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MODULE 1 (A) CELL THEORIES  Learning Objectives explain the postulates of the cell theory describe the structure and function of major and subcellular organelles To compare/contrast the similarities/differences between plant and animal cell organelles CELL THEORY The Microscop...

MODULE 1 (A) CELL THEORIES  Learning Objectives explain the postulates of the cell theory describe the structure and function of major and subcellular organelles To compare/contrast the similarities/differences between plant and animal cell organelles CELL THEORY The Microscope and the Origins of Cell Biology As a major subfield of biology, Cytology, which is the study of the structures and functions of plant and animal cells, would not have grown and progressed if not for the discovery of the microscope. Image credit: https://en.wikipedia.org/wiki/Optical_microscope#/media/File:Opti cal_microscope_nikon_alphaphot_%2B.jpg  Cell Theory Timeline Rudolf Robert Hooke Matthias Virchow (1665) Schleiden (1858) (1838) Anton van Theodor Leeuwenhoek Schwann (1676) (1839)  Cell Theory Biologists 1. Robert Hooke was the first to illustrate and demonstrate cork cells in his 1665 book Micrographia. Image credit: https://en.wikipedia.org/wiki/Robert_Hooke#/media/File:13_Portrait_of_Ro bert_Hooke.JPG Image credit: https://en.wikipedia.org/wiki/Cork_cambium#/media/File:Cork_cambium_1.jpg  2. Anton van Leeuwenhoek was the first to observe blood and sperm cells with the use of the microscope. In his 1676 published works, he introduced the first unicellular organisms, which he called the animalcules. Image credit: https://en.wikipedia.org/wiki/Antonie_van_Leeuwenhoek#/media/File:Anthonie_van_Lee uwenhoek_(1632-1723)._Natuurkundige_te_Delft_Rijksmuseum_SK-A-957.jpeg  3. While working with his microscope, Matthias Schleiden discovered the plant cell out of which vegetative/meristemati c tissues and embryonic plants originated. Image credit: https://de.wikipedia.org/wiki/Matthias_Jacob_Schleiden#/media/File:Matthias_Ja cob_Schleiden_Botaniker_Jena_Th%C3%BCringen_Portrait_Stahlstich_um_185 0_b.jpg  4. Theodor Schwann discovered animal cells, particularly muscle and nerve fiber tissues now named as the Schwann cell in his honor. Image credit: Theodor Schwann Litho by Rudollf Hoffmann. Retrieved from https://en.wikipedia.org/wiki/Theodor_Schwann#/media/File:Theodor_Schwann_ Litho.jpg 5. Rudolf Virchow was the proponent of the Cell Theory’s 3rd postulate, which states that all cells come from pre-existing cells.  The Three Postulates of the Cell Theory 1. All living organisms are composed of one or more cells. 2. The cell is the basic unit of life in all living things. 3. All cells come from pre-existing cells.  Examples of Postulate 1 I. Unicellular Organisms a) Amoeba Image credit: A "Giant Amoeba” by Dr. Tsukii Yuuji. Retrieved from https://en.wikipedia.org/wiki/Amoeba#/media/File:Chaos_carolinense.jpg b) Bacteria Image credit: https://en.wikipedia.org/wiki/Ultrastructure#/media/File:Bacillus_subtilis.jpg c) Euglena Image credit: https://en.wikipedia.org/wiki/Euglena#/media/File:Euglena_sp.jpg d) Paramecium Image credit: Paramecium Aurelia by Barfooz. Retrieved from https://en.wikipedia.org/wiki/Paramecium#/media/File:Paramecium.jpg e) Protozoa Image credit: https://en.wikipedia.org/wiki/Protozoa#/media/File:Mikrofoto.de-Blepharisma_japonicum_15.jpg II. Multicellular Organisms a) Fungi b) Plant cells (Douglas fir tree wood stem cells) c) Animal cells (red blood cells of the chicken) Image credit: https://en.wikipedia.org/wiki/Blood#/media/File:Chickenrbc1000x.jpg d) Human cells (red blood cells) Image credit: https://en.wikipedia.org/wiki/Blood#/media/File:Humanrbc1000x.jpg Examples of Postulate 2 a) Breast cancer cells Image credit: https://en.wikipedia.org/wiki/Cancer_cell#/media/File:Breast_cancer_cells.jpg b) Human embryonic stem cells Image credit: ttps://commons.wikimedia.org/wiki/File:Human_embryonic_stem_cells_only_A.png b) Skin cells  MODULE 1 (B) CELL STRUCTURE AND FUNCTIONS  Learning Objectives explain the postulates of the cell theory describe the structure and function of major and subcellular organelles To compare/contrast the similarities/differences between plant and animal cell organelles CELL ORGANELLES AND FUNCTIONS  What Are Cell Organelles? Cell organelles (little organs) are separated membranous compartments inside the cells of the organs of living organisms. Image credit: https://en.wikipedia.org/wiki/Eukaryote#/media/File:Cell_animal.jpg Functions of Cell Organelles Maintain the shape and structure of cells Act as storage of nutrients Manufacture proteins Harvest energy Repair cell parts Digest substances  Cell Organelles 1. Cell membrane surrounds the cell to selectively screen the kinds of substances that go in and out of the cell. Image credit https://en.wikipedia.org/wiki/Eukaryote#/media/File:Cell_animal.jpg  2. Cytoplasm is a gel-like substance made from dissolved proteins and liquid encasing the cell and giving it a fluid nature. Image credit https://en.wikipedia.org/wiki/Eukaryote#/media/File:Cell_animal.jpg  3. Nucleus (only found in eukaryotic cells) stores the cell’s hereditary DNA and controls cellular activities like growth, metabolism, protein synthesis and reproduction. Image credit: https://en.wikipedia.org/wiki/File:Blausen_0212_CellNucleus.png  a. Nucleolus is a sub organelle of the nucleus composed of proteins and ribonucleic acids (RNA) whose role is to assemble rRNA codes for protein synthesis. Image credit: https://en.wikipedia.org/wiki/File:Blausen_0212_CellNucleus.png  b. Nuclear envelope is a double membrane lipid layer enclosing the nucleus to protect the DNA and nucleoplasm. Image credit: https://en.wikipedia.org/wiki/File:Blausen_0212_CellNucleus.png  c. Nuclear pores are permeable barriers that limit the entry of proteins and RNA but allow the free passage of water, ATP, ions and other small molecules. Image credit: https://en.wikipedia.org/wiki/File:Blausen_0212_CellNucleus.png  d. Nucleoplasm is a gelatinous liquid inside the nucleus containing the enzymes and nucleotides. Image credit: from https://en.wikipedia.org/wiki/Nucleoplasm#/media/File:Diagram_human_cell_nucleus.svg  e. Chromatin are cellular bundles made up of complex macromolecules of DNA, RNA and protein. Image credit: from https://en.wikipedia.org/wiki/Nucleoplasm#/media/File:Diagram_human_cell_nucleus.svg  4. Mitochondrion is the site of cellular respiration and the production of ATP energy molecules which gave it the title “powerhouse of the cell”. Image credit: https://en.wikipedia.org/wiki/File:Animal_mitochondrion_diagram_en_(edit).svg  5. Endoplasmic Reticulum (ER) is the network of membranous tubules that transport the materials needed by the cell (nutrients, enzymes, hormones, etc.). Image credit: https://en.wikipedia.org/wiki/Endoplasmic_reticulum#/media/File:Blausen_0350_EndoplasmicReticulum.png a. Rough Endoplasmic Reticulum The grainy rough structure comes from its attached ribosomes and is in charge of the manufacture of glycoproteins. b. Smooth Endoplasmic Reticulum The absence of ribosomes makes it smooth while taking charge of the metabolism/synthesis of carbohydrates, lipid, enzymes, etc.  6. Golgi bodies consist of stacks of flattened sacs called cisternae that receive proteins and fats from the rough ER for processing/packing into sealed droplets called vesicles that would then be stored and distributed to the other parts of the cell. Image Credit: https://en.wikipedia.org/wiki/Golgi_apparatus#/media/File:Blausen_0435_GolgiApparatus.png  7. Vacuole is a membrane- enclosed sac for storing essential materials while disposing off poisonous or harmful wastes. It is larger in plants, where it is known as tonoplast/central Image credit: vacuole that can flexibly https://en.wikipedia.org/wiki/Vacuole#/media/File:Plant_cell_structure_svg_vacuole.svg expand to absorb water.  8. Lysosome, is an organelle found only in animal cells that is responsible for intracellular digestion with the help of hydrolytic enzymes stored in its membranes that are powerful enough to break down macromolecules. Image credit: http://images.protopage.com/view/721661/d2xcwgacndd83n36ri3820g14.jpg 9. Chloroplast is found exclusively in plant cells and contains the green chlorophyll pigments which, together with the action of sunlight and H2O in the process called photosynthesis, manufactures food for the entire plant.  a. Thylakoid is a membranous compartment of flattened sacs that in turn are made up of several stacks called grana. This is the site of storage/distribution for the Image credit: https://opentextbc.ca/biology/wp-content/uploads/sites/96/2015/08/Figure_03_03_09- manufactured plant food. e14271309071452.jpg  b. Stroma is a highly concentrated fluid composed of enzymes, DNA, and ribosomes where with/without sunlight, photosynthesis occurs and carbon dioxide is converted to glucose. It is found in the external spaces of the thylakoid. Image credit: https://opentextbc.ca/biology/wp-content/uploads/sites/96/2015/08/Figure_03_03_09- e14271309071452.jpg  Rea,M.A, Dequillo, M.Z, and Chua,J.L (2017) General Biology 1;First Edition, Rex Bookstore, Manila City.  Retrieved from https://www.deped.gov.ph/wp- content/uploads/2019/01/General-Biology-1.pdf  Reece, Jane. B. et. al. Campbell Biology (9th ed.). Boston: Pearson, 2011.  MODULE 1.1 (A) Prokaryotic and Eukaryotic Cells  Learning Objectives To understand how plant and animal cells are classified and organized according to structure distinguish prokaryotic and eukaryotic cells according to their distinguishing features describe some cell modifications that lead to adaptation to carry out specialized functions (e.g., microvilli, root hair) PROKARYOTES AND EUKARYOTES Two Types of Cellular Organisms 1. Prokaryote 2. Eukaryote 1. Prokaryote  Absence of a nucleus  Absence of membrane enclosed organelles  Unicellular organisms 2. Eukaryote  Presence of a nucleus that contains the cell’s genetic materials  Presence of membrane enclosed organelles with specific functions  Mostly multicellular except for unicellular euglena, paramecium and amoeba  Commonalities Between Prokaryotes and Eukaryotes Both have cytoplasm Both have cell wall Both have plasma membrane  Prokaryotic Kingdom 1. Archaebacteria A large class of about 250 bacteria species with no specific structure but are classified into three types based on the substance they create and the environment they live in Image Credit: https://upload.wikimedia.org/wikipedia/jv/1/18/Archaebacteria.jpg  a. Methanogens Produce methane and mostly thrive in sewage facilities, bogs, and inside the intestines of ruminant animals like cows, goats, and sheep Image credit: https://seunghun.wikispaces.com/file/view/dmethanopyrus.jpg/179878689/dmethanopyrus.jpg  b. Halophiles Want salty environments and thrive in salt lakes and pools of sea water Image credit: https://en.wikipedia.org/wiki/Archaea#/media/File:Halobacteria.jpg  c. Thermophiles Attracted to heat and thrive in hot places such as geothermal vents and hot springs Image Credit: Colorful Archaea at Midway Geyser by Wing-Chi Poon. Retrieved from https://simple.wikipedia.org/wiki/Archaea#/media/File:Colourful_Thermophilic_Archae bacteria_Stain_in_Midway_Geyser_Basin.jpg 2. Eubacteria (or the “true bacteria”) Constitute the most number of species and possess rigid cell walls with peptidoglycan that can either be motile or non-motile Disease-causing bacteria belong to this type.  Eukaryotic Kingdom 1. Euglena A big family of about 800 species that is very intriguing as they exhibit both animal- and plant-like traits ‒ flagella tails for movement and the presence of green Image credit: https://en.wikipedia.org/wiki/Euglena#/media/File:Euglena_sp.jpg chloroplasts for photosynthesis  2. Paramecium A genus of the Protozoa class known for its ciliated structure that has become the favorite model organism of scientists for their researches It can also be found mostly in Image credit: https://en.wikipedia.org/wiki/Paramecium#/media/File:Paramecium.jpg freshwater, brackish, and marine environments.  3. Diatoms (“gems of the sea”) Have transparent cell walls made of silicon dioxide hydrated by water which gives them their very colorful and beautiful patterns Image credit: https://en.wikipedia.org/wiki/Diatom#/media/File:Diatom2.jpg  4. Fungi A very big family that consists of yeasts, molds and mushrooms Chitin found in their cell walls including digestive enzyme secretions are Image credit: https://en.wikipedia.org/wiki/Fungus#/media/File:Fungi_collage.jpg some of their distinct traits.  5. Plantae World of plants composed of grasses, trees, shrubs, vines, leaves, and flowering plants Image credit: https://en.wikipedia.org/wiki/Plant#/media/File:Diversity_of_plants_im age_version_5.png  a. Oryza Grass Group Characterized by their blade-like pointed leaves that grow very tall and serve as primary sources of carbohydrate foods Image credit: https://en.wikipedia.org/wiki/Oryza_sativa#/media/File:Oryza_sativa_- _K%C3%B6hler%E2%80%93s_Medizinal-Pflanzen-232.jpg  b. Angiospermae Group The biggest phylum in the plant kingdom with around 300,000 species of flowering trees, fruits, seeds, and flowers. Angiospermae came from the Greek words angeion and sperma which, when Image credit: https://en.wikipedia.org/wiki/Camellia_japonica#/media/File:Camellia_japonica-IMG_2051.jpg combined, stands for “enclosed seeds.” c. Gymnospermae Group Also seed-bearing plants but instead of flowers come in the form of cones. Most of its 1,000 species are highly valuable timber and lumber trees. 6. Animalia The largest group composed of millions of species that are characterized by their motility, adaptation/survival mechanisms and predation  Rea,M.A, Dequillo, M.Z, and Chua,J.L (2017) General Biology 1;First Edition, Rex Bookstore, Manila City.  Retrieved from https://www.deped.gov.ph/wp- content/uploads/2019/01/General-Biology-1.pdf  Reece, Jane. B. et. al. Campbell Biology (9th ed.). Boston: Pearson, 2011. MODULE 1.2 CELL CYCLE THE CELL CYCLE  Learning Objective explain the significance or applications of mitosis/meiosis discuss crossing over and recombination in meiosis describe the stages of mitosis/meiosis given 2n=6 characterize the phases of the cell cycle and their control points  What Is the Cell Cycle? The cell cycle consists of sequential phases of events wherein the parent cell divides and replicates DNA materials to produce two daughter cells. Why Do Cells Have to Undergo Cell Cycle Processes? For growth For cell differentiation For repair and healing of damaged tissues For replication of genetic materials For reproduction of species MITOSIS  Types of Cell Division 1. Mitosis A five-stage process of cell division solely for eukaryotic cells wherein the replicated traits of the chromosomes separate into two new nuclei  a. Prophase This starting stage of the mitotic phase sees the chromatin of the nucleus condensing to form chromosomes. Image credit: https://en.wikipedia.org/wiki/Mitosis#/media/File:CONDENSING_CHROMOSOMES_2.jpg  b. Prometaphase It is the transition stage wherein the nuclear envelope breaks down causing interaction of the spindle and the chromosomes to form spindle fibers that will then bind with the kinetochore of Image credit: Kelvinsonghttps://en.wikipedia.org/wiki/Prometaphase#/media/File:Prometaphase.svg the centromere.  c. Metaphase Occurs after the spindle fibers have attached to the kinetochores, from whence they begin moving to the center poles to eventually align with the metaphase plate Image credit: https://en.wikipedia.org/wiki/Metaphase#/media/File:Metaphase.svg  d. Anaphase Involves the replicated chromosomes called daughter chromatids splitting apart and moving towards the opposite poles of the cell Image credit: https://en.wikipedia.org/wiki/Anaphase#/media/File:Anaphase_IF.jpg  e. Telophase Sees the shortening of the microtubules of the kinetochores thereby pulling the pair of chromatid sisters towards the opposite poles Image credit: http://study.com/cimages/multimages/16/anaphase_photos.png MEIOSIS 2. Meiosis It is a two-round set of cell division stages occurring solely among eukaryotic cells with gametes. Its end result shall be the reduction of chromosome number into half. a. Meiosis I Involves the sorting and pairing up of homologous chromosomes (genes with similar traits) from both male parent and female parent resulting to a thick four- strand tetrad of two diploid cells  a.1. Prophase I Sees homologous chromosomes from both parents pairing up into tetrads (synapsis) and exchanging DNA (homologous recombination) resulting Image credit: https://qph.ec.quoracdn.net/main-qimg-890c1bc2159aeb37ac037cab0dad6a72?convert_to_webp=true in crossovers of new combination of alleles  a.2. Metaphase I It consists of homologous pairs moving together and aligning with the metaphase plate. This stage also sees a protein substance called cohesin binding Image credit: https://taksreview.wikispaces.com/file/view/metaphase.gif/138796915/metaphase.gif the replicated sister chromatids.  a.3. Anaphase I During this phase, the homologous chromosomes move to opposite ends of the cell. Image credit: http://study.com/cimages/multimages/16/anaphase_photos.png  a.4. Telophase I It sees the pair of chromosomes reaching the opposite poles with their chromosomal number halved. The spindles disappear, two new nuclear membrane is formed encasing each of the Image credit: http://www.aboutthemcat.org/images/biology/telophase1.png haploid daughter cells, and the cell also divides into two. b. Meiosis II These stages are very similar to mitosis. The final output shall yield four daughter cells from the pair of haploid cells produced in Meiosis I.  b.1. Prophase II Sees the disappearance of both the nuclear envelope and the nucleoli while the chromatids condense and the centromeres move to the poles and assemble Image credit: http://botit.botany.wisc.edu/Resources/Botany/Meiosis/Lily%20Micros porogenesis/Prophase%20II.jpg spindle fibers for the next cell division  b.2. Metaphase II Involves the two kinetochores of the centromeres attaching to the spindle fibers of the centrosomes of the opposite poles to align at Image credit: http://f.tqn.com/y/biology/1/S/l/h/meiosis_metaphase_2.jpg the metaphase plate  b.3. Anaphase II Consists of the centromeres breaking up and the sister chromatids moving to the opposite poles and thereby becoming unreplicated and Image credit: http://f.tqn.com/y/biology/1/S/S/n/meiosis_anaphase_2.jpg individual chromosomes  b.4. Telophase II Is similar to Telophase I but instead of two daughter cells four will be produced Image credit: http://f.tqn.com/y/biology/1/S/n/h/meiosis_telophase_2.jpg 3. Interphase Describes the cell’s daily functions of growth, metabolism, and the copying of DNA in preparation for either mitosis or meiosis  a. Gap 1 (G1) Stage Sees the cell preparing for DNA replication by increasing its metabolism, proteins, and available organelles Image credit: http://www.news- medical.net/image.axd?picture=2016%2F6%2FCell_division_shutterstock_137897120.jpg  b. Synthesis (S) Stage Involves the actual replication of DNA materials leading to the doubling of the cell’s chromosomal number Image credit: http://www.news- medical.net/image.axd?picture=2016%2F6%2FCell_division_shutterstock_137897120.jpg  c. Gap 2 (G2) Stage Sees the cell continuing to grow in preparation for mitosis or meiosis Image credit: http://www.news- medical.net/image.axd?picture=2016%2F6%2FCell_division_shutterstock_137897120.jpg 4. Cytokinesis In eukaryotic cells, it sees the nuclear membrane dividing into two and will produce two daughter cells with inherent traits similar to the parent cell. Image credit: https://en.wikipedia.org/wiki/Cytokinesis#/media/File:Unk.cilliate.jpg 5. Binary fission In prokaryotic cells, it is very much similar to cytokinesis except for the absence of a nucleus and spindle fibers. Image credit: https://s-media-cache- ak0.pinimg.com/564x/62/28/8d/62288da33b272d6248a37fc3b86140c6.jpg  Rea,M.A, Dequillo, M.Z, and Chua,J.L (2017) General Biology 1;First Edition, Rex Bookstore, Manila City.  Retrieved from https://www.deped.gov.ph/wp- content/uploads/2019/01/General-Biology-1.pdf  Reece, Jane. B. et. al. Campbell Biology (9th ed.). Boston: Pearson, 2011.