Week 2 Cell Theory and Structure PDF

THE BEAUTY OF BIOLOGY Inspired by Mission, Driven by Excellence  Key Questions: 1. How did you feel while you are watching the video? 2. Why is it significant to study Biology? 3. How can you love General Biology 1?...

THE BEAUTY OF BIOLOGY Inspired by Mission, Driven by Excellence  Key Questions: 1. How did you feel while you are watching the video? 2. Why is it significant to study Biology? 3. How can you love General Biology 1? Inspired by Mission, Driven by Excellence  LEARNING OBJECTIVES By the end of the lesson, the learners should have: 2. Acquired motivation to finish the subject with excitement and enthusiasm; 3. Traced the history and development of the cell theory; 4. Enumerated the postulates of the cell theory; 5. Explained the postulates of the cell theory; and 6. Identified and described the structures and function of major and subcellular organelles. Inspired by Mission, Driven by Excellence MICROSCOPY AND THE DISCOVERY OF THE CELL Inspired by Mission, Driven by Excellence ROBERT HOOKE - Botanist - In 1665, he examined a thin slice of dried cork tissue using a very simple microscope. - It appeared to be similar to honeycomb chambers, which reminded him small monastery rooms. Inspired by Mission, Driven by Excellence OVERVIEW OF THE HISTORICAL DEVELOPMENT OF THE MICROSCOPE 1590 - They placed multiple lenses in a tube and found out that objects seen through the tube appear greatly enlarged. Inspired by Mission, Driven by Excellence OVERVIEW OF THE HISTORICAL DEVELOPMENT OF THE MICROSCOPE 1609 - He invented a compound microscope using convex and concave lenses. Galileo Galilei Inspired by Mission, Driven by Excellence OVERVIEW OF THE HISTORICAL DEVELOPMENT OF THE MICROSCOPE 1665 - He coined the term “cell” in his publication, Micrographia. He was the first to see a plant cell under a single lens microscope. Robert Hooke Inspired by Mission, Driven by Excellence OVERVIEW OF THE HISTORICAL DEVELOPMENT OF THE MICROSCOPE 1676 - He first to see living cells using his own single lens microscope. - He examined blood cells, yeast, and insects. Antonie van Leeuwenhoek Inspired by Mission, Driven by Excellence OVERVIEW OF THE HISTORICAL DEVELOPMENT OF THE MICROSCOPE 1830 - He reduced spherical aberrations by using several weak lenses together at certain distances to get a good magnification without blurring the image. Joseph Lister Inspired by Mission, Driven by Excellence OVERVIEW OF THE HISTORICAL DEVELOPMENT OF THE MICROSCOPE 1874 - He introduced a mathematical formula that correlates resolving power to the wavelength of light. It made the calculation of the theoretical maximum resolution of a microscope possible. Ernst Abbe Inspired by Mission, Driven by Excellence OVERVIEW OF THE HISTORICAL DEVELOPMENT OF THE MICROSCOPE 1931 - They designed and built the first transmission electron microscope. The electron microscope does not depend on light but on electrons. It can visualize objects as the diameter of an atom. Maxx Knoll and Ernst Ruska Inspired by Mission, Driven by Excellence OVERVIEW OF THE HISTORICAL DEVELOPMENT OF THE MICROSCOPE 1932 - He invented the first phase contrast illumination which allows the imaging of transparent samples. Objects can be seen without staining. Frits Zernike Inspired by Mission, Driven by Excellence OVERVIEW OF THE HISTORICAL DEVELOPMENT OF THE MICROSCOPE 1942 - He invented the first scanning electron microscope. It transmits a beam of electrons across the surface of a specimen. Ernst Ruska Inspired by Mission, Driven by Excellence OVERVIEW OF THE HISTORICAL DEVELOPMENT OF THE MICROSCOPE 1957 - He introduced the principle of confocal imaging, which gives a resolution that is higher than that of conventional light. Marvin Minsky Inspired by Mission, Driven by Excellence OVERVIEW OF THE HISTORICAL DEVELOPMENT OF THE MICROSCOPE 1972 - They developed the Computerized Axial Tomography (CAT) scanner. It can generate cross- sectional views and three-dimensional images of internal organs and structures. Inspired by Mission, Driven by Excellence OVERVIEW OF THE HISTORICAL DEVELOPMENT OF THE MICROSCOPE 1978 - They developed the first practical confocal laser scanning microscope. This instruments uses focused laser beams to scan objects. Thomas and Cristoph Cremer Inspired by Mission, Driven by Excellence OVERVIEW OF THE HISTORICAL DEVELOPMENT OF THE MICROSCOPE 1981 - They invented the scanning tunneling microscope (STM). It can visualize individual atoms within materials. Gerd Binnig and Heinrich Rohrer Inspired by Mission, Driven by Excellence OVERVIEW OF THE HISTORICAL DEVELOPMENT OF THE MICROSCOPE 1986 - Ernst Ruska won the Noble Prize for his contributions to the study of microscopy. - A noble Prize was also awarded Binnig and Rohrer. Ernst Ruska Gerd Binnig and Heinrich Rohrer Inspired by Mission, Driven by Excellence OVERVIEW OF THE HISTORICAL DEVELOPMENT OF THE MICROSCOPE 1992 - He cloned the green fluorescent protein that he used in fluorescent microscopy. Douglas Prasher Inspired by Mission, Driven by Excellence OVERVIEW OF THE HISTORICAL DEVELOPMENT OF THE MICROSCOPE 1993-1996 - He pioneered the first super-resolution microscopy. Stefan Hell (STimulated Emission Depletion) microscopy Inspired by Mission, Driven by Excellence OVERVIEW OF THE HISTORICAL DEVELOPMENT OF THE MICROSCOPE 2010 - Researchers at the University of California, Los Angeles used a cryoelectron microscope to see the atoms of a virus. University of California, Los Angeles Inspired by Mission, Driven by Excellence OVERVIEW OF THE HISTORICAL DEVELOPMENT OF THE MICROSCOPE 2014 - They got the Nobel prize in Chemistry for the super microscopes they invented. - It can see matter smaller than 0.2 μm Inspired by Mission, Driven by Excellence  THE PARTS OF THE MICROSCOPE AND THEIR FUNCTIONS Ocular lens x Example: 10x Objective X 10x= 100x lens= Total (100 times magnification larger) Inspired by Mission, Driven by Excellence  OCULAR LENS/ EYEPIECE EYEPIECE TUBE/BODY TUBE REVOLVING NOSEPIECE ARM OBJECTIVES STAGE CLIP STAGE COARSE AJUSTMENT KNOB IRIS DIAPHRAM FINE ADJUSTMENT KNOB LIGH SOURCE BASE Inspired by Mission, Driven by Excellence I. MECHANICAL PARTS - It involves in giving support or strength to the instrument. - Movable and can be adjusted. a. BODY TUBE- a hollow tube through which light passes from the objective to the eyepiece. b. REVOLVING NOSEPIECE- Hold the objectives. It can be rotated to select the appropriate objective. The lenses must be “clicked” into place to successfully view a specimen. c. ARM- Connects the base and the body tube together. It serves as a handle for carrying the microscope. d. STAGE CLIP- Holds the slide in place. e. STAGE- The platform where the slide or specimen to be examined is placed. It has an opening at the center that allows light to pass from below to the specimen. f. BASE- The part where the microscope is firmly anchored. It gives support to the whole microscope and is the part where the illuminators are attached. g. INCLINATION JOINT- a joint found in some microscopes at which the arm is attached to the pillar of the microscope. It is used for tilting the microscope. Inspired by Mission, Driven by Excellence  II. ILLUMINATING PARTS - It provides and captures light for illumination. a. Mirror- Reflects light from the surroundings to the specimen on the stage. The concave side of the mirror is used for natural light while the flat side is used for artificial light. b. Condenser- Concentrates the light source or mirror onto the object of specimen being studied. It I located below the stage, and it is held in place by a rack. c. Iris diaphragm- Regulates the amount of light that reaches the specimen. It is attached beneath the condenser. Inspired by Mission, Driven by Excellence  III. MAGNIFYING PARTS - Involved in magnifying the image of the specimens, including the resolution. a. EYEPIECE/OCULAR- The part through which an observer looks to view a specimen. It usually has a magnification of 10x, though eyepieces with 4x to 30x magnification are also available. b. OBJECTIVES- The main lenses that magnify the specimen being observed. Usually, microscopes have three objectives, but more modern ones house for or even five objectives. Typical objectives have magnifying powers of 4x, 10x, 40x, and even 100x. Inspired by Mission, Driven by Excellence Inspired by Mission, Driven by Excellence Watch and Learn cum Timeline-Making Inspired by Mission, Driven by Excellence Watch and Learn cum Timeline-Making Inspired by Mission, Driven by Excellence  Key Questions: 1. Who are the scientists behind the cell theory? 2. Explain the different postulates of the cell theory. Inspired by Mission, Driven by Excellence  Key Questions: 1. Who are the scientists behind the cell theory? - Robert Hooke - Anton van Leeuwenhoek “Father of Microbiology” - Theodore Schwann - Matthias Jakob Schleiden - Rudolf Virchow Inspired by Mission, Driven by Excellence  Key Questions: 2. Explain the different postulates of the cell theory. a. All living organisms composed of one or more cells. b. Cell is the basic unit of life. c. All cells arise only from pre-existing cells. Inspired by Mission, Driven by Excellence  CELL THEORY: THE UNIFYING FOUNDATION OF CELL BIOLOGY Inspired by Mission, Driven by Excellence ROBERT BROWN - Botanist - In 1820s, he first observed the spherical structure in plant cells. - “nucleus” THEODORE SCHWANN - Zoologist - He discovered the presence of cells in animal tissues. Inspired by Mission, Driven by Excellence MATTHIAS SHLEIDEN - Botanist - He concluded that all plant tissues are composed of cells. RUDOLF VIRCHOW - Physician by profession - He studied the growth and development of cells and discovered that all cells arise from pre existing cells. Inspired by Mission, Driven by Excellence TENETS/POSTULATES: a. Cells are the smallest unit of life. All living things are composed of one or more cells. b. Cells are the basic unit of organization of all organisms. c. Cells come from preexisting cells. Inspired by Mission, Driven by Excellence Two additional key points: a. Cells carry and pass on the offspring heredity units during cell division. b. All cells are relatively the same in terms of chemical composition and metabolic activity. Inspired by Mission, Driven by Excellence CELL STRUCTURES AND THEIR FUNCTIONS Inspired by Mission, Driven by Excellence CELL SIZE Bacterial cell- 1-10 μm Plant and animal cells- 10-50 μm Inspired by Mission, Driven by Excellence CELL SHAPE Neuron/ Nerve cell - has a cytoplasmic extensions, such as axons and dendrites, that are Pyramid type shape important in the performance of its functions. Inspired by Mission, Driven by Excellence CELL SHAPE Skin Cell - Flat cells that help cover the body from the external environment. Inspired by Mission, Driven by Excellence CELL SHAPE Blood cells - Can change shape, helping them digest and kill disease- causing germs that invade the body. Inspired by Mission, Driven by Excellence CELL SHAPE Leaf cell - More ball-shaped - A single leaf cell may be designed to simply photosynthesize, or create sugars from the energy in light. Inspired by Mission, Driven by Excellence CELL SHAPE Pollen cell - Round, ovule, triangular, disc or in a bean-shape with a smooth to spiky texture. - Used for transferring haploid male genetic material from the anther of a single flower to the stigma of another in cross-pollination. Inspired by Mission, Driven by Excellence CELL SHAPE Plant root hair cell - Cylindrical in shape - Serves to increase the surface area of plant roots and help the plant extract more water from the soil as well as more efficiently extract nutrients from the soil. Inspired by Mission, Driven by Excellence CELL SHAPE Sperm cell - An oval head with a long tail - Provides half of the genetic material needed to form a fertilized zygote or embryo during sexual reproduction with an egg in the female body. Inspired by Mission, Driven by Excellence INTERNAL ORGANIZATION For example, a plant and animal cell. - These two cells show great variations in parts because they function differently to perform specific task. For example, glandular cell. - Produces secretory materials such as mucus and hormones, which is why they are provided with more ribosomes and Golgi bodies. Muscle cells, on the other hand, are provided with more mitochondria to produce more energy needed in muscle contraction. Inspired by Mission, Driven by Excellence