Microscopy and Cell Discovery - 2nd Quarter Lesson 1 PDF

Introduction to Microscopy and its Historical Development  eyepiece revolving coarse nosepiece adjustment knob objective...

Introduction to Microscopy and its Historical Development  eyepiece revolving coarse nosepiece adjustment knob objective Parts of a lenses Compound Microscope fine adjustment knob stage arm mirror/light base source  Science Trivia! Before the development of microscope, the general belief was that illnesses and diseases were caused by evil spirits or poisonous gases. The invention of microscopes helped in the observation of bacteria and other microorganisms, which in turn helped in the development of appropriate cures or medicines. Zacharias Janssen and Hans Janssen Invented the first optical microscope in 1590. First Simple Microscope The earliest simple microscopes were simply magnifying glasses with the magnification of 6x to 10x (low power). These microscopes were referred to as flea glasses since they were mostly used for the purposes of observing tiny insects such as fleas. Robert Hooke Used the compound microscope to observe cork. Hooke observed that cork is composed of small, hollow compartments. Hooke’s Observation in Cork The parts prompted Hooke to think of small rooms (cells) in a monastery, so he gave them the same name: CELLS. Investigated cork through experimenting with the compound microscope and came up with the name cells! Key Note: Hooke discovered the cell in 1665, which started formulating the cell theory! HOOKE’S INVESTIGATION/EXPERIMENT Hooke’s Microscope Hooke’s Observation Anton van Leeuwenhoek Father of Microbiology Study new approaches for creating lenses to observe cloth. Leeuwenhoek’s microscope was more powerful than Hooke’s compound microscope. From investigating and experimenting with his microscope, Leeuwenhoek became one of the first scientists to refer to living cells when he observed an abundant number of single-celled organisms, which he called animalcules (plant & animal), swimming in a drop of pond water! LEEUWENHOEK’S INVESTIGATIONS/EXPERIMENT Leeuwenhoek’s Microscope Leeuwenhoek’s Observation  A microscope is an instrument designed for observing small objects, including cells. It What is a microscope? magnifies the image of an object using at least one lens. A simple microscope uses a single magnifying lens to produce an enlarged image. Simple Microscope  A microscope is an instrument designed for observing small objects, including cells. It What is a microscope? magnifies the image of an object using at least one lens. A compound microscope is defined as a high-resolution instrument that uses two sets of lenses to produce a two-dimensional image of a sample. Compound Microscope  A microscope is an instrument designed for observing small objects, including cells. It What is a microscope? magnifies the image of an object using at least one lens. Electron microscopes can provide high-resolution images at high magnification levels. These are often used when compound light microscopes cannot provide an effective image. Electron Microscope  Parts of a Compound Microscope Parts and Function of a Compound Microscope Eyepiec e Part of the microscope that magnifies the image produced by the microscope's objective so that it can be seen by the human eye. Parts and Function of a Compound Microscope Eyepiece Tube Holds the eyepiece lens for comfortable viewing on a microscope. Parts and Function of a Compound Microscope Body Tube Body tube is a component of microscope that holds the objectives and the eyepiece at the proper working distance from each other Parts and Function of a Compound Microscope Coarse Focus Located on the arm of the microscope moves the stage up and down to bring the specimen into focus. Parts and Function of a Compound Microscope Fine Focus Sometimes located inside course adjustment knob (smaller in size), used to bring the specimen into sharp focus under low power and is used for all focusing when using high power lenses. Parts and Function of a Compound Microscope Objective Lens Magnify specimens, typically from 4x to 100x, for detailed observation. Parts and Function of a Compound Microscope Revolving Nosepiece Also known as the revolving turret. It holds the objective lenses. It is movable hence it can revolves the objective lenses depending on the magnification power of the lens. Parts and Function of a Compound Microscope Ar m Connects the microscope head to the base, providing stability for viewing adjustments. Parts and Function of a Compound Microscope Specimen Stage The section on which the specimen is placed for viewing. Parts and Function of a Compound Microscope Stage Clips Use to hold the specimen slides in place. Parts and Function of a Compound Microscope Illuminator Located at the base. It is used instead of a mirror. It captures light from an external source of a low voltage of about 100v. Parts and Function of a Compound Microscope Diaphrag m Also known as the iris. It’s found under the stage of the microscope and its primary role is to control the amount of light that reaches the specimen. Parts and Function of a Compound Microscope Base Provides support, houses the light source, and serves as a platform on a flat surface. CELL THEORY Matthias Schleiden Discovered that plants were made of cells. (1838) Fascinated with plant cells, Schleiden used the compound microscope and studied plant cells. From investigating and experimenting with plants, projected plant parts are made of cells! Discussed what he observed with his dear friend, German scientist Theodor Schwann. Theodor Schwann States “all animals are made of cells.” (1839) Studied plant & animal cells, and was intrigued by the similarities between the two. From investigating and experimenting with plant & animal cells, Schwann was able to determine that all animals are made of cells! Schwann published the 1st statement of the cell theory: all living things are made of cells and cell products! William Henry Perkin Develops an intense purple dye, which is used to stain slides. (1856)  Rudolf Virchow “Where a cell exists, there must have been a preexisting cell.” (1858) Based on his investigations and experiments, he stated that all cells come from preexisting cells, which is the 2nd part of the cell theory: all existing cells are produced by other living cells!  Three Major Definition Part of Cell Theory 1. All organisms are made of cells. 2.All existing cells are produced by other living cells. 3.The cell is the most basic unit of life.  PLANT CELL VS ANIMAL CELL  WHAT ARE CELLS? Cell is the basic and the smallest structural unit capable of performing life functions.  PROKARYOTIC CELLS A cell without "true nucleus" and without membrane-bound organelles.  UNICELLULAR An organism without "true nucleus" and is only composed of one cell or single cell. Example: Bacteria/bacterium EUKARYOTIC CELLS A cell with a "true nucleus" and membrane-bound organelles or a cell that has a complete set of organelles.  MULTICELLULAR An organism with two or more cells. Example: Animals and Plants PLASMA MEMBRANE Thin sheet or membrane that surrounds cells and also the membranes that surround organelles within the cell. CYTOPLASM Gel-like substance within the cell. Hosts chemical reactions, metabolic processes, and organelle movement. Provides structural support. NUCLEUS Control center enclosed by a membrane. Holds DNA, which guides protein production and cell functions. Essential for cell division (growth and repair). RIBOSOMES “Protein Construction team” They are like construction guys who build proteins ENDOPLASMIC RETICULUM The ER functions act as a manufacturing and packaging system. It works closely with the Golgi apparatus and ribosomes. It makes and transports lipids, it also packages proteins GOLGI APPARATUS Also known as the Golgi complex, Golgi body, or simply the Golgi Packaging organelle, it packages vesicles. LYSOSOMES lysosomes are “little digestion machines”, they go to work when the cell absorbs or eats some food particles, wastes, and foreign substances “janitor of the cell” CENTRIOLES Every animal-like cell has two small organelles called centrioles. They are there to help the cell when it comes time to divide (cell division) CELL WALL Cell walls made of cellulose are only found around plant cells and a few other organisms CHLOROPLASTS Chloroplasts are the “food producers” of the cell. The organelles are only found in plant cells and some protists such as algae. MITOCHONDRI A The “powerhouse of the cell” The working organelles that keep the cell full of energy