Pharmaceutical Botany with Taxonomy Laboratory PDF

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BIO |Science - BiologyLesson 1: Cell Cycle and Reproduction ______________________________________________________Objectives | The student will be able to identify the phases of the cell cycle and mitotic stages by description and or graphic representation.Some DefinitionsSomatic Cells - body cells ...

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BIO | Science - Biology Lesson 1: Cell Cycle and Reproduction ______________________________________________________

Objectives | The student will be able to identify the phases of the cell cycle and mitotic stages by description and or graphic representation. Some Definitions Somatic Cells - body cells ● Produced through mitosis ● Has 46 chromosomes (23 pairs) Homologous Chromosomes – each member of a chromosome pair Diploid (2n) – total of 46 chromosomes in people – zygote & somatic cells Haploid (n) – total of 23 chromosomes in people, gametes (sperm & egg)

The Cell Cycle | The sequence of growth and division of a cell. 95% of cell cycle in interphase 5% of cell cycle in mitosis

Chromosomes | Genetic information is passed from one generation to the next on chromosomes. Before cell division, each chromosome is duplicated, or copied.

Interphase Growth Stage 1 (G1) Synthesis Stage (S) Growth Stage 2 (G2) Events of the Cell Cycle During G1 (Growth Stage 1) Cell increases in size synthesizes new proteins and organelles During the S phase (Synthesis Phase), chromosomes are replicated DNA synthesis takes place ● Once a cell enters the S phase, it usually completes the rest of the cell cycle. The G2 Phase (Second Growth Phase) organelles and molecules required for cell division are produced Once G2 is complete, the cell is ready to start the M phase—Mitosis Each chromosome consists of two identical “sister” chromatids. Each pair of chromatids is attached at an area called the centromere.

Mitosis | Happens in all cells Cell division process 5 major stages Prophase Nuclear envelope disappears

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Chromosomes condense – can see sister chromatids and centromere Spindle forms

Why would a cell need to divide? GQ- Can a cell just keep getting bigger and bigger? Think about it: Mr. Whitaker’s classroom supply rule Has your body changed in the past six months? How did you recognize this change? Has anyone broken a bone or required stitches? How does your body repair itself? ● Cells have to make more of themselves to repair wounds, heal bones, replace worn-out cells, and to allow an organism to grow in size. Cell Division | is the process by which a cell divides into 2 new daughter cells ● Solves the problem of information overload on cell resources ● Increases the surface area to volume ratio so that diffusion can efficiently reach the interior of the cell. What is reproduction? ● The Cell theory says that all cells come from pre-existing cells. Reproduction | the formation of new individuals from existing individuals. ● One of the most important characteristics of living things. ● There are two types of reproduction: ○ Asexual reproduction ○ Sexual reproduction

EQ: What is the Cell Cycle? Cell Cycle | Is the series of events that cells go through as they grow and divide. There are 4 stages: G1- cells grow S- DNA replicates G2- organelles double M- mitosis and cytokinesis The cell cycle is a continuous process Chromosomes | are bundles of Genetic information known as DNA ● The chromosome is made up of super condensed chromatin: a complex of DNA and histones (a protein) ● The coiling of chromatin into a chromosome allows for the equal division of the DNA during cell division Chromosome structure Chromatid | one of the two copies of the genetic material of a cell. Centromere | attachment site for the sister chromatids. Holds them together.

EQ: What is asexual reproduction? Asexual reproduction | Production of new organisms from a single parent cell or organism.

Human Karyotype

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Does not involve the fusion of nuclei New organisms are identical to the parent. Involves both cell division and genetic material

Examples of Asexual reproduction

Interphase | Often called the Resting phase ● 3 phases of cell cycle are in interphase ● What happens: ○ Cell grows in size- G1 ○ DNA replicates - S

Anaphase | chromosomes are pulled apart at the centromere by the spindle fibers ● The separated Chromatids move to opposite poles GQ: Why is it important for the DNA to replicate before the cell divides? So that each new daughter cell will have a complete copy of the DNA

EQ: What is Mitosis: Mitosis | An orderly series of changes in the nucleus ● Comes after the exact duplication of the complete set of chromosomes in a cell ● Involves the equal separation of these chromosomes into two new nuclei Each nuclei gets a complete set of chromosomes 4 Stages of Mitosis:

Prophase | DNA forms chromosomes - (Chromosomes Condenses or coils) ● Spindle forms ● Centrioles move toward opposite poles ● Nuclear membrane starts to disappear

Metaphase | Nucleus has disappeared completely ● Chromosomes line up in the middle of the cell “equator”

Telophase | Nuclear membrane forms around each group of chromosomes ● Chromosomes uncoil ● Cytokinesis begins Cytokinesis | the separation of the cytoplasm to divide the two new nuclei into separate cells. It starts towards the end of Telophase. It results in the formation of 2 cells.

Animal Cell Vs. Plant Cell While both animal and plant cells have similar cell cycles and proceed through the same stages of mitosis, there are two significant differences: 1). In cytokinesis: • In animal cells, the plasma membrane pinches in forming a cleavage furrow which form two new cells. • In plant cells, a cell plate forms between the cells. 2). Plant cells do not have centrioles to attach to the spindle fibers. End result of mitosis 1. Two daughter cells are formed 2. Each daughter cell contains the exact kind and number of chromosomes form the parent cell.

EQ: What is sexual reproduction Sexual Reproduction | The production of a new organism that involves two parent organisms Each parent contributes 1/2 of the genetic material for the new individual. Involves the fusion of nuclei New individual is NOT identical to either parent Cell Division in Sexual Reproduction

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Some gametes will have too many chromosomes, others will not have enough. *Can be a source of disease and syndromes. People with Downs syndrome have an extra chromosome (trisomy 21)

d). Telophase I - Nuclear membrane reforms around chromosomes e). Cytokinesis takes place forming two new cells. note: cross this line off in your notes. However, the genetic material is not like the parent cell.

Diploid: 2N means that a cell has two sets of chromosomes. Humans have 23 pairs of chromosomes. The diploid number is 46. Haploid:1N means that a cell has only a single set of chromosomes. Gametes are cells that are haploid Gametogenesis: process in which gametes are produced Occurs in the gonads (ovaries, testes) Results in cells that are haploid. When gametes (1N) combine a diploid (2N) zygote is formed EQ: What is Meiosis? Meiosis | type of cell division where number of chromosomes are cut in half. ● Produces 4 haploid cells from one diploid cell. ● There are two distinct divisions in Meiosis. ○ Meiosis I ○ Meiosis II

Process of Meiosis II ● The cells produced in the first division now enter a second round of division known as Meiosis II. ● NO Chromosome Replication takes place between the end of Meiosis I and the start of Meiosis II. ● The phases are similar to mitosis and Meiosis I and are called prophase II, metaphase II, anaphase II, and telophase II.

Process of Meiosis I ● Consists of Interphase, Prophase I, Metaphase I, Anaphase I, and Telophase I. ● The phases in Meiosis I are similar to those in Mitosis except for a few things: a). In Prophase 1: Synapsis occurs. ● This is when the matching (homologous) chromosomes join to form a tetrad. What is the importance of Synapsis and tetrad formation? ● ● ●

Tetrads contain 4 sister chromatids called homologous pairs Allows for exchange of segments between the chromatids by a process called Crossing Over. Crossing over increases genetic variability

Process of Meiosis I b). Metaphase I: Tetrads line up at the equator c). Anaphase I: Tetrads separate from each other and move to the poles of the cell. Occasionally the tetrads do not separate correctly. This is called nondisjunction. Importance of Nondisjunction ● Nondisjunction results in an unequal division of the chromosomes. ● Why might this be a problem?

Result of Meiosis ● Formation of 4 daughter cells ● Each daughter cell is haploid: contains only 1 set of chromosomes Meiosis in sexual reproduction Spermatogenesis: 1. in testes, males produce sperm 2. Each sperm contains 23 chromosomes 3. Each sperm is motile Oogenesis: 1. In ovaries, eggs (ova) are produced 2. 4 cells are produced, only one becomes an egg 3. The three remaining ones are small and degenerate. They are called polar bodies. Karyotype of a gamete produced by meiosis

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Cancers are caused by defects in genes that regulate cell growth and division. Some sources of gene defects are smoking tobacco, radiation exposure, defective genes, and viral infection. A damaged or defective p53 gene is common in cancer cells. It causes cells to lose the information needed to respond to growth signals.

Lesson 1: CELL STRUCTURE and TISSUES ______________________________________________________

From One Cell to Many THINK ABOUT IT ● The human body contains over a 100 Trillion cells all of which came from a single cell, the fertilized egg called the zygote ● There are hundreds of different cell types that perform different functions. ex: liver cells, red blood cells, nerve cells How do the cells get to be so different from each other? ● The process by which cells become specialized is known as differentiation. ● Differentiation is controlled by genes, the genetic instructions encoded in the DNA of every cell ● Genes instruct each cell how and when to build the proteins that allow it to create the structures, and perform the functions, specific to its type of cells

Cell Theory | Detailed study of the cell began in the 1830s ● A unifying concept in biology ● Originated from the work of biologists Schleiden and Schwann in 1838-9 ● States that: ○ All organisms are composed of cells ○ German botanist Matthais Schleiden in 1838 ○ German zoologist Theodor Schwann in 1839 ● All cells come only from preexisting cells ○ German physician Rudolph Virchow in 1850’s ● Cells are the smallest structural and functional unit of organisms Organisms and Cells

Stem Cells Embryonic Stem Cells | Researchers have grown stem cells isolated from human embryos in culture. ● Their experiments confirmed that embryonic stem cells have the capacity to produce most cell types in the human body. Adult Stem Cells | Adult organisms contain some types of stem cells. ● They can produce many types of differentiated cells. ● Adult stem cells of a given organ or tissue typically produce only the types of cells that are unique to that tissue.

Sizes of Living Things

Cell cycle regulation | There are regulatory proteins that control the cell cycle so that cells do not grow and divide continually when new cells are not needed ● These proteins are called cyclins ● The genes that produce regulatory proteins can be turned on and off like a switch. Ex: p53, Mad1 What happens when the controls fail? ● When the controls of the cell cycle fail, cell growth and division goes unchecked. ● Cancer is a disorder in which body cells lose the ability to control cell growth. Cancer cells divide uncontrollably to form a mass of cells called a tumor. What Causes Cancer?

Cell Size | Cells range in size from one millimeter down to one micrometer ● Cells need a large surface area of plasma membrane to adequately exchange materials. ● The surface-area-to-volume ratio requires that cells be small

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Large cells - surface area relative to volume decreases Volume is living cytoplasm, which demands nutrients and produces wastes Cells specialized in absorption utilize membrane modifications such as microvilli to greatly increase surface area per unit volume

Transmission Electron Microscope

Surface to Volume Ratio

Microscopy Today: Compound Light Microscope ● Light passed through specimen ● Focused by glass lenses ● Image formed on human retina ● Max magnification about 1000X ● Resolves objects separated by 0.2 m, 500X better than human eye

Microscopy Today: Scanning Electron Microscope ● Abbreviated S.E.M. ● Specimen sprayed with thin coat of metal ○ Electron beam scanned across surface of specimen ○ Metal emits secondary electrons ● Emitted electrons focused by magnetic lenses ● Image formed on fluorescent screen ○ Similar to TV screen ○ Image is then photographed

Scanning Electron Microscope

Compound Light Microscope

Microscopy Today: Transmission Electron Microscope ● Abbreviated T.E.M. ● Electrons passed through specimen ● Focused by magnetic lenses ● Image formed on fluorescent screen ● Similar to TV screen ○ Image is then photographed ○ Max magnification 1000,000sX ● Resolves objects separated by 0.00002 m, 100,000X better than human eye

Microscopy Today: Immunofluorescence Light Microscope ● Antibodies developed against a specific protein ○ Fluorescent dye molecule attached to antibody molecules ○ Specimen exposed to fluorescent antibodies ● Ultra-violet light (black light) passed through specimen ○ Fluorescent dye glows in color where antigen is located ○ Emitted light is focused by glass lenses onto human retina ● Allows mapping distribution of a specific protein in cell

○ Microscopy Today: Confocal Microscopy ● Narrow laser beam scanned across transparent specimen ● Beam is focused at a very thin plane ● Allows microscopist to optically section a specimen ○ Sections made at different levels ○ Allows assembly of 3d image on computer screen that can be rotated

Glycocalyx - layer of polysaccharides on the outside of the cell wall ■ Well organized and resistant to removal (capsule)

Microscopy and Amoeba proteus

Microscopy and Cheek Cells

Prokaryotic Cells | Lack a membrane-bound nucleus ● Structurally smaller and simpler than eukaryotic cells (which have a nucleus). ● Prokaryotic cells are placed in two taxonomic domains: ○ Bacteria ○ Archaea ■ Live in extreme habitats ○ Domains are structurally similar but biochemically different

The Structure of Bacteria ● Extremely small - 1–1.5 μm wide and 2–6 μm long ● Occur in three basic shapes: ○ Spherical coccus, ○ Rod-shaped bacillus, ○ Spiral spirillum (if rigid) or spirochete (if flexible). ● Cell Envelope includes: ○ Plasma membrane - lipid bilayer with imbedded and peripheral protein ■ Form internal pouches (mesosomes) ○ Cell wall - maintains the shape of the cell and is strengthened by peptidoglycan

The Structure of Bacteria Cytoplasm & Appendages ● Cytoplasm ○ Semifluid solution ■ Bounded by plasma membrane ■ Contains water, inorganic and organic molecules, and enzymes. ○ Nucleoid is a region that contains the single, circular DNA molecule. ○ Plasmids are small accessory (extrachromosomal) rings of DNA ● Appendages ○ Flagella – Provide motility ○ Fimbriae – small, bristle-like fibers that sprout from the cell surface

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Sex pili – rigid tubular structures used to pass DNA from cell to cell

Cell Fractionation and Differential Centrifugation ●

Eukaryotic Cells ● Domain Eukarya includes: ○ Protists ○ Fungi ○ Plants ○ Animals ● Cells contain: ○ Membrane-bound nucleus that houses DNA ○ Specialized organelles ○ Plasma membrane ○ Much larger than prokaryotic cells ○ Some cells (e.g., plant cells) have a cell wall

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Cell fractionation is the breaking apart of cellular components Differential centrifugation: ○ Allows separation of cell parts ○ Separated out by size & density Works like spin cycle of washer The faster the machine spins, the smaller the parts that are settled out

Hypothesized Origin of Eukaryotic Cells

Animal Cell Anatomy

Eukaryotic Cells: Organelles ● Eukaryotic cells are compartmentalized ○ They contain small structures called organelles ■ Perform specific functions ■ Isolates reactions from others ● Two classes of organelles: ○ Endomembrane system: ■ Organelles that communicate with one another ■ Via membrane channels ■ Via small vesicles ○ Energy related organelles ■ Mitochondria & chloroplasts ■ Basically independent & self-sufficient

Plant Cell Anatomy

Plasma Membrane

Nucleus ● Command center of cell, usually near center

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Separated from cytoplasm by nuclear envelope ○ Consists of double layer of membrane ○ Nuclear pores permit exchange between nucleoplasm & cytoplasm Contains chromatin in semifluid nucleoplasm ○ Chromatin contains DNA of genes, and proteins ○ Condenses to form chromosomes ■ Chromosomes are formed during cell division Dark nucleolus composed of rRNA ○ Produces subunits of ribosomes

Anatomy of the Nucleus

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Are the site of protein synthesis in the cell Composed of rRNA ○ Consists of a large subunit and a small subunit ○ Subunits made in nucleolus May be located: ○ On the endoplasmic reticulum (thereby making it “rough”), or ○ Free in the cytoplasm, either singly or in groups, called polyribosomes

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Consists of: ○ Nuclear envelope ○ Membranes of endoplasmic reticulum ○ Golgi apparatus ○ Vesicles ■ Several types ■ Transport materials between organelles of system

Endomembrane System: The Endoplasmic Reticulum ● A system of membrane channels and saccules (flattened vesicles) continuous with the outer membrane of the nuclear envelope ● Rough ER ○ Studded with ribosomes on cytoplasmic side ○ Protein anabolism ■ Synthesizes proteins ■ Modifies and processes proteins ■ Adds sugar to protein ■ Results in glycoproteins ● Smooth ER ○ No ribosomes ○ Synthesis of lipids ○ Site of various synthetic processes, detoxification, and storage ○ Forms transport vesicles Endoplasmic Reticulum

Nucleus, Ribosomes, & ER

Endomembrane System: The Golgi Apparatus ● Consists of 3-20 flattened, curved saccules ● Resembles stack of hollow pancakes ● Modifies proteins and lipids ○ Receives vesicles from ER on cis (or inner face) ○ Packages them in vesicles ○ Prepares for “shipment” in v Packages them in vesicles from trans (or outer face) ■ Within cell ■ Export from cell (secretion, exocytosis) Endomembrane System ● Series of intracellular membranes that compartmentalize the cell ● Restrict enzymatic reactions to specific compartments within cell

Endomembrane System: Lysosomes ● Membrane-bound vesicles (not in plants) ○ Produced by the Golgi apparatus ○ Contain powerful digestive enzymes and are highly acidic ■ Digestion of large molecules ■ Recycling of cellular resources ■ Apoptosis (programmed cell death, like tadpole losing tail) ● Some genetic diseases ○ Caused by defect in lysosomal enzyme ○ Lysosomal storage diseases (Tay-Sachs) Lysosomes

Endomembrane System: Summary ● Proteins produced in rough ER and lipids from smooth ER are carried in vesicles to the Golgi apparatus. ● The Golgi apparatus modifies these products and then sorts and packages them into vesicles that go to various cell destinations. ● Secretory vesicles carry products to the membrane where exocytosis produces secretions. ● Lysosomes fuse with incoming vesicles and digest macromolecules Endomembrane System: A Visual Summary

.Peroxisomes ● Similar to lysosomes ○ Membrane-bounded vesicles ○ Enclose enzymes ● However ○ Enzymes synthesized by free ribosomes in cytoplasm (instead of ER) ○ Active in lipid metabolism ○ Catalyze reactions that produce hydrogen peroxide H2O2 ■ Toxic ■ Broken down to water & O2 by catalase

Vacuoles ● Membranous sacs that are larger than vesicles ○ Store materials that occur in exce...