Cells Anatomy and Physiology PDF

ANATOMY AND PHYSIOLOGY CHAPTER II: CELLS AND TISSUES https://www.pinterest.com/ As you study the various parts of a cell and their...

ANATOMY AND PHYSIOLOGY CHAPTER II: CELLS AND TISSUES https://www.pinterest.com/ As you study the various parts of a cell and their relationships to one another, you will learn that cell structure and function are intimately related. This Unit is divided into three (3) Lessons: Cell Structure and Functions, Cell Division and Movement through the Cell membrane. Are you ready? Let’s continue with our lesson! In this Chapter, you will learn about: (1) Cells. Its cell structures and functions including a brief history of the study of the cell, cell division and movement through the cell membrane; and (2) Tissues. The different types of tissues and cell junction. LESSON 1. CELLS Introduction of the Lesson and Presentation of Outcomes In this section you will learn about: 1. cell structures and functions including a brief history of the study of the cell, 2. cell division and 3. movement through the cell membrane. At the end of the lesson, you must have: a. Identified at least two (2) pioneers in the study of the cell, b. Identified at least five (5) structures of the Cell, c. Differentiated at least three (3) functions of the cell, d. Identified the two ways of cell division, e. Identified the different phases of cell division, f. Identified the two main methods of movement of materials across the cell membrane, g. Differentiated diffusion, osmosis, filtration and dialysis and h. Differentiated between phagocytosis and pinocytosis.  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES Warm-up Activity THREE WORDS: As quick as you can, think of three words (3) that comes into your mind about Cells. Write them down and at the end of the lesson. Get back to them after the lesson in cells and see if you still think of cells that way. Central Activities 1.1 CELL STRUCTURE AND FUNCTIONS a. BRIEF HISTORY The study of the cell, its structures and functions, would not have been possible if not for the different scientists who were inquisitive enough to try and explore the unknown. Discovery of the cell was made possible because of the invention of the compound microscope. The invention of this technology has made tremendous advances in the study of the cell. Some of notable scientists are as follow: 1. ROBERT HOOKE (1665) Robert Hooke, being interested in learning more about the microscopic world, improved the design of the existing compound microscope. His microscope used three lenses and a stage light, which illuminated and enlarged the specimens. He concluded that certain thing is composed of water, some organic and inorganic substances and some organelles. He coined the word “Cell”. Although, according to him, he believed that it only existed in plants. Robert Hook © Painting by Rita Greer, digitized Rudolf Virchow© Photos.com/Jupiterimages by the Department of Engineering Science, Oxford University Mariano Marcos State University College of Health Sciences 39 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES 2. RUDOLF CARL VIRCHOW (1855) Rudolf Virchow pioneered the modern concept of pathological processes by his application of the “Cell Theory” to explain the effects of disease in the organs and tissues of the body. He emphasized that diseases arose, not in organs or tissues in general, but primarily in their individual cells. At Würzburg he began to realize that one form of the cell theory, which postulated that every cell originated from a preexisting cell rather than from amorphous material, could give new insight into pathological processes. In 1855, he further developed his ideas by publishing his famous aphorism omnis cellula e cellula which became a part of the foundation for cell theory. Virchow’s theory stated that just as animals are unable to arise without previously existing animals, cells are unable to arise without previously existing cells. “The idea expressed by Virchow’s omnis cellula e cellula (“every cell is derived from a [preexisting] cell”) is not completely original. It was coined by François Vincent i.pinimg.com Raspail in 1825. “ Want to learn more? Here is a link where you can learn more about the different scientists discussed in your lesson. https://www.britannica.com/biography/Rudolf- Virchow 3. THEODOR SCHWANN (1838) & MATTHIAS SCHLEIDEN (1839) Matthias Jakob Schleiden Theodor Schwann https://www.britannica.com/biography/ https://www.britannica.com/biography/ Mariano Marcos State University College of Health Sciences 40 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES Theodor Schwann and Matthias Jakob Schleiden are two German scientists who founded the “Cell Theory”. They advanced one of the most important and unifying concept in biology -- CELL THEORY. Schleiden discovered cells in plants in (1838) while Schwann proved that animals are also made up of cells (1839). They believed that Protoplasm is the living substance of the cell (Cell-99% CHON and 1% trace elements). According to the CELL THEORY :  The Cell is the basic structural and functional unit of organism.  All cells came from reproduction of pre-existing cells  All living things are made up of one or more cells A knowledge of chemistry is Important because the cells are made up of molecules responsible for the characteristics of life - C, O2, H, Na and small amount of Fe, Na, K The so-called cell theory, which was enunciated about 1838, was never actually a theory. As Edmund Beecher Wilson, the noted American cytologist, stated in his great work, The Cell, “By force of habit we still continue to speak of the cell ‘theory’ i.pinimg.com but it is a theory only in name. In substance it is a comprehensive general statement of fact and as such stands today beside the evolution theory among the foundation stones of modern biology.” Want to learn more? Here is a link where you can learn more about the different scientists discussed in your lesson. https://www.britannica.com/science/zoology/Areas-of- study#ref498473 Now you’re done with the brief history of the Cell. Hooray! Now let’s get down to some more exciting lessons: The Cell Structure and it’s Functions. Mariano Marcos State University College of Health Sciences 41 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES You’ve learned that the Cell is the basic structural and functional unit of an organism. What does that mean? Do you believe that all organisms are made up cells? But wait, don’t answer just yet! Let’s try to gather more information. The following lesson will help you learn about the different functions of the Cell. b. FUNCTIONS OF THE CELL 1. Basic unit of life o The cell is the smallest part to which the organism can be reduced that still retains the characteristics of life. 2. Protection and support o Cells produce/secrete various molecules. o Bone cells surrounded by mineralized material making the bone a hard tissue and thus protects the brain and other organs 3. Movement o All movement of the body occur because of molecules located within specific cells (muscle cells) 4. Communication o Cells produce and receive chemical and electrical signals that allows them to communicate with one another o Nerve cells communicate with one another and muscle cells cause them to contract. 5. Cell metabolism and energy release o During metabolism, energy is released, which is needed for cell activities (synthesis of new molecules, muscle contraction, and heat production- maintains body temperature) 6. Inheritance o Each cell has a copy of genetic information of individual - specialized cells- transmit to next generation. Now, can you answer the question prior to the library.com/excellence- discussion? What makes the Cell, a basic structural http://clipart- and functional unit of an organism? Excellent! cliparts.html Mariano Marcos State University College of Health Sciences 42 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES c. PARTS OF THE CELL Cell. Copyright © 2014. © Gerard J. Tortora, L.L.C., Bryan Derrickson, John Wiley & Sons, Inc. The Cell is made up of different structures that work together to keep the cell efficient. In this section you will learn about these different structures and be able to understand how they all work together to keep the cell running. 1. PLASMA MEMBRANE/CELL MEMBRANE The Plasma Membrane or the Cell Membrane is the outermost component of a cell. It encloses the cytoplasm and forms the boundary between material inside the cell (which we call Intracellular substances) and materials outside the cell (or Extracellular substances). The Cell Membrane is a flexible yet sturdy barrier that consists mainly of lipids & proteins. This LIPID BILAYER (two back-to-back layers made up of three types of lipid molecules—phospholipids, cholesterol, and glycolipids) provides the framework of the membrane, hence, supporting the cell contents. Mariano Marcos State University College of Health Sciences 43 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES Cell Membrane. Copyright © 2014. © Gerard J. Tortora, L.L.C., Bryan Derrickson, John Wiley & Sons, Inc. Generally, the types of lipids in cellular membranes vary only slightly. In contrast, the membranes of different cells and various intracellular organelles have remarkably different assortments of proteins that determine many of the membrane’s functions In Summary the Functions of Membrane Proteins are: Ion Channel Some integral proteins form ion channels, pores or holes that specific ions, such as potassium ions (K), can flow through to get into or out of the cell. Most ion channels are selective; they allow only a single type of ion to pass through. Ion channel. Copyright © 2014. © Gerard J. Tortora, L.L.C., Bryan Derrickson, John Wiley & Sons, Inc. Carrier/Transport Other integral proteins act as carriers, selectively moving a polar substance or ion from one side of the membrane to the other. Carriers are also known as transporters. Carrier. Copyright © 2014. © Gerard 44 J. Tortora, L.L.C., Bryan Derrickson, John Wiley & Sons, Inc. Mariano Marcos State University College of Health Sciences Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES Receptor Integral proteins called receptors serve as cellular recognition sites. Each type of receptor recognizes and binds a specific type of molecule. For instance, insulin receptors bind the hormone insulin. A specific molecule that binds to Carrier. Copyright © 2014. © Gerard J. Tortora, L.L.C., Bryan a receptor is called a ligand of that Derrickson, John Wiley & Sons, Inc. receptor. Enzyme Some integral proteins are enzymes that catalyze specific chemical reactions at the inside or outside surface of the cell. Enzyme.. Copyright © 2014. © Gerard J. Tortora, L.L.C., Bryan Derrickson, John Wiley & Sons, Inc. Linker Integral proteins may also serve as linkers that anchor proteins in the plasma membranes of neighboring cells to one another or to protein filaments inside and outside the cell. Peripheral proteins also serve as enzymes and linkers. Linker. Copyright © 2014. © Gerard J. Tortora, L.L.C., Bryan Derrickson, John Wiley & Sons, Inc. Cell Identity Marker Membrane glycoproteins and glycolipids often serve as cell-identity markers. They may enable a cell to (1) recognize other cells of the same kind during tissue formation or (2) recognize and respond to potentially dangerous foreign Cell identity market. Copyright © 2014. © Gerard J. 45 Tortora, L.L.C., Bryan Derrickson, John Wiley & Sons, Inc. Mariano Marcos State University College of Health Sciences Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES cells. The ABO blood type markers are one example of cell-identity markers. When you receive a blood transfusion, the blood type must be compatible with your own, or red blood cells may clump together. Generally, the types of lipids in cellular membranes slightly differs. In difference, the membranes of diverse cells and various intracellular organelles have remarkably dissimilar varieties of proteins that determine many of the membrane’s functions. In summary, the Cell Membrane, considered a Selective screen/barrier, determines what moves into and out of the cell or what you call Selective Permeability, provides communication between cells and provides abundant surface for chemical reactions. 2. NUCLEUS The Nucleus is one of the largest organelles, usually located near the center of the cell. It is considered the “HEADQUARTER/CONTROL CENTER”, meaning it directs the activity of the cell. DID YOU KNOW?  All Cells have a nucleus at some point in their life span.  Most cells have a single nucleus, although some, such as mature red blood cells, have none. In contrast, skeletal muscle cells and a few other types of cells have multiple nuclei. i.pinimg.com Within the nucleus lies even smaller structures. They are as follow: Nucleus. Copyright © 2014. © Gerard J. Tortora, L.L.C., Bryan Derrickson, John Wiley & Sons, Inc. Mariano Marcos State University College of Health Sciences 46 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES a. NUCLEAR ENVELOPE/MEMBRANE The Nuclear Envelope/Membrane Consists of inner and outer membrane with a narrow space in between them. It composed of the same bilipid layer as the cell membrane. It is the outer covering of the nucleus that separate it from the cytoplasm. Hence, it is an avenue for exchange of materials between the nucleoplasm and cytoplasm. The outer membrane of the nuclear envelope is Nuclear continuous with the rough ER and is similar in structure. Envelope Along the membrane are openings composed of circular arrangement of proteins with a central opening 10 times wider than the openings in a cell membrane. Nuclear pores Nuclear control the movement of substances between the nucleus Pore and the cytoplasm. b. NUCELOLUS/NUCLEOLI The Nucleolus/Nucleoli may be one or more small, Nuclear envelope & nuclear dark-staining essentially round bodies. It is the site for/ where pore.. Copyright © 2014. © ribosomes are assembled. Gerard J. Tortora, L.L.C., Bryan Derrickson, John Wiley It is called the PACEMAKER OF THE CELL. Why? It here & Sons, Inc. were synthesis of rRNA and assembly of rRNA and proteins into ribosomal units take place. Remember that within the nucleus are most of the cell’s hereditary units we call as “genes”, which control cellular structure and direct cellular activities. Nucleus. Photo credit: https://elenaazzadbiology1.weebly.com/orga nelle-functions.html c. NUCLEOPLASM The Nucleoplasm is a Jelly-like fluid in which nucleoli and chromatin are suspended. Mariano Marcos State University College of Health Sciences 47 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES d. CHROMATIN GRANULES Chromatin Granules are smaller than nucleoli and irregular in size and shape. It carries the hereditary characteristics of the gene. 3. CYTOPLASM The Cytoplasm is composed of cellular material outside nucleus and inside the plasma membrane, such as water, CHON, CHO, lipid and inorganic substances. It is a watery fluid that surrounds the nucleus and contains organelles. CYTOPLASM. https://www.thoughtco.com/ribosomes-meaning-373363 It also known as “THE FACTORY AREA OF THE CELL” because it is the site of most cellular activities and consists of all cellular contents between the plasma membrane and the nucleus and has two components: a. CYTOSOL is the semitransparent fluid that suspend other elements. It is the site of many chemical reactions required for a cell’s existence. For example, enzymes in cytosol catalyze glycolysis, a series of 10 chemical reactions that produce two molecules of ATP from one molecule of glucose. b. ORGANELLES are specialized structures within the cell that performs a specific function. Mariano Marcos State University College of Health Sciences 48 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES b.1 RIBOSOMES are the site of protein synthesis. They are molecular machines that make CHON, hence the name, "Cell's CHON factories”. Ribosomes are the smallest structures, attached to the lining of the membrane of endoplasmic reticulum. B.2 ENDOPLASMIC RETICULUM is known as the “mini circulatory system” or “transportation system” of the cell. It is an interconnected system of canal channels, a network located deep inside the cytoplasm. It Ribosomes and Endoplasmic Reticulum. where enzymes are https://www.thoughtco.com/ribosomes-meaning-373363 stored. The ER has 2 types: B.2.1 ROUGH ENDOPLASMIC RETICULUM (RER) It contains innumerable small granules (ribosomes) which dot the outer surface of the membranous walls and give it its rough appearance. A large amount of it in a cell indicates that it is synthesizing large amount of CHON for export from the cell. B.2.2 SMOOTH ENDOPLASMIC RETICULUM (SER) The Smooth ER is the site for lipid synthesis in the cell. It extends from the rough ER to form a network of membrane tubules. It doesn’t contain ribosomes; hence, it doesn’t synthesize proteins. It does, however, synthesize fatty acids and steroids such as estrogens and testosterone. It contains unique enzymes. Just like the smooth ER in liver cells, the enzyme help release glucose into the bloodstream. It even participates in detoxification of chemicals within the cell. In skeletal muscle cells, the Smooth ER stores calcium ions. Mariano Marcos State University College of Health Sciences 49 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES ROUGH ENDOPLASMIC RETICULUM SMOOTH ENDOPLASMIC RETICULUM Rough ER and Smooth ER. Copyright © 2014. © Gerard J. Tortora, L.L.C., Bryan Derrickson, John Wiley & Sons, Inc. B.3 GOLGI APPARATUS/COMPLEX Discovered by Camilo Golgi in 1898, the Golgi Apparatus consists of closely packed slacks of curved, membrane bound sacs with bulging edges called cisternae (cavities). The cisternae are often bowed which gives the Golgi Apparatus its cuplike shape. Transport vesicle from rough ER Entry or cis face Medial cisterna Transfer vesicle Exit or trans face Secretory vesicles Golgi Complex/Apparatus. Copyright © 2014. The Golgi Apparatus is also known as the © Gerard J. Tortora, L.L.C., Bryan Derrickson, Packaging center of the cell. It collects, John Wiley & Sons, Inc. modifies, packages and distributes CHON and lipid manufactured. It packages material for secretion from the cell, being the first step in the transport pathway. Mariano Marcos State University College of Health Sciences 50 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES b.4 MITOCHONDRIA Mitochondrial The mitochondria look like a Cristae tiny sausage shape and are made up of double membrane, with a small fluid-filled space in between. Just like the plasma membrane, the mitochondria membranes are similar in structure. These slender rod or filaments are about 0.2 um (millimicron) in diameter and 2-6 um long. It is known as the Powerhouse of the cell. Why do you think? Because they produce most of the ATP via aerobic respiration. The inner Mitochondria. Copyright © 2014. © Gerard J. mitochondrial membrane contains a Tortora, L.L.C., Bryan Derrickson, John Wiley & sequence of folds called mitochondrial Sons, Inc. cristae. The cristae provide a massive surface area for the aerobic phase in cellular respiration. More information on the different Organelles can be read on your suggested references. b.5 LYSOSOME Lysosomes are digestive organ of the cell. About 0.25-0.5 um in diameter. Describes as vesicles enclosed in a membrane, they breakdown the ingested material and dispose the degraded material. Digestive Enzymes Lysosome. Copyright © 2014. © Gerard J. Tortora, L.L.C., Bryan Derrickson, John Wiley & Sons, Inc. Lysosomes are even smaller than mitochondria containing several powerful enzymes (about 60 chemical subs that causes chemical reaction to take place). Mariano Marcos State University College of Health Sciences 51 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES b.6 CENTRIOLES Centrioles are involved in the movement of chromosomes during cell division. They occur in pairs, rod-shaped bodies that lie at right angles to each other and referred to as Diplosomes/Centrosome. They lie close to the nucleus and are made up internally by fine microtubules. They function by directing the formation of the mitotic spindle during cell division. Centrioles. Copyright © 2014. © Gerard J. Tortora, L.L.C., Bryan Derrickson, John Wiley & Sons, Inc. b.7 CYTOSKELETON The Cytoskeleton is an elaborate network of CHON structures which extend throughout the cytoplasm. It acts as the cell's bones and muscles by furnishing an internal framework that determines the cell's shape and supports other organelles and provides the machinery needed for intracellular transport and various types of cellular movement. There are 3 types of Cytoskeleton. According to size (largest to smallest in diameter), they are: b.7.1 MICROTUBULES are the largest of the Cytoskeleton and determines the overall shape of a cell and the distribution of organelles. They are hollow structure formed from CHON subunits (tubulin). They help support the cytoplasm, assist in cell division and form essential components of certain organelles (cilia and flagella). Microtubules. Copyright © 2014. © Gerard J. Tortora, L.L.C., Bryan Derrickson, John Wiley & Sons, Inc. b.7.2 INTERMEDIATE FILAMENTS help form chromosomes and helps resist pulling forces in the cell. They are between microtubules and microfilaments in such a way that it is thinner than microtubules but thinner than microfilaments. Provide mechanical support to the cell as it is composed of several kinds of proteins which are identified as remarkably sturdy. Mariano Marcos State University College of Health Sciences 52 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES Intermediate Filaments. Copyright © 2014. © Gerard J. Tortora, L.L.C., Bryan Derrickson, John Wiley & Sons, Inc. b.7.3 MICROFILAMENTS are involved in cell motility and in producing changes in cell shape. They are small fibrils that structurally support the cytoplasm. They are considered the thinnest elements of the cytoskeleton and are made up of protein actin and myosin. Microfilaments. Copyright © 2014. © Gerard J. Tortora, L.L.C., Bryan Derrickson, John Wiley & Sons, Inc. b.8 ACCESSORY STRUCTURES Accessory structures may or may not be present to all cells depending on their functions. Cilia b.8.1 CILIA are projections, whip like cellular extensions that move substances along the cell surface. Example would be the cilia Cilia. Copyright © 2014. © Gerard J. found in the respiratory tract that Tortora, L.L.C., Bryan Derrickson, John function to move trapped foreign Wiley & Sons, Inc. particles from mucus away from the lungs. Mariano Marcos State University College of Health Sciences 53 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES b.8.2 FLAGELLA is a structure is similar to that of Flagellum cilia but is much longer. There is only one flagellum per cell. While cilia propel other substances across a cell's surface, the flagellum propels the cell itself. A classic example would be the sperm cell’s tail which help thrust the sperm towards the egg cell. Flagellum. Copyright © 2014. © Gerard J. Tortora, L.L.C., Bryan Derrickson, John Wiley & Sons, Inc. b.8.3 MICROVILLI are cylindrical structures of the cell membrane. They do not move and function to increase the surface area of the cell. They abundant on the surface of cells that line the intestines and kidney, cells that function in absorption. CYTOPLASMIC INCLUSIONS are lifeless and dispensable constituents of the cell. Can you give examples? i.pinimg.com Activity 1.1 Test your knowledge! Before we move on to the next section, it’s time for you to evaluate first what you have learned by answering the following questions. Are you ready? Let’s get going! You will find the Answer Key at the end of the lesson. 1. What was/were Robert Hooke’s contribution in the study of the Cell? 2. Who among notable scientists pioneered the modern concept of pathological processes by his application of the “Cell Theory” to explain the effects of disease in the organs and tissues of the body? 3. What do you call the function of the cell where it sends and receives chemical signals from other cells? 4. What do you call the function of the cell where it produces and releases ATP needed for cell activities? 5. What do you call the function of the cell where an example are bone cells that surround brain and other organs? 6. It is the control center of the cell. Mariano Marcos State University College of Health Sciences 54 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES 7. It is the factory area of the cell. 8. The plasma membrane is made up of two back-to-back layers made up of lipid molecules called ____________. 9. It is the site of protein synthesis. 10. It is the powerhouse of the cell. You’re doing great! Now, you can move on to the next lesson. 1.2 CELL DIVISION & LIFE CYCLE CELL DIVISION is the process by which cells reproduce themselves. New cells must reproduce by cell division as replacement. Cells have different life spans and thus, at some point must reproduce to replace old or worn out cells and even damaged cells. THE CELL LIFE CYCLE is a series of changes a cell goes thru from the time it is formed until it divides. Some cells have the capacity to divide more than other cells. There are TWO TYPES OF CELL DIVISION: MITOSIS & MEIOSIS a. MITOSIS In Mitosis, cells undergo nuclear division (mitosis) and cytoplasmic division (cytokinesis). In the nuclear division, the duplicated chromosomes separate to form two identical daughter nuclei. Somatic cells, cells other than germ cell, undergo cell division to replace old, worn out or damaged cells. In mitosis, new cells necessary for growth and tissue repair are formed. b. MEIOSIS In Meiosis, the number of chromosomes is reduced. It occurs in primitive sex cells during the process of their becoming mature sex cells called gametes (sperm or oocyte). The cells divide and the number of chromosomes in the nucleus are reduced by half, then followed by cytokinesis. Meiosis is necessary for reproduction. Meiosis will be discussed in detail during the discussion of the Reproductive system. Mitosis has 2 Major Periods: 1. INTERPHASE Interphase is the period of cell cycle between cell division. In this phase, NO cell division takes place. It is also called the metabolic phase as this is the stage where the cell grows exponentially. Interphase is also the stage where DNA replication/duplication takes place. Mariano Marcos State University College of Health Sciences 55 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES Interphase has three (3) Distinct Phases: Flagellum. Copyright © 2014. © Gerard J. Tortora, L.L.C., Bryan Derrickson, John Wiley & Sons, Inc. 1.1 G1 PHASE (G=GAP OR GROWTH) It is also called the Post Mitotic Phase. Cells are engaged in growth, metabolism and production of substances required for division. No replication of DNA occurs in this stage. 1.2 S PHASE S Phase is the stage between G1 and G2. It is where chromosomal replication takes place. The result at a later stage of cell division will be two identical cells with the same genetic component. 1.3 G2 PHASE G2 Phase is also called the Pre-Mitotic Phase as it is the phase between S Phase and Mitotic Phase. Cell growth continues and enzymes and other proteins are synthesized. 2. MITOSIS It is divided into four stages: 2.1 PROPHASE In Prophase, chromatins condense into chromosomes. Each chromosome consists of 2 chromatids joined/inked at the Centromere and the Centrioles move Mariano Marcos State University College of Health Sciences 56 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES to the opposite ends of the cell. The nucleolus and nuclear membrane disappear at later part. 2.2 METAPHASE In Metaphase, chromosomes align in the center of the cell in association with the spindle fibers. 2.3 ANAPHASE At the early part, centromeres separate. So, the chromatids separate to form 2 sets of identical chromosomes. The chromosomes assisted by the spindle fibers, move toward the centrioles at each end of the cell. 2.4 TELOPHASE In this phase, chromosomes disperse, the nuclear envelopes and nucleoli forms and the cytoplasm begins to form two cells. At the end of Telophase, Mitosis is complete, and a new interphase begins. The i.pinimg.com chromosomes have unraveled to become chromatin. Cell division produced 2 daughter cells, each with DNA that is identical to the DNA of parent cell. Mariano Marcos State University College of Health Sciences 57 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES Cell Division. Copyright © 2014. © Gerard J. Tortora, L.L.C., Bryan Derrickson, John Wiley & Sons, Inc. Mariano Marcos State University College of Health Sciences 58 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES Activity 1.2 Test your knowledge! Before we move on to the next section, it’s time for you to evaluate first what you have learned by answering the following questions. Are you ready? Let’s get going! You will find the Answer Key at the end of the lesson. 1. Cell division is a necessary process for cells to produce new cells. Two methods of cell division are ___________ and meiosis. 2. TRUE OR FALSE. Somatic cells undergo mitosis and meiosis. 3. It is the phase between cell cycle and cell division. a. Interphase c. Anaphase b. Prophase d. Telophase 4. It is the phase where chromosomes align at the center of the cell. a. Prophase c. Anaphase b. Metaphase d. Telophase 5. It is the pre-mitotic phase. a. G1 Phase c. G2 Phase b. S Phase d. Prophase Keep it up! https://www.pinter est.co.kr/pin/27577 1.3. MOVEMENT THRU THE CELL MEMBRANE Recall from previous lessons that the cell has selective permeability. This means that the plasma/cell membrane allows some substances to pass through readily than others. It is highly permeable to oxygen (O2), carbon dioxide (CO2) and steroids while it is moderately permeable to water and urea and impermeable to ions and large molecules like glucose. How then, can glucose enter the cell? You will learn more as you keep on reading. In order to maintain life, the cell needs essential materials that needs to be transported across the cell membrane. There are substances that needs to move into the cell to support metabolic reactions. And there are those produced by the cell such as waste products that needs to move out of the cell. Generally, substances move across the cell membrane thru transport processes classified as passive or active transport. A. PASSIVE TRANSPORT Passive Transport is the movement of substances across the membrane without requiring any energy expenditure from the cell. Particles move by using energy they already have (kinetic energy). Understanding Passive Transport means understanding the different ways particles move across the cell membrane. Mariano Marcos State University College of Health Sciences 59 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES 1. DIFFUSION In Diffusion, the movement of solute molecule is from an area of higher concentration to an area of lower concentration in a solution, until there is a uniform distribution of molecules to maintain equilibrium. Hence, there is a downward movement of the concentration gradient. It is a means of transporting substance thru the extracellular fluid (ECF) and intracellular fluid (ICF) in the body. Some nutrients enter and some waste products leave the cell by diffusion. Diffusion can be Simple Diffusion, Channel-Mediated Facilitated Diffusion and Carrier-Mediated Diffusion. Such molecules like oxygen, carbon dioxide, and nitrogen gases; fatty acids; steroids; and fat-soluble vitamins (A, D, E, and K), small, uncharged polar molecules such as water, urea, and small alcohols also pass through the lipid bilayer by simple diffusion. SIMPLE DIFFUSION is vital in the movement of oxygen and carbon dioxide between blood and body cells, and between blood and air within the lungs during breathing. It also is the route for absorption of some nutrients and excretion of some wastes by body cells. In CHANNEL-MEDIATED FACILITATED DIFFUSION, a solute moves down its concentration gradient across the lipid bilayer through a membrane channel. Numerous Potassium ions (K+) Chloride ions (Cl-) and a few Sodium ions (Na+) or Calcium ions (Ca2+) diffuse through these channels. In CARRIER-MEDIATED FACILITATED DIFFUSION, a carrier (also called a transporter) moves a solute down its concentration gradient across the plasma membrane wit no cellular energy expenditure. The carrier changes shape as it moves a solute from an area of higher concentration of solute. Glucose, fructose, galactose, and some vitamins move across the cell membrane via carrier-mediated facilitated diffusion. Mariano Marcos State University College of Health Sciences 60 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES 2. OSMOSIS Osmosis is the movement of fluid/water/solvent across a semi-permeable membrane from an area of a lesser solute concentration to an area of greater solute concentration in a solution. OSMOTIC PRESSURE  ls the pressure required to prevent the movement of water i.pinimg.com across a selectively permeable membrane  Measure of the tendency of water to move by osmosis across a selective permeable membrane Answer the following: 1. What happens when cell is immersed in a hypotonic solution? 2. What happens when cell is immersed in a hypertonic solution? 3. What happens when cell is immersed in an isotonic solution? Mariano Marcos State University College of Health Sciences 61 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES Any solution in which a cell—for example, a red blood cell (RBC)—maintains its normal shape and volume is an ISOTONIC SOLUTION. The concentrations of solutes that cannot cross the plasma membrane are the same on both sides of the membrane in this solution. For instance, a 0.9% NaCl solution (0.9 gram of sodium chloride in 100 mL of solution), called a normal (physiological) saline solution, is isotonic for RBCs. The RBC plasma membrane permits the water to move back and forth, but it behaves as though it is impermeable to Na and Cl, the solutes. (Any Na or Cl ions that enter the cell through channels or transporters are immediately moved back out by active transport or other means.) When RBCs are bathed in 0.9% NaCl, water molecules enter and exit at the same rate, allowing the RBCs to keep their normal shape and volume. A different situation results if RBCs are placed in a HYPOTONIC SOLUTION, a solution that has a lower concentration of solutes than the cytosol inside the RBCs. In this case, water molecules enter the cells faster than they leave, causing the RBCs to swell and eventually to burst. The rupture of RBCs in this manner is called hemolysis; the rupture of other types of cells due to placement in a hypotonic solution is referred to simply as lysis. Pure water is very hypotonic and causes rapid hemolysis. A HYPERTONIC SOLUTION has a higher concentration of solutes than does the cytosol inside RBCs. One example of a hypertonic solution is a 2% NaCl solution. In such a solution, water molecules move out of the cells faster than they enter, causing the cells to shrink. Such shrinkage of cells is called crenation. Mariano Marcos State University College of Health Sciences 62 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES 3. FILTRATION Filtration is the movement of a liquid thru a filter (partition with small holes) which prevent some or all of the substances in the liquid from passing It is a process by which water and solutes are forced thru a membrane (or capillary wall) by fluid or hydrostatic pressure (usually exerted by blood). 4. DIALYSIS Small molecules move thru o selectively permeable membrane, leaving large molecules behind. B. ACTIVE TRANSPORT/MOVEMENT In Active Transport, the cell provides the metabolic energy (ATP) that drives the transport process. It is a mediated process that requires ATP and can move substances against a concentration gradient. Mariano Marcos State University College of Health Sciences 63 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES 1. ENDOCYTOSIS In Endocytosis, it is the transport of substances that require ATP by engulfing or taking up extracellular substances and enclosing them in small membrane vesicles. It can be: a. PHAGOCYTOSIS It is also known as "CELL EATING" as it ingests of solid particles. Certain WBC and other professional phagocytes of the body act as scavenger cells that police and protect the body by ingesting bacteria and other foreign debris as well as dead body cells. It is a process in which the cell membrane develops a small sac and slowly envelops a particle bringing it into the inside of the cell. b. PINOCYTOSIS It is also known as "CELL DRINKING” as it is used to take in liquids that contain dissolved CHON and fats. It is a routine activity of most cells and especially important to cells that function in absorption. The plasma membrane invaginates to form a tiny pod and then its edges fuse around the droplet of ECF which contains dissolved CHON and fats. 2. EXOCYTOSIS Exocytosis moves substances out of the cell. It is a means by which cells actively secrete hormones, mucus and other cell or eject certain cellular wastes. Mariano Marcos State University College of Health Sciences 64 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES Can you GUESS THE PICTURE? This a small portion of a picture. Clue: Cells Answer at the end of the lesson. ANSWER: A dialysis machine. Recall that movement across the membrane can be via diffusion, osmosis, filtration and dialysis. In dialysis, small molecules can pass thru the membrane. Activity 1.3 Test your knowledge! Before we move on to the next section, it’s time for you to evaluate first what you have learned by answering the following questions. Are you ready? Let’s get going! You will find the Answer Key at the end of the lesson. 1. The transport of materials across the cell membrane without energy expenditure on the part of the cell. a. Active Transport b. Passive Transport 2. The “cell eating” or ingestion of solid particles. a.Phagocytosis b. Pinocytosis 3. It is the movement of substance out of the cell that requires energy from the cell. a.Endocytosis c. Exocytosis b. Phagocytosis d. Pinocytosis 4. What happens when the cell is immersed in a hypertonic solution? a. It does not change its shape and volume b. It shrinks c. It swells d. It bursts 5. It is the movement of solute molecule from an area of higher concentration to an area of lower concentration in a solution. a. Filtration b. Osmosis b. Dialysis d. Diffusion Mariano Marcos State University College of Health Sciences 65 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES Wrap-up Activity RECALL: Cell Structure and Function 1. The cell is the smallest functional unit to which an organism can be reduced and still retains the characteristics of life. 2. The cell functions as the basic unit of life, protects and supports and organism, allows movement, communication and even cell metabolism, releases energy and has the ability to copy genetic information which can be transmitted to the next generarion. 3. The cell has three (3) main parts: plasma membrane, nucleus and cytoplasm. The cell also contains organelles, specialized structures within the cell that performs a specific function. 4. The plasma membrane or cell membrane, encloses the cytoplasm, supports the cell contents and provides a selective barrier that determines the movement of substances into and out of the cell. 5. The nucleus is considered the CONTROL CENTER of the cell. Some cell have single nucleus while others have multiple nuclei. The nucleolus is the PACEMAKER of the CELL, the site of rRNA synthesis, where genes are located that control cellular structure and direct cellular activities. 6. The cytoplasm, contains cellular materials outside the nucleus and inside the plasma membrane. It is called the FACTORY AREA OF THE CELL, consisting of the cytosol, a semitransparent fluid that suspend other elements, and organelles, tiny structures that perform different functions in the cell. Cell Division & Cell Life Cycle 7. Cell division is a process by which cells reproduce themselves. 8. Cell life cycle is a series of changes a cell undergoes from the time it is formed until it divides. 9. Cell division is via mitosis and meiosis. 10. In mitosis, nuclear division and chromosomal duplication occurs to produce two identical daughter cells. 11. In meiosis, primitive sex cells divide the number of chromosomes by half then followed by cytokinesis. 12. Mitosis has 2 major periods: Interphase and Mitosis. 13. Interphase is the period of DNA replication but no cell division occurs. It has 3 distinct phases: G1 phase (Post Mitotic Phase), S phase (chromosomal replication) and G2 phase (Pre Mitotic Phase). 14. Mitosis has four phases: Prophase, Metaphase, Anaphase and Telophase. 15. Transport of materials across the plasma membrane is essential to maintain life in a cell. Movement thru the Cell Membrane 16. Movement across the plasma membrane can be Passive transport or Active Transport. 17. Passive transport is the movement of substances across the membrane without energy expenditure from the cell. Passive transport is classified as diffusion, osmosis, filtration and dialysis. Mariano Marcos State University College of Health Sciences 66 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES 18. Diffusion is the movement of solute molecule from an area of higher concentration to an area of lower concentration in a solution. Osmosis is the movement of fluid/water/solvent across a semi-permeable membrane from an area of a lesser solute concentration to an area of greater solute concentration in a solution. Filtration is the movement of a liquid thru a filter. Dialysis is the movement of small molecules thru a selectively permeable membrane. 19. Active transport is the movement of substances across the membrane that requires energy expenditure from the cell. It is either endocytosis or exocytosis. 20. Endocytosis take up/engulf extracellular substances by enclosing them in small membrane vesicles. It is further classified as Phagocytosis (cell eating) and Pinocytosis (cell drinking). 21. Exocytosis moves substances out of the cell. CONGRATULATIONS! You made it! You were great! You are done with the Cells. After finishing the lesson, you have acquired the basic knowledge that will help you further understand the different body systems in your course, CN 100. Review your lesson in preparation for your quiz, which will be scheduled and administered online by your Instructor. There are also websites listed in your syllabus that you can visit to help enhance your learning in Anatomy and Physiology. Keep it up! Mariano Marcos State University College of Health Sciences 67 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES FEEDBACK Answer Key: Activity 1 1. Robert Hooke coined the word “Cell”. He concluded that a certain thing is composed of water, some organic and inorganic substances and some organelles. He discovered and believed that it only existed in plants. 2. Rudolf Virchow 3. Communication 4. Cell metabolism and energy release 5. Protection and support 6. Nucleus 7. Cytoplasm 8. Lipid Bilayer/ Bilipid Layer 9. Ribosomes 10. Mitochondria Activity 2 1. Mitosis 2. FALSE 3. a 4. b 5. c Activity 3 1. a 2. a 3. c 4. b 5. d How did it go with your practice test? Are you satisfied with your score? Do you need further study? Do you have more questions about the topics? How do you find the lesson, did it help you with your learning? Feel free to contact your Instructor at his/her given consultation time for the course. Mariano Marcos State University College of Health Sciences 68 Department of Nursing  CN 100 ANATOMY AND PHYSIOLOGY: CHAPTER 2 CELLS AND TISSUES REFERENCE MATERIALS  National Geographic Society. (2019, May 23). National Geographic. Retrieved from National Geographic: https://www.nationalgeographic.org/article/history-cell- discovering-cell/  Kearl, M. (2012, March 17). The Embryo Project Encylopedia. Retrieved from embryo.asu: https://embryo.asu.edu/pages/rudolf-carl-virchow-1821- 1902#:~:text=In%201855%2C%20he%20further%20developed%20his%20ideas%20b y,are%20unable%20to%20arise%20without%20previously%20existing%20cells.  Biga, L. M., Dawson, S., Harwell, A., Kauffmann, J., LeMaster, M., Matern, P.,... Runyeon, J. (nd). Anatomy & Physiology. Oregon: Oregon State University. Retrieved August 23, 2020, from Oregon State: https://open.oregonstate.education/aandp/chapter/1-4-anatomical-terminology/  Bergman, R. A. (n.d.). Anatomy Atlases. Retrieved from Anatomy Atlases website: http://www.anatomyatlases.org  Marieb, Elaine. 2014 Essentials of Human Anatomy and Physiology11th edition. Philippines: Pearson Education South Asia.  Seeley, Rod R. et al. 2011. Essentials of Anatomy and Physiology 11th edition. New York: McGraw-Hill.  Tortora, Gerard/ Derrickson Bryan 2013. Principles of Anatomy and Physiology 14th edition  Underwood, E. A. (2019, October 9). Encyclopaedia Britannica. Retrieved from Britannica: https://www.britannica.com/biography/Rudolf-Virchow  Visible Body. (n.d.). Retrieved from visiblebody.com: http://www.visiblebody.com Mariano Marcos State University College of Health Sciences 69 Department of Nursing