Botany - The Chemical Composition of Cells PDF

BOTANY Ms. Sofia Dela Peña Nickel-Eating Plant Discovered in Philippines Hyperaccumulator plant species Phytoremediation refers to the use of hyperacccumulator plants to remove heavy metals in contaminated soils Phytomining is the use of hyperacccumulator plants to grow and harves...

BOTANY Ms. Sofia Dela Peña Nickel-Eating Plant Discovered in Philippines Hyperaccumulator plant species Phytoremediation refers to the use of hyperacccumulator plants to remove heavy metals in contaminated soils Phytomining is the use of hyperacccumulator plants to grow and harvest in order to recover commercially valuable metals in plant shoots from metal-rich sites.  Elements of Life Chemical Bonds Inorganic Compounds Organic Compounds  Proton - positive electric charge, small mass Neutron - uncharged, about same mass as proton Electron - negative charge, extremely small mass © https://chemistrytalk.org/protons-neutrons-electrons/  Move around the nucleus at different energy levels Allow elements to combine chemically to form chemical compounds Ions are atoms which tend to gain or lose electrons © https://commons.wikimedia.org/wiki/File:Atom_animation.gif  An electrostatic attraction between oppositely charged ions © https://sciencenotes.org/ionic-vs-covalent-bonds/ A chemical bond involving one or more shared pairs of electrons Covalent Bonding in Methane © https://taylorsciencegeeks.weebly.com/blog/the-tale-of-the-periodic-table An attraction between a slightly positive hydrogen atom in one molecule and a slightly negative atom (usually oxygen) in another molecule © https://socratic.org/questions/how-are-hydrogen-bonds-related-to-cohesion  Discuss the properties of water, and explain the importance of water to life  Has a strong dissolving ability Molecules form hydrogen bonds with one another (cohesion) Molecules form hydrogen bonds to substances with ionic or polar regions (adhesion) Adhesion & Cohesion are particularly important for transport All living things require water to survive Almost all chemical reactions that sustain life occur in aqueous solution High Boiling & Freezing Points Insulation Property after freezing (e.g., lakes)  Acids dissociate in water to form hydrogen ions (protons, H+) Bases dissociate in water to yield negatively charged hydroxide ions (OH-)  A measure of the relative concentrations of H+ and OH- in a solution A solution’s acidity or alkalinity is expressed in terms of the pH scale  Describe the chemical compositions and functions of carbohydrates, lipids, proteins, and nucleic acids  An organic compound containing carbon, hydrogen, and oxygen in the approximate ratio of 1C:2H:1O Include sugars, starches, cellulose Important fuel molecules, components of molecules (nucleic acids) and cell walls  Monosaccharides - simple sugars Disaccharides - two monosaccharide units Polysaccharides - many monosaccharide units  Any of a group of organic compounds that are insoluble in water but soluble in fat solvents. Have a greasy consistency, do not readily dissolve in water Important fuel molecules, components of cell membranes, waterproof coverings over plant surfaces, light-gathering molecules for photosynthesis A neutral fat or oil molecule is composed of a molecule of glycerol plus one, two or three fatty acids  A large, complex organic compound composed of amino acid subunits A macromolecule composed of amino acids joined by peptide bonds Order of amino acids determines structure and function of a protein molecule Enzymes: Proteins that increase the rate of chemical reactions  Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) Large, complex organic molecules composed of nucleotides Control the cell’s life processes Deoxyribonucleic acid (DNA) - Transmits information from one generation to the next Ribonucleic acid (RNA) - Involved in protein synthesis  Repeating units that form nucleic acids Order of nucleotides in a nucleic acid chain determines the specific information encoded Adenosine triphosphate (ATP) A modified nucleotide compound important in energy transfers in biological systems 1. Helicase enzymes separate two strands of nucleotides (break the H-bonds that hold bases together). -the point at which the 2 strands of DNA separate is called the replication fork. 2. Another enzyme (DNA polymerase) binds to separated strands and starts moving along original DNA. 3. DNA polymerase assembles a complementary strand from free nucleotides that are found in the nucleoplasm  An organic compound of prime importance for energy transfers in biological systems. ATP is a nucleotide that performs many essential roles in the cell. It is the major energy currency of the cell, providing the energy for most of the energy-consuming activities of the cell. It is one of the monomers used in the synthesis of RNA and, after conversion to deoxyATP (dATP), DNA. It regulates many biochemical pathways. Large Molecules: Polymers and their Movements Building Biomolecules Biological Role Block Carbohydrates Monosaccharide Structural, energy reservoirs Proteins Amino acids Framework material Lipids Fatty acids + Mechanical protection, glycerol thermal insulation Nucleic Acids Nucleotide Storage and transmission of genetic material  Discuss the role of enzymes in cells  An organic catalyst, produced within an organism, that accelerates specific chemical reactions The energy required to initiate a chemical reaction  Speed up a chemical reaction by lowering its activation energy (energy needed to initiate the reaction) Most enzymes are highly specific and catalyze only a single chemical reaction Without enzymes, chemical reactions in cells would occur too slowly to support life  Energy can be stored and can move or change matter: Potential energy is stored energy, while kinetic energy is energy having to do with motion. The first law of thermodynamics states energy can be harnessed and transformed but not created or destroyed. The second law of thermodynamics states that every transfer of energy increases the entropy (disorder) of matter in the universe.  State the first and second laws of thermodynamics, and describe how each applies to plants and other organisms  FIRST LAW OF THERMODYNAMICS Energy cannot be created or destroyed, although it can be transformed from one form to another SECOND LAW OF THERMODYNAMICS When energy is converted from one form to another, some of it is degraded into a lower-quality, less useful form  The ability to do work Plants and other organisms cannot create the energy they require to live, but must capture energy from the environment and use it to do biological work  Continuously increases in the universe as usable energy is converted to lower-quality, less usable form (heat) As each energy transformation occurs in organisms, some energy changes to heat Given off into the surroundings Can never be used again for biological work Secondary Metabolites Primary metabolites are compounds that are directly involved in the growth and development of a plant whereas secondary metabolites are organic compounds produced in other metabolic pathways. They are not directly involved in the normal growth, development or reproduction of an organism. Secondary Metabolites often play an important role in plant defense. Humans use secondary metabolites as medicines, flavorings, and recreational drugs. Biosynthesis is the term for the in vivo synthesis of metabolites. ○ Alkaloids ○ Terpenoids ○ Phenolics Secondary Metabolites Secondary metabolites such as phenolics, alkaloids, and terpenoids often protect or strengthen plants Secondary Metabolites Alkaloids ○ a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. o produced by a large variety of organisms, including bacteria, fungi, plants, and animals, and are part of the group of natural products. o They often have pharmacological effects and are used as medications, as recreational drugs, or in entheogenic rituals. Secondary Metabolites Phenolics ○ Organisms that synthesize phenolic compounds do so in response to ecological pressures such as pathogen and insect attack, UV radiation and wounding. ○ they are present in plants used in traditional medicine of several cultures ○ their role in human health and disease is a subject of research because some phenols are found to have germicidal property and are used in formulating disinfectants. Secondary Metabolites Minor classes Plant Uses of secondary metabolite Papaver somniferum (opium poppy Analgesic (painkiller) Morphine Erythroxylum coca (coca) Anesthetic in eye Cocaine surgery and dentistry; often abused as an illegal substance Coffea arabica (coffee), Stimulant Caffeine Cannellia sinensis (tea), Theobroma cacao (cocoa) Nicotiana tabacum Stimulant; highly toxic, causing (tobacco plant Nicotine leaves) harmful effects from cigarette smoking Menthol Mints and eucalyptus Strong aroma; used in Eucalyptol* tree cough medicines