NUR 101 HB1 Lecture 2- Cells _ Tissues 020924 PDF

AY2425 NUR101 Human Biological Science I Cells & Tissues Ms. Cissy Soong (Reg. MLT I, RN) Senior Lecturer Saint Francis University Learning Objectives Understand the anatomy of the cell and its 01 structural features...

AY2425 NUR101 Human Biological Science I Cells & Tissues Ms. Cissy Soong (Reg. MLT I, RN) Senior Lecturer Saint Francis University Learning Objectives Understand the anatomy of the cell and its 01 structural features that enable it to perform those functions Describe and explain different cellular 02 metabolisms- cellular aspiration, protein synthesis, packaging and processing and its relationship with the structure Describe the stages of the cell life cycle, 03 including interphase, mitosis, cytokinesis and explain their significance 04 Identify different types of tissues, describe their roles and discuss their functions Cells Cells The basic structural and functional units of all living organisms Primary formed by carbon, oxygen, hydrogen, and nitrogen All cells are created by cell division. After division, they differentiate into different cell types for their purpose Classification by size, shape and function Each cell maintains homeostasis at the cellular level 2 main types of cells in human body: Sex Cells (Germ Cells) Reproductive cells, reproduce by meiosis, e.g. Male sperm, Female oocyte Somatic Cells All body cells except sex cells, reproduce by mitosis (Shier, 2015)  Cell Structure A General View of the Cell A cell consists of 3 main parts: Plasma Membrane A sturdy yet flexible outer surface A selective barrier Very important in cell communication Cytoplasm Cytosol Organelles Nucleus Cell control center Contain heredity information (Shier, 2015)  A semipermeable lipid bilayer found outside the cytoplasm of a cell and surround the inner contents. The membrane consists of Phospholipids (~75-98%): The polar heads of the phospholipid are hydrophilic and are attracted to water; The non-polar tails of the phospholipid are hydrophobic which avoid water and line up in the center of the membrane Plasma Glycolipids (~5%): Protect plasma membrane from injury; Enable the immune system to recognize the host cell; Forms the basics of transfusion and transplant compatibility; Allow cells to stick to other tissues; Enable Membrane sperm to recognize and bind to the egg; Guides embryonic cells to their destination Cholesterol (~20%): Holds the phospholipid together; Stiffen the membrane Proteins (2%): Act as receptors; Involved in second messenger systems, Act as enzymes, carriers, channel proteins, cell marker, and cell adhesion molecules (Shier, 2015)  Function of Plasma Membrane Isolation and Protection A physical barrier that separate the inside of the cell from Selectively Permeability the surrounding extracellular fluid Allow some substances to move into or out of the Protect the cellular organelles cell but restricts the passage of other substances E.g. Permeable to water, most lipid soluble Sensitivity to the environment and molecules communication Not permeable to ions and charged/ polar molecules Consists of receptors to allow the cell to recognize and respond to the environment Receive chemical signals from other cells to activate or deactivate cellular activities Channels and Transporters Pores to allow substances move in and out Control materials entry and exit the cell Transporters (Carriers) change shape as they move a substance one side of the membrane Entry of ions and nutrients to the other Elimination of waste Release of secretions Structural Support  Membrane Transport Active Transport The movement of ions or molecules from a region of low concentration to a region of high concentration Occurs against the concentration gradient Require energy- ATP for transportation Active transport Vesicular transport 01 Passive Transport Action Potential Passive Transport Active Transport 02 A simple process that no energy is required for molecules movement Substances move across the membrane down their concentration or electrical gradient, E.g. Simple diffusion Facilitated diffusion Osmosis (Shier, 2015) Passive Transport- Simple Diffusion (Martini, 2015) Molecules movement from a region of high concentration to low concentration region, down the concentration gradient Membrane may not be needed Factors like increased temperature, light, and small particles, increase in membrane surface area, and steeper the concentration gradient speed up the diffusion rate (Martini, 2015) Diffusion Across the Plasma Membrane In the body, diffusion occurs across the lipid bilayer, e.g. Exchange of O2 and CO2 between blood and cells, between blood and air within lungs Absorption of lipid-soluble molecules Release waste from body cells Diffusion occurs through pores of channels, e.g. Ion channels “Gated” channels- moving in one direction to open, and in another direction to close (Martini, 2015)  Passive Transport- Osmosis Diffusion of Water Net movement of water through a selectively permeable membrane, from an area of higher water concentration to an area of lower water concentration Occurs when a membrane is permeable to water, but is permeable to certain solutes (Martini, 2015)  Osmolarity and Tonicity Osmolarity of body fluids is ~300mOsm/L Tonicity- the ability of a solution to affect the fluid volume or pressure in a cell Water moves in and out of a cell depending on whether the cell’s environment is isotonic, hypotonic or hypertonic Hypertonic Isotonic Hypotonic In a hypertonic solution, the concentration of When two environments are isotonic, the In a hypotonic solution, the concentration of solute particles is greater than the concentration of solutes is same in both of them solute is less than that of a cell concentration in a cell Water comes in and out during cell Water comes into the cell Water comes out from the cell to the solution No net gain or net loss of water from cell  You can simply impress your audience and add a unique zing and appeal to your Presentations. Easy to change colors, photos and Text. Get a modern PowerPoint Presentation that is beautifully designed. You can simply impress your audience and add a unique zing and appeal to your Presentations. Easy to change colors, photos and Text. Get a modern PowerPoint Presentation that is beautifully designed. (Martini, 2015) Substances that cannot diffuse through the lipid bilayer or ion channels Transport assisted by carrier protein- Specific Passive Transport- transporter for the specific substance Substance binds to a specific transporter on one Facilitated Diffusion side of the membrane, then released on the other side after the transporter changes shape Not require energy E.g Transport of glucose into the cells  Primary Active Transport Movement of molecules from a low concentration Active area to a high concentration area with the help of an Ionic Pump which uses ATP to provide energy to move the ions against the concentration gradient Transport Energy is required E.g. Na+, K+, Ca2+, amino acids, monosaccharides (Martini, 2015)  Secondary Active Transport Require energy indirectly Carrier protein can move another substance at the same time as with facilitated diffusion, without regard to its concentration gradient Another substance gets a “free ride” (Martini, 2015) E.g Sodium-glucose transporters The transporter does not need energy Need the energy to pump out the sodium in the Na+-K+ pump Endocytosis Materials move into a cell in You can simply impress your audience and add a unique zing and appeal to your a vesicle formed from the Presentations. Easy to change colors, plasma membrane photos and Text. Get a modern PowerPoint Presentation that is beautifully Require ATP designed. You can simply impress your Three types of endocytosis- audience and add a unique zing and appeal to your Presentations. Easy to Pinocytosis change colors, photos and Text. Get a Phagocytosis modern PowerPoint Presentation that is beautifully designed. Receptor-mediated Exocytosis endocytosis Materials move out of a cell by the fusion with the plasma membrane of vesicular inside the cell All cells carry out exocytosis, especially important in- Vesicular Secretory cells that secrete digestive enzymes, hormones, mucus or other secretions Transport Nerve cells that release neurotransmitters  Pinocytosis (Cell drinking) Tiny droplets of extracellular fluid are taken up Vesicle Transport- Endocytosis Receptor- mediated Endocytosis A more selective form of phagocytosis or pinocytosis Minimum unnecessary matter is taken Phagocytosis (Cell eating) The cell engulf large solid molecules like bacteria, dust Vesicle is call phagosome (Martini, 2015) Cytoplasm Consists of all cellular contents between the plasma membrane and the nucleus 2 components included- Cytosol (Intracellular fluid) Site of many chemical reactions Organelles (Tiny structures that perform different functions in the cell) Organelles Organelles with Membrane Endoplasmic reticulum Golgi apparatus Mitochondria Lysosomes Peroxisomes Non-membranous Organelles Centrosome & Centrioles Cytoskeleton Cilia & Flagella Microvilli Ribosome (Martini, 2015)  Endoplasmic Reticulum (ER) System of interconnected channels Extends from the nuclear membrane throughout the cytoplasm, more than half of membrane surface within the cytoplasm of the cell 2 forms of endoplasmic reticulum (ER): Rough ER Smooth ER Covered with ribosomes No ribosomes Functions: Functions: Involved in protein synthesis- Involved in the attach sugar groups to synthesis of fatty proteins acid and steroid Proteins are bound in Detoxification of vesicles for transport to drugs/ toxic Golgi apparatus Calcium storage External face synthesize phospholipids (Shier, 2015) Mitochondria Rod-like organelle surrounded by a double membrane The powerhouse of a cell Generate ATP to provide energy through aerobic respiration A cell may have thousands of mitochondria, depending on its activity (Shier, 2015) Golgi Apparatus/ Complex Small flattened membrane and associated vesicles close to the nucleus Cupcake shape Functions: Synthesis carbohydrates Package, modifies, and segregates proteins for secretion from the cell, inclusion of lysosomes, and incorporation into the plasma membrane (Shier, 2015)  Lysosome & Peroxisomes Lysosome Membrane-enclosed vesicles Form from the Golgi apparatus Contain digestive and hydrolytic enzymes Break down a wide variety Peroxisomes/ Microbodies of molecules Help recycle worn-out cell Structurally similar to lysosomes structures but smaller Removal of pathogens Contain oxidases- enzyme that can break down fats and other organic compounds Neutralize toxic compound Abundant in liver and kidney In mitochondria, peroxisomes decompose fatty acids to generate energy for ATP synthesis (Martini, 2015) Centrosome Consists of 2 hollow cylinders called centrioles Located near the Golgi apparatus and nucleus Contain a pair of centrioles at the right angle Form mitotic spindle- essential for the movement of chromosomes during the cell division Form the basal bodies found at the base of cilia and flagella Centrosome & Centrioles (Shier, 2015)  Microvilli, Cilia & Flagella Flagella Similar structure with cilia but much longer Generate forward motion of the entire cell (e.g. sperm) (Martini, 2015) (Shier, 2015) (Martini, 2015) Cytoskeleton A network of protein filaments that extends throughout the cytosol Support the cell shape Organize the contents in cell Direct movements within the cell Contribute movement of cell Consist of 3 structures: Microtubules Microfilaments Determine cell shapes Assist movement Intermediate Help the Provide support filaments organelles Assist in movement stabilize organelles position Help attach cells to others (Shier, 2015)  Ribosomes Free or attached to rough ER High content of ribosomal RNA (rRNA) Some are free in the cytosol, some located within the mitochondria Contain of 2 tRNA binding sites Function: Site of protein synthesis (Shier, 2015)  Nucleus Large organelle and most prominent feature of a cell Most cells have a single nucleus except mature red blood cells (no cell nuclei) and skeletal muscle cells (with multiple nuclei) Contain fluid nucleoplasm, nucleoli, and chromatin Functions: Control center of a cell Storage and processing of genetic information, provide instructions for protein synthesis Nuclear envelope: separate the nucleoplasm from the cytoplasm and (Shier, 2015) regulates the passage of substances to and from the nucleus Chromatin: DNA constitutes the genes  DNA, Chromatin, Chromosome & Chromatid Chromatin is a complex of macromolecules composed of DNA, RNA, and protein, which is found inside the nucleus of eukaryotic cells The primary protein components of chromatin are histones that help to organize DNA into “bead-like” structures called nucleosomes by providing a base on which the DNA can be wrapped around The nucleosome can be further folded to produce the chromatin fiber Chromatin fibers are coiled and condensed to form chromosomes when cell is preparing for division Chromatin makes it possible for a number of cell processes to occur including DNA replication, transcription, and cell division Chromatid is one half of a duplicated chromosome (Shier, 2015) Section Break TOILET TIME  Cellular Metabolism Protein Cellular Synthesis; Cell Cycle & Respiration Package, Cell Division Processing & Secretion  Cellular respiration is a series of chemical reaction processes that take place within a cell for the generation of energy, usually in the form of ATP, from dietary proteins, fats, and carbohydrates 3 main processes are- i. Glycolysis ii. The Citric Acid Cycle (Krebs Cycle) iii. Oxidative phosphorylation/ Electron transport chain Glycolysis starts in the cytosol and the others occur in the mitochondria Cellular Respiration Cellular Respiration 1. Glycolysis (Anaerobic pathway) Glycolysis breaks down 6-carbon glucose molecule producing two 3-carbon pyruvic acid molecules and a net gain of 2 ATP molecules that the body uses as cellular energy Each 3-carbon pyruvic acid molecules enters the mitochondria to start the Citric Acid Cycle 2. The Citric Acid Cycle (Aerobic pathway) 2 more ATP are created and carbon dioxide is released as a waste product 3. The Oxidative Phosphorylation Involves the electron transport chain and chemiosmosis in the inner mitochondrial membrane. Most ATP molecules are created 3 steps of cellular respiration can produce (Shier, 2015) up to 38 ATP molecules Nucleic Acid, DNA & RNA Nucleic acid- huge molecule contain carbon, hydrogen, oxygen, nitrogen, and phosphorus Monomers is nucleotides made with pentose sugar-deoxyribose & ribose, phosphate group and nitrogen bases (Adenine, Guanine, Thymine, Cytosine, Uracil) 2 types of nucleic acid- DNA- Deoxyribose Nucleic Acid Long double helix chain of nucleotides Consists of deoxyribose and bases (A,T,G,C) Complementary base pairing- A with T, G with C Forms the inherited genetic material inside each human cell Gene- a segment of a DNA molecule RNA- Ribose Nucleic Acid Single strain of nucleotides Consists of ribose and bases (A,U,G,C) Relays instructions from the genes to (Martini, 2015) transcript amino acids  Types of RNA Amino acid Anticodon 02 Ribosomal RNA (rRNA) 03 Transfer RNA (tRNA) 01 Messenger RNA (mRNA) Found in the cytoplasm Formed in nucleus Involved in the synthesis of 06 Carries anticodon Rewrite the sequences of peptides in the ribosomes Transfer specific amino acids to bases in a section of DNA ribosomes during transcription Ensure the alignment of these Serve as template for the amino acids in the proper 05 protein synthesis sequence prior to the peptide bond formation  Protein Transcription Synthesis The DNA of the nucleus controls cell structure and function through synthesis of specific proteins Protein synthesis is the assembling of functional polypeptides in the cytoplasm The major events of protein synthesis are Transcription and Translation Transcription Translation Translation DNA ➔ RNA ➔ Protein (Marieb, 2019) Transcription Nucleus Transcription is the synthesis of messenger RNA (mRNA) from a DNA template catalyzed by RNA polymerase Occurs in the cell nucleus Start at a DNA nucleotide sequence called promoter The mRNA then leaves the nucleus to the cytoplasm through the nuclear pore after synthesis Translation Translation is the synthesis of a linear chain of Cytoplasm amino acids using the transcribed information provided by the mRNA Occurs in the cytoplasm Each amino acid in a protein is specified by three nitrogen bases in the DNA sequences called codon tRNAs with matched anti-codon bring the specific amino acid to the ribosome and start the translation process Base pair complementation between mRNA codon and tRNA anticodon tRNA Peptide bond formation happens between the amino acids that the tRNAs bought within the ribosome Ribosome translocate to another codon along the mRNA and continue the amino acid chain synthesis The completed amino acid chain released after synthesis Process of Translation tRNA (Martini, 2015) Codons for Protein Synthesis tRNA (Shier, 2015)  Gene Mutation A gene mutation involves a change in the order of the nitrogen bases (A, C, G, T) that makes up the genes The change in the DNA sequence can lead to a subsequent change in the mRNA sequence The altered mRNA sequence would lead to a change in the amino acid sequence (the primary protein structure) and may alter bonding in the protein molecule leading to the protein being inactive or problem-causing Types of mutation Deletion- base missing 01 E.g. AGTCTGC ➔ AGCTGC Addition- extra base added E.g. AGTCTGC ➔ AGTCGTGC Substitution- one base is replaced by another base E.g. AGTCTGC ➔ AGGCTGC Effects of gene mutation Proteins produced may be beneficial or harmful, or may 02 have no effect at all The effect can be positive, negative or neutral Protein Package, Processing & Secretion tRNA (Martini, 2015)  Cell Cycle A cell life from it forms until it divides consists of a series of phases called cell cycle The major phases are Interphase Mitosis Cytokinesis (Cytoplasmic division) (Shier, 2015) Types of Cell Division Reproductive Cell Division Somatic Cell Division Any cell of the body except sex cells Reproductive Cell Division Undergo nuclear division (Mitosis) and Undergo 2-step division called cytoplasmic division (Cytokinesis) Meiosis Produce 2 genetically identically cells- same The number of chromosomes in number and kind of chromosomes as the original the nucleus is reduced by half cell, i.e. 23 pairs of chromosomes cell (n=46) (n=23) to become Haploid cells called Diploid cells Somatic Cell Division (Shier, 2015) Cell Cycle- Interphase Interphase consists of 4 phases: G0 Phase- Resting phase G1 Phase- Organelle duplication and protein synthesis occur S Phase- Cell duplicate centrioles and conduct DNA replication G2 Phase- Cell continues growing to: Makes more organelles Finishes replicating centrioles tRNA Synthesis enzymes for cell division Checks DNA and repairs any errors (Shier, 2015)  DNA Replication Occur in S phase: DNA helix unwinded by helicases into single template strand and expose the nitrogenous bases, ATP required DNA polymerase read the exposed short segments of nitrogenous bases and assemble the sequence of the new strand with complementary nitrogenous tRNA bases with the RNA primers DNA ligase joins the short segments together (Martini, 2013)  Happens in the nucleus Functions- Growth, repair, replace, wore out cells The replicated chromatin becomes tightly coiled and easier to see under the microscope Consists of 4 sub-phases: Prophase Metaphase Anaphase Telophase Mitosis (M Phase) (Shier, 2015)  Process of Mitosis (Marieb, 2019) Early Prophase Late Prophase Metaphase Anaphase Telophase Chromatin fibers Centrioles get pushed The chromatids Centromeres split by Chromosomes are in opposite ends, condense and apart to each pole of align on the enzyme uncoil and revert to chromatin form shorten into the cell by spindle center of the Sister chromatids Nuclear envelope reform, nucleoli chromosomes fibers spindle fibers, separated and reappear in the identical nuclei Spindle fibers attached Mitotic spindle breaks up Each attached by their move toward to the centromere on Following telophase, cytokinesis chromosome centromeres opposite poles of the chromosomes consists of a pair cell occurs- the cytosol, intracellular Nucleoli disappear and of identical the nuclear envelope Chromatids become organelles and plasma membrane strands called breaks down chromosomes after split to form 2 identical daughter chromatids separated cells  Sex cells are produced through Meiosis Involves 2 cell division instead of one, and produces four genetically unique cells rather than two identical cells Sex cells are haploid cells that contain only half of the full set of 46 chromosomes Because of haploid and genetically unique, it can combine with another sex cell during fertilization to create offspring with genetic variation Detail process discussed in the reproductive system Meiosis Cell Differentiation All cells in human body comes from stem cells, through the processes of mitosis and differentiation- process enables cells to specialize and become mature cells (Shier, 2015) Section Break TOILET TIME Tissues  Groups of similar cells working together to perform a particular function 8 types of tissues- blood, bone, epithelial tissue, cartilage tissue, adipose tissue, connective tissue, muscle tissue, and nervous tissue Types of Body Tissues Epithelial Tissue Cover body surface Line hollow organs, body cavities and ducts Form glands and membranes Classification of Epithelial Tissue tRNA Simple Epithelial Tissue Location Function Found in heart, blood and Reduce friction lymphatic vessels linings Control vessels permeability Epithelial layer of peritoneum, Perform diffusion pleura and pericardium Perform secretion Located at glands, ducts, kidney Secretion and absorption tubules Makes up secreting portion of thyroid gland and ducts of pancreas Lining of stomach, guts, gall bladder, Secretion uterine tubes, collecting ducts of Absorption kidney Protection tRNA Ciliated: Lining of nasal cavity, Secrete mucus to trap foreign particles trachea and bronchi Cilia sweep away mucus for Non-ciliated: Lining of large ducts, elimination from the body epididymis, and part of male urethra Absorption and protection Stratified & Transitional Epithelial Tissue Location Function Found in skin surface Protect against abrasion, water loss, Linings of mouth, throat, ultraviolet radiation, and foreign oesophagus, rectum and vagina invasion Covers tongue Form the first line of defense against microbes Ducts of sweat glands and Protection oesophageal glands Limited secretion and absorption Part of male urethra Part of urethra, large excretory Protection and secretion ducts tRNA Lines several parts of the urinary Variable appearance, subject to tract, including bladder expansion Glandular Epithelium Found in cells or organs that secrets substances for use in other body parts Include Endocrine and Exocrine glands Endocrine No ducts Secrete directly into blood (Martini, 2015) Secretions are known as hormones Exocrine Contact with the surface by means of duct- an epithelial tube that brings secretion to the surface, e.g. Sweat and tears Secretion released to the body surface or into the cavity or lumen of another organic, e.g. Saliva and digestive enzymes (Shier, 2015) Membranes in the Body Line body cavities and cover the viscera (internal organs) Cutaneous Membrane (Skin) Largest membrane in the body Dry Mucous Membrane (Mucosa) Line all body cavities that open to the outside of the body, e.g. Digestive tract, Respiratory tract, Urogenital tract Serous Membrane (Serosa) Internal membrane that covers organs and lines walls of body cavities, e.g. Pleura, Pericardium, Peritoneum (Martini, 2015) Connective Tissue The most abundant tissue and widely distributed Materials found between cells Functions: Support and binds structures together, e.g. Bone, Cartilage, Ligament, and Tendon Store energy, e.g. Adipose tissue Provides immunity to disease, e.g. White blood cells Loose Connective Tissues Fill up space between organs Act as cushion and stabilize cells Surround and support blood vessels and nerves Store Lipids Provide a route for diffusion of materials E.g. Matrix as in areolar, adipose tissue, finely woven reticular fibers tRNA (Martini, 2015) Dense Connective Tissues Collagenous tissues Contain elastic fibers Can tolerate cycles of extension and recoil, e.g. Lung, Vessels Connect, provide strength and support, e.g. Tendon tRNA (Martini, 2015)  Fluid Connective Tissue Transports oxygen from lungs to body cells Bring waste, carbon dioxide from cells to lungs Transports nutrients and hormones, regulate body temperature, body defense and prevent excessive blood loss from injury Consists of Red blood cells, White blood cells and Platelet Diffuse lymphatic tissue Found in connective tissue of almost all organs Found in lymphatic ducts and nodules Lymph Supporting Connective Tissues- Cartilage Strong, flexible and avascular Covers the ends of long bones Connects bones Resists compressions and absorbs shock 3 types: Hyaline cartilage Elastic cartilage Fibrocartilage tRNA (Martini, 2015)  Supporting Connective Tissue- Bone Bone/ Osseous Tissue Hardest form of connective tissue Functions: Protection to visceral organs Support Blood cell formation (Hemopoiesis) Red bone marrow produces red blood cells, white blood cells and platelets Storage of minerals & lipid Calcium, phosphate Yellow bone marrow consists adipose cells which store triglycerides and act as energy reserve Leverage for muscles Provide balance for the body Assistance in movement (Marieb, 2019) Muscle Tissue Able to contract and relax Functions: Provide movement within the body and of the body itself Muscle contraction requires a rich blood supply providing sufficient oxygen, calcium and nutrients and removing waste products 3 types of contractile cells: Skeletal muscle cell Smooth muscle cell Cardiac muscle cell (Martini, 2015)  Types of Muscle Tissue Skeletal Muscle Cardiac Muscle tRNA Smooth Muscle (Martini, 2015) Nervous Tissue Located in the brain, spinal cord and nerves Function: Transmit the information from one part of the body to another, by means of nerve impulse Nervous cells called Neurons consists of 3 parts- Cell body: Contain nucleus and other organelles Dendrites: Short projections to receive inputs Axon: Single, thin and long projection to conduct output impulse Cells support them called neuroglia (Shier, 2015) Q & A  REFERENCE Marieb, E. N., & Keller, S. M. (2019). Essentials of Human Anatomy & Physiology, Global Edition. Pearson. Martini, F. H., Nath, J. L., Bartholomew, E. F., & Ober, W. (2015). Fundamentals of Anatomy and Physiology. 2001. Pentice Hall: New Jersey, 657-687. McKinley M, O’Loughlin VD. Human Anatomy: McGraw-Hill International Edition. 2006. McGraw-Hill: New York. Shier, D., Butler, J., & Lewis, R. (2015). Hole’s human anatomy and physiology. McGraw- Hill Education. Tomkins, Z. (2020). Applied Anatomy & Physiology: an interdisciplinary approach. Elsevier Health Sciences, 195-225. Vander, A. J., Sherman, J. H., & Luciano, D. S. (1998). Human physiology: the mechanism of body function. Burr Ridge, IL: WCB McGraw-Hill. Reference Videos Passive Transport https://youtu.be/-ZwXUrZolD0 Cell Biology: Active Transport https://youtu.be/5asMngTQqxQ DNA & RNA- Overview of DNA & RNA https://youtu.be/GhABWQC3YDs DNA & RNA- Transcription https://youtu.be/YlOqI3PQwjo From DNA to Protein https://youtu.be/gG7uCskUOrA DNA & RNA- DNA Replication https://youtu.be/Mu2bJgEZtwE M phase of the cell cycle https://youtu.be/5bq1To_RKEo Overview of cell division https://youtu.be/XKZhcYetvsc THANK YOU