General Biology 1 Notes PDF

General Biology 1 19th Century – the Age of Engineering Unit 1: The Cell as the Basic Unit of Life 20th Century – the Age of Chemistry and Physics Chapter 1:...

General Biology 1 19th Century – the Age of Engineering Unit 1: The Cell as the Basic Unit of Life 20th Century – the Age of Chemistry and Physics Chapter 1: Biology: It’s All About You 21st Century – the Age of Biology Concept in a box Century of Biology Completion of Human Genome Project Scientific milestones and discoveries Revolutionary ways in solving problems that threaten humankind Genome Sequencing 1990 – the Human Genome Project – aimed to sequence three billion DNA bases in the human cell. – was finished in 2003 – provided new insights in understanding the Biology of Homo sapiens, its evolution, and the proper and accurate diagnosis of human diseases. – was hailed as one of the most significant scientific endeavors ever accomplished Lesson 1.1: The Study of Life Life Sciences – play a key role in tackling global challenges Biology – study of life Bios – life; Logos – study The first living cells came as a result of ancient events wherein – it deals with structures, functions, and relationships of lifeless matter became organized, capable of supporting life. organisms with their environment – tells that ours is an environment that began 3.8 billion years ago, aquatic and devoid of life – studied at various level Various levels: Molecular Cellular Organismal Population The diversity of life started with simple organisms that were able to Community evolved from one generation to the next. Ecosystem Levels of Structural Organization Traditional Branches of Biological Sciences Carbon Atom Taxonomy – naming and classifying organisms DNA Molecule – groups of atoms Dumb – smallest unit of most chemical compound King Organelle Philip Cell – smallest functional unit of life Came Group of Cells – tissues, organs, and organ systems Over Tissue From Organ Great Organ System Spain Organism – individual living thing Population – group of organisms of one type that live in the Cytology – structures and functions of cells same area Embryology – function and development of organisms Community – populations that live together in a defined are Anatomy – structures and parts of organisms Ecosystem – has a community of organisms and its Physiology – functions of living organisms and their parts nonliving surroundings Biochemistry – biochemical compositions and processes of Biosphere – the part of the Earth that contains all living things ecosystems Genetics – heredity and variation Evolution – origin and differentiation of various organisms Ecology – relationships of organisms with each other and their environment New Subdisciplines in Biology – because of rapidly changing technology Three Major Divisions of Biological Sciences: Bioinformatics – Biological data using computer programs Genomics – entire genetic material (genome) of an Microbiology – study of microscopic organisms organism – those being unicellular, multicellular, or Molecular biology – molecules that make up the cells of acellular living organisms Botany – scientific study of plants Pharmacogenomics– how genes affect a person’s response – including their physiology, structure, genetics, and to drugs ecology Proteomics – Proteins in a living organism Zoology – the scientific study of the behavior, structure, Synthetic biology – artificial biological systems physiology, classification, and distribution of Systems biology – computational and mathematical animals modeling of biological systems Lesson 2.1: Importance of Studying Biology This will enable us to determine the biases of investigators, mass media, and others that we encounter, thus, we are Biology can help solve societal problems guided to make sound judgments on biological scenarios in Studying biology helps you understand the functions and daily life. reactions of your body. Lesson 1.3: Biology as a Science It explains your similarities and differences with other Biology is an objective, logical, and repeatable attempt to organisms. understand the principles and forces operating in the natural It helps in understanding how animals survive, respond, and world. interact with the environment. Science is an objective, logical, and repeatable attempt to Organisms keep the balance in the environment, esp. in the understand the principles and forces operating in the natural world. food chain. Science is a body of systematized information about living things Other animals (mice, frogs, and monkeys) are used as derived from observations and experiments. specimens to further understand the body systems. Knowledge in biology and its immense data is dependent on the Biology encompasses the study of different causative study of structures and processes that need to be validated either agents of diseases such as bacteria and viruses. directly or indirectly with the help of tools, such as microscopes, that extend the physical capacity of your senses. People find ways to fight and prevent the spread of diseases caused by various infections. Biologists blend two main approaches in scientific investigations: Biology helps you respond to the demands of human population, esp. in food production, which is made possible Hypothesis-Based Science Discovery-Based Science by careful study and research. Involves the use of Scientific Relies mainly on verifiable Method results and measurements Biology also studies reproduction and population growth of Requires proposing and Knowledge of cells to the living organisms to assure that problems regarding testing of hypothesis levels of biosphere overpopulation will be solved. Experimental Design Sequencing of human genome Biology takes into realm the study of plants, which provide us food, oxygen, medicines, clothing, and various materials. Scientific Method Understanding biological processes that lead to natural calamities can help preserve these endangered species and Observation their ecosystems. Hypothesis Experiment Biology helps you think critically, make informed choices, Conclusion and solve problems. Observation : identifying and clearly defining problem – one tends to jump into general : it starts with being curious and asking questions observations from only few : may be done anytime and anywhere specific findings : uses the 5 senses Note: “General Rule” might even (eventually) turn out : think of related questions you need to find answers to be wrong most of the time to in order to identify a scientific problem Deductive Reasoning – general principles to more specific observations Hypothesis : formulating a possible logical answer to the identified – “from the Top Down” problem – used by biologist to test existing : after gathering observation and existing knowledge theories or hypothesis on a particular phenomenon, it’s time for REASONING. Deduction – starts with a general idea and determines Two Kinds of Scientific Reasoning whether it applies to specific observations Inductive Reasoning Hypothesis – possible logical answer; not an ordinary Deductive Reasoning guess; based on existing knowledge Experiment : conducting controlled attempts to test one or more hypothesis and includes recording and analyzing results : a set of procedures to test a hypothesis : based on an experimental design : involves the use of various references and extensive related literature Types of Variables Independent Variable Inductive Reasoning – specific to general Dependent Variable – involves using many individual Controlled Variable observations to make a Independent Variable – changeable generalization – limit to only one in an experiment – based on tentative hypothesis that – cause change in an experimental can later be tested before set up producing a general conclusion. – cause Inductive Leap – a common pitfall condition to this approach  Dependent Variable – change that happens because of the – explains the natural world independent variable – well-accepted by the scientific community. – effect Controlled Variable – everything you want to remain Common Biological Theories constant and unchanging Cell Theory Cell is the basic unit of life. All – unexposed group organisms are composed of cells. All Ex. Plants cells come from preexisting cells Gene Theory Inherited information dictates the Independent – liquid used to water the plant structure, function, and behavior of Dependent – height/health of plant organism Controlled – type of plant used, pot size, Theory of Evolution Organisms possess inherited traits that amount of liquid, soil type, etc. by Natural Selection may make them adaptable to changing conditions in their environment. Conclusion : formulating generalization about the results that may accept, reject or modify the hypothesis : Experimental data are analyzed : Repeatability of the experiment led to more accurate and reliable findings Repeated Findings = reliability Scientific Laws Scientific Theories Based on alterable facts Based on observation Proven Proven, but still testable Has evidence and results Has evidence States that something will happen Attempts to explain why under certain conditions something happens Can be represented by a No mathematical mathematical statement statement Newton’s Law, Law of Inertia Theory of Relativity, Big Bang Theory Edward Jenner – Father of Vaccine – he used pus from cow pox to treat small pox Theories – tested scientific results that contribute to the existing body of knowledge  Studies on Spontaneous Generation John Needham (1745) – an English experimenter and priest – common knowledge at that time that boiling cab kill microorganisms – challenged Redi’s experiment – broth turned cloudy due to microorganisms Conclusion: life in the broth was caused by spontaneous generation. In actuality, he did not heat it long enough to kill all the microbes in the broth. Lesson 1.4: Life and Its Beginnings Studies to prove Biogenesis Early Beliefs About the Origin of Life Lazzaro Spallanzani (1767) – challenged Needham’s experiment – he boiled broth in two bottles, left one bottle open and Abiogenesis / The Theory of Spontaneous Generation one closed, and found that new microorganisms – proposed by Aristotle in 4th century that lasted until appeared only in the open bottle. 17th century – small organisms are spontaneously generated from Conclusion: life occurred from something that entered the nonliving matter unsealed flask and that it was the one responsible for life to grow. Ex. Flies can grow from cattle manure, the microorganisms entered the bottle through the air; mice from wheat stored in the dark they were not generated spontaneously in the broth Biogenesis – belief that life originates from preexisting life 19th Century Advancement Experiments to prove Biogenesis LOUIS PASTEUR (1861) – designed flasks with long, specially Francesco Redi (1688) – Italian physician who experimented on curved, swanlike necks and boiled the fresh meat in jars sugar solution with yeasts in it. – disprove the theory of spontaneous The flasks were open to allow air to enter but there’s no generation organism developed in the mixture. Conclusion: that life arose from living matter, such as Microorganism settled on the bottom of the curved neck of maggots from eggs of flies, and not from the the flask and could not reach the mixture spontaneous generation in the meat  Conclusion: This suggests that new bacteria appear only when Lesson 1.5: Unifying Themes about Life they are produced by existing bacteria. Living Things demonstrate common characteristics clustered CURRENT Beliefs About the Origin of Life into themes: Divine Creation Adapting and evolving Spontaneous Origin Living and interacting with the environment Panspermia Gathering and using energy Maintaining internal balance Divine Creation – oldest hypothesis that life came from a Reproducing and continuing life divine being Responding to changes in the surroundings – supernatural power than naturalistic means Creationism – the belief that life arose from nothing but PROPERTIES OF LIFE the power of divine being in six-day period Gathering and Using Energy Spontaneous Origin – simple molecules combined to form Maintaining Internal Balance complex ones Responding, Adapting and Evolving Energy – lighting, geothermal, electric sparks Reproducing and Continuing Life Living and Interacting PRIMORDIAL SOUP – organic broth on Earth’s early surface GATHERING AND USING ENERGY (Nutrient Uptake and Processing) Miller-Urey experiment – suggested that lightning may have helped trigger the creation of the Using energy and matter for survival key building blocks of life on Earth during the All living things require ENERGY, which is produced when earliest time periods. complex organic matter is broken down into simpler units Panspermia – Swedish scientist Svante Arrhenius ENERGY – the ability of organisms to do work that Life arose outside Earth and life forms were transported allows them to move from another planet to seed life on Earth CELLULAR RESPIRATION – the process by which A meteor or cosmic dust may have carried to Earth energy is released by the breakdown of significant amounts of organic molecules, which started the food substances evolution of life METABOLISM – sum of all chemical processes, Despite the influx of information, the question about how life reactions and energy changes happening began on Earth remain unanswered because there is no inside the body of an organism account on what happened 4.5 billion years ago.  NUTRITION – the process by which organisms Organ systems work together to keep the organism alive acquire food RESPONDING, ADAPTING AND EVOLVING (Motility, Irritability, Adaptation) Organisms react to changes in their surroundings in a predictable and meaningful way. MOTILITY OR LOCOMOTION – movement from one place to another by walking, flying, swimming, gliding, or jumping Plants absorb water and minerals from the soil and take CO2 from the air Animals move for a variety of reasons – for food, for Animals feed / consume organic food obtained from plants reproduction and for response to changes in the and animals environment. Living organisms process these raw materials inside their TROPISM OR RESPONSE – reaction of organism to bodies through various chemical reactions for essential stimuli activities of the human body. Stimuli: light, sound, temperature, pressure, food sources, or presence of MAINTAINING INTERNAL BALANCE chemical of chemical substances (Waste Elimination) : a factor in the environment that (Excretion and Homeostasis) causes the organism to respond in a EXCRETION – process of eliminating wastes from the predictable way body SENSITIVITY OR IRRITABILITY – ability to respond Enzymes ensure efficient coordination during chemical appropriately against a stimulus reactions inside the organism’s body. (Metabolic Level) ADAPTATION – is the ability to adjust to changes in Enzymes – help regulate the rate at which these the environment reactions occur, including the amount of CAMOUFLAGE – the ability of some animals to nutrients to be processed into other forms change color and body structure to Hormones are chemical regulators of the body as they blend with their environment control the functions of activities, growth and development. Limited food supply, temperature fluctuations (Organismal Level) and natural calamities may be experienced HOMEOSTASIS – maintenance of the body’s internal by the organism environment and balance  EVOLUTION – changes in the characteristics of a Sexual Reproduction – the union of sex cells from group pf organisms (species) two parents to produce a over time unique individual of their kind Evolutionary adaptation is a gradual or Asexual Reproduction – occurs when an organism rapid change in body structure or behavior to makes copies of itself be better suited and to survive a new HEREDITY – Unity in Diversity environment The presence of DNA in every living organism explains the unity of life. REPRODUCING AND CONTINUING LIFE LIVING AND INTERACTING (Growth, Development, Reproduction, Heredity) (Levels of biological organization in vertical and horizontal DEVELOPMENT – undergoing defined stages of living dimensions) things’ life cycle Biological organization in vertical dimension GROWTH – increase in size and volume by converting food to become part of body cells INTUSSUSCEPTION – a process by which living things exhibit growth from within the cells ORGANOGENESIS – complex processes of cell differentiation and formation of new organs ACCRETION – growth by external addition of substances REPRODUCTION – the process of passing genetic information to produce offspring DNA – used as a physical carrier of transferred genetic information through sexual reproduction – differentiates a living from nonliving organism Biological organization in horizontal dimension Lawyers / Legal experts Molecular Biologists (Medicolegal and Criminal Laboratories) Public servants and consultants (Government agencies) Geneticists (insurance companies) Human Resource Managers Science reporters, editors and writers (Mass Media) Experts and researchers (Agriculture and Fisheries) Biologists Six Kingdom System (field of research) Archaebacteria oldest known single-celled Genetic engineers living organism Molecular biologists Eubacteria E. Coli, Cyanobacteria Biochemists Algae, Paramecium, Diatom, Pharmacologists Protista Slime Mold Immunologists Single-celled organisms BIOTECHNOLOGY is the application of biological concepts and All flowering plants, mosses and ferns systems to make products beneficial to humans. It uses the basic Plantae Multi-celled, complex molecules of life to make new products. organisms Genetically modified organism (GMO), organism whose genome Autotrophs has been engineered in the laboratory in order to favor the Fungi Mushrooms, molds, mildews, expression of desired physiological traits or the generation of and yeasts desired biological products. multi-celled organisms Animalia ranging from sea sponge Gene therapy involves the transfer of genetic material into the colonies to elephants appropriate cells. In genetic diseases, the stem cells of the Heterotrophs afflicted tissue are often targeted. The adult stem cells of the tissue can replenish the specialized cells. Lesson 1.6: Biology Careers in the Twenty-First Century Organisms that have altered genomes are known as transgenic. Academician or Medical Doctors Most transgenic organisms are generated in the laboratory for Computer Analysts / Software Designers research purposes. (Bioinformatics) Dolly – world’s first sheep cloned from adult somatic cell  Bonnie – Dolly’s firstborn lamb Anton Van Leeuwenhoek – a Dutch naturalist and shopkeeper Milly – first cloned pig – credited to be the first to study magnified cells Polly – first transgenic lamb cloned by nuclear transfer – inspired by Hooke’s Micrographia – was able to devise more than 500 lenses and one of which can even magnify up to 270 times Chapter 2: Life in a cell – Father of Microscopy and Microbiology Lesson 2.1: The cell and Its Beginnings First invention was a simple microscope with only one lens Earliest Microscopic Observations Leeuwenhoek realized that he can observe even microscopic things that were moving in pond water, which he call “ANIMALCULES” 1595 – Hans and Zacharias Janssen credited with the first meaning little animals. compound microscope Animalcules – known today as single-celled organism called 1661 – King Charles II of England commissioned a microscopic “protozoa” examination of the natural world, as the focus of the royal interest that time was on insect anatomy. He studied many specimens such as blood, semen, feces, pepper, and tartar. Robert Hooke – an English scientist He was the first to observe living cells. He was also the first – curator of Instruments for the Royal Society of England to record microscopic observations of muscle fibers, – He was very fascinated with the microscopic world. bacteria, spermatozoa and blood flow in capillaries (small – devised one of the earliest microscopes that can magnify blood vessels). every sort of material such as glass, crystal, point of a pin, body of a flea, and even frozen urine. – most commemorative work came from a thin slice of cork After more than 200 years, from a bark of an oak tree Formulation of the Cell Theory – observed lining matter (cork cells) through a compound microscope, which reveals empty cells. 1838 – German Botanist, Matthias Jakob Schleiden, concluded that – He is the first to call the spaces in the cork “cellulae” which all plant parts are made of cells means little rooms. 1839 – German physiologist, Theodor Schwann, who was a close – However, these hollow chambers drawn by Hooke were friend of Schleiden, stated that all animal tissues are actually dead. composed of cells. Robert Hooke refined the design of the compound microscope 1855 – Robert Remak a prominent neurologist and embryologist, around 1665 and published a book “Micrographia” which illustrated published convincing evidence that cells are derived from his findings using the instrument. Hooke was first credited in seeing other cells as a result of cell division. However, this idea was a cell in 1666, but he cannot fully define what he saw. questioned by many in the scientific community. 1858 - Rudolf Ludwig Karl Virchow, the “Father of Pathology” Three years later, a well-respected pathologist published an Organic Chemical Evolution – life originated as primitive cells editorial essay entitled “Cellular Pathology” (protocells) from inorganic and organic molecules in Earth’s prebiotic oceans some 3.5 – 4 billion years ago “Omnis cellula e cellula” All cells come from pre-existing cells. 1938 – Russian Biochemist, Aleksandr Ivanovich Oparin proposed The Cell Theory – the explanation of the relationship between cells that organic molecules might have been assembled in and all living organisms Earth’s primitive atmosphere in the presence of strong Three Tenets of the Cell Theory energy Schleiden and Schwann Miller-Urey Experiment – all organisms are composed of one or more cells 1953 – American chemist Stanley Miller and Harold Urey designed – cells are the smallest and basic units of structure an experiment to test Oparin’s hypothesis by placing a and function in organism mixture of inorganic compounds in a closed system, that Virchow – cells arise only from previously existing cells resembles the primitive Earth. The Cell Theory Timeline Miller heated, circulated the mixture and applied an electric spark. After a week, amino acids and other organic compounds were recovered from the setup. The experiment used water (H2O), methane (CH4), ammonia (NH3), and hydrogen (H2). The chemicals were all sealed inside a sterile 5-liter glass flask connected to a 500 ml flask half-full of water. Modern day analysis indicate that an even more complete list of amino acids was successfully synthesized in the Miller-Urey Experiment. Miller and Urey concluded that the basis of spontaneous organic compound synthesis or early earth was due to the Every living thing on the planet is related, connected by primarily reducing atmosphere that existed then. series of cell divisions from earliest ancestors The ORGANIC CHEMICAL EVOLUTION hypothesis states The first cells inhabit inconceivable places in the planet. that the first life forms have evolved from PROTOCELLS. Existing forms of living organisms today are the products of Protocells are hypothesized to have been formed by the long and still continuing evolution from much simpler polymerization of organic molecules in heated rocks or in organisms. clay. These might have been enclosed by a lipid-protein membrane and might have possessed an enzymatic activity.  It evolved over billions of years into a self-replicating Two important parameters in microscopy: system that gave rise to the first true living cell. Magnification Resolution Modern Cell Theory Magnification – a measure of how much larger a microscope (or set of lenses within a microscope) causes an object to 1. All living organisms are made of cells appear 2. Cells are the basic unit of life – the measure of optical instruments for an object to appear 3. Cells arise from pre-existing cells larger than its actual size. 4. Hereditary information is passed from cell 5. All cells have the basic chemical composition Resolution – the smallest distance by which two points can be 6. Energy Flow occurs within cells separated and still be distinguished as separate objects Current Interpretation of Modern Cell Theory – It indicates clarity of an image Scientists, biologists, researchers and scholars, though still using the Magnification = magnification of ocular lens x magnification of fundamental tenets of cell theory, conclude the following on the objective lens modern interpretation of cell theory: DDDDDDDDDDDDDDDDDDDDD Energy flow – metabolism and biochemistry – happens within cells. Resolving Power of Microscopes – level of detail that we can see Cells contain passed on from cell to genetic information in the – the smaller this value, the higher the resolving power of the form of DNA cell during division. microscope and the better the clarity and detail of the image. In the organisms of similar species, all cells are fundamentally the Both magnification and resolution are important if you want a same. clear picture of something very tiny. For example, if a microscope All living organisms consist of one or more cells. has high magnification but low resolution, all you’ll get is a bigger version of a blurry image Lesson 2.2: The invisible World through the Lens of a Microscope High magnification and resolution are important in revealing the Microscopes are important biological tools in revealing the intricacies of extremely small specimens with enough clarity. intricate parts of the cells Microscopes in a biology laboratory differ in terms of their Micrographs – are images produced by a microscope magnification and resolution capabilities. – specifies the type of microscope used to produce Light Microscope/Compound Microscope the image as well as the magnification value of the image commonly used in schools can enlarge objects up to hundred times, most powerful type has a 2000x magnification  used to examine cells and sections of tissues with the use of It is the best to use as it clearly illuminates bacteria and sunlight or artificial light microscopic organisms a benefit of light microscopy is that it can often be Light Microscope Electron Microscope performed on living cells, so it’s possible to watch cells Uses visible light Uses beam of electrons carrying out their normal behaviors (e.g., migrating or Lower resolution and Higher resolution and dividing) under the microscope. magnification magnification More complex compound microscopes may not produce an inverted Cells can be alive or dead Cells must be dead image because they include an additional lens that “re-inverts” the Inexpensive, relatively small Expensive, very large image back to its normal state. DDDDDDDDDDDDDDDDDDDDD Two Major Types of Electron Microscopy Stereo microscope Transmission electron microscope (TEM) Scanning electron microscope (SEM) Stereo Microscopes enable 3D viewing of specimens visible to the naked eye. Transmission Electron Microscopy (TEM) They are commonly known as Low Power or Dissecting the sample is cut into extremely thin slices (for instance, Microscopes. using a diamond cutting edge) before imaging, and the An estimated 99% of stereo applications employ less than electron beam passes through the slice rather than skimming 50x magnification. Use them for viewing insects, crystals, over its surface. plant life, circuit boards. TEM is often used to obtain detailed images of the internal It is used to examine the externa structures of a specimen structures of cells through sectioned specimens. such as insects Scanning electron microscope (SEM) Phase Contact Microscope – It is used to examine highly transparent objects such as in contrast, is used to study the 3D surface structures or unstained cells shapes of objects such as viruses. These micrographs are always black and white, scientists Electron Microscope often add artificial colors for better visibility. Uses streams of electrons instead of beams of light to Fluorescent microscope enlarge objects up to 10 000 000x Electrons have much a shorter wavelength than visible light, It illuminates objects stained with fluorescent dyes that glow and this allows electron microscopes to produce higher- in the dark. resolution images than standard light microscopes. Fluorescent microscopy had been used extensively in Electron microscopes can be used to examine not just whole studying the location of certain organelles or substances cells, but also the subcellular structures and compartments inside the cell. within them.  Confocal Scanning Microscope – it is used to examine the Cells need to produce chemical energy (via metabolism) to survive 3D structure of a cell or organelle without cutting the and this requires the exchange of materials with the environment specimen into sections The rate of metabolism of a cell is a function of its mass / – uses laser beams to scan across the specimen volume (larger cells need more energy to sustain essential Video Microscopy functions) The rate of material exchange is a function of its surface A process where objects examined using different area (large membrane surface equates to more material microscopes can be photographed or viewed on TV or movement) computer screens. Brought by technological advancements in image processing As a cell grows, volume (units3) increases faster than surface area (units2), leading to a decreased SA:Vol ratio If metabolic rate exceeds the rate of exchange of vital WHY ARE CELLS SO SMALL? materials and wastes (low SA:Vol ratio), the cell will In order to survive, cells must constantly interact with their eventually die surrounding environment Hence, growing cells tend to divide and remain small in order to maintain a high SA:Vol ratio suitable for survival Nutrients, water, oxygen, carbon dioxide and waste products enter or leave a cell through plasma membrane. Each cell must have abundant surface area to accommodate these changes. As an object grows, its volume increases much more quickly than its surface area. Small size maximizes the ratio of surface area to volume Surface Area to Volume Ratio DDDDDDDDD Surface area is the area of the outside of the cell, called the plasma membrane. The volume is how much space is inside the cell. The ratio is the surface area divided by the volume. This indicates how much surface area is available compared to how big the cell is.  GENETIC MATERIAL (DNA) - located at a central region that provides instructions to make proteins, regulates activities, and enables cells to reproduce Cytoskeleton – it is inside the cytoplasm are organelles that are suspended in microscopic fibers Ribosomes – molecular machines that synthesize proteins Two Main Type of Cells: the presence of the specific type of cell allows biologist to classify organisms based on their complexities Prokaryotes Eukaryotes Prokaryotes – simple – pro meaning “before” and karyon meaning “nut,” which all means “before the nut” Prokaryotic – complex cell wall Eukaryotes – more complex – Greek eu meaning “true” karyon meaning “nut” Eukaryotic – with compartmentalization/membrane-bound organelles Lesson 2.3: Basic Cell Types Fossil records show that the first kind of cell to develop about 3.5 All living things have cells that share fundamental structural parts, Billion years ago are Prokaryotes which include: Bacteria Cell Membrane or Plasma Membrane – an outer boundary that Blue-Green Algae regulates the passage of materials into and out of the cell Archeans Cytoplasm – a gel-like substance making up the cell’s internal that can thrive / can be found in air, water, soil, bodies of environment host Bodies of water extreme environments Nucleus – central genetic region  Some prokaryotes have a CAPSULE - acts as a protective layer made up of polysaccharides lying outside the cell wall Lacks a distinct nucleus, but has a Nucleoid Region - it stores its genetic material in the form of DNA It has a CYTOPLASM - not organized into distinct compartments Scattered RIBOSOMES - Located on cytoplasm, these small structures make proteins Some possess PLASMID - an independent circular DNA structure, apart from its chromosomal DNA - its presence provides the bacteria with genetic advantages, such as antibacterial resistance - Used by scientist for genetic cloning and manipulation APPENDAGES of Bacterial Cell: FLAGELLA (Flagellum) - taillike, whiplike tail, allow locomotion / propel the bacteria - located at the end part of the cell FRIMBRIAE (Fimbria) - additional smaller and bristle-like fibers - they help the bacteria to attach themselves to different surfaces CONJUGATION PILLI (Conjugation pilus) - tubular structures that function for cell-to-cell communication, as well as to pass Structures of a Bacterial Cell DNA from one bacterium to the next Plasma Membrane – a semipermeable membrane responsible for - These structures are particularly important because some the prokaryote to allow waste products to pass through bacteria are very successful in developing drug resistance while preventing the diffusion of essential products to the across bacterial generations. external environment All these appendages enable the bacteria to communicate Cell wall – responsible for maintaining its shape especially when information form cell to cell cells are exposed to high water influx  Flagella Consist of two Complex; consist of protein building multiple blocks microtubules Cell Wall Usually present; Only in plant cells chemically complex and fungi (chemically simpler) Characteristic Prokaryotic Cell Eukaryotic Cell Plasma membrane Usually No Yes with steroid Cytoplasm No Cytoskeleton or Cytoskeleton; cytoplasmic cytoplasmic About 1.8 billion years ago, a new kind of cell evolved to a larger streaming streaming size and more complex structural components. Ribosomes Smaller Larger Cell Division Binary Fission Mitosis Complex cells known as EUKARYOTIC CELLS Number of One, but not true More than one Chromosomes chromosomes possessed by HIGHER FORMS of organisms - Fungi, Sexual No meiosis; transfer Involves Meiosis Animals, Plants, and Protists Reproduction of DNA fragments Distinct NUCLEUS - Houses its genetic material, DNA only (conjugation) They are HIGHLY-ORGANIZED - Membrane-bound compartments and organelles are neatly Characteristics Prokaryotic Cell Eukaryotic Cell Size of Cell Typically 0.2-2.0𝜇𝑚 Typically 10-100 𝜇𝑚 in diameter in diameter Example Bacteria and Animals and Plants Archaea Nucleus Absent Present Membrane- Absent Present example: enclosed Lysosomes, Golgi organelles Complex, Endoplasmic reticulum, mitochondria & chloroplasts