• Author / Uploaded
• Bianca Braza

• Categories
• Crianza selectiva
• Proteínas
• Las bacterias
• Enzima
• Seleccion natural

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SELECTIVE BREEDING  Artificial selection  Process by which humans breed plants and animals of a particular characteristic  Farming: hunter-gatherer  farmer  Started with breeding wild crops into food crops (rice from streams and wetlands to paddy fields for larger regular grains)  Vs. natural selection  Proposed by Charles Darwin as the way species evolve  Same gene can encode for varying traits  Varying traits are favorable or non-favorable  “Superior” trait persists  Nature decides which species is more fit  Steps Decide which characteristics are important Choose parents that show these Select the best offspring to breed for next gen Repeat the process continuously 

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Applications  Utility  Insect resistance in food and crops  Animals that produce more meat or milk  Domestication  Dogs with gentle nature  Przewalki’s horse  modern horse  Athletic horse & horse for carriages  South Asian wolf  domestic dog  Hypoallergenic cat (short hair)  Munchkin cat (short legs)  Aesthetics  Large or unusual flowers  Garden flowers for bright colors and nice smell  Dogs for cute traits  Livestock  Size of chicken has increased  Auroch  domestic cattle  Friesan cow: dairy breed  Aberdeen Angus bull: beef  Plants  Quality of crop increases  Disease-resistant wheat  Teosinte  modern corn (larger cobs with more kernels that are softer and more edible)  Wild mustard plant: broccoli (flower development), cabbage (intermode length), kale (leaves enlargement), cauliflower (sterility of flowers), kohlrabi (enhancement of lateral meristems) Problems  Species are selected for pleasing traits not favorable for survival (corgi, bull terrier, English bulldog, boxer)

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Limitations  Production of desirable trait requires generations for breeding  “Unnatural selection”, weak traits propagated  Reduced genetic variability which may obliterate an entire population when there is high environmental stress  Human intervention results in unintentional artificial selection (fish population in fishing, small fish instead of both small and large) Eugenics  Selective breeding in humans  Francis Galton  Improve intellectual, economic, and social level of humankind  Support in late 19th and early 20th century  Legislation passed favoring forces sterilization of criminals, those with mental disorders, and specific ethnic groups  Ignored the fact that human traits are influenced by genetic and environmental factors (mental disorders)  Hereditarianism: misconception that human traits are determined solely by genetic inheritance  Used to pass restrictive immigration laws in the United States (immigrants from south and eastern EU were said to be genetically inferior)  Followed by the rise of the Nazi movement (1933 law for the protection against genetically defensive offspring in Germany, allowed killing of the “defective” individuals)  Nazis imposed forced sterilization/infanticide  Eugentics was used to justify the holocaust

PROTEINS  Mendel’s study established that physical trait is due to presence of a gene  Protein ties gene to trait  Given protein assumes a specific function (structural, mechanical, enzymes, hormones, antibodies, fluid balance, acid-base balance, channels and pumps, transport)  Gene for yellow peas codes for a protein that breaks down chlorophyll (PAO)  Gene for tall pea plants codes for protein that makes gibberellin (growth hormone)  Gene for purple flower codes for a protein that makes anthocyanin (purple pigment)  Foods high in protein: meat, fish, cheese, eggs, beans, bread, hummus, nuts and seeds  Proteins are source of amino acids  Made up of amino acids  Body breaks down the protein we eat into amino acids  Body takes carbs to break it down to glucose (source of energy)

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Body takes protein to break down to amino acids (needed to make more proteins that the body needs; tissue, plasma, ammonium, etc.) 9 Essential Amino Acids  Human body cannot synthesize these amino acids  We get them from the proteins we eat  Histidine, Isoleucine, Leucine, lysine, Methionine, Phenylalanine, Threonine, Tryptophan, Valine  Protein Molecule  Digestion  Amino Acid Proteins are workhorses of the cell  Insulin (sugar metabolism)  Cytochrome C (cell respiration)  Growth Hormone (anti-aging)  Hemoglobin (oxygen transport)  Hexokinase (glycolysis)  Gamma Globulin (immune system in blood)  Myosin (muscle action) 50% of cell is made of proteins  4 macromolecules: carbs, lipids, proteins, nucleic acids Proteins have complex structures that allow them to have various functions  Proteins fold in such a way that hydrophilic is exposed and hydrophobic is hidden from the water environment  Primary, secondary, tertiary, quaternary Amino acids have charges that make them hydrophilic (charge), hydrophobic (no charge), or neutral Microtubules are made up of tubulin proteins Histones are round, allowing DNA to wound around them Aquaporins are channels through which water enters the cell Different uses of protein in the body  Transport: hemoglobin (carry oxygen and circulate it around the body, RBC)  Hormone: insulin (tells body to store glucose)  Neurotransmitters: serotonin  Enzyme: amylase

PROTEINS IN BIOTECH  Proteins are important to all organisms  Microorganisms produce proteins that can be utilized by humans  Penicillin  Produced in great amounts by letting mold grow in tanks  Binds to a protein in the cell wall and prevents cell wall synthesis  Without cell wall, bacterial cell dies (only gram positive bacteria thick cell wall)  Treatment of bacterial infections (Pharyngitis by Streptococcus, Pneumonia by Pnemococcus, Skin infections by Staphy)  Not effective against gram negative bacteria like E. Coli and Salmonella  Waksman studied soil microorganisms to screen for naturally occurring antibiotic compounds (discovered

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antibiotics actinomycin and steptomysin, coined “antibiotic”) Antibiotics are antimicrobial drugs used to treat bacterial infections Actinomycin, from soil bacteria steptomyces antibioticus, is a protein that can inactivate DNA  Effective against a wide range of bacteria  Structure-function at work  Actinomycin fits right in DNA groove  When DNA s inactivated, the cell cannot perform its functions properly, such as cell division Why would a bacterium be producing an antibiotic protein?  Ward off competition  Steptomyces lives in soil and competes for resources Actinomycin was developed to become an anti-cancer drug (cannot replicate) Streptomycin: binds to bacterial ribosomes to prevent protein production Bacteria harnessed to secrete bioluminescent proteins (Luciferin protein is needed)  Luciferase catalyzes  Allows oxygen to combine with luciferin  Reaction produces light Squid lives in symbiosis with a fluorescence-producing bacteria (Vibrio fischeri)  Squid uses the bioluminescent bacteria to emit light in its body parts and ward off predators, attract prey, or find mates  Special organ were bacteria can live Bioluminescent proteins: bacteria from squid are isolated and cultured as a marker for successful genetic modification of proteins Proteins by animals also used in biotech Insulin  Tells body to store glucose  Diabetes: insulin production is defective  Pigs and cows were source of insulin in traditional biotech  Pic/cow pancreas are run through grinder; insulin proteins are filtered out then packaged Antivenom  Horse as source of antibody  Antibodies: defensive proteins against foreign materials  Antibodies are shaped to fit their target  Bacteria, viruses, snake venom look different  Venom extraction, animal immunization, blood collection, Antivenom  Antivenom antibody “IgG”  Treatment has to be immediate, so antivenom antibodies are supplied externally in drug form Plants can also be source of protein-based meds  Cortisone is steroid hormone and can be synthesized from wild yam root  Cortisone relieves pain in arthritis  37 steps to synthesize it before and expensive

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Fungus to cut down synthesis to 11 steps, allowed for microbial hydroxylation Starting substance: diosgenin to synthesize cortisone Wild yam root & Rhizopus fungus

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 ENZYMES  Every chemical synthesis needs a starting reactant to jump-start the process  Bovine bile acid (starting material of reaction)  Proteins are useful in research  Marine organism houses bioluminescent bacteria to ward off predators, attract prey, and find mates  Bacteria use bioluminescence for communication: Quorum Sensing  Cellular processes that need more bacteria to become efficient are achieved by this (antibiotic production, conjugation, virulence factors, biofilm formation, bioluminescence)  Need many cells for a process to exert a significant function (bacteria are small)  BLB use it to monitor the environment for the presence of other BLB (reach a quorum by sending out a signal)  Should we luminesce?  Sends our chemical signal “AHL” aka autoinducer  AHL signal in environment: not enough OR  AHL signal in environment: threshold concentration reached  Autoinducers use Lux genes to produce luciferase  Luciferase is an enzyme and allows bioluminescence chemical reaction to proceed  BLB need to exist in a large number to luminesce (live in marine organism)  Luciferase induces bioluminescence chemical reaction (protein AND ezyme)  Enzymes are proteins

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Unassisted, chemical reactions need a high amount of energy to proceed Enzyme lowers the energy hill because it provides the optimal environment for reaction Catalyzes the reaction: faster Luciferase is an enzyme  Substrate: luciferin  Product: Oxyluciferin + light Examples of Enzymes  Amylase  Saliva  Digests starch into simpler sugars  Aldehyde dehydrogenase  Liver  Breaks down alcohol metabolite  Alcohol flush reaction if lacking enzyme  Pepsin  Stomach  Breaks down proteins  Rennin  Stomach  Curdle milk and make it easier to help the young digest the milk  Cheese fermentation  Diastase  First plant enzyme to be purified and studied  1800’s “starch-liquefying principle from germinated barley”  Isolated an active compound from barley in powder form  Can turn starch into liquid  Ability lost when heated  When dissolved in water, gained back ability = Active components can be isolated and can perform function Does fermentation need living organisms?  Wilhelm Friedrich Kuhne coined the word enzyme for this type of ferment  Edward Buchner experiment proved that alcoholic fermentation can occur in absence of yeast cells  Zymase: enzyme in yeast that induced alcoholic fermentation  Proteins are workhorses of cell; they enact the instruction encoded in DNA  Enzyme was behind alcoholic fermentation  For the first time, it was possible to observe fermentation in absence of living yeast  Enzyme actually responsible for the chemical conversions, not the microorganism

ENZYMES IN BIOTECH  Industrial biotech ethos = IMRPOVE PROCESS  Become more efficient  Fermentation by accident  Large-scale fermentation in bioreactors  Improved large scale fermentation in bioreactors  Isolate enzymes to make certain processes easier  Why are microorganisms still used in industrial scale fermentation?  Enzymes are produced by the microorganisms  Easier and cheaper to use microorganisms  Isolating and purifying enzymes has a corresponding cost  Microorganisms reproduce on their own  Enzymes used in the industry  Amylase for industrial applications (textiles, brewing, dextrose syrup)  Amylase used to convert starchy paper into a smoother and stronger product  Sucrose vs Glucose vs. Fructose  Sucrose (sugar cane/beet)  Glucose not as sweet (corn, potato)  Fructose 2x sweeter than sucrose  Starchy materials  syrup  Amylase used to convert starch to glucose  Glucose isomerase converts glucose to fructose  Rennins in dairy industry  Stomach of calves contain rennin  Coagulates milk and makes cheese  Rennin is enzyme that breaks down milk proteins (curdles milk during fermentation)  Amylase, glucose, and proteases in beer fermentation  Enzymes used to break down starch into simpler sugar, protein into amino acids  Products are used by yeast for fermentation  Cellulase in the biofuel industry  Biofuel used plant material, which is rich in cellulose  Has to be broke down before it can be used  Proteases in detergent industry  Help with the removal of protein stains from clothes  Protease producing bacteria are cultured in large flasks  Protease is later purified and mixed with detergent product