General Biology 1 Module 1 PDF

General Biology 1 MODULE 1: CELL – THE BUILDING BLOCKS OF LIFE This module discusses the characteristics of living things. Features which make them different from non –living things. The different molecules that constitute a living system. It also focuses on cells, as...

General Biology 1 MODULE 1: CELL – THE BUILDING BLOCKS OF LIFE This module discusses the characteristics of living things. Features which make them different from non –living things. The different molecules that constitute a living system. It also focuses on cells, as the basic structural unit of Life. Most Essential Learning Competencies (MELCs): At the end of this module, you should be able to: 1. Explain the postulates of the cell theory. 2. Categorize the biological molecules. 3. Explain the role of each biological molecule in each specific metabolic process. 4. Describe the structure and function of major and subcellular organelles. 5. Distinguish prokaryotic and eukaryotic cells according to their distinguishing features. 6. Classify different cell types (of plant/animal tissues) and specify the functions of each. 7. Describe some cell modifications that lead to adaptation to carry out specialized functions (e.g., microvilli, root hair). Learning Objectives: Having successfully completed module 1, you will be able to: 1. describe the what makes things alive; 2. distinguish the structure and function of the four biological molecule; 3.describe the different nutritional content in food; 4. show appreciation on the importance of a balanced diet; 5. recognize that all organisms are made of cells; 6. explain the parts and functions of plant, animal and bacterial cell; and 7. display appreciation of the contributions of biologists in the field of health and medicine, education, agriculture, sports and recreation, fishery and other field for human consumption. Where ever you look, you see trees, busy people, moving cars, variant plants and animals, pile of garbage and a lot more. You see living and non- living things. How will you distinguish living thing from non –living thing? What are the features of being alive? Are these traits common to all living? Have a tour in your backyard or garden. If you do not have a backyard or garden, a tour inside your house will do. Randomly observe at least ten things you see in your tour. Take note of the characteristics of life is present in them. Record your observations below.  General Biology 1 Self – assessment 1: What make things ALIVE?. List down at least 5 common traits that you observed. _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ __________________________________________________ Perhaps you observed that living things, move, fly, crawl, reproduce , uses energy and respond to the environment. These are only few of the common traits that make things alive. As we go through the module, we will be discussing the vital signs of life, biochemical composition of life,and cell as the basic fundamental unit and building blocksof life. This include the cell thoeries, cell structure and functions, cell types and its modifications and or specializations. Below are three microscopic pictures of different cells. Which belongs to animal cell, palnt cell and bacterial cell? Which is unicellular and multicellular? Which is eukaryotic and prokaryotic cell? Lesson Outline A. Characterisrics of Life B. Biological Molecules C. Cellular Structure and Functions  General Biology 1 Unit 1: Characteristics of Life Recall your answer in your self – assessment task 1. Compare your list with the characteristics of living things presented below. 1. Complex Organization Any organism has a complex organizational level. An organism can be organized into the following levels: Atoms – the smallest unit of matter that form molecules Molecules – make up cell organelles and structures Cell – basic unit of structure and function of all living things Tissue – group of cells of the same kind Organ – structure composed of one or more types of tissues working together to perform a specific function. Organ system – group of organs that work together to perform certain function. Organism – Individual living thing that may be made up of one or more organ systems. Population –are group of same species living in the same place. Community – group of populations that live in the same place. Ecosystem – group of different communities together with non –living things (abiotic factors) interacting with each other. Biosphere – place where life exist, including water, land and air. 2. All living things uses energy All organisms need energy to move, grow, reproduce, respond to their environment, and maintain structures. Organisms obtain and use energy through the process of metabolism. Metabolism is the transformation of chemical energy into a specific form of energy called adenosine triphosphate (ATP), the energy currency of the cell. 3. Living things reproduce or produce new organism of the same type. Reproduction is a process by which new individual organism is produced from their parents in which genetic information is passed from parents to offspring. 4. Living things respond to changes in the environment Abiotic factors like light, sound, temperature, wind and chemical substances, affect living things. These factors are called stimuli (singular; stimulus). The ability of an organism to react to stimuli or changes in the environment is called ‘irritability”. Organisms make appropriate responses depending on the kind of stimulus. 5. Living things grow and develop Examine your body. You have grown and developed into a young adult. Your increase in size and volume results from the metabolism of food that becomes part of your body. Living things exhibit growth from within the cells through intussusception. Among multicellular organisms, growth involves more complex processes of differentiation and formation of new organs (organogenesis). All organisms undergo stages of development. Just like the monarch butterfly, it undergoes metamorphosis. In some cases, https://images.app.goo.gl/svwAXAyQdCgwikpm7 non – living things also grow like stones. It grows by the external addition of substances. This increase in size is called accretion.  General Biology 1 6. Living things maintain internal balance, homeostasis One of the fascinating traits of living things is the ability to maintain internal balance despite of environmental changes. For example, an organism needs to regulate body temperature through a process known as thermoregulation. During hot climate, your body perspire to shed excess body heat. 7. Living things move Just like you and me, animals move from place to place in search for food, find a mate or in response to changes in the environment. Such movement is called locomotion. Flowers bloom, tendrils twirl unto branches and roots run deep the soil. Microorganisms also move through their locomotory structures such as cilia, flagella and pseudopods. Non –living things may also move but their movement is dependent on the external force like gravity, water or wind. https://images.app.goo.gl/QbNJTGpMxjgwcxRt8 8. Living things evolve Organisms evolved in response to changes in the environment. Over generations, a heritable trait that provides a fitness advantage become more and more common in a population, making the population better suited to its environment. This process is called adaptation. https://images.app.goo.gl/S2eJ4MjrM1AN6omF9 For additional information, log in to the link below and or open in your flash drive the video file entitled “Characteristics of Life”. https://www.youtube.com/watch?v=ltRApt0IpCE Unit 2: Biological Molecules All organisms are mostly made up of 4 elements namely carbon, hydrogen, oxygen, nitrogen and some trace elements like phosphorous, sulfur, potassium, calcium and iron. When these elements chemically combine, they form compounds of inorganic and organic. Inorganic compounds are compounds that does not contain the element carbon. Water, acids, bases, and salts are the four main types of inorganic compounds found in the living system. Water is the most abundant inorganic compound in an organism Organic compounds contain significant amount of carbon; thus, it is also called carbon compounds. They form part of the organism; hence they are called biomolecules. A biomolecule refers to any molecule that is produced by living organisms. Biomolecules have unique properties that determine how they contribute to the structure and function of cells, and how they participate in the processes necessary to maintain life. Most of these biomolecules are organic compounds. Being “organic”, it means that, in general, they contain carbon atoms covalently bound to other atoms, especially Carbon-Carbon (C-C) and Carbon-Hydrogen (C-H). The four major element constituents are carbon, hydrogen, oxygen and nitrogen. Many of the biomolecules are polymers. A polymer is a compound made up of several repeating units (monomers) or protomers and produced by polymerization. Monomers are the simplest type of a particular biomolecule.  General Biology 1 A. Different Types of Biomolecules a. Carbohydrate Carbohydrates, glycans as they are often called, form a very large group of naturally occurring organic compounds produced in plants by the process of photosynthesis. Many carbohydrates are sweet in taste and all sweet carbohydrates are called as sugars. Common polysaccharides such as starch, cellulose, glycogen and gums not sweet in taste, hence they are also called non-sugars. b. Lipids The lipids include a large number of biomolecules of different types. The term lipid originated from a Greek word ‘Lipos’ meaning fat. In general, those constituents of the cell which are insoluble in water and soluble in organic solvents of low polarity (such as chloroform, ether, benzene etc.) are termed as lipids. Lipids are the one class of large biological molecules that does not include true polymers, and they are generally not big enough to be considered macromolecules. c. Proteins Proteins are the most abundant macromolecules in living cells. The name protein is derived from the Greek word ‘proteios’ meaning ‘of prime importance’. These are high molecular mass complex amino acids. Proteins are most essential class of biomolecules because they play the most important role in all biological processes. A living system contains thousands of different proteins for its various functions. d. Nucleic Acids Two types of nucleic acids exist: DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) which differ in their chemical composition as well as in functions. A nucleotide consists of three subunits: a nitrogen containing heterocyclic aromatic compound (called base), a pentose sugar and a molecule of phosphoric acid. Nucleic acids are important in protein synthesis, wherein the information from the DNA is transmitted and used as a template for the production of proteins. Below is a table to further describe and differentiate the different biomolecules. Carbohydrate Lipid Protein Nucleic Acid Element C H O (1:2:1) CHO CHONS CHONP Monomer Monosaccharide Fatty acids, glycerol Amino acid Nucleotide Polymer Polysaccharide Triacylglycerol Polypeptide Polynucleotides Linkages Glycosidic bonding Ester Peptide Phosphodiester Name -ose -ide -in ending Enzymes: -ase Function Primary source of Needed for growth and Energy storage Genetic information energy repair (long-term), storage and protein absorption of fat- insulation, cell synthesis soluble vitamins A, D, E membrane, and K Hormones Examples Sugar, Starches, Oil, wax, fat Muscle, Hair, DNA, RNA Cellulose Nails, Enzymes  General Biology 1 Diagram Of a monomer chemical structure Food Honey, Bread, Meat, Eggs, Fish, Butter, Mayo Chromosomes Source Potato, Corn Cheese https://www.youtube.com/watch?v=YO244P1e9QM Unit 3: Cellular Structure and Functions of Life Cells Cells are the basic units of all living things including humans. Like a building brick in a house. For example, microorganism like bacteria is made up of cells so are all fungi and plants Cells are so tiny that you cannot see it with our naked eyes. You have to use a microscope to see cells. Cells vary in sizes, shapes, and characteristics Cytology or Cell biology is the study of cells. Cell Size Limitation Cell size is limited by the relationship of the cell’s outer surface to its volume or its surface area – volume – ratio. As the cell grows, its volume increases faster that its surface area. In effect, the entry and exit of substances are greatly affected. Cells’ cell membrane will not allow materials to pass through it, making the cell unbalanced. As a result, cells are microscopic in size, which is favorable for the movement of materials in and out of the cell. The smaller the size of the cell, the quicker the materials to enter or leave the cell in an efficient manner. The discovery of cells The first observation of cells was made in 1665 by Robert Hooke, who used a crude microscope. He examined a thin piece of cork and observed that the empty spaces in the specimen he is observing is likened to the room of the monastery. He then named this empty room as “Cells”. Ten years later Anton von Leeuwenhoek (1632-1723), a Dutch businessman and a contemporary of Hooke used his own (single lens) monocular microscopes and was the first person to observe bacteria and protozoa, a single- celled organism. Robert Brown, an English Botanist discovered the nucleus in plant cells. In 1838, Mathias Schleiden and Theodore Schwann were enjoying after-dinner coffee and talking about their studies on cells. It has been suggested that when Schwann heard Schleiden describe plant cells with nuclei, he was struck by the similarity of these plant cells to cells he had observed in animal tissues. Schleiden summarized his observations into three doctrines about cells but this third conclusion “cells form by free – cell formation “is wrong. The correct interpretation of cell formation by mitosis, the division of cells was postulated by Rudolf Virchow in his famous dictum, “Omnis cellula e cellula” …. “All cells only arise from pre – existing cells”. Schleiden, Schwann and Virchow are credited for the formulation of the Cell Theories, one of the basic principles in the study of life. Cell Theory  General Biology 1 The cell theory is an accepted explanation about cell. It was developed after many observations of living things. The Cell Theory states that: ✓ All living organisms are composed of one (unicellular) or more cells (multicellular). ✓ The cell is the basic unit of structure and function of all organisms. ✓ All cells arise only from preexisting cell. They are not derived from spontaneous generation. With the innovation of powerful microscope, modern version of the Cell Theory was formulated. These ideas include: ✓ All energy flow (metabolism and biochemistry) of life occurs within cells. ✓ Cell contains hereditary information (Deoxyribonucleic acid, DNA) which is passed from cell to cell during cell division. ✓ All cells have the same basic chemical composition. Aside from the cell theory, the gene theory, evolution, homeostasis, and the laws of thermodynamics form the basic principles that laid the foundation for the study of life. Exceptions to the cell theory: 1. Mitochondria and chloroplasts are self-replicating 2. Viruses are not true cells Two types of Cells The many organisms that we see are grouped into two main types of organisms based on the structures of their cells. The most important difference in structure is the presence of a nucleus. A. Prokaryotes -these cells came before the cells that have a true nucleus - are independent, single-celled organisms (e.g., bacteria, archaea) 1. Bacterial Cell -DNA is localized in a region but is not bound by a membrane -obtain nutrition from organic and inorganic materials, some from photosynthesis Cell shapes: Cocci, bacilli, spiral, vibrio, spirochetes, stellar, rectangular (Haloarcula), triangular Cell Arrangement: Single, Diplo, strep, tetrad, sarcinae, staphy Prokaryotic Cell Arrangement Parts: Description Arrangement Illustration Name a. Flagella- for motility Example Atrichous - w/o projection Single Coci Peritricous- flagella is attached in In Pair Diplo Diplococci the entire cell In linear Strep Streptococci Polar ends: arrangement Monotrichousc- 1 fagellum at 1 Group of Tetra Tetracocci pole fours Lophotrichous - many flagella in 1 Group of 8 Sarcina Sarcinacocci pole Amphitrichous - 1 flagella in each Clusters Staphy Staphylococci pole  General Biology 1 b. Fimbrae - numerous; adhere to surfaces c. Pili - longer, one or 2 per cell -for motility and DNA transfer during conjugation d. Cell wall- prevent rapture, maintains shape, anchorage of flagella -made from peptidoglycan Glycocalyx- viscous, coats the cell wall; composed of polysaccharides, polypeptide or both; forms the capsule when firmly attaches to the cell wall e. Capsule- protection from phagocytosis, dehydration, attachment f. Cell membrane- mostly phospholipid, no sterol-less rigid g. Ribosome- protein synthesis h. Nucleoid-contains the Genetic material 2. Archaeal Cell -may have cell walls without peptidoglycan -often found in extreme environment -known to cause diseases -Either considered a methanogen, extreme halophiles or thermophiles B. Eukaryotes - have cells with a membrane-bound nucleus containing DNA -contain many other structures called organelles (“little organs”) that perform specific functions -have a network of specialized structures called filaments and tubules organized into the cytoskeleton, which gives shape to PROKARYOTIC EUKARYOTIC the cell and allows intracellular movement. CELLS CELLS Number of Unicellular Unicellular, All eukaryotic cells have three basic Cells multicellular compositions: Size Smaller (< 5 Bigger (greater than 1. plasma membrane -outer boundary of the micrometers) 10 micrometers) cell Nucleus No true nucleus Presence of a true - separates the internal metabolic events nucleus from the environment and allows them to Chromoso Circular Linear proceed in organized, controlled ways mes - has specific receptors for external Cytoplasm Contains Contains molecules that alter the cell’s function. ribosomes, compartmentalized 2. Cytoplasm - portion of the cell outside the thylakoids & organelles nucleus enclosed by the plasma membrane innumerable -it is comprised of the cytosol, the semifluid enzymes portion of the cytoplasm and the organelles Organelles No membrane Have a membrane are suspended in it bound organelle bound organelle 3. The Nucleus containing the genetic Examples All organisms in All the other material (in some books, the nucleus is Kingdom Monera Kingdoms (Protists, considered as an organelle) like bacteria Fungi, Plants & -DNA is contained in the chromosomes and Animals) except is separated from the cytoplasm by its own Kingdom Monera nuclear envelope -nucleoplasm is the semifluid material in the nucleus Parts of the Eukaryotic Cell 1. CELL MEMBRANE - fluid-mosaic model – (1972) by S. Jonathan Singer and Garth Nicolson -membrane is a double layer (bilayer) of proteins and phospholipids, and is fluid rather than solid -in a constant state of flux—shifting and changing, while retaining its uniform structure  General Biology 1 Functions of the cell/plasma membrane - regulate material moving into and out of the cell, and from one part of the cell to another - separate the inside of the cell from the outside; various organelles within the cell and cells from one another - provide a large surface area on which specific chemical reactions can occur - a site for receptors containing specific cell identification markers that differentiate one cell type from another https://images.app.goo.gl/MDniUj4o74bQMQSa9 Components A. Membrane Lipids-98% 1. Phospholipids- constitute 75% of the membrane lipids -have one polar end and one nonpolar end - compose of a glycerol and phosphate unit (head) + two fatty acid chains (tail) *Polar ends- are oriented towards the outside of the cell, hydrophilic head *Nonpolar ends- face each other in the middle of the bilayer, hydrophobic tail 2. Cholesterol- constitute 20% of the membrane lipids -embedded in the interior of the membrane -help to make the membrane less permeable to water-soluble substances -rigid structure of the cholesterol molecules helps to stabilize the membrane 3. Glycolipids -constitute 5% of the membrane lipids -phospholipids with short carbohydrate chains bound to them -it contributes to the glycocalyx  General Biology 1 B. Membrane proteins -2%, but 50% of the weight Two kinds: a. Integral proteins – proteins that pass all the way through the cell membrane Most integral proteins are glycoproteins – proteins with carbohydrate chains bound to them; - glycoproteins also contribute to the glycocalyx b. Peripheral proteins – proteins that adhere to the surface of the cell membrane attached to the inner or outer membrane surface Functions of membrane proteins: Ion channels – ions like K + and Na + can flow into and out of the cell Carriers – as transporters in moving a polar molecule or ion from one side of the membrane to the other. Receptors – serve as cellular recognition sites. Example, insulin receptors bind the hormone insulin. A specific molecule called ligand binds to the receptor. Enzymes – acts as a catalyst to a specific chemical reaction at the inside or outside surface of the cell. Linkers – some integral proteins anchor proteins to the cell membrane of nearby cells or to protein filaments inside and outside the cell. Cell identity markers - Glycoproteins and glycolipids serve are cell identity markers. Meaning, they may enable a cell to recognize and respond to potentially dangerous foreign cells. Example, 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. Lastly, peripheral proteins help support the plasma membrane, anchor integral proteins, and participate in mechanical activities such as moving materials and organelles within cells, changing cell shape in dividing and muscle cells, and attaching cells to one another. C. Carbohydrates- unite with proteins to form glycoproteins or with lipids to form glycolipids on the surface of a plasma membrane -surface carbohydrates and portions of the proteins and lipids make up the glycocalyx (“cell coat”) which is necessary for cell-to-cell recognition and the behavior of certain cells, and is a key component in coordinating cell behavior in animals functions: cushion the cell membrane and protection from physical and chemical injury cell identity markers cell adhesion molecules 2. CYTOPLASM -has two distinct parts a. Cytosol- the fluid which suspends the organelles and contains various dissolved molecules The cytosol (intracellular fluid) is the fluid portion of the cytoplasm that surrounds organelles and constitutes about 55% of total cell volume. Although it varies in composition and consistency from one part of a cell to another, cytosol is 75–90% water plus various dissolved and suspended components. Among these are different types of ions, glucose, amino acids, fatty acids, proteins, lipids, ATP, and waste products, some of which we have already discussed. Also present in some cells are various organic molecules that aggregate into masses for storage. These aggregations may appear and disappear at different times in the life of a cell. Examples include lipid droplets that contain triglycerides, and clusters of glycogen molecules called glycogen granules. The cytosol 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  General Biology 1 of glucose. Other types of cytosolic reactions provide the building blocks for maintenance of cell structures and for cell growth. b. Organelles- consists of well-defined structures; highly organized subcellular structure each having a characteristic shape and specific function in cellular growth, maintenance and reproduction Types of Organelles: a. Non-membrane bound- lack membranes and directly in contact with the cytosol b. Membrane bound- surrounded by one or two bilayer lipid membrane A. Membrane bound LYSOSOMES -membrane bond spherical organelle that contain enzymes called acid hydrolase which is capable of digesting organic molecules under acidic condition -enzymes are synthesized in the ER -Lysosome fuses with phagocytic vesicles PROTEASOMES - tiny barrel shaped structures consisting of four stacked rings of proteins around a central core - contain myriad proteases, enzymes that cut proteins into small peptides - continuous destruction of unneeded, damaged, or faulty proteins - plays a part in negative feedback by halting a pathway once the appropriate response has been achieved MITOCHONDRIA -double membrane -inner membrane folds into cristae -site for cellular respiration where catabolic process that generates ATP by extracting energy from sugar, fats and other fuels with the help of O₂ -matrix contains ribosomes, circular DNA and other material -semi-autonomous organelle -usually multiply when a cell reacts to produce more energy -single large mitochondria to thousands correlated with the cell’s metabolic activity CHLOROPLAST -found only in plants - presence of two pigments: chlorophyll a and chlorophyll b that makes the cell green -have their own DNA -site for photosynthesis Parts: Thylakoid- extensively folded and characterized by the presence of closed disks Grana- thylakoids arranged in tight stacks Lumen- central aqueous region  General Biology 1 Stroma- the space between the inner membrane and the thylakoid membrane Matrix- contains, dissolved enzymes, starch, granules, and copies of the chloroplast genome. PEROXISOME -contains enzymes that transfer Hydrogen from various substrates to O₂ producing H₂O₂ -O₂ is used to break fatty acids into smaller molecules that can be transported to mitochondria as fuel for cellular respiration * Liver cells- detoxify alcohol and other harmful compounds by transferring Hydrogen from the compounds to O₂ -then converts H₂O₂ to H₂O VACUOLES -membranous sacs -occur in different sizes and shape Functions: food storage -with cilia collect water and pump it to the outside to maintain homeostasis Ex. sponges, protozoa GLYSOSOMES -found in fat storing tissues of plant seeds -converts fatty acids to sugar (energy and carbon source) while the plant is unable to photosynthesize NUCLEUS -RBC and Phloem don’t have nucleus -contains most of the DNA -enclosed by a nuclear envelope (lipid bilayer) ▪ Nuclear Lamina- net-like array of protein intermediate filaments that maintains the shape of nucleus ▪ Nuclear Pore- 3, 000 plus, allow entry/exit of materials -gives direct contact with the ER ▪ Nuclear Envelope- consist of two membranes ▪ Nucleolus-2-3 nucleoli in most cells; thousands in others ex. amphibian eggs -ribosomal RNA is synthesized, assembled with proteins from the cytoplasm into the ribosomal sub-unit The nucleus stores chromatin (DNA plus proteins) in a gel-like substance called the nucleoplasm. The nucleolus is a condensed region of chromatin where ribosome synthesis occurs. The boundary of the nucleus is called the nuclear envelope. It consists of two phospholipid bilayers: an outer membrane and an inner membrane. The nuclear membrane is continuous with the endoplasmic reticulum.Nuclear pores allow substances to enter and exit the nucleus. ENDOPLASMIC RETICULUM -continuous from the nuclear envelope to plasma membrane -a series of channels that helps materials to circulate through the cytoplasm  General Biology 1 -storage unit for enzymes and other proteins and a point of attachment for ribosomes Smooth ER- cytoplasmic surface lacks ribosomes -site for synthesis of lipids (oil, phospholipids, steroids-sex hormones) -site for metabolism of carbohydrates and detoxification of drugs and poisons -adds hydroxyl to substances makes them soluble, making these substances easier to flush from the body -ER membrane is involved in the Calcium ion pump for muscle contraction Rough ER- contains ribosomes -produce secretory proteins and transport vesicles GOLGI APPARATUS -1898 by Camillo Golgi -sorts, packages and secretes proteins and lipids -proteins are concentrated and chemically modified to mark and sort proteins into different batches for different destinations -abundant in cells that secrete chemical substances Ex. pancreatic and nerve cells -produces lysosomes Cisternae- the inner portion of the Golgi where proteins and lipids are modified; maybe altered Cis face- receiving side near ER where transport vesicles from the ER fuses Trans face- shipping side where vesicles pinch off B. Non-membrane bound RIBOSOMES -non-membrane bound -site for protein synthesis for insertion in membranes, packaging within the organelles or export from the cell -contains protein and ribosomal RNA -2 subunits (small and large) Free Ribosomes- suspended in the cytosol where it functions Ex. enzymes for sugar breakdown Bound Ribosomes- attached to the ER or nuclear envelope -both type of ribosomes is structurally identical and can interchange roles  General Biology 1 CYTOSKELETON -network of fibers extending throughout the cytoplasm -organizes structures and activities of the cells -provides structural support and maintain its shape -involved in cell motility Centrosome/ pericentriolar area - where microtubules grow out; region located near the nucleus, organizing center for the mitotic spindle Centrioles- located within the centrosome; composed of 9 sets of triplet microtubules arranged in a ring Types of Fibers Microtubules- thickest, found in cytoplasm made up of globular protein- Tubulin -involved in shape changes during specialization Function: movement of organelles and chromosomes during division Microfilaments (Actin Fibers)- thinnest made from actin fibers -help muscle cells to shorten/contract -provide mechanical support -form contractile systems for some cellular movement ex. amoeboid movement -bear tension (pulling forces) *Both microtubules and microfilaments can be disassembled and reassembled Intermediate Filaments- protein fibers -intermediate size -help in maintaining cell shape and the spatial organization of organelles -promote mechanical activities within the cytoplasm -made up of keratin, thus more permanent CILIA and FLAGELLA -elongated appendages on the surface of some cells -helps propel the cell -membrane bound cylinders enclosing a matrix Matrix- axomere/axial filaments with 9 pairs of microtubules Cilia – moves fluid over a cells surface Flagella – move an entire cell  General Biology 1 Cell Structure and Function: Comparison in Plant,Animal and Bacteria Bases Eukaryotes Prokaryotes Animal Cell Plant Cell Bacteria Cell wall Absent Present (formed of Present made of cellulose) peptidoglycan Shape Round( irregular shape) Rectangular ( fixed; rigid varried shape) Vacuole One or more small One,large central vacuole Absent vacuoles Centrioles Present in all animal Only present in lower plant Absent cells forms ( ex. Chamydomonas) Chloroplast Absent Plant cells have Absent chloroplast to make their own food Cytoplasm Present Present Present Ribosomes Present Present Present (small amount) Mitochondria Present Present Absent Plastids Absent Present Absent Endoplasmic Present Present Absent reticulum Peroxisomes Present Present Absent Golgi apparatus Present Present Absent Cell membrane Present Present Absent Microtubules/microfil Present Present Rarely have microtubules aments Flagella Present in some cells: Present in some cells (ex. Present: simple complex ( ex. Spems of bryophytes and Mammalian sperm cells) pteridophytes, cycads and ginko) Lysosomes present –occur in Lysosomes usually not Absent cytoplasm evident Nucleus Present Present Nucleod (no membrane Chromosomes Multiple consisting of Multiple consisting of DNA envelope) DNA and much proteins and much proteins DNA is in a single circular ring Cilia Present Most plant cells do not Present contain cilia Glyoxysome Common None Absent Peroxisome Often Often Absent  General Biology 1 Cell shapes Cell arrangement: a. Simple- consists of one layer of cells b. Pseudostratified- have a single layer of cell though it looks like it is composed of two or several layers of cells c. Stratified- contains more than one layer of cells Naming cells according to shapes and arrangement: Ex. Simple squamous cells, Columnar Pseudostratified cells, Polygonal stratified cells, etc. The Virus -strand of genetic material either DNA (warts, chicken pox, mononucleosis) or RNA (HIV, Influenza, Rabies) -microscopic infectious agent smaller than bacterial cells -infects host cells to reproduce -learn to adopt to immune response making them difficult to treat compared to bacteria -do not have ribosome, mitochondria and other cell organelles Virion- fully formed virus capable of infecting a host cell *Naked virus does not have the envelope called Capsid https://quizlet.com/382994038/virus-bacteriophage- shapes-and-functions-diagram/  General Biology 1 Overview of a plant cell structure https://images.app.goo.gl/mFWAAPM6qxUdCFQs6 Overview of an Animal Cell Structure https://images.app.goo.gl/Q3tW3dJE2ktnaX3X6  General Biology 1 ANSWERS TO SELF-ASSESSMENT ACTIVITIES SELF – ASSESSMENT 1: What make things ALIVE? Below are the possible answers in your self – assessment 1 List of things Characteristics of Life Living or non -living 1. butterfly Alive things are… living - organized 2. Monstera plant living -capable of locomotion 3. Persian cat -respond to stimuli living 4. Peace lily -able to reproduce living - evolving 5. house bird living -capable of adapting to changes 6. Siberian husky -maintain internal balance living 7. goat -using energy to sustain life living 8. clouds Non -living 9. pots Non - living 10. cars Non -living