheek cell you are looking at through a microscope is magnified 400 x? 40 x 100 x High Power Magnification Lens

Meet Mr. Cell Cell: the basic unit of living organisms Unicellular- one celled (ex: bacteria) Multicellular- many celled organism (ex: humans) Cell Theory: All organisms are composed of one or more cells The cell is the basic unit of structure and organization of organisms All cells come from preexisting cells ***The cell is the basic unit of: 1)structure, 2) function, and 3)heredity in all life

2 Types: Prokaryotic: Eukaryotic: Primitive Unicellular No true nucleus or membrane bound parts Only example: Bacteria Eukaryotic: Unicellular & Multicellular True nucleus & membrane bound parts Example: all other life

Scientists Leeuwenhoek (1632-1723) Robert Hooke (1635-1703) 1st microscope Observed sperm, pond scum, & red blood cells (RBC’s) Robert Hooke (1635-1703) Observed “cells” in cork Robert Brown (1831) Observed nucleus Matthias Schleiden (1838) Observed plants were made of cells Theodor Schwann (1839) Observed animals were made of cells 1st cell theory Ruduof Virchow (1855) Observed cell division “All cells come from preexisting cells”

Cell Compartmentalization Cells are compartmentalized which allows for specialization! Cells are analogous to a city Compartments: Mailing Center-Golgi Apparatus Town Hall- Nucleus Mail Carriers- Ribosomes Compartments = Organelles Aka “little organs” Brain = nucleus Lungs= mitochondria Stomach = lysosomes Cell = our body - just like we have organs that do certain things -heart pumps blood, stomach digestion, lungs breath we have organelles in our cells that are specialized and work together as a whole

Cell Wall “Plant Wall” Barrier between cell & it’s environment Protects plant cells Made up of cellulose (polysaccharide) Only in plant cells! Plant, Fungi, and Bacteria

Plasma Membrane (Cell Membrane) Selectively Permeable (semi-permeable membrane) Allows only certain material to move through Permeability depends on solute size and solubility “Gate Keeper” Controls what goes in and out of the cell & maintains homeostasis Barrier between cell & it’s environment Plant & Animal

Fluid Mosaic Model: Membrane is fluid, and the molecules are always moving Same consistency as olive oil

Nucleus Nucleolus “Cell Brain” Controls the cell Nuclear membrane Surrounds nucleus Controls what goes in and out of nucleus Plant & Animal “Ribosome Factories” Plant & Animal Makes ribosomes Disappears during cell division

Chromatin “Threads of Life” Holds DNA ***DNA = genetic code DNA + Protein that makes up chromosomes: Coiled DNA Plant & Animal

Ribosomes Endoplasmic Reticulum “Protein Factories” Produce Proteins Plant & Animal Endoplasmic Reticulum “Roadway” Rough ER: w/ ribosomes Site of protein production Smooth ER w/out ribosomes Site of lipid production Plant & Animal

Mitochondria “Powerhouse” Produces ATP using energy stored in food molecules (ATP:adenosine tri-phosphate) Cells that requires lots of energy have lots of mitochondria (muscle cells) Smooth outer membrane & folded inner membrane (cristae) Plant and Animal

Chloroplast “Green Capsules” Produces chlorophyll Double membrane: green pigment that makes plants green traps sunlight for photosynthesis (makes energy for plants) Double membrane: Outer smooth Inner: Stacks of sacs called: thylakoids The stacks of thylakoids = grana Stroma: gel-like innermost part of chloroplast Plants

Vacuoles “Storage Cavities” Stores food, water, metabolic and toxic waste, and in plants it stores sugars Plants and Animals Plants- single, large vacuole, largest organelle Animals- small

Cytoplasm Cytoskeleton “Living Matter” Holds organelles in place Fills up the inside of the cell Plant & Animal “Cell Skeleton” Holds cell shape & allows for movement: Intracellular transport Cell Division Microtubules –protein tubes Microfilaments- protein fibers Plant & Animal

Centrioles Cilia Flagella “Cell Cylinders” For cell division Animal “Cell Hair” Tiny hair-like structure Movement Animal Flagella “Cell Whip” Long whip-like Movement Animal

Organelle Nickname Function Plant/Animal Cell Wall Plant Wall Protection & Structure Plant Plasma Membrane Cell Gate Keeper Controls movement in/out of cell P & A Nucleus Cell Brain Controls cell (Nuclear Membrane = nucleus gate keeper) Nucleolus Ribosome Factory Produces Ribosomes Chromatin & Chromosomes Thread of Life Holds DNA = genetic code

Organelle Nickname Function Plant/Animal Ribosomes Protein Factories Produces Protein P & A Endoplasmic Reticulum Rough Smooth Roadway a. w/ ribosomes -site of protein production b. w/out ribosomes -site of lipid production Mitochondria Powerhouse Produces Energy = ATP Both Chloroplast Green Capsules Makes plants green Captures light for photosynthesis P lant Vacuoles Storage Cavities Stores food, water, & waste

Organelle Nickname Function Plant/Animal Cytoplasm Living Matter Holds organelles in place Fills up cell P & A Cytoskeleton: Microtubules & Microfilaments Cell Skeleton Holds cell shape Centrioles Cell Cylinders Animal Cell Division Animal Cilia Cell Hair Movement Flagella Cell Whip

Plant & Animal Cell Differences Plants have: Animals have: Cell Wall Centrioles 1 Large Vacuole Cilia & Flagella Chloroplast