Biology 2nd Quarter (Ppt Notes + Other Notes)

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  • 8/3/2019 Biology 2nd Quarter (Ppt Notes + Other Notes)

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    Amica !

    Biology 2nd

    Quarter

    I. Origin of LifeA. Formation of the Universe

    Big Bang Theory- massive blast allowed all the universe's known

    matter and energyeven space and time

    themselvesto spring from some ancient and

    unknown type of energy

    Biological Evolution- Populations of organisms change over the

    course of many generations (genetic changes)

    B. Formation of The Solar System Explosion of a Super Nova

    - disturbed cloud of gas and dust- cloud grew hotter and denser in the center (hot

    center, cool edges)

    C. Formation of the EarthStage 1: Origin of Organic Molecules (Nucleotides and

    amino acids were produced prior to the existence of

    cells)

    Alexander Oparin- One of the two scientists who independently

    hypothesized the abiotic formation of organic

    compounds

    - Coacervates (stable, mostly hydrophobic)** Microspheres cool water + organic compounds

    JBS Haldane- One of the two scientists who independently

    hypothesized the abiotic formation of organic

    compounds

    Prebiotic Soup // Primordial Soup- Abiotic synthesis of small organic molecules

    amino acids and nucleotides

    - Slow accumulations of molecules in earlyoceans over a long period of time

    - Key event that preceded the origin of life Reducing Atmosphere Hypothesis

    - Primitive earth was rich in H20, H2, CH4, NH3;no oxygen

    - Later concluded that atmosphere was notreducing but was a neutral environment mostly

    of CO2, CO, N2, H20 (UV destroys CH4 & NH3)

    Extraterrestrial Hypothesis- Sufficient organic carbon would have been

    present in the asteroids and comets

    Why Spontaneous Generation cannot happen today:1. because atmosphere is oxygen rich2. oxidizing atmosphere today not conducive3. o2 attacks chemical bonds extracting electrons4. less UV radiation that helps in forming organic

    molecules

    Spontaneous Generationa. Francesco Redi- Flies produce maggots- Conclusion: maggots form only when fibers

    come in contact with the meat

    b. John Needham- Spontaneous generation could occur under the

    right conditions

    - Sealed and heated bottle of gravyc. Lazaro Spallanzani- Needham had not heated his samples enough- Microorganisms in the concealed jar were off

    springs of microorganisms that had entered the

    jar through the air

    d. Louis Pasteur- S shaped flask- All living things come from other living things

    Harold Urey- One of two scientists who tested the Oparin-

    Haldane Hypothesis

    - Teacher Stanley Miller

    - One of two scientists who tested the Oparin-Haldane Hypothesis

    - Student

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    Rain or

    waves

    Dilutesolutions ofmonomers

    LAVAProteinoids

    andpolymers

    water

    Experiment:

    Early atmosphere - H2O, H2, CH4, NH3, CO, CO2,N2, water vapour

    The experiment had produced - 20 Amino acidsfound in organisms, sugars, lipids, purines,

    pyrimidines, even ATP

    ** Lab simulations of the early earth conditions produced

    organic polymers

    ** Natural process in organisms: Enzymes catalyze reactions

    Sydney Fox- Protenoids: polypeptides from abiotic means

    Stage 2: Organic polymers from surface of clay (nucleotides

    and amino acids polymerized)

    J. Bernal- Prebiotic synthesis of polymers took place on

    clay

    A. G. Cains-Smith- clays might have been the first templates for

    self-replicating systems

    - Pyrite: Charged surfaceStage 3: Cell-like structures when polymers were enclosed by

    a boundary (polymers in membranes)

    Protobionts- Aggregates of abiotically produced molecules

    that cant reproduce precisely

    - First non-living structures that evolved intoliving cells

    - Boundary separated it from the externalenvironment

    - Polymers contained information- Polymers had enzymatic functions- Capable of self replication but not precisely

    Coacervates (Oparin)- Droplets that form spontaneously from

    association of charged polymers (cluster)

    Liposomes- Vesicles surrounded by a lipid bilayer

    Microspheres- Small water filled vesicles surrounded by a

    macromolecular boundary

    Stage 4: Cellular Properties via Chemical Solution; RNA World

    RNA- first genetic material- short polymers of ribonucleotides have been

    produced abiotically in the laboratory

    - revolution thinking about the evolution of lifewhen they discovered that RNA molecules are

    important catalysts in modern cells

    - ribosomes use rna catalyts: rRNA (ribosomal),tRNA(transcription) and mRNA(messenger)

    - capable of self replication RNA World

    - When both information needed for life andenzymatic activity for living cells were

    contained only in the RNA molecules

    DNA- Stores information for the amino acid sequence

    of proteins

    Central Dogma- DNA, RNA and Protein- DNA RNA (transcription)- RNA DNA (reverse transcription retro

    viruses)

    - RNA Proteins (translation) 5 Descriptions of FIRST LIFE

    1. Unicellular2. Asexually reproducing3. Aquatic environment4. RNA containing5. Heterotrophic

    II. Cell: Organic Unit of Life Cell

    - basic unit of structure and function- Can be:o Unicellularo Multicellular - Bodies are cooperative of

    specialized cells; Cannot survive for long on

    their own

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    How do we study cells?- Telescope // Microscope- Anton von Leeuwenhoek: first to explore

    things: microscopic view

    ESSENTIAL SCIENTISTS

    a. Robert Hooke- Cells composed of thousands of chambers

    b. Robert Bown- Nucleus: Dark structure

    c. Matthias Schleiden- all plants are made up of cells

    d. Theodor Schwann- all animals are made up of cells

    e. Rudolf Virchow- Cells arise from the division of pre-existing cells

    CELL THEORY most fundamental discovery: nature of living things forms basic framework formulated by Schwann, Schleiden and Virchow

    States that:

    all living things are composed of cells cells are the basic unit of structure and function all cells come from pre-existing cells

    PROKARYOTIC VS EUKARYOTIC

    ORGANELLES

    Nucleus- contains most of the genes*Nuclear envelope

    > Encloses nucleus

    > Double membrane (lipid bilayer with proteins)

    Nuclear lamina - netlike array of proteinfilaments maintains the shape of the nucleus

    Nucleolus - Site: components of ribosomes aresynthesized and assembled; Components pass

    through the nuclear pore to the cytoplasm;

    Appears as a mass of densely stained granules

    and fibers adjusting part of chromatin

    Ribosomes- Protein factory- cells with active protein synthesis- prominent nucleoli- Free ribosomes: cytosol- Bound ribosomes: for inclusion, transport,

    packaging

    ENDOMEMBRANE SYSTEM

    Membranes that are related either: direct physicalcontinuity or transfer of membrane segments

    Includes: VAly PLAne GOerNuclear Envelope, ER, Golgi Apparatus, Lysosomes,

    Vacuoles, Plasma Membrane

    Endoplasmic Reticulum- more than half the total membrane of cells- reticulum Greek word for networka. Smooth ER

    o Smooth walls of the sacs are not studdedwith ribosomes

    o Functions: SYLIP me car DE DRUPSynthesis of lipids

    Metabolism of carbohydrates

    Detoxification of drugs and poison

    b. Rough ERo studded with ribosomeso Functions:

    synthesis of secretory protein

    membrane production

    synthesis of proteins

    Golgi Apparatus- Center of: MWSS

    Manufacturing Warehousing Sorting Shipping

    - Products from the ER are: SMS Modified Stored Sent to other destinations

    Vacuoles- membrane bound sacs in a cell- Repository of inorganic ions- Storage of pigments- Helps to protect against predators- food vacuole- formed by phagocytosis- Contractile vacuole

    Pumps out water out- Central Vacuole- filled with liquid

    PROKARYOTIC

    Pro- before Karyon- kernel no nucleus DNA: concentrated in

    a NUCLEOID

    With cytoplasm w/ Plasma Membrane

    EUKARYOTIC

    Eu- true Karyon- kernel Has NUCLEUS With cytoplasm

    Cytosol w/ Plasma Membrane

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    Tonoplast organic compounds (proteins in seed) Disposal sites for metabolic products

    Lysosomes- membrane bounded sacs of hydrolytic enzymes- digestion of macromolecules-

    works best in acidic medium ~pH 5- maintains internal pH- excessive leak of a large number- leads to auto digestion

    Plasma Membrane- Controls traffic into and out of the cell- Selective permeable- Membrane structure: Charles Overton - it is made of lipids- RBC- composed of lipids and proteins- made up of phospholipids- Amphiphatic Irvin Langmuir - Artificial membranes;

    Phospholipids in benzene* + water

    Gunter and F. Grendel - phospholipid bilayer;Suggests: stable boundary between two

    aqueous compartments; Measured lipid

    content in RBC

    S.J. Singer and G. Nicolson Fluid MosaicModel: mosaic of protein molecules in a fluid

    bilayer of phospholipids

    OTHER MEMBRANE ORGANELLES

    not part of Endo-Membrane System membranes not made by ER

    Free ribosomes and Ribomes of Mitochondriaand Cytoplasm

    contain small amounts of DNA semi- autonomous Mitochondria

    - power house of the cell- site of cellular respiration

    Catabolic process that generates ATP- number related to cells metabolic activity- enclosed by two membranes

    Outer- smooth Inner- convoluted with infoldings (cristae)

    Chloroplast- found in plants and eukaryotic algae- site of photosynthesis- Solar energy chemical energy- member of plastids- Amyloplasts- colorless, stores starch

    - Chromoplast- stores pigments- contains another membranous system THYLAKOIDS- flattened sacs- forms GRANA- bathed with stroma

    Peroxisomes- specialized metabolic compartment bounded

    by a single membrane

    - sontains enzymes that produces* H2O2 as a byproduct

    - Function:Use O2 to break Fatty acids

    Detoxify alcohol

    Transferring H2 from the poisons to oxygen

    Cytoskeleton- Organization of structures and its activities- Mechanical support- Maintains shape

    Important to animal cells- Anchorage for organelles- cell motility3 MAIN TYPES of FIBERS Microtubules - Straight hollow rods; Made from

    Tubulin; Shape and support; Tracks for

    organelles equipped with motor proteins;

    Involved in cell division

    Cilia and Flagella - Core of microtubulessheathed in an extension of the Plasma Mem.

    Microfilaments - Solid rods; bear tension Cell Wall

    - Plant cells only- Protection- Maintains shape- Prevents excessive uptake of water- Made up of cellulose

    Extracellular Matrix- Support; Adhesion; Movement; Regulation- Components: Collagen: forms strong fibers outside the cell;

    Protein rich in carbohydrates

    Fibronectin: attached to the ECM; Bind toreceptor proteins INTEGRIN*

    - Regulate cell behavior- Influence activity of genes

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    III. Terms in Microscopy Magnification

    - how much larger the object appears comparedto pts real size

    Resolving power- Measure of the clarity of the image-

    Minimum distance two points can be separatedand still be distinguished as 2 separate points

    Resolution- Limited by the wavelength of light used to

    illuminate the specimen

    TYPES OF MICROSCOPES

    a. Light Microscopes- visible light is passed through the specimen- lenses: refract light (image is magnified)- can magnify effectively to about 1000x the size

    of actual specimen

    b. Electron Microscope- focuses beam of electrons- uses shorter wavelengths- Resolution power: inversely proportional to the

    wavelength of radiation

    Transmission Electron Microscopeo aims an electron beam through a thin

    specimen

    o Uses electromagnetso image is focused on a screen or on

    photographic film

    o heavy metals for staining Scanning Electron Microscope- detailed study of the surface of specimen- electron beam scans the surface- coated with thin film of gold- electron beam excites the electron on the

    samples surface

    IV. DiseaseDisease

    -

    any change (other than an injury) that interferes withthe normal body function

    - impair normal tissue functionInfectious Disease

    - caused by infectious agents- acquired: contact w someone carrying disease;

    contaminated objects, food, air

    - Spread:olio virus contaious not virulent bolahemorrhaic fever virulent not contaious

    D: results from the invasion and growth of a pathogen; tissue

    function is impaired

    I: results when a pathogen invades and begins growing within a

    host; bodily function: normal

    Can be:

    a. Genetic (Cystic fibrosis, Hemophilia)b. Aging (Atherocslerosis, osteoporosis)c. Infectious (German measles, Chicken pox, Malaria)

    Pathogens

    - microorganisms that are capable of causing disease- infectious agent that causes disease in virtually any

    susceptible host

    Opportunistic Pathogens

    - potentially infectious agents- Found on

    elderly immuno suppressed cancer patients immuno- compromised people who have AIDS or are HIV-positive (immuno-

    compromised

    Types:

    a. Viral Infections (colds, influenza, measles, chickenpox, West Nile virus, hepatitis, AIDS)

    b. Bacterial infection (pneumonia, strep throat, boils,acne, streptococcal infection, bubonic plague, and

    anthrax)

    c. Protozoan infections (Malaria, amoebiasis andDiarrhea)

    d. Fungal infections (yeast infections, ringworm andathlete's foot)

    e. Helminthes Infection - simple, invertebrate animals,some of which are infectious parasites

    (Schistosomiasis Liver fluke disease)

    How they harm the host...

    1. enter the host body2. adhere to specific host cells (invade and colonize)3. multiply between host cells or within body fluids

    (cause tissue damage)

    4. production of toxins or destructive enzymesGerm Theory

    - states that microorganisms can cause diseases- infectious disease is caused by an infectious agent- Loius Pasteur, Robert Koch

    Robert Koch

    - use of agar as solid medium.- invented nutrient broth and nutrient agar

    Kochs ostulates

    1. The pathogen should always be found in the body ofa sick organism

    2. Pathogen should be grown and isolated in the lab inpure culture

    3. When placed in a new host, pathogen should causethe same disease

    4. Injected pathogen should be re-isolated

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    Vectors animals who carry the disease

    Modes of Infection:

    a. Direct contact with reservoirb. Indirect contact - when a pathogen can withstand the

    environment outside its host for a long period of time

    before infecting another individual

    c. ir - borne droplet infection colds, flu, sinusinfections, German measles

    d. Vectors - carry disease throuh other animals einsect bites typhus, rabies, H- fever, malaria, dengue

    Defense:

    Structural Defense- Skin, mucous membranes- perspiration salts and fatty acids- tears (contain lysozyme which can break down

    bacterial cell all

    - acid secretion in stomach l Cellular

    -

    Phagocytosis (leucocytes in WBC)

    Antibiotics- Interfere with the cellular process of microorganisms

    Specific mechanisms of host resistance

    - white blood cells called lymphocytes:- -cells produced from lymphocytes that matured in

    the thymus land

    - B-cells (produced from lymphocytes that matured inthe bone marrow)

    V. VirusesVirus

    - infectious agent (parasites of animals, plants andsome bacteria)

    - parasitic non-cellular particle- Consists of: nucleic acid core -protein coat- metabolism and reproduction: needs living cell / host

    Reproduction1. initiates the synthesis of viral proteins2. undergoes replication3. new viruses are released

    VIRUS VS. FREE LIVING CELLVIRUS

    Acellular can not live independently Either DNA or RNA

    FREE LIVING CELL

    can grow, reproduce, regulate gene expression can evolve independently

    Tobacco Mosaic Virus- bleached spots that form a pattern that farmers

    called a mosaic

    - leaves turn yellow, wither and fall off, killing the plant Dimitri Iwanowski

    - juice taken from diseased plants-

    placed extract on the leaves of healthy plants- healthy plants became infected

    Martinus Beijerinck- named the disease causin particle virus Latin for

    poison

    Wendell Stanley- chemically isolates and identifies the disease causing

    particle as the Tobacco Mosaic Virus (TMV)

    - through electron microscopyBASIC STRUCTURE

    CLASSIFICATION OF VIRUSES

    a. Genetic Material DNA or RNA (never both)b. Shapec. Sized. Presence of Envelope - enveloped viruses enclosed by a

    membrane (portion of host cell or nuclear membrane)

    e. Specificityf. Disease Type Prions

    - Infectious proteins- Scrapie in sheep- Creutzfeldt Jacob Disease- humans

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    Viroids- Naked circular molecules of RNA that infect plants- Disrupts plants metabolism

    LIFE CYCLE

    1. Infection - chance of contact2. Growth - DNA of the virus

    RNA polymerase viral mRNAwrecking crew

    3. Replication - 25min (in E. coli Lysogenic cycle temperate/ avirulent phage

    IMPORTANCE OF VIRUS

    Pathogenic- Defense vs. viral infection- Discovery of vaccines

    ORIGIN OF VIRUSES

    Pieces of cellular DNA became a part of an infectiousparticle

    Not likely to have been the 1st living things on earth Evolved from the genetic material of living cells