General Biology 1 (1st Quarter) PDF

General Biology 1 (1st Quarter) - Stated that John Needham's experiments had several mistakes: SPONTANEOUS GENERATION 1. He did not boil the broth long...

General Biology 1 (1st Quarter) - Stated that John Needham's experiments had several mistakes: SPONTANEOUS GENERATION 1. He did not boil the broth long enough 2. He left the flask - A superseded scientific theory which states that living things open and new microorganisms entered come from nonliving things - Replicated John Needham's experiment with major changes - Also called abiogenesis - Three setups experiment - First setup: Boiled broth in a flask for 1 hour and sealed it Biogenesis immediately- no microorganisms grew - Life comes from life - Second setup: Boiled broth in a flask for a few minutes, exposed it to air, and sealed it - microorganisms grew Key People - Third setup: Boiled broth in a flask and left it open - microorganisms grew Francesco Redi - Conclusion: - Three setups of jars with meat inside. 1. Few minutes of boiling was not enough to sterilize the broth - One opened, one covered in gauze, and one tightly sealed, soup after a few days, maggots formed inside the opened jar and no 2. Microbes came from the air maggots formed in the gauze and tightly sealed jar - Needham counter argued that: - Additionally it was observed that maggots were present on 1. Spallanzani heated the broth for too long which destroyed the outside of the gauze covered jars the "life force" necessary for life. - Conclusion: rotting meat did not produce maggots 2. Spallanzani did not introduce air ("life force") to the microbe-free flask hence microbes did not grow John Needham - This Experiment sparked a more heated debate about - Disagreed with Francesco, claiming that Francesco did not spontaneous generation fully disprove spontaneous generation - Argued that spontaneous generation did not occur in large Louis Pasteur organisms but could still take place in smaller organisms under - Conclusively disproved spontaneous generation theory the right conditions - Boiled broth in various flasks for one hour. The flask were all - One setup experiment open and shaped differently (one had a straight opening, one - Boiled broth in a flask, let it cool, sealed it, and in several with a swan shape opening, one with cotton plugged in the days, it was teeming with bacteria and mold opening, etc.) - Conclusion: This was proof of spontaneous generation - After boiling he cooled the flasks, allowing them to draw fresh air (the so called "life force") inside the flasks Lazzaro Spallanzani - Flask with straight opening - microbes grew - Disagreed with John Needham's experiment - Flask with swan shape opening - sterile - Flask with Cotton plugged opening - sterile - a German scientist who added that cells must come from - Titled flask with swan shape opening - microbes grew other cells - Conclusion: "Life force" does not exist and spontaneous - stole the idea from Polish scientist Robert Remak generation does not occur in this manner. Life only comes from Life Cell Theory CELL THEORY 1. All living organisms are made of cells -A scientific theory which states that all living organisms are 2. The cell is the basic unit of life made up of cells 3. New cells arise from pre-existing cells Prior to 1600s - no one had seen a cell up close Robert Hooke - a British scientist who first observed "dead" cells under a MODERN CELL THEORY microscope 1. All known living organisms are made up of cells - gave cells their name in his book "Micrographia" 2. All cells arise from pre-existing cells through division - his specimen was a dead cork tissue 3. Cells are the basic unit of structure and function in living - the name "cell" was inspired from monk cells things 4. The activity of an organism depends on the total activity of Anton van Leewonheuk independent cells - a Dutch shopkeeper and crafter of lenses who first observed 5. Energy flow (metabolism and biochemistry) occurs within moving "living" cells cells - was inspired by Hooke's book in the 1670s and made 6. Cells contain DNA found specifically in the chromosome powerful microscopes and the RNA found in the nucleus and cytoplasm - called the single celled organisms he observed (bacteria and 7. All cells basically have the same chemical composition in sperm) as "animalcules" organism of similar species 8. DNA is passed from cell to cell Botanist Mathias Schleiden and Zoologist Theodor Schwann 9. All cells have the same basic composition - proposed in the 1830s that: 10. All living organisms depend on cells to function normally 1. All the different parts of animals and plants are made of cells STRUCTURE OF A CELL 2. Cells can be produced from other cells All cells share four components: Rudolf Virchow 1. Plasma membrane a.k.a. Cell Membrane BACTERIA - An outer covering protecting the cell's interior from the 1. Cell membrane surrounding environment 2. Ribosome - Formed by a phospholipid bilayer made of phospholipids 3. Chromosomes (DNA) (composed of a hydrophilic phosphate head pointing outwards and a hydrophobic fatty acid tail pointing inwards) 4. Nucleoid Region - The area where DNA is found 2. Cytoplasm - The region containing the cytosol where organelles are 5. Cell Wall suspended - Made of peptidoglycan - In prokaryotes, it is everything found inside the plasma - Extra layer of protection membrane - In eukaryotes, it's the region outside the nucleus but inside 6. Capsule the plasma membrane - A sticky outer layer which helps the bacteria stick to its environment 3. DNA - Locomotion - Blueprint of Life 7. Fimbriae 4. Ribosome - a class of cell protrusions that are numerous, relatively short, - Where protein synthesis is done and involved in attachment to surfaces PROKARYOTIC CELLS - "Pro" - meaning -Before- and "Kary" - meaning -Nucleus- = 8. Pili Before Nucleus - a class of cell protrusions that are less numerous, longer, and - Single Compartment House more specialized cell surface protrusions - Kingdom Eubacteria (Bacteria) and Kingdom Archaebacteria (Archaea) 9. Flagella - are whip like structures that act as rotary motors which help Main Features: cells move Single looped DNA Presence of chloroplast and cell wall Free - floating DNA EUKARYOTIC CELLS Organelles are not enveloped in a membrane - Multi - Compartment House 0.1 - 5 micrometers - Membrane bound nucleus (DNA is not scattered) - Membrane bound organelles - Multiple Linear Chromosomes - Consists of the ER, Golgi Apparatus, Vacuole, and Lysosomes ANIMAL CELL 1. Nucleus a. Endoplasmic Reticulum - Where DNA is stored and synthesized - It is connected to the nucleus through the two layers of the nuclear envelope by a thin space a. Nucleoplasm - Space inside the ER is called Lumen - A gel - like substance which stores the chromatin - Site where proteins are modified and lipids are synthesized - If modified proteins are not destined to stay in the ER they b. Nuclear Envelope are packaged in vesicles, a small membrane used for - Encloses the nucleoplasm transport that is then shipped to the Golgi Apparatus. c. Nucleolus a.1. Rough Endoplasmic Reticulum - A dark spot in the nucleus where new ribosomes assemble - ER with ribosomes - Where ribosomes are formed - Modifies proteins d. Nuclear Pores a.2. Smooth Endoplasmic Reticulum - Small channels in the nuclear envelope which controls which - ER without or with little ribosomes substances go in and out - Modifies lipids, carbohydrates, and steroid hormones e. Chromatin (DNA + Proteins) b. Golgi Apparatus - Located inside the nucleus - Group of flattened membrane sacs - Sorts, tags, packages, and distributes vesicles so they end 2. Ribosomes up at the right place - Made of RNA and proteins - 'Cis face' is the receiving side of the GA while 'Trans face' is - Site where proteins are synthesized the opposite side - Transport vesicles from the ER fuse with the 'Cis face' and 3. Peroxisome empty their contents in the lumen - Produces hydrogen peroxide and carries out oxidation - Proteins and carbs are further modified here and sorted and reactions packaged into vesicles which bud from the 'Trans face' 4. Endomembrane System c. Vacuole See- A group of organelles which work to transport and - Stores the food and water wastes package proteins, etc. - Also has enzymes which can break down hazardous components - Has directionality, two ends with different structures - Can assemble and disassemble quickly, a quality used in d. Lysosome movement - Has digestive enzymes which break down cell parts for later - Serve as tracks for a motor protein called myosin, because of use this, it is involved in many cellular events involving movement - Organelle recycling center of the animal cell such as muscle movement - The structure where actin and myosin muscle form 10. Mitochondrion overlapping filaments is called sarcomeres - Plural mitochondria - When actin, myosin, and muscle cells slide past each other, - Powerhouse of the cell the muscles contract - There's a theory where the mitochondria evolved as a - Can also act as a highway for cargos / vesicles prokaryotic cell and eventually lived in symbiosis in a larger - Also provides structure eukaryotic cell (endosymbiotic theory) - Has its own DNA (most likely from your mother) 5. Cytoplasm b. Intermediate Filament - The area outside the nucleus but inside the plasma - 8 to 10 nm membrane - Cytoskeleton made of fibrous proteins wound together - Made of keratin, a protein found in hair, nails, etc. a. Cytosol - More permanent and plays a structural role in the cell - Gel like substance where organelles are suspended - Carbon, hydrogen, nitrogen, oxygen, phosphorous, and c. Microtubule sulfur (CHNOPS) - 25 nm - Has enzymes, water, salts - Has directionality, two ends with different structures - Made of tubulin proteins arranged to form a hollow tube, 6. Cytoskeletal fibers each tubulin contains two sub - units: alpha tubulin and beta - Provides structure of the cell, aids in correct positioning of tubulin organelles, aids in vesicle transport, and allows the cell to - Are dynamic and can grow and shrink quickly with the move addition of tubulin proteins - There are 3 types of Protein fibers: - Plays a structural role, preventing compression forces 7. Microfilament (Actin) 8. Centriole - 7nm - A cylinder made of 9 triplets of microtubules - Also known as actin filaments - Aids in chromosome division by attaching spindle fibers to each chromosome and tears them apart 7. Golgi Apparatus 8. Mitochondrion 9. Flagellum (Plural: Flagella) 9. Peroxisome - Tail like whip used for locomotion 10. Intermediate Filament - Usually one or few 11. Microfilament (Actin) 12. Microtubule 10. Cilium (Plural: Cillia) - Much more numerous and shorter than flagella 13. Chloroplast - Has a 'basal body' located at its base which plays a key role - Responsible for capturing light to make sugars during in assembling cilia. photosynthesis - The 'basal body' is just a modified centriole - Is made of membrane disks known as "thylakoids" arranged - Their collective beating helps move materials across the in interconnected stacks called "grana" (singular granum) surface of a tissue - Has its own ribosome and DNA - Like mitochondria, likely began as a prokaryotic cell and lived 11. Centrosomes in a bigger eukaryotic cell - Structure made of microtubule which acts as microtubule organizing centers 14. Central Vacuole - Made of two centrioles oriented perpendicularly to each other - Gives the plant cell its shape - Is much much bigger than an animal cell 12. Secretory Vesicle - Store and releases material into the cell or inside or outside 15. Cell Wall the extracellular environment - Gives the plant cell its structure - Passageway of waste and outside and inside materials - Stores molecules and proteins from the endoplasmic FUNCTIONS OF THE CELL reticulum and Golgi apparatus until the cell is ready to release 1. Biosynthesis them. - Production of chemical compound by living organism PLANT CELL 2. Excretion 1. Smooth Endoplasmic Reticulum - Discharge of digested materials of an organism ( urine, etc.) 2. Rough Endoplasmic Reticulum 3. Chromatin (DNA + Proteins) 3. Egestion 4. Nuclear Envelope - Discharge of undigested materials of an organism (gas, etc.) 5. Nucleolus 6. Ribosomes 4. Assimilation - Process of converting food to nutrients Translation and transcription are coupled (cytosol) Includes bacteria and archaea 5. Respiration Short cell cycle (20 to 60 minutes) - Utilizing 02 and producing C02 waste Asexual reproduction Unicellular 6. Mobility - Movement Eukaryotes Membrane-bound organelles 7. Irritability Multiple linear chromosomes - Response to stimuli 10 to 100 micrometers in diameter Has a membrane bound nucleus 8. Nutrition Is much more complex - Cells use nutrition Some examples include animal, plant, fungi and protist cells Mainly diploid genome 9. Reproduction Translation and transcription are not coupled (translation: - Ability to divide or multiple nucleus, transcription: cytoplasm) Chemically simple cell wall (plants:cellulose, fungi: chitin) 10. Secretion Has lots of microtubules - Sweat Has cytoskeleton (actin, Aerobic PROKARYOTIC AND EUKARYOTIC CELL ACTIVITY Includes Animal, Plant, Fungi, and Protist Kingdom Sexual reproduction (mitosis and meiosis) Prokaryotes Multicellular and unicellular Organelles are not enveloped in a membrane Have a single looped DNA Similarity: Presence of chloroplast and cell wall Both have cell membranes, DNA, ribosomes, and cytoplasm Free-floating DNA Both undergo cell division 0.1-5 micrometers in diameter Haploid genome PROKARYOTES No lysosomes, peroxisomes, vacuoles, mitochondria, and cytoskeleton Kingdom Monera Chemically complex cell wall (peptidoglycan) 1. Higher Bacteria May have glycocalyx cover 2. Lower Bacteria Most are strict anaerobes (grows without air) 3. True Bacteria  3. Streptobacilli - linear arrangement, round Higher Bacteria 4. Staphylococci - cluster arrangement, round 1. Spirochete - unicellular with thin flexible walls, wavy, amd helical Bacilli - Example: Treponema pallidum => causes syphilis, bejel, and 1. Bacillus - single, oval yaws 2. Diplobacilli - paired end to end, oval 2. Actinomycetes 3. Streptobacilli - linear arrangement, oval - branched bacteria resembling fungi - Example: Mycobacterium tuberculosis => causes Spirals tuberculosis (TB) 1. Spirochete - single stranded, helical 2. Vibrio - single flagellum, oval 3. Gliding Bacteria 3. Spirilla - multiple stranded, helical - embedded in a slime layer, found in mud stagnant polluted lakes/ponds A. External Structure - Example: Stigmatella aurantiaca 1. Flagella (flagellum, whip) - 3 to 20 nanometers long Lower Bacteria Types: 1. Mycoplasma 1. Monotrichous - single flagellum, one side - "pleuro- pneumonia lile organism" 2. Lophotrichous - multiple flagella, one side - no cell wall but with cell membrane 3. Amphitrichous - multiple flagella, both sides - causative agent of plant and animal disease 4. Peritrichous - multiple flagella, all sides - Example: Mycoplasma pneumoniae 2. Pili or Fimbriae 2. Rickettsiae - hairlike appendages - small obligate parasites - attachment and adhesion - intermediate between bacteria and viruses - *f pilus for males - transmitted by vectors (mice, lice,fleas, and ticks) - cause human and animal disease (typhus, rocky mountain, 3. Capsule spotted fever, chlamydia) - viscous envelope or slime layer formed by organic substances in some bacteria Basic Morphological Shapes - protective device Cocci - for tissue attachment 1. Coccus - single, round - serves as an antibiotic barrier 2. Diplococcus - paired, round - serves as a basis of classification  d. Compounds containing nitrogen 4. Cell Wall - adds extra layer of protection 5. Nucleoid or Chromatin Body - offers rigidity for the cell - lacks nuclear membrane - single circular molecule of double stranded DNA 5. Plasma/Cell Membrane - separates cell wall from cytoplasm Special Structures: - consist of lipids and proteins 6. Axial Filament - semi - permeable - found only in spirochetes - consists of fimbriae wound spirally around the organism for B. Internal Structure mobility 1. Cytoplasm or cell sap - 80% water 7. Endospores - Nucleic acids - minute highly durable oval bodies formed within the cell - Proteins - Inorganic ions Properties: - Variety of compounds a. Resistant to heat, desiccation, and freezing b. Resistant to chemicals 2. Mesosome c. Thick walled, refractile, unstainable - internal fold or invaginations of the bacteria d. Can be viable for years - generally found in gram + bacteria Functions: Examples: a. Chromosome attachment during cell divisions Clostridium tetani - tetanus b. Site for energy metabolism - respiration Clostridium botulinum - food poisoning Clostridium perfringens - gangrene 3. Chromatophores (bacteriochlorophyll) EUKARYOTIC - special membrane systems found in photosynthetic bacteria - Kingdom Protista, Fungi, Animalia, and Plantae and blue gram algae Kingdom Protista 4. Inclusions: Granules - consist of Algae and Protozoan a. Glycogen b. Inorganic metaphosphate Algae c. Sulfur - Schizophyta (smaller) and Kelp(bigger) - edible cell) that functions especially as an organ of locomotion or in - are producers =>undergo photosynthesis => have chlorophyll taking up food or other particulate matter. and chloroplast (some don't) - source of oxygen 3. Class Sporozoa - causes undesirable odor and taste of water supply when - has the smallest most complex life cycle abundant - Plasmodium falciparum, Plasmodium malariae - 70 hours, Plasmodium vivax - 48 hours => vector: mosquitos Protozoan (moving) - observed by Anton Van Leewonheuk ( called these ' 4. Class Ciliata animalcules') - possess cilia - free living (independent) - intestinal parasite (Balantidium coli) - commensals (benefitting; do no harm) and parasitic - 1 to 4 micrometers Kingdom Fungi - used as fish foods - molds, yeasts, mushrooms (all unicellular) - cause diseases - the study of molds is mycology - there are photosynthetic protozoans, such as Euglena Molds 4 General Classes of Protozoans - microscopic individual cells which are eukaryotic 1. Class Mastigophora - no chlorophyll - flagellated protozoans (free-living, pathogenic (causes - visible in patches diseases)) - composed of filaments, with cross walls or no cross walls - Example: - mycelium (branched fungi threads or hyphae) Trichomonas vaginalis - STD Giarda lamblia- STD 4 General Classes of Molds Trypanosoma gambiense - cheche fly (sleeping disorder) 1. Phycomycetes (Zygomycetes) Dinoflagellates - Gonyaulax catenella and Gymnodinium - called sporangium fungi since their spores are enclosed in a brevis - red tide sac - Example: Rhizopus nigricans (bread mold) 2. Class Sarcodina - protozoans capable of forming pseudopods (false feet) 2. Ascomycetes - aspagophytosis =>how they eat - sac fungi (ascus) - Example: Penicillium notatum and Aspergillus flavus Pseudopod - a temporary protrusion or retractile process of the cytoplasm of a cell (such as an amoeba or a white blood 3. Basidiomycetes - Basidium fungi; spores are formed in club shaped (basidia) - Example: Stomach cells - Example: Puccinia graminis and Agaricus campestris d. Transitional 4. Deuteromycetes - no exact shape, can be squamos, cuboidal, or columnar - composed of pathogenic yeasts such as dermatophytes - Example: Bladder cells - cutaneous infections Types of Epithelial Cells in Body: CELL TYPES AND MODIFICATIONS a. Simple Squamous Animal Tissues: - found inside blood vessels, alveoli, heart - single layer of flat cells w/ irregular boundaries 1. Epithelial Tissues - regulates the passage of substances into underlying tissue - comprises the epithelial(surface) cells - can be arranged in a single layer or multiple layers b. Simple Cuboidal depending on location or function - found in secreting tissue and kidney tubules - single layer of short cylindrical cells Types (Based on Arrangement) - absorption and secretion a. Simple - 1 layer c. Simple Columnar b. Stratified - 2 or more layers - found in digestive tract and upper respiratory tract lining c. Pseudostratified - closely packed cells appearing to be - single layer of columnar cells and often ciliated arranged in layers due to various sizes but in reality has only - protection, absorption, mucus secretion one layer. d. Stratified Squamous Types (Based on Shape) - found in skin, lining of mouth, and vagina a. Squamous - several layers of cells, continuously sloughed off and - flat and sheet/scale like in appearance regenerated - Example: Cheek cells - protection against microorganisms and water loss b. Cuboidal e. Stratified Cuboidal - cube like structure (equal, width, height, and depth) - found in excretory ducts of salivary and sweat glands, - Example: Kidney cells mammary glands - upper layer is cuboid and others are maybe cuboidal or other c. Columnar types - column like appearance (taller than wide) - protection of ducts in various glands  2. Secretion f. Stratified Columnar 3. Absorption - found in mucus membrane, conjunctiva (lining the eyelids), 4. Filtration male urethra 5. Sensory reception - layer of columnar cells present in squamous, columnar, or cuboidal cells 2. Muscular Tissues - protection and secretion - composed of muscular cells which shortens and contracts to produce movement g. Pseudostratified Columnar - they are also excitable, meaning they respond to stimulus - found in respiratory tract often with cilia - similar to columnar epithelium but cells are not of similar Muscle Types: height a. Skeletal Muscle - protection, secretion, and movement of mucous - attached to bones and around emtry and exit sites of body - long, cylindrical fiber, has striations, nucleated Types Based On Specialized Functions: - aids in voluntary movement, produces heat, protects organs a. Transitional Epithelium b. Smooth Muscle - found in urinary tract - found in walls of major organs and passageways - several layers of cells - short spindle shaped, single centrally located nucleus, lack - contraction and expansion of organs striations - involuntary movement of organs, control of respiration, b. Glandular Epithelium moves food and secretions, regulates blood flow by - found in glands contraction - arranged in structures known as glands, which can be a single cell or a group of cells c. Cardiac Muscle - production, secretion of materials - hormones, proteins, water - found in heart - has branching fibers, one nucleus per cell, striations, c. Olfactory Epithelium intercalated disks - found in nasal cavity - involuntary movement, contracts to pump blood - thin cellular tissue - protection, pass smell Functions: Functions of Epithelial Cells 1. Movement 1. Protection 2. Posture 3. Joint stabilization - Lines organs and body cavities to insulate the body against 4. Heat generation heat loss 3. Connective Tissues 4. Nervous Tissue - made of cells and an extracellular matrix which fills the - found in brain, spinal cord, and nerves spaces between organs and tissues and provides structural - responsible for coordinating and controlling many body and metabolic support for other tissues and organs. activities - comprises of neurons/nerve cells Types: a. Blood Plant Tissues: - made of cells in plasma - connects organ systems by supplying nutrients and Types of Modification transporting signal molecules - transports gasses, hormones, water, and waste products A. Meristematic Tissue - works for the growth of plants b. Bones - has 3 types based on location - hardest connective tissue - maintains posture and shape of body A.1. Apical - supports muscles and other organs - located at tips of stems allowing plant to extend c. Cartilage A.2. Intercalary - flexible connective tissue - located at the stem at the base of the leaves - provides support for certain structures in adult humans A.3. Lateral d. Tendon - increase in diameter of the organ - attaches two bones together B. Permanent e. Areolar - do not cell divide - present under skin - supports epithelium B.1. Simple Permanent Tissue - supports internal organs and help in repairing tissue - composed of same type of cells that perform the same function f. Adipose - stores fats as lipids a. Parenchyma - cells have oval or round shape 4. Telophase - cell is thin walled - 12 chromosomes and 12 chromatids - have vacuoles and very small nucleus - photosynthesis, food storage, secretion Correct Version: b. Collenchyma MITOSIS (equational division) - cells are long and thick walled 1. Prophase - living cells - 6 chromosomes and 12 chromatids - few chloroplast for photosynthesis 2. Metaphase - 6 chromosomes and 12 chromatids c. Sclerenchyma 3. Anaphase - cells are thick walled with many size and shape - 12 chromosomes and 0 chromatids - dead cells => structural support to the plant 4. Telophase - 12 chromosomes and 0 chromatids C. Complex Permanent Tissue 5. End of Mitosis - composed of several types of cells with various functions - 6 chromosomes and 0 chromatids in each cell a. Xylem MEIOSIS I (reductional division) - transports water and minerals from the roots to different parts 1. Prophase I of the plant - 6 chromosomes, 12 chromatids, 6 centromeres 2. Metaphase I b. Phloem - 6 chromosomes, 12 chromatids, 6 centromeres - transports organic compounds such as sugars from the site 3. Anaphase I of photosynthesis to the rest of the plant - 6 chromosomes, 12 chromatids and 6 centromeres 4. Telophase I CELL DIVISION ACTIVITY - 6 chromosomes, 12 chromatids and 6 centromeres 5. End of Meiosis I Mitosis - 3 chromosomes, 6 chromatids, and 3 centromeres in each 1. Prophase cell - 6 chromosomes and 12 chromatids 2. Metaphase MEIOSIS II (equational division) - 6 chromosomes and 12 chromatids 1. Prophase II 3. Anaphase - 3 chromosomes, 6 chromatids, 3 centromeres - 12 chromosomes and 12 chromatids 2. Metaphase II - 3 chromosomes, 6 chromatids, 3 centromeres 3. Anaphase II 4. Anaphase - 6 chromosomes, 0 chromatids and 0 centromeres - spindle fibers pull chromosomes away towards the opposite 4. Telophase II ends of poles - 6 chromosomes, 0 chromatids and 0 centromeres - formation of cleavage furrow in animal cells 5. End of Meiosis II - 3 chromosomes, 0 chromatids, and 0 centromeres in each 5. Telophase cell - chromosomes finished moving to opposite ends of cell CELL DIVISION Cytokinesis - cytoplasmic division (unequal) MITOSIS (equational division) Karyokinesis - nuclear division (equal) Interphase a. Gap/Growth Phase 1 (G1) MEIOSIS I (reductional division) - checks for cell size, nutrients, growth factor, and DNA 1. Prophase I: damage a. Leptotene b. Synthesis - condensation of chromosomes - DNA replication and microtubule duplication c. Gap/Growth Phase 2 (G2) b. Zygotene - checks for DNA damage and DNA replication completeness - synapsis begins (pairing of 2 chromosomes) d. G0 phase - formation of synaptonemal complex - inactive state c. Pachytene 1. Early Prophase - crossing over of non - sister chromatids - spindle fibers form - chromosomes condense d. Diplotene - nucleolus disappears - synapsis ends 2. Late Prophase - spindle fibers attach to condensed chromosomes e. Diakinesis - nuclear membrane disappears - chromosomes are fully condensed - nuclear membrane and nucleolus disintegrates 3. Metaphase - chromosomes align at metaphase plate 2. Metaphase I - homologous chromosomes (tetrads) align at the equator Primary Spermatocyte 3. Anaphase I (no tails, immature) (23 chromosomes) - homologous chromosomes separate --Meiosis II➜ Secondary Spermatocyte 4. Telophase (immature) (23 chromosomes) - cell divides into two daughter cells with halved number of --Diffetentiation➜ chromosomes from parent cell Spermatids (immature) (23 chromosomes) MEIOSIS II (equational division) --Spermatogenesis➜ 1. Prophase II Spermatozoa - nucleus disintegrates (mature sperm cell) (23 chromosomes) - spindle fibers form - centrosomes form Parts of Sperm Cell 1. Head 2. Metaphase II -contains macrosomes (digestive enzymes) - chromosomes align at the cells equator(metaphase plate) 2. Middle piece - middle part of sperm cell 3. Anaphase II - where mitochondria is located - chromosomes separate - supplies energy to propel sperm cell 3. Tail 4. Telophase II - for motility - total of four daughter cells are produced with same number - tail will be cut after fertilization of chromosomes from parent cell OOGENESIS GAMETOGENESIS (Production of egg cells) - takes place in the ovaries SPERMATOGONIUM (Production of sperm cells) Process: - takes place in the testes, specifically the seminiferous Before Birth: tubules (nurse cells) Primordial Germ Cell (46 chromosomes) --Mitosis➜ Process: Oogonium and Polar Body (smaller) Primordial germ cell (46 chromosomes) --Mitosis➜ (46 chromosomes) Spermatogonium (46 chromosomes) --Meiosis I➜ --Meiosis I (arrests in Prophase I)➜ After Puberty: PASSIVE DIFFUSION Primary Oocyte, Polar Body is recycled - is a process by which molecules move from an area of higher (23 chromosomes) concentration to an area of lower concentration without the --Meiosis continues (arrests at Metaphase II)➜ need for energy input Secondary Oocyte - occurs due to the natural kinetic energy of molecules and (23 chromosomes) continues until equilibrium is reached. --Resumes with sperm fertilization➜ Ovum (mature egg cell) Types of Passive Diffusion 1. Simple Diffusion: GENETIC DISORDERS - movement of small or nonpolar molecules (e.g., oxygen, carbon dioxide) directly through the lipid bilayer of the cell Down syndrome (trisomy 21) membrane. - flat face, small head and short neck, and upward slanting - molecules move down their concentration gradient without eyes the assistance of membrane proteins -have 47 chromosomes in their cells instead of 46 (extra in chromosome 21) 2. Facilitated Diffusion: - movement of larger or polar molecules (e.g., sugars, amino acids) across the cell membrane through specific transport Klinefelter syndrome proteins. - known as XXY condition that affects male physical and - uses carrier proteins or channel proteins to help molecules cognitive development cross the membrane, which are still moving down their - caused by extra X chromosome concentration gradient Tay-Sachs Disease - inability to synthesize an enzyme that prevent lipid build up in brain cells Transport Proteins: - caused by an alteration in the HEXA gene on chromosome 1. Channel Proteins 15. - form pores in the cell membrane, allowing specific molecules or ions to pass through Turner syndrome - can be either open or gated. - affects only females - results when one of the X chromosomes is missing or a. Open Channels partially missing - channels that are always open - allow molecules to pass through freely. area. - increased pressure can increase the rate of diffusion, b. Gated Channels especially in gasses. - channels that open or close in response to specific stimuli, - higher pressure forces molecules closer together, increasing such as voltage changes, ligand binding, or mechanical stress. their interactions and the likelihood of diffusion. 2. Carrier Proteins 5. Temperature (direct) - bind to specific molecules on one side of the membrane, - a measure of the thermal energy of a system. undergo a conformational change, and release the molecules - higher temperatures increase the kinetic energy of on the other side. molecules, causing them to move faster and thus diffuse more - slower compared to channel-mediated diffusion. rapidly. Factors Affecting Diffusion: 6. Molecule Size (inverse) 1. Concentration Gradient (direct) - smaller molecules diffuse faster than larger ones - the difference in concentration of a substance between two regions. For Faciliatated Diffusion: - the greater the concentration gradient, the faster the rate of 7. Number of Transport Proteins diffusion. - more transport proteins increase the rate of diffusion, as more molecules can be transported simultaneously. 2. Solute Density (inverse) - the mass of solute particles in a given volume of solvent. 8. Saturation - higher solute density can slow down diffusion because the - when all transport proteins are occupied, the rate of diffusion particles are more crowded, making it harder for them to move reaches a maximum and cannot increase further, regardless of freely the concentration gradient. 3. Solute Solubility (direct) Molecule Characteristics - the ability of a solute to dissolve in a solvent. 1. Size (macromolecule, micromolecule) - solutes that are more soluble in the solvent will diffuse more - small molecules (e.g., gases like O₂ and CO₂) can easily quickly. diffuse through the cell membrane - gasses like oxygen and carbon dioxide diffuse rapidly in water because they are highly soluble 2. Polarity (polar, non-polar) - nonpolar molecules diffuse more readily through the lipid 4. Pressure (direct) bilayer - the force exerted by the molecules of a substance per unit - polar molecules need facilitated diffusion 3. Charge (+ or -) Types of Osmosis - ions and charged molecules need channel proteins for 1. Endosmosis: facilitated diffusion because of the hydrophobic nature of the - movement of water into a cell when placed in a hypotonic lipid bilayer. solution. 4. Solubility - the cell swells and bursts or becomes turgid - the ability of a molecule to dissolve in a solvent, particularly - example: plant cells absorbing water from the soil. in the lipid bilayer of cell membranes. - molecules that are more soluble in the lipid bilayer will diffuse 2. Exosmosis: more easily through the cell membrane. - movement of water out of a cell when placed in a hypertonic - lipid-soluble molecules (like steroid hormones) can pass solution. through the membrane more readily than water-soluble - the cell shrinks and becomes plasmolyzed or shriveled. molecules - example: red blood cells losing water in a concentrated salt - water-soluble molecules require transport proteins to solution. facilitate movement across the membrane Tonicity Distinguishing Characteristics: - strength of a solution in relation to osmosis 1. Concentration Gradient - molecules move from an area of high concentration to an 1. Isotonic Solution: area of low concentration. - a solution with the same solute concentration as the cell's - continues until the concentration is equal on both sides of the cytoplasm. membrane - no net movement of water; the cell remains the same size. - example: saline solution used in medical drips. 2. No Energy Requirement - passive diffusion does not require cellular energy (ATP) as it 2. Hypotonic Solution: relies on the natural kinetic energy of molecules - a solution with a lower solute concentration than the cell's cytoplasm. OSMOSIS - water enters the cell, causing it to swell and potentially burst - is the movement of water molecules through a selectively (lyse) in animal cells; plant cells become turgid but do not permeable membrane from an area of lower solute burst due to their cell wall. concentration to an area of higher solute concentration - example: freshwater environment for aquatic plants. - aims to equalize the solute concentrations on both sides of the membrane 3. Hypertonic Solution. - special type of passive diffusion - a solution with a higher solute concentration than the cell's cytoplasm. - direct use of metabolic energy (ATP) to transport molecules - water leaves the cell, causing it to shrink (crenate in animal across a membrane. cells, plasmolyze in plant cells). - ATP is hydrolyzed by transport proteins (pumps) to move - example: saltwater environment for marine organisms. molecules against their concentration gradient. - example: sodium-potassium pump (Na⁺/K⁺ ATPase), Osmotic Pressure maintains the electrochemical gradient in cells by pumping - the pressure required to stop the flow of water through a three sodium ions out and two potassium ions into the cell semipermeable membrane. 2. Secondary Active Transport: Importance of Osmosis - indirect use of energy 1. Cellular Homeostasis - the transport of one molecule against its concentration - maintains the balance of water and solutes within cells. gradient is coupled with the transport of another molecule 2. Nutrient Absorption down its gradient. - helps in absorption of nutrients and minerals from the soil in - uses the energy stored in the form of an electrochemical plants. gradient created by primary active transport. 3. Waste Removal - assists in removal of waste products from cells. Types: 4. Turgor Pressure 1. Symport - in plant cells, osmosis helps maintain turgor pressure, which - both molecules move in the same direction keeps the plant upright and supports growth. - example: sodium-glucose co-transporter 2. Antiport ACTIVE DIFFUSION - molecules move in opposite directions. - example: sodium-calcium exchanger Active diffusion - more commonly known as active transport Sodium-Potassium Pump - movement of molecules or ions across a cell membrane from (Na⁺/K⁺ ATPase) an area of lower concentration to an area of higher - example of primary active transport. concentration. - maintains the resting membrane potential and proper cell - uses energy, usually in the form of adenosine triphosphate function. (ATP), because it moves substances against their concentration gradient Process: 1. Binding Types of Active Transport - Three sodium ions (Na⁺) from the cytoplasm bind to the 1. Primary Active Transport: pump. 2. Phosphorylation inside. - ATP is hydrolyzed to ADP, and a phosphate group is 2. Potassium (K⁺) transferred to the pump. - higher concentration inside the cell (cytoplasm) than outside. 3. Transport - The pump changes shape, releasing the three sodium ions Importance of Sodium-Potassium Pump: outside the cell. 1. Electrochemical Gradient 4. Binding - controls nerve impulse transmission and muscle contraction. - Two potassium ions (K⁺) from the extracellular fluid bind to 2. Cell Volume the pump. - prevents cells from swelling and bursting by controlling ion 5. Dephosphorylation concentrations. - The phosphate group is released, causing the pump to revert to its original shape. 6. Transport - The two potassium ions are released into the cytoplasm. ATP and ADP 1. ATP (Adenosine Triphosphate) - the primary energy carrier in cells - releases energy when its terminal phosphate bond is broken, converting it to ADP (adenosine diphosphate) 2. ADP (Adenosine Diphosphate) - the product of ATP dephosphorylation - can be recharged back into ATP through cellular respiration Direction of Sodium and Potassium Flow 1. Sodium (Na⁺) - three sodium ions are pumped out of the cell. 2. Potassium (K⁺) - two potassium ions are pumped into the cell. Sodium and Potassium Concentration 1. Sodium (Na⁺): - higher concentration outside the cell (extracellular fluid) than