Ch. 2 Chemical Properties - blank (1) PDF

Chapter 2 Chemical Properties BIO 214: General Microbiology Outline Organic vs Inorganic compounds Macromolecules Carbohydrates Lipids Proteins Nucleic Acids Denaturation Inorganic vs Organic Compounds ____________ compounds – compounds that contain carbon-hydr...

Chapter 2 Chemical Properties BIO 214: General Microbiology Outline Organic vs Inorganic compounds Macromolecules Carbohydrates Lipids Proteins Nucleic Acids Denaturation Inorganic vs Organic Compounds ____________ compounds – compounds that contain carbon-hydrogen bonds (C-H) ____________ compounds – compounds that lack C-H bonds Organic compounds are vital to cells Life as we know if wouldn’t be possible without organic compounds The molecules that provide structure and perform functions Ball and stick models Black – carbon White – hydrogen Red – oxygen Blue – nitrogen Isoleucine, an amino acid Carbon dioxide (example of an organic compound) (example of an inorganic compound) Inorganic Compounds pH scale Water (H2O) 0 Most abundant compound in cells (65-75%) H 1 Stomach acid Increasingly ACIDIC + 2 Lemon juice Salts (e.g. NaCl, KH2PO4) OH– 3 Grapefruit juice Acids and Bases Acidic solution 4 Wine Tomato juice Highly acidic  low pH 5 Highly alkaline (basic)  high pH 6 Urine pH affects how organic molecules interact (e.g. protein folding)NEUTRAL Milk 7 Pure water [H ] = [OH ] + – Human blood Gases (e.g. CO2, O2) 8 Seawater Increasingly BASIC Neutral solution 9 10 Milk of magnesia 11 Household ammonia 12 Household bleach 13 Oven cleaner Basic solution 14 Limewater Organic Molecules Macromolecules – large biological molecules Four types: Carbohydrates (polysaccharide) Lipids Nucleic acids (DNA, RNA) Proteins Macromolecules are ____________, made up of many _____________ linked together by _____________ bonds Macromolecules are unique to living organisms Provide structure and perform functions DNA store genetic information Proteins catalyze enzymatic reaction, also structural Lipids form membranes Carbohydrates Made of carbon (C), hydrogen (H), and oxygen (O)  CHO Carbohydrates are used by many microbes as carbon and energy sources Three major types: Monosaccharide – a single monomer (e.g. glucose) Disaccharide – two monosaccharides joined by a __________________ (e.g. sucrose, lactose) Glycosidic bond – special type of ______________ bond Polysaccharide – tens-hundreds of monosaccharides joined by glycosidic bonds (e.g. glycogen, cellulose, chitin, starch) Bacteria have a cell wall made of peptidoglycan (polysaccharide chains linked together) glucose sucrose glycogen Lipids Essential component of biological membranes Fatty acids tails are nonpolar (uniform neutral charge)  Head Phospha ______________ (‘water-fearing’) te group Phospholipids are composed of: Glycerol A glycerol Two fatty acids A phosphate group bonded to one of several organic groups The phosphate group imparts an inherent negative charge to membranes Fatty acids The nonpolar fatty acid tails (nonpolar, hydrophobic) repel from water, forming a lipid ___________________ consisting of two ________________ Leaflet Lipid bilayer Leaflet Tail Proteins Make up 50% of cell (by dry weight) Essential to cell structure and function ________________ - proteins that catalyze reactions Composed of amino acids linked together by ___________________ (covalent) Carboxyl (C) and amino (N) ends 20 different amino acids, each with a different R group  each with different properties (e.g. charge, size) Proteins are encoded by genes Different proteins have different lengths and amino acid sequences  different shapes  different functions Proteins Primary structure: polypeptide strand (amino acid sequence) Secondary structure: helix and pleated sheet (with three polypeptide strands) Tertiary structure: helix and pleated sheets fold into a 3D shape ________________________ occurs due to hydrogen bonds Quaternary structure: the relationship of several folded polypeptide chains, forming a protein Nucleic Acids Deoxyribonucleic acid (DNA) is the genetic material for all cellular organisms Viruses (noncellular) can use RNA For cells, RNA (ribonucleic acid) serves as a transcript – an intermediate between DNA and protein DNA and RNA nucleotides are the same except for the presence/absence of a single -OH group Nucleic acids are polymers of _________________ (monomer) Base (adenine) Nucleotides are composed of: __________ Phosphate __________ __________ (A, T, C, G) Responsible for base pairing (A-T and G-C) DNA forms a double helix structure, RNA does not Sugar  Nucleic Acids (DNA) Base Base Phosphate Sugar (adenine) (thymine) Sugar Phosphate Sugar phosphate backbone (covalent bonds) Base pairing (hydrogen bonds) Sugar phosphate backbone (covalent bonds) Phosphate Sugar Base Base Sugar Phosphate (guanine) (cytosine) Nucleic Acids (DNA) Guanine nucleotide Hydrogen bonds Cytosine nucleotide Sugars Sugar-phosphate backbone Phosphates DNA double helix Key Adenine Thymine Deoxyribose sugar Guanine Cytosine Phosphate Hydrogen bond Denaturation The conformation (shape) of DNA (double helix) forms due to _____________________ between the base pairs The conformation of DNA is essential for storing genetic material in an accessible manner In contrast, adjacent nucleotides are linked by covalent bonds __________________ – refers to the breaking of hydrogen bonds Hydrogen bonds are much weaker than covalent bonds When DNA denatures, it separates into single strains Caused by heat Denaturation The conformation of ______________ is also due to hydrogen bonding Protein folding Adjacent amino acids are held together by covalent bonds but distant amino acids interact through hydrogen bonds If a protein denatures, it is no longer functional  Microbiologist Spotlight Rosalind Franklin Mid-20th century chemist (Kings College London) Accomplished X-ray crystallographer X-ray crystallography is a method used to determine the structure of macromolecules Her research student captured ‘Photo 51’ which led to the discovery of the DNA’s double helix structure Unbeknownst to Franklin, the photo was shared with other researchers, who interpreted the observations These researchers (James Watson, Francis Crick, Maurice Wilkens) were awarded the Nobel Prize in Physiology or Medicine in 1962 for their discovery Franklin’s contributions were never recognized Died from ovarian cancer in 1958, Nobel Prize not awarded posthumously