Zoology First Semester Midterm PDF

ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx HIERARCHY OF TAXONOMY WHAT IS BIOLOGY? broadest to most specific: biology - study of life bios - life 1. Domain – The hi...

ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx HIERARCHY OF TAXONOMY WHAT IS BIOLOGY? broadest to most specific: biology - study of life bios - life 1. Domain – The highest level of logos - study classification (e.g., Bacteria, Archaea, Eukarya). HISTORY OF BIOLOGY 2. Kingdom – Groups within each domain (e.g., Animalia, Plantae, 350 BC ARISTOTLE founded zoology - Fungi). also proposed spontaneous generation 3. Phylum – Major divisions within kingdoms (e.g., Chordata for Spontaneous Generation: The animals with a backbone). hypothetical process by which living 4. Class – Subdivisions within phyla organisms develop from nonliving (e.g., Mammalia for mammals). matter. 5. Order – Groups within classes (e.g., Carnivora for carnivorous Examples: Dust creates fleas, mammals). maggots arise from rotting meat, 6. Family – Groups within orders and bread left in the dark corner (e.g., Felidae for cats). produces mice. 7. Genus – Groups within families (e.g., Panthera for large cats like 300 BC HEROPHILOS dissects human lions and tigers). body, DIOCLES coined the term anatomy 8. Species – The most specific level, and wrote the 1st known anatomy book identifying individual organisms (e.g., Panthera leo for lions). 1590 ZACHARIAS and HANS JANSSEN invented 1st compound microscope 1651 WILLIAM HARVEY all animals 1802 JEAN-BAPTISTE LAMARCK coined develop from eggs biology 1663 ROBERT HOOKE discovered cells Lamarck's theory of evolution proposed that giraffes developed 1668 FRANCESCO REDI disproved their elongated necks and front legs spontaneous generation by generations of stretching to reach high tree leaves. According to 1673 ANTON VAN LEEUWENHOEK Lamarck, acquired characteristics describes microscopic life, observes bacteria were inheritable, and the giraffe's habit of stretching its neck resulted 1673 ANTON VAN LEEUWENHOEK in gradual lengthening of the limbs describes microscopic life and neck, which would then be passed on to the next generation. 1735 CARLOS LINNAEUS taxonomic classifications 1 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx 1809 JEAN-BAPTISTE LAMARCK 4. Common Descent: All species of proposed modern theory of evolution organisms arise and develop through the natural selection of 1833 ROBERT BROWN discovered the small, inherited variations that nucleus increase the individual’s ability to 1838 MATTHIAS SCHLEIDEN proposes compete, survive, and reproduce1. that all plants are composed of cells 1839 THEODOR SCHWANN proposes that > THREE LAWS OF GENETICS all animals tissues are composed of cells Law of Segregation: Each individual has 1856 LOUIS PASTEUR microorganisms two alleles for each trait, which separate and fermentation during gamete formation. Offspring inherit one allele from each parent. 1858 RUDOLF VIRCHOW cells arise from pre existing cell Law of Independent Assortment: Genes for different traits are passed independently 1859 CHARLES DARWIN published of one another, as long as they are on natural selection - theory of evolution different chromosomes or far apart on the same chromosome. THEORY OF EVOLUTION: KEY POINTS Law of Dominance: In a pair of alleles, one 1. Natural Selection: Darwin proposed (dominant) can mask the expression of the that species evolve over time other (recessive). through a process called natural selection. This means that individuals with traits better suited 1866 GREGOR MENDEL formulated his to their environment are more likely laws of inheritance to survive and reproduce, passing those advantageous traits to the 1869 FRIEDRICH MIESCHER discovered next generation1. nucleic acids 1 2. Variation: Within any given > CELL THEORY population, there is natural variation in traits. These variations can be All Living Organisms Are Composed of due to mutations, genetic Cells: Every living organism, from the recombination, and other factors2. smallest bacteria to the largest mammals, is 3. Struggle for Existence: Organisms made up of cells. Cells are the basic produce more offspring than can structural and functional units of life. survive, leading to a struggle for existence. Only those best adapted The Cell Is the Basic Unit of Life: The cell is the smallest unit that can carry out all the to their environment tend to survive processes necessary for life, including and reproduce2. metabolism, growth, and reproduction. 2 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx All Cells Come from Preexisting Cells: Characteristics of Life New cells are produced by the division of existing cells. This means that cells arise ORDER from other cells through processes like mitosis and meiosis, rather than All living things are made up of cells spontaneously forming. these cells divide or multiply to form complex form and structure 1884 WALTER FLEMING coins the terms cells comes from pre-existing cells mitosis life follows the order and has levels of an organization. 1884 EDWARD STRASBOURG coins the term cytoplasm Biosphere, ecosystems, communities, population, organism, organ system, 1905 WILLIAM BATESON coined the term organs, tissues, cells, organelles, molecules genetics ADAPTATION 1929 PHOEBUS LEVENE discovers the sugar deoxyribose in nucleic acids Living organisms can adapt to their environment through the process of 1952 ROSALIND FRANKLIN's x-ray evolution. diffraction images provided key evidence Survival of the fittest that dna is a double helix Changes can occur in populations depending on its natural 1953 JAMES WATSON and FRANCIS environment. CRICK discovered the double helix Adaptation helps in evolution in the structure process of speciation. Speciation is the emergence of Importance of Biology new, distinct species during evolution. understand organism, their roles, Ex. Pygmy seahorse and how they interact improve quality of life (medicine, METABOLISM agriculture, biotechnology) genetics and evolution give insights Intake of nutrients needed by an into the past and help shape the organism to survive. future Metabolism generally involves the Ecology and conservation research release or use of chemical energy sheds light on how to preserve the derived from these nutrients. It is a rich biodiversity of this planet. way of energy processing. Anabolism: putting together MAJOR BRANCHES OF BIOLOGY Catabolism: Breaking down complex substances to simpler zoology, botany, microbiology form. Butterfly feeding on flower nectar 3 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx REGULATION indicator of growth among living things. Regulation is a way how an organism copes up to its environment to maintain homeostasis inside the body. ZOOLOGY If anything happens within or to an organism that affects its normal zoon, animal + logos, study state, processes to restore the normal state begin. BRANCHES OF ZOOLOGY Ex. Jackrabbit’s ear Ex. Pag mababa blood sugar mo, zoography, descriptive zoology nagrerelease katawan mo ng comparative zoology glucagon which makes your body soil zoology produce glucose mammalogy comparative anatomy RESPONSIVENESS herpetology animal physiology Respond to stimuli: light, heat, entomology sound, chemical & mechanical behavioral ecology contact ornithology Motility (animals) ethology studies animal behavior Tropism (plants) Ex. venus flytrap's rapid action REPRODUCTION CHEMISTRY OF LIFE Ability of an organism to reproduce COMPOUND and pass their genetic information to Its offspring. - substance consisting of two or SEXUAL REPRODUCTION: Two more elements combined in a fixed parents contribute to the formation ratio of a new individual (ex. mammals). ASEXUAL REPRODUCTION: ORGANIC involves only one parent, and the resulting cells are generally - molecules that contain carbon identical to the parent cell (ex. atoms bonded to hydrogen atoms Binary fission of Bacteria) - ex. dna, sugar, methane, ethanol GROWTH & DEVELOPMENT INORGANIC To accomplish change, an organism - molecules without the element expends some of the energy it carbon and a few molecules with acquires during metabolism. carbon, but no carbon-hydrogen An increase in size until they bonds become an adult is usually an - ex. table salt, hydrochloric acid, quartz, carbon dioxide 4 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx TYPES OF ORGANIC COMPOUNDS CARBOHYDRATES contains carbon hydrogen and oxygen is present in the same ratio as water provides and stores energy, forms body structure Cn(H2O)n MONOSACCHARIDES simple sugar DISACCHARIDES contain one sugar molecules Consists of two molecules of Examples: monosaccharides. Triose (3C atoms) glycerose Examples: C3H6O3 Tetrose (4C atoms) threose Sucrose (glucose and fructose) - C4H8O4 Common table sugar, an extract of Pentose (5C atoms) ribose beet or sugar cane. C5H10O5 Lactose (glucose and galactose) - Hexose (6C atoms) glucose, sugar found in milk fructose, galactose, mannose Maltose (glucose and glucose) - C6H12O6 fruit juices and sprouting grains. most important is the hexoses: glucoses found in syrup or honey POLYSACCHARIDES fructose found in fruit galactose found in dairy products - Consists of a large number of monosaccharide units. Examples: In animals. Glycogen: glucose polymer, found in liver & skeletal muscle. In plants Starch: used for energy storage (rice, potatoes, grains) 5 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx Cellulose: used for structural support (Cell walls) In fungi Chitin: fungal cell walls In protists Pectin/carrageenan from algae, in food items (jam, yogurt, ice cream) to give a creamy consistency. LIPIDS UNSATURATED These are groups of carbon has double bonds in hydrocarbon containing compounds chains characterized by its insolubility Contain double bonds between In water (hydrophobic). carbons. HYDROPHOBIC: Insoluble in polar Characteristics of Plant fats. solvents like water. Less hazardous as far as health Is FUNCTIONS: stores energy, forms concerned. cell membranes, carries messages. TYPES OF LIPIDS FATS Constructed from two kinds of smaller molecules: glycerol and trimesters of fatty acids Saturated & Unsaturated fats SATURATED no double bonds in hydrocarbon PHOSPHOLIPIDS chains Do not contain double bonds structurally similar to fats, except a between carbons. group containing phosphorus or Characteristics of animal fats. nitrogen is attached to one of the Excess of these may lead to carbons of glycerol cholesterol deposits leading to cardiovascular disease. 6 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx oxygen. (Building blocks for proteins. Made up of 20 or more polypeptide chains) STEROIDS Composed of 4 fused carbon rings with various functional groups attached to them Don't have fatty acids. Example: Cholesterol (holds phospholipids together para di magalaw?) Testosterone (promotes secondary sexual characteristics) Estrogen (promotes secondary sexual characteristics) PROTEINS A biologically functional molecule made up of one or more polypeptides, each folded and coiled into a specific three-dimensional structure. building blocks from which the cells are formed, and they regulate the chemical activity inside the cell. 50% of the dry mass of most cells POLYPEPTIDE: Chain of amino acids EXAMPLE: ENZYME AMINO ACIDS: organic compounds composed mainly of nitrogen, carbon, hydrogen, and 7 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx NON-ESSENTIAL AMINO ACIDS These are synthesized in the body. EXAMPLE: alanine, serine, glycine, aspartic acid, glutamic acid, proline, hydroxyproline, citrulline, cysteine, tyrosine, norleucine, and hydroxy glutamic acid. ESSENTIAL AMINO ACIDS These are not synthesized in the body. EXAMPLE: histidine, Isoleucine, leucine, lysine, methionine, arginine, phenylalanine, threonine, valine, tryptophan VITAMINS These are the organic substances present in small amounts in natural foodstuffs which are essential for growth and normal metabolism Ligands - any molecule that binds with receptor proteins which reads the message Fat-Soluble of signaling molecules readily soluble in fats and oils AMINO ACIDS A, D, E, K formed through transcription Water-Soluble Solubility in water and their nitrogen content 8 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx Example: Thiamine (B2) The Watson-Crick Model (double helix) Riboflavin (b2) Niacin/ Nicotinic Acid (B3) base composition analysis of Pyridoxine (B6) hydrolyzed samples of DNA Cyanobalamine (B12) x-ray diffraction studies of DNA Ascorbic Acid (Vitamin C) > DNA is a long molecule made up of monomers called nucleotides NUCLEOTIDES Consists of a five-carbon sugar to which is attached a phosphate group and a nitrogen-containing/aromatic base Pyrimidines: smaller molecules, consisting of a single ring (Thymine, Cytosine, Uracil) NUCLEIC ACIDS Purines: larger, consisting of two rings (Adenine, Guanine) these are macromolecules found in animal and plant cells they participate in the storage, transmission, and translation of Ribonucleic Acid genetic information DNA and RNA mRNA - encodes proteins Deoxyribonucleic acid (DNA) - molecule tRNA - acts as adaptor between mRNA and that carries genetic information for the amino acids development and functioning of an organism. rRNA - forms the ribosome DNA is genetic material that organisms inherit from their parents DNA is a double helix (spiral Macromolecules structure; twisted ladder) Denaturation of DNA can be Oxygen caused by several factors such as: Carbon acids, alkali, heat Hydrogen Nitrogen Where is DNA found? Micromolecules DNA is in every cell of every living thing. It is found within the chromosomes of the cell. Calcium 9 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx Phosphorus Refers to unequal distribution of overall charge. The water's V-ike hydrogen - production of atp shape is due to unequal sharing of electrons. carbon - component of organic molecules COHESION AND ADHESION oxygen - for cellular respiration COHESION: attraction between like nitrogen - large chunk of amine group molecules chlorine - contains the negative charge of Water has a high cohesive property. the cell - high surface tension in water iron - component of hemoglobin, transfers allowing water striders to walk oxygen within rbc across the top of the pond > lower than.1% are called trace elements, ADHESION: attraction between different excess can cause denaturation or toxicity molecules. Water is also attracted to other materials. INORGANIC COMPOUNDS - ex. water drops clinging on the leaf surfaces. - do not contain carbon to carbon or carbon to hydrogen bond 1. mineral elements 2. water CAPILLARY ACTION 3. acids and bases The ability of the liquid to rise in narrow tubes due to cohesion and adhesion of liquid molecules. WATER HEAT CAPACITY Tasteless, transparent, odoress, almost incompressible liquid. The amount of heat energy needed The only common element to exist to raise the temperature of 1g of a in the natural environment in all substance to 1 C. three physical states of matter. Water has a high specific heat Comprises 60%-90% of the total capacity composition of the cell. Important property to cells of living Polar molecule organisms VOLATILITY: capacity of something to evaporate POLARITY HEAT OF VAPORIZATION 10 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx the amount of heat energy needed What function uses metabolic reaction? in to change a liquid into gas once it humans reached its boiling point water has a high heat of actin and niacin vaporization repair in our cells , muscles important property in regulating the internal temperature of organisms ATP (Adenosine Triphosphate) HEAT OF FUSION the primary energy carrier in cells, providing energy for various cellular the amount of heat energy needed processes, these are produced to transform 1g of a solid into its during cellular respiration liquid form water has a high heat of fusion to PYRUVATE melt ice important property in protecting a three-carbon compound produced organisms from freezing during cold during glycolysis, which is further weather broken down in the mitochondria during the krebs cycle DENSITY WATER NADH (Nicotinamide Adenine water expands, solidifies, and Dinucleotide) becomes less dense as it freezes compared to liquid water. an electron carrier molecule that stores energy used to make ATP ACIDS AND BASES produced during glycolysis and the Krebs cycle and donated electrons 0-6 acidic to the ETC 7-14 basic 14-17 alkaline NADH, stable molecule, reduced ACIDS: substances that increase H atoms NAD+, unstable molecule, oxidized when added to water BASES: are substances that increase OH atoms when added to water FADH2 (Flavin Adenine Dinucleotide) another electron carrier molecule similar to NADH, produced during CELLULAR RESPIRATION (scraps) the Krebs cycle and used in the ETC to generate ATP >> READ WHOLE LECTURE SA BOOK Acetyl-COA a molecule that conveys carbon Cellular Respiration atoms within the acetyl group to the 11 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx Krebs cycle for energy production Reduction after glycolysis. gain of electrons and the Mitochondria corresponding decrease in the oxidation state of a reactant organelles known as the “powerhouse” of the cell, where the Oxidizing Agent: substance getting Krebs cycle, ETC, and oxidative reduced in a chemical reaction phosphorylation occur. (electron-accepting species) Aerobic Respiration Reducing Agent: substance getting oxidized (electron-donating agent) cellular respiration that requires oxygen to produce ATP o - oxidation it includes glycolysis, the Krebs i - is cycle, and oxidative l - loss phosphorylation Anaerobic Respiration r - reduction respiration that occur in the i - is absence of oxygen, producing less g - gained ATP and resulting in by products like lactic acid or ethanol Chemiosmosis CELLULAR RESPIRATION IS CATABOLISM the movement of ions (specifically protons) across a semipermeable investment phase or preparatory phase membrane, down their electrochemical gradient, which is 1 phosphorylation used to generate ATP during oxidative phosphorylation. adding phosphate glucose is converted to glucose 6 > osmosis, diffusion of water, solely for phosphate using hexokinase water kinase means there is always atp involved REDUCTION-OXIDATION PROCESS atp loses one phosphate and it is attached in the glucose in carbon 6 electron is lost and gained happens simultaneously 2 isomerization Oxidation isomerase meaning changing structure of compound loss of electrons and the sugar to fructose corresponding increase in the oxidation state of a given reactant 12 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx GOAL IS TO CONVERT LARGE carboxyl group is unstable due to MOLECULES TO SMALLER multiple oxidation acetate reacts with coenzyme a it 3 second phosphorylation becomes acetyl coa atp is attached to carbon one SUMMARY 4 cleavage 1 GLUCOSE = 6CO2 (2 Pyruvate Oxidation, 4 Kreb Cycle) 6 carbon molecule is broken down to two 3 carbon molecule (daph and 2 Pyruvate > 2 Acetyl CoA g3p) 2 ATP (Glycolysis) cleaved meaning to cut or divide 2 NADH (Glycolysis), 2 NADH (Pyruvate Oxidation) 5 conversion of dhap into gadp 2 ATP (Krebs Cycle) 6 NADH (Krebs Cycle) >> 2 ATP SPENT IN THIS PHASE 2 FADH2 (Krebs Cycle) 28 ATP (Oxidative Phosphorylation) next phase TOTAL: 10 NADH, 2 FAD 6 oxidation dehydrogenase, meaning removal of a hydrogen molecule phosphate is added in carbon 1 7 dephosphorylation removal of phosphate group phosphorylation, addition of phosphate group phosphate in carbon one is remove and transferred to adp making it atp RANDOMZ: 8 phosphate transfer >> one acetyl coa is equals to two cycles, so yung products times two mutase, helps transfer molecules >> FMN flavin mononucleotide 9 dehydration >> last electron acceptor in aerobic enolase, removes water respiration is oxygen and then it attracts two hydrogen atoms and then it develops into 10 second dephosphorylation water and used in idk yung sa krebs part na may water PYRUVATE OXIDATION 13 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx CELL STRUCTURE AND FUNCTION What is a cell? Prokaryotes Eukaryotes basic unit of life Endoplasmic absent present the simplest structural, functional, Reticulum and biological unit of all living forms two types: prokaryotic and plasmids present very rarely eukaryotic. What are their found in differences? eukaryotes ribosomes small large Prokaryotes Eukaryotes ribosomes ribosomes type of cell always unicellular lysosome lysosomes lysosomes unicellular and and and multicellular centrosomes centrosomes are absent are present cell size ranges in ranges from size from 10μm- cell division binary fission mitosis 0.2μm- 100μm in 2.0μm in diameter flagella smaller in larger in size diameter size cell wall usually when present reproduction asexual sexual and present chemically asexual chemically simple in complex in nature example bacteria and plant and nature archaea animal cell nucleus absent present instead, they The Brains have nucleoid Antoni Van Leeuwenhoek region in the cell father of microbiology ribosomes present, present, a dutch inventor smaller in comparativel first to device his own light size and y larger in microscope spherical in size and revealed a wide variety of shape linear in organisms not visible to the naked shape eye his contribution is the beginning to DNA circular linear understand the chemical reactions arrangement involved in the living material cytoplasm present, cell present, cell organelles organelles absent present 14 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx Robert Hooke Theodore Schwann british scientist german physiologist observed tiny slices of cork through all animals are composed of animal a microscope cells and that within an individual described it as a mass of tiny organisms all the cells are identical cavities similar to honeycomb founded modern histology be compared it to small rooms in the defining the cell as the basic unit of monastery and coined the term animal structure CELLS Rudolf Virchow Robert Brown viennese pathologist scottish botanist published his observation that new he discovered the nucleus of a cell cells arise only from pre-existing he is perhaps best known for the cells discovery of the random movement works with the other scientists to of microscopic particles in a establish the cell theory surrounding solution called used the theory to lay the Brownian Movement groundwork for cellular pathology or he developed alternative plant the disease at the cellular level classifications Karl Nageli Felix Dujardin swiss botanist french biologist and cytologist born discussed the nature of cell division in Tours noted for his studies in the Gregor Mendel classification of protozoans and invertebrates father of genetics he viewed living cells with a discovered the basic rules of microscope heredity of garden pea an individual organism has two Matthias Jacob Schleiden alternative heredity units for a given trait (dominant vs. recessive) german botanist and a co-founder of cell theory Johann Friedrich Miescher he proposed that all plants are made up of cells discovered DNA and named it recognized the importance of cell nuclein nucleus and sensed its connection with cell division first german botanist to accept Charles Darwin’s theory of evolution 15 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx Three Tenets nucleolus, rna synthesis and creates rrna (ribosomal rna) that will 1. all organisms consists of one or merge into certain proteins that will more cells produce ribosomes 2. the cell is the basic unit of structure chromatin: fiber like structures and function for all organisms euchromatin: loose, in the inner 3. all cells arise from pre existing cells portion of nucleus, transcriptional heterochromatin: tight, located in Basic Properties of Cells the periphery of the inner membrane, non-transcriptional, complex and organized regulates the genes expression of possess genetic program and the the nucleus means to use it DNA capable of producing more of themselves Central Dogma acquire and utilize energy carry out a variety of chemical 1. Replication, to copy pr increase in reactions number (Nucleus) engage in mechanical activities 2. transcription, transcribe DNA to respond to stimuli RNA (Nucleus) cells evolve 3. Translation (RER) Criteria an Entity to be Considered Alive Rough Endoplasmic Reticulum information mrna translation > amino acids > metabolism polypeptide chain > protein membrane site of protein synthesis protein folding Viruses are nonliving things, they don’t glycosylation (n-linked), adding metabolize outside the host. sugar to the nitrogen group to give special characteristic to each The Animal Cell protein mas marami RER ng cell if Nucleus nagpoproduce ng enzyme, it varies depending on the characteristics covered by nuclear vesicles that will lead to the golgi membrane/envelope, the structure apparatus is same as the cell membrane outer: ribosomes are embedded Proteins Synthesized in the RER: and nuclear pores, to protect the components inside nucleus 1. lysosomal protein inner: protects the components 2. membrane protein inside the nucleus, there is an inner 3. excretory protein (such as lining that maintains the stability of hormones, digestive enzymes) the envelope (protein called lamins) nuclear pores, passageway (membrane proteins) 16 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx Smooth Endoplasmic Reticulum eukaryotic cells use to digest (hydrolyze) macromolecules. walang ribosomes Lysosomal enzymes work best in lipid synthesis (fatty acids, the acidic environment found in phospholipids, cholesterol; lysosomes. promotes less fluidity of the cell) hydrolytic enzymes: proteases cytochrome P450 (enzymes (proteins), nucleases (nucleic CYP450; it will add OH in the toxic acids), lipases (lipids) substance then will make it more macromolecule breakdown soluble in the water so that it’ll be autophagy of organelles easier to go out through urines), for autolysis of damaged cells detoxification digesting and breaking down glucose 6 phosphate metabolism: molecules last stage of conversion of glycogen to glucose Peroxisomes calcium ion storage (sarcoplasmic reticulum), important in muscle cells Peroxisomes contain enzymes that remove hydrogen atoms from Cells that contains many SER: adipocytes, various substrates and transfer muscle cells, hepatocytes them to oxygen (O2), producing hydrogen peroxide (H2O2) as a Golgi Apparatus by-product (from which the organelle derives its name). receives vesicles from RER and Some peroxisomes use oxygen to SER break fatty acids down into smaller modification of proteins molecules that are transported to glycosylation (n-linked and o-linked) mitochondria and used as fuel for phosphorylation cellular respiration. package molecules: lysosomes, Peroxisomes in the liver detoxify membranes, excreted alcohol and other harmful sorting center of the cell compounds by transferring hydrogen from the poisonous Cell Membrane compounds to oxygen. The H2O2 formed by peroxisomes is itself phospholipid bilayer toxic, but the organelle also cholesterol contains an enzyme that converts carbohydrates H2O2 to water. glycolipids contains catalase and oxidase proteins: integral (serves as the gate), peripheral (supports the Catalase integrity of the cell membrane) decomposition of hydrogen Lysosomes peroxide breaks down hydrogen A lysosome is a membranous sac peroxide (H2O2), a toxic of hydrolytic enzymes that many byproduct of metabolism, 17 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx into water (H2O) and cell motility generally requires oxygen (O2) interaction of the cytoskeleton with protection against reactive motor proteins oxygen species (ROS microtubules are the thickest of the support for other metabolic three types; microfilaments (also processes called actin filaments) are the thinnest; and intermediate filaments Oxidase are fibers with diameters in a middle range fatty acid beta-oxidation microfilaments detoxification of toxins intermediate filaments amino acid metabolism microtubules Mitochondria Mitochondria (singular, mitochondrion) are the sites of cellular respiration, the metabolic process that uses oxygen to drive the generation of ATP by extracting energy from sugars, fats, and other fuels. ATP synthesis metabolic reactions mitochondrial DNA Ribosome carries out protein synthesis composed: large subunit (60s), small subunit (40s) s unit: Svedberg membrane-bound ribosomes: engaged in the synthesis of proteins that are being concurrently translocated into the ER cytosolic ribosomes: co-purify with mitochondria and can be stabilized on the outer membrane Cytoskeleton give mechanical support to the cell and maintain its shape 18 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx 19 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx MICROSCOPE lamp in the base to illuminate the specimen Parts and Function condenser used to focus light onto the specimen Maximum measurement that human eyes can perceive is one millimeter. Ocular and Objective Lens Magnification ocular lens: closest to the eye forms the virtual image, received by a clear, glass sphere can magnify the eye and converted into a retinal most objects or virtual image results from a complex interaction objective lens: the lens closest to between visible light waves and the the specimen curvature of a lens forms the real image Refraction Magnifying Power bending or change in the angle of the magnifying power of the the light ray as it passes through a microscope is calculated by medium such as lens multiplying the power of the the greater the difference between objective lens the two substances, the greater the refraction Resolution and Resolving Formation of an Image Resolution occurs when an object is placed at the ability to see two objects as a certain distance from the distinct/the rendering of detail spherical lens and illuminated with microorganisms cannot be resolved light by the naked eye depending on the size and limiting factor; light curvature of the lens, the image is enlarged to a certain degree, called Resolving Power its power of magnification (x or times) the minimum distance two objects can be apart and still be Microscope Design distinguished separately determined by a combination of First Microscope characteristics of the objective lens and the wavelength of light being simple magnifying lens and a few used to illuminate the sample working parts optical microscopes use to visible light Later Compound Microscopes The Electromagnetic Spectrum second magnifying lens Oil Immersion Lens 20 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx a drop of oil must be placed on the slide when using oil immersion (100x) objective lenses oil has the same optical qualities of glass oil prevents the scattering of light rays and increases the numerical aperture and resolution oil immersion can resolve objects that are 0.2μm apart Contrast the degree of contrast between a magnified image and its surroundings is measured by a quality called the refractive index: refers to the degree of bending that light undergoes as it passes from one medium to another the higher the refractive index, the greater the contrast Other considerations Depth of Field/Field of View - distance through which you can move the specimen and still have it in focus - depend on the properties of the objective (higher magnification = lower depth of field) 21 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx Cell Membrane uses kinetic energy input metabolic energy is not A phospholipid is an amphipathic required molecule, meaning it has both a hydrophilic (“water-loving”) region Example: ATP, ADP, NADH, and ion and a hydro- phobic gradient (“water-fearing”) region. A phospholipid bilayer can exist as transports molecules from higher to a stable boundary between two lower concentration aqueous compartments because consists of two type: simple and the molecular arrangement shelters facilitated diffusion the hydrophobic tails of the phospholipids from water while Factors affecting rate of diffusion exposing the hydrophilic heads to water. higher the temperature, faster rate of diffusion Cell Transport Mechanism smaller particle, faster rate of diffusion Swimming Stroke - spends ,ore energy than larger surface area, faster rate of floating, moves you against current diffusion (comparable to active transport) higher concentration gradient (greater difference), faster rate of Floating - minimal energy, move with the diffusion current (comparable to passive transport) more permeable, faster rate of diffusion Cell Membrane Structure Simple Diffusion Lipid Bilayer - amphipathic (polar and bipolar) unassisted movement down the gradient Cellular Transport no transport proteins needed downhill movement/no intrinsic the movement substances across directionality the semipermeable membrane consist of two types: passive Allowed: (diffusion) and active transport hydrophobic (non polar) Concentration Gradient example: gasses, steroids, fatty acids the magnitude of the difference in small and polar concentration of a particular substance on opposite sides of the Osmosis membrane the diffusion of water Passive Transport (Diffusion) high to low concentration 22 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx Effects of Osmosis 2. the splitting of ATP provides energy to change the shape of the channel. Hypotonic: less concentration of solutes The sodium ions are driven through (inside: more solvent, outside: more solute) the channel 3. the sodium ions are released to the Isotonic: equal amount of solute and solvent outside membrane, and the new shape of the channel allows Hypertonic: more solute concentration potassium ions to bind (inside: more solute, outside: more solvent) 4. release of phosphate allows the channel to revert to its original form, Facilitated Diffusion releasing the potassium ions on. the side of the membrane protein-mediated movement down the gradient Channel protein is faster than carrier diffusion of molecules protein. Classes of Transport Proteins Bulk Transport (Vesicular Transport) 1.Channel Protein Endocytosis form hydrophilic channels through the cell takes in molecules and membrane particulate matter by forming new passage of solutes without major vesicles from the plasma change in conformation membrane movement of ions is more Phagocytosis 2. Carrier Protein a cell engulfs a particle by alternates between two shapes, extending pseudopodia around it moving a solute across the and packaging it within a membrane during the shape membranous sac called food change vacuole the particle will be digested after the Active Transport food vacuole fuses with a lysosome containing hydrolytic enzymes low to high metabolic energy and ion gradient Pinocytosis input of metabolic energy is required a cell continually “gulps” droplets of extracellular fluid into tiny vesicles, Sodium-Potassium Pump formed by foldings of the plasma membrane 1. the sodium-potassium pump binds the part of plasma membrane that three sodium ions and a molecule form vesicles are lined on their of ATP cytoplasmic side by a fuzzy layer of coat protein; the ‘pits’ and resulting vesicles are called coated pits 23 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx Receptor Mediated Endocytosis Nucleus is a specialized type of pinocytosis - located in the center of the cell, that enables the cell to acquire bulk surrounded by a membrane which quantities of specific substances, keeps all the chromosomes inside even though those substances may not be very concentrated Chromosomes 1. Ligand binds to receptor 2. receptor ligand moves to clathrin - organizes the DNA coated pit - structures that organized 3. membrane folds inwards organism’s DNA, with its arrays of 4. vesicle enters genes and serve as vehicle 5. loses clathrin coat 6. receptors and ligands separate 7. ligands go to lysosomes or golgi for processing DNA 8. receptors move to the membrane 9. vesicle fuses with the membrane - deoxyribonucleic acid 10. exocytosis - molecule that carries genetic information for the development Exocytosis and functioning of an organism the cell secretes certain molecules Genes by fusion of vesicles with the plasma membrane - basic unit of inheritance - coded instructions for making everything the body needs like amino acids, proteins, and etc - a gene is the fundamental physical and functional unit of heredity What is Genetics? Allele - study of heredity - an allele is each of the two or more versions of a gene - an individual inherits two alleles for Nucleus: information is located inside each each gene; one from the father and cell the other from the mother - alleles are located at the same Chromosomes: contains DNA position within homologous chromosomes Chromatin: forms chromosomes - contains a category example eye color DNA: contains the nucleotides/alphabet Homozygous: if both alleles are identical, the individual is homozygous for this gene 24 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx Heterozygous: if both alleles are different, - mitosis is essential for the growth the individual is heterozygous for this gene and development of multicellular organisms. Genome - it allows cells to divide and multiply, leading to the formation of tissues, - all the genetic material in the organ, and organ systems chromosomes of a particular organism; its size is generally given Repair and Maintenance as its total number of base pairs - when tissues are damaged, such as in the case of a cut or injury, mitosis allows for the replacement of Heredity damaged cells with new, healthy cells - passing of characteristics from one generation to another Asexual Reproduction Ploidy - in some organisms, mitosis allows for the reproduction of genetically - number of sets of chromosomes identical daughter cells, ensuring that the offspring are identical to the Haploid: one chromatids parent cell Diploid: two sisters chromatids CELL DIVISION Why is Cell Division fundamental? - growth and development - repair and maintenance - asexual reproduction Growth and Development MITOSIS 25 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx - process by which a single cell divides into two identical daughter cells - this type of division is essential for growth and repair in multicellular organisms, as well as for asexual reproduction in some singe-celled organisms MEIOSIS - process by which a single cell divides into four daughter cells, each with half the number of MITOSIS chromosomes of the parent cell - critical for sexual reproduction, as it allows for the production of gametes cell: basic unit of life and the smallest functional and structural unit of living organisms split chromosome: a chromosome that has undergone a structural change, resulting in the separation of the chromosome chromosome: structure found in the nucleus of cells that carries genetic information in the form of DNA centrosome - carries the centrioles and organizes the spindle fibers: small organelle found in eukaryotic cells which functions as a microtubule organizing center spindle fiber:microtubules that separates the chromosomes into two daughter cells centrioles - helps the contraction of spindle fiber: cylindrical organelles found in eukaryotic cells that are involved in the organization of cell division two phases: interphase and mitotic phase the number of chromosomes depends on the number of centrosome INTERPHASE 26 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx G1 Phase: Cell Growth ensures that the cell increase in number of organelles, increase cell increase number of organelles, they size, and synthesis of nutrients are duplicated needed increase in size of the cell or the DNA regulation surface area it will not proceed if conditions were synthesis of proteins or enzymes not met important for DNA replication it is important so that there are S-G2 Checkpoint equal number of organelles distributed to two daughter cells checks is cells undergone dito raw usually nagtatagal yung replication, synthesis, and DNA of mga cells the cell is replicated Classification of Cell during Cell Cycle G2 Checkpoint 1. Proliferative cells (dividing cells): checks if cell undergone growth, continuously dividing or undergoing DNA synthesis, and nutrient cell cycle such as skin cells, synthesis hematopoietic stem cells, epithelial cells Interphase 2. stable cells (G0 cells): rest at G0, it will divide once it is strongly chromosomes are extended and stimulated by a factor such as uncoiled forming chromatin growth hormones (examples: hepatocytes or liver cell) MITOSIS 3. Permanent Cells or Non-Dividing Cells: it will not divide or proceed to Prophase another cell cycle (example: neurons, skeletal muscle cells, chromosomes starts to coil and cardiac cells) condense nuclear membrane is broken down Synthesis Phase (using the enzymes synthesized in prophase) DNA synthesis/replicated it is important to breakdown the 46 chromosomes to 92 nuclear membrane so that spindle fibers will attach to the kinetochore G2 Phase migration of the centrosomes to the opposite pole more growth, preparation for attachment of spindle fibers to the mitosis kinetochore increased level of cytoplasm increased level of nutrients such as Pro-metaphase proteins, amino acids, enzymes chromosomes are clearly double G1-S Checkpoint structures 27 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx centrioles reach the opposite poles; - plant cell, cell plate spindle fibers form nuclear membrane if finally broken MEIOSIS down Importance of crossing over: increase Metaphase variability and diversity that will promote survival the chromosomes are align to the metaphase plate Prophase 1 the alignment is important so that there will be equal number of before prophase 1 there will be an chromosomes interphase Cohesin attach two sister chromatids Stage 1: Leptotene Separase breaks down cohesin the chromosomes begin to condense and are connected to the Shugoshin guards the cohesin from being nuclear membrane by their degraded by separase telomeres in leptotene coiling and condensing of Shugoshin deactivates during anaphase, chromosomes allowing the chromatids to separate Step 2: Zygotene Anaphase a synaptonemal complex forms migration of chromosomes to the between homologous opposite poles chromosomes at the start of zygotene-synapsis Telophase homologous pairing synapsis and formation of chromosomes are on the opposite chiasmata poles reappearing of nuclear membrane Step 3: Pachytene chromosomes uncoil appearance of cleavage furrow non-sister chromatids exchange contractile ring: composed of actin genetic material (crossing-over) and myosin, it will contract and crossing over tighten that will eventually separate two daughter cells or cytokinesis Step 4: Diplotene which is the separation of the cytoplasm end of crossing over removal of synapsis Step 5: Diakinesis Cytokinesis fully condensed chromosomes - animal cell, cleavage furrow 28 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx breakdown of nuclear membrane Meiosis II: Metaphase 1 Prophase II: Chromosomes condense again, and a new spindle form a metaphase plate apparatus forms. Metaphase II: Chromosomes align Anaphase 1 at the equator. Anaphase II: Sister chromatids are Telophase 1 pulled apart to opposite poles. Telophase II: The two cells divide > Chromosomes produce during this phase again, resulting in four haploid are haploid gametes. > Production of two daughter cells that are Oogenesis is the process of egg (ovum) haploid development in female organisms, primarily occurring in the ovaries. It involves several Meiosis 2 stages: will no longer undergo interphase 1. Oogonia: The process begins with oogonia, which are diploid germ Prophase 2 cells that undergo mitosis. 2. Primary Oocytes: Oogonia Metaphase 2 develop into primary oocytes, which enter meiosis but are arrested in Anaphase 2 prophase I until puberty. 3. Secondary Oocytes: At puberty, > 4 haploid daughter cells after meiosis 2, hormonal changes stimulate the 23 chromosomes each cells in humans completion of the first meiotic division, resulting in a secondary oocyte and a smaller polar body, which typically disintegrates. 4. Ovulation: The secondary oocyte Meiosis I: is released during ovulation. If fertilization occurs, it completes Prophase I: Homologous meiosis II, producing a mature chromosomes pair and exchange ovum and another polar body. genetic material through crossing over. Products of Oogenesis: Metaphase I: Paired chromosomes align at the cell's equator. Typically, one functional ovum and Anaphase I: Homologous three polar bodies (which are chromosomes are pulled to non-functional) are produced from opposite poles. each primary oocyte. The ovum is Telophase I: The cell divides into the only gamete that can be two, each with half the original fertilized. chromosome number. SPERMATOGENESIS 29 ZOOLOGY: FIRST SEMESTER - MIDTERM dollmdocx Spermatogenesis ○ Begins with spermatogonia (diploid stem cells) that reside in the outer layer of the seminiferous tubules. ○ Spermatogonia undergo mitotic divisions, resulting in more spermatogonia and some differentiating into primary spermatocytes. Meiosis: ○ Each primary spermatocyte undergoes meiosis I, producing two secondary spermatocytes (haploid). ○ Each secondary spermatocyte then undergoes meiosis II, resulting in a total of four spermatids from each primary spermatocyte. Spermiogenesis: ○ Spermatids transform into mature spermatozoa through several changes: Development of the acrosome (a cap that contains enzymes for fertilization). Formation of a flagellum for motility. Condensation of the nucleus and shedding of excess cytoplasm. Final Products: The ultimate result of spermatogenesis is four functional spermatozoa for each primary spermatocyte, ready for ejaculation and potential fertilization. 30