Unit 2: Origin and Chemical of Life Francisco Redi experiment Open meat.  They make use of a cover and cut off fresh air necessary for spontaneous generation  Ginamitan ng gos  Do not arise spontaneously  There is a necessity of fresh air for life. John Needham  Broth experiment  Heated the broth  To kill the organisms  He sealed it  placed a broth, or gravy, into a bottle, heated the bottle to kill anything inside, then sealed it. Days later, he reported the presence of life in the broth and announced that life had been created from nonlife Lazzaro Spallanzani  Review both theories  Concluded sealed bottles have no occurrence of microorganisms.  Needed air. Louis Pasteur  Lived the system open to air  No life of jar because  Contamination to life forms from the air.  In summary, Pasteur boiled a meat broth in a flask that had a long neck that curved downward, like a goose. The idea was that the bend in the neck prevented falling particles from reaching the broth, while still allowing the free flow of air. The flask remained free of growth for an extended period.  Spontaneous Generation. Abiogenesis  the origin of life from nonliving matter specifically : a theory in the evolution of early life on earth: organic molecules and subsequent simple life forms first originated from inorganic substances Biogenesis  Life comes from pre-existing life  Bio means life and genesis means beginning.  Proposed by Rudolf Virchow proven by Pasteur.  1861. Special Creation  Life was created by supernatural or divine forces  Faith is the foundation of this theory  Cannot be proved or disproved. Interplanetary/ Cosmozoic theory  Richter (1865) helmholtz (1884) and Arrhenius (1908)  Suggested that life reached the earth from some heavy body through meteorites. Panspermia- a primitive form of life. Biochemical Theory  Chemical and physical processes in Earth’s primordial environment eventually produced the simple cells.  Molecules capable of self-replication eventually would be produced, ultimately leading to the assembly of living microorganisms Recipe of life  Carbon  Sulphur  Nitrogen  Hydrogen  Oxygen  Phosphorous Mix together in a warm, moist environment. Dry out occasionally Add time and energy Allow combining orderly, patterned ways. Properties of Water

1. High specific heat capacity= 4.18j      A Large amount of energy is required to change the temperature of the water.      Heat is not equal to temperature.
2. High heat of vaporization      All hydrogen bonds between water molecules and their neighbors must be ruptured before that water molecule can escape the surface and enter the air.      The evaporation of water from a surface causes the cooling of that surface.      Water evaporation in the form of sweat results in significant heat loss from the body- stabilizing body temperature > and protecting living organisms from extreme thermal fluctuation.
3. Unique Density behavior ( during changes in temperature)      Maximum density of water is at 4 Degree C while still a liquid, then becomes less dense with further cooling.
4. High Surface Tension      Produces Cohesiveness      Important for maintaining protoplasmic form and movement.
5. Low Viscosity- flow      Permitting movement of blood through minute capillaries and of cytoplasm inside cellular boundaries.
6. Universal Solvent      Dissolves molecules and ions      Dipolar nature of water, which causes it to orient around charged particles dissolved in it.      Because water has hydrogen and oxygen      Has positive and negative charge kaya tinawag na polar.
7. Participates in many chemical reactions.      hydrolysis: compounds are split into smaller pieces by the addition of a molecule of water.      Condensation reactions: larger compounds may be synthesized from smaller components by the reverse of hydrolysis     Carbohydrates: Nature’s most abundant organic structure.      Compounds of carbon, hydrogen, and oxygen(1:2;1)      Glucose :      Functions as structural elements (protoplasm) and as sources of energy (C-H covalent bonding); generates ATP.      Synthesized by green plants from water and carbon dioxide, with the aid of solar energy > photosynthesis with the aid of solar energy.      Cellulose-     Monosaccharides – single sugar     Glucose – dextrose      The most common monosaccharide      Central importance in the chemistry of life     Fructose      Sugar is found in honey and fruits.     Galactose      Sugar is found in dairy products.     Disaccharides      Consist of monosaccharides joined by a. glycosidic linkage      examples:      maltose= glucose + fructose      sucrose =     Polysaccharides      composed of many molecules of simple sugars (usually glucose) linked in long chains called polymers      energy storage for animals(glycogen), plants (cellulose or starch)      Structural support of fungi, insects, and anthropods is called chitin.     Lipids: fuel storage and building material      Fats and fatlike substances      Molecules of low polarity      Hydrophobic molecules      2 main purpose      Fat stores excess calories in a safe way so you can mobilize the fat stores when you are hungry      Fat releases hormones     Triglycerides      True fats- major fuels in animals.      Stored fats      Stored fats are deprived directly from dietary fats or indirectly from dietary carbohydrates that the body has converted to fat for storage.      Triglycerides – contain glycerol and 3 molecules of fatty acids.      Saturated- single bond      Unsaturated-double bond or triple bond      Transfat: liquid fats that are converted to solid fats during food processing techniques.      Monounsaturated; isang double bond. An example would be Oleic Acid.      Poly unsaturated: maraming double bonds. An example would be Oleic Acid.     Phospholipid      When this added to water, they self-assemble into double-layered structures called bilayers, shielding their hydrophobic portions from water.     Steroids      Complex alcohols.      2 principal biological functions      Important components of cell membranes that alter membrane fidelity      Signaling molecules.      Includes cholesterol, vitamin d3, adrenocortical hormones, and sex hormones     Amino acids and Proteins:      Proteins are large complex molecules composed of 20 kinds of amino acids      Amino acids are linked by peptide bonds to form a long, chain-like polymers      Through condensation process.      Protein performs the structural framework of our protoplasm and other cellular      Amino, Carboxyl, Amino, Carboxyl > peptide bond + H2O = Water condensation.     4 levels of protein Organization     Primary      Sequence of amino acids composing polypeptide chain.     Secondary      Highly regular local sub-structures on the actual polypeptide backbone chain.     Tertiary      Three-dimensional structure of monomeric and multimeric protein molecules.     Quaternary      Contain more than one polypeptide chain.     Prions      Misfolded proteins that could transmit their misfolded shape onto normal variants of the same protein.      Mad cow disease.      Scrapie in sheep.     Nucleic Acid      Complex polymeric molecules whose sequence of nitrogenous bases encodes the genetic information necessary for biological inheritance.      Store directions for the synthesis of enzymes and other proteins.      The only molecules that can replicate themselves.     2 kinds of Nucleic acids:      Deoxyribonucleic acid (DNA): Double-stranded that is responsible for storing and transferring genetic information.      Ribonucleic acid (RNA): single-stranded that directly codes for amino acids and acts as a messenger between DNA and Ribosomes to make proteins.      They are polymers of repeated units called Nucleotides.      sugar      nitrogenous bases      phosphate group.     Roles of nucleic Acids.      Dna and Rna synthesis; this entire process is called gene expression.     3 step Process: Central Dogma      Replication      Transcription      Translation     States that the pattern of information that occurs most frequently in our cells is: from existing DNA to make new DNA (Replication); From DNA to make new Protein (Transcription); From Rna to Proteins (translation)     Organic of Living Systems:     After a week of Continuous sparking, approximately 15% of the carbon from the reducing “atmosphere” had been converted into organic compounds that were collected in the ocean.     The most striking finding was that many compounds related to life were synthesized.     Formation of Polymers.
8. The abiotic synthesis of small organic molecules > monomers.
9. Joining these small molecules into polymers.
   10. Origin of self-replicating molecules.
   11. Packaging of these molecules into “protobionts”.     Protobionts: precursor to early life and resemble very simple cells.     Proteinoid (polypeptides)     Coacervate (polypeptide + nucleic Acids + polysaccharides)     Rna (nucleic Acid)     Two rich sources for early prokaryote fossils:
   12. Stromatolites:      Fossilized layered microbial mats.      3.5 billion years old.
   13. Sediments from ancient hydrothermal vent habitats.     Origin of Metabolism:     Autotrophs      Organisms that can synthesize their own food from inorganic sources using light or another source of energy.     Heterotrophs:      Organisms that obtained their food supplies directly from the environment.     Primary Heterotrophs:      The earliest postulated microorganisms.      They relied on their environmental sources for their food and existed prior to the evolution of any autotrophs.     The appearance of photosynthesis and oxidative metabolism:     Photosynthesis: Carbon + water Light> Sugar+oxygen      Cyanobacteria are primarily responsible for the generation of atmospheric oxygen early in life’s history.     Oxidative (aerobic) metabolism      New and highly efficient kind of metabolism      Oxygen is used to make energy from carbohydrates (sugars)     Prokaryotes and the Age of cyanobacteria blue-green algae)     Precambrian     Prokaryotes      Like cyanobacteria, the earliest bacterium-like organism      Age blue-green algae.     Eukaryotes      Fossil evidence suggests that single-celled eukaryotes arose at least 1.5 billion years ago.      Endosymbiotic Theory – Lyn Margulis.     Cambrian Explosion:      Cambrian explosion, the unparalleled emergence of organisms between 541 million and approximately 530 million years ago at the beginning of the Cambrian Period.      The event was characterized by the appearance of many of the major phyla (between 20 and 35) that make up modern animal life. Many other phyla also evolved during this time, the great majority of which became extinct during the following 50 to 100 million years.      Ironically, many of the most successful modern phyla (including the chordates, which encompass all vertebrates) are rare elements in Cambrian assemblages;      phyla that include the arthropods and sponges contained the most numerically dominant taxa (taxonomic groups) during the Cambrian, and those were the taxa that became extinct.