Chemical Level of Organization PPT Part 2 - PDF
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This document provides an overview of the chemical level of organization in biology. It discusses various biological molecules, including enzymes, lipids, proteins, nucleic acids, and energy, suitable for secondary school biology students. The document does not appear to be an exam paper and thus no specific board or year can be identified.
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Chemical Level of Organizati on PT 2 Enzymes Enzymes are catalysts: – proteins that lower the activation energy of a chemical reaction – Are not changed or used up in the reaction – Speeds up the reactions Example:...
Chemical Level of Organizati on PT 2 Enzymes Enzymes are catalysts: – proteins that lower the activation energy of a chemical reaction – Are not changed or used up in the reaction – Speeds up the reactions Example: – Frogs leaping over rock wall – Higher the barrier (activation energy) – Less frogs get over (Less product) Substrates: How reactants in enzymatic reactions Enzymes Active site: a location on an enzyme that fits a Work particular substrate Enzyme Helpers Cofactor: – an ion or molecule that binds to an enzyme before substrates can bind Coenzyme: – nonprotein organic cofactors (vitamins) – Enzyme Animation Vid eo Clip Energy In, Energy Out Exergonic reactions: produce more energy than they use Endergonic reactions: use more energy than they produce Glycoproteins: – large protein + small carbohydrate Protein includes enzymes, Combinatio antibodies, hormones, and mucus production ns Proteoglycans: – large polysaccharides + polypeptides promote viscosity Connective tissue components Lipids Mainly hydrophobic molecules such as fats, oils, and waxes Made mostly of carbon and hydrogen atoms – Is this organic or inorganic? Classes of Lipids Fatty acids Eicosanoids Glycerides Steroids Phospholipids and glycolipids Fatty Acids Building blocks of fats in our bodies and in the food we eat Long chain of carbons bound to hydrogen Saturated and Unsaturated Fatty acids may be: – saturated with hydrogen (no double bonds) – unsaturated (1 or more double bonds) Eicosanoids Fatty acids that are derived from arachidonic acid Act as hormones Triglyceride s Triglyceride: – 3-carbon glycerol linked to 3 fatty- acid tails – fat storage molecule – High level linked to cardiovascular problems Steroids Made of 4 carbon rings Cholesterol: – component of cell membranes Sex hormones – Estrogens and testosterone: Corticosteroids and calcitrol: – metabolic regulation Phospholipids Amphipathic: – Hydrophilic head and hydrophobic tails Create the cell membrane Two fatty acid chains and phosphate head. Nucleic Acids Large organic molecules, found in the nucleus, which store and process information at the molecular level- includes DNA and RNA DNA in the cell nucleus contains the information needed to construct all of the proteins in the body DNA to RNA to Protein DNA in the cell nucleus contains the information needed to construct all of the proteins in the body RNA and DNA Nucleic Acids – Long chains of nucleotides (the monomers of nucleic acids) form RNA and DNA RNA: – a single strand DNA: – a double helix joined at bases by hydrogen bonds Nucleotides Are the building blocks of DNA Have 3 molecular parts: – sugar (deoxyribose) – phosphate group – nitrogenous base (A, G, T, C) Nitrogenous Bases Difference between DNA and RNA DNA: – adenine (A) and thymine (T) – cytosine (C) and guanine (G) RNA: – uracil (U) replaces thymine (T) Deoxyribonucleic Acid (DNA) Determines inherited characteristics Directs protein synthesis Controls enzyme production Controls metabolism Ribonucl eic Acid (RNA) Codes intermediate steps in protein synthesis Forms of RNA RNA can have many roles messenger RNA (mRNA)- corresponds to a gene and is read by rRNA in the process of creating a protein ribosomal RNA (rRNA)- “reads” the mRNA and holds it in place as tRNA brings the appropriate amino acids to add to the protein transfer RNA (tRNA)- brings amino acids to attach to the growing peptide chain held by the rRNA ADP and ATP aka the body’s energy adenosine triphosphate (ATP): – Molecule with 3 phosphate groups tri = 3 When 3rd phosphate group is broken off energy is released and it becomes ADP adenosine diphosphate (ADP): – 2 phosphate groups di = 2 DEphosphorylation Dephosphorylation - cleaving a phosphate group from ATP to form the lower-energy compound ADP + Pi – THIS RELEASES ENERGY! – ATPase - the enzyme that catalyzes DEPHOSPHORYLATI ON Phosphorylation Adding a phosphate group to ADP forms the high-energy compound ATP is called phosphorylateion -The bond between the 2nd and 3rd phosphate group is where the energy is stored Energy is needed to add the third phosphate To decrease energy needed we use ATP synthase: – the enzyme that catalyzes phosphorylation ATP Dephosphorylation & Phosphorylation
