Chapter 2 Lecture Outline-1 PDF

Chapter 2 Chemical Principles 1 Inorganic Compounds vs Organic Compounds Inorganic Compounds Small, simple molecules which usually lack carbon Examples - H2O, O2, salts, acids & bases Organic Compounds Large, structurally complex Always contain carbon Held together by covalent bonds 2 Organic C...

Chapter 2 Chemical Principles 1 Inorganic Compounds vs Organic Compounds Inorganic Compounds Small, simple molecules which usually lack carbon Examples - H2O, O2, salts, acids & bases Organic Compounds Large, structurally complex Always contain carbon Held together by covalent bonds 2 Organic Compounds What are the 4 most common elements in organic compounds? Usually contain a chain of carbon atoms  “carbon skeleton” Functional Groups - groups of atoms that can bind to the carbon skeleton  Adding different functional groups  different kinds of organic compounds formed 3 Functional Groups 4 Building-Up vs Breaking-Down of Molecules (Compounds) Build-up of molecules through Dehydration Synthesis Several small monomers combine to form one large polymer Make covalent bonds Break-down of molecules through Hydrolysis One large polymer breaks down to form several small monomers Break covalent bonds 5 Dehydration Synthesis vs Hydrolysis Dehydration Synthesis: Hydrolysis: 6 Dehydration Synthesis vs Hydrolysis Figure 2.8 7 The Major Organic Compounds The 4 major organic compounds are: 1. 2. 3. 4. Carbohydrates Proteins Lipids Nucleic Acids For each organic compound, know the following:     Building blocks (what is the organic compound composed of?) Any group/category types Key function(s) Example(s) 8 Example of Table for Carbohydrates 9 Carbohydrates AKA “carbs” or “sugars” Made of carbons, hydrogens and oxygens Consist of subunits (building blocks) called monosaccharides Usually end in “-ose” Classified into 3 major groups based on size: 1. Monosaccharides 2. Disaccharides 3. Polysaccharides 10 Monosaccharides Called “simple sugars,” containing 3 - 7 carbon atoms Sweet tasting, water-soluble Serve as building blocks for large, complex carbohydrates Provide quick source of energy for living cells ( ex - glucose for humans) Examples - glucose, deoxyribose, fructose 11 Disaccharides Made when 2 monosaccharides form a covalent bond (called glycosidic bond) via dehydration synthesis Provide structural component for bacterial cell walls Examples - sucrose, lactose 12 Polysaccharides Consist of tens or hundreds of monosaccharides joined through dehydration synthesis Provide long-term energy source and structural component for plant cell walls Examples - starch, glycogen and cellulose are all polymers of glucose 13 Proteins Made of C, H, O, N, and sometimes S Are essential in cell structure and cell function Are structurally & functionally the most diverse among the organic compounds Protein examples & key functions: Structural protein Transporter proteins Enzymes Antibodies Bacterial toxins 14 Amino Acid Proteins consist of subunits (building blocks) called amino acids There are a total of 20 amino acids Contain a central carbon that has an attached: 1. 2. 3. 4. Amino group Carboxyl group Hydrogen Side group (R group) Figure 2.12 15 The 20 Amino Acids found in Proteins 16 The 20 Amino Acids found in Proteins 17 Peptide Bonds Two amino acids are linked together by a covalent bond called a peptide bond via dehydration synthesis Figure 2.14 18 Protein Structure Big Picture: protein structure determines the protein function! Protein structure can undergo denaturation If protein loses/changes its shape (structure) it loses/changes its function Denaturation occurs when proteins encounter harsh/hostile environments such as high temperatures and low pH; may be permanent 19 Levels of Protein Structure There are 4 “Levels of Protein Structure” 1. 2. 3. 4. Primary structure Secondary structure Tertiary structure Quaternary structure 1° structure  2° structure  3° structure  4° structure 20 Example of Table for Protein Structure Levels 21 Primary Structure The primary structure is a sequence of Amino Acids; polypeptide chain/strand Figure 2.15 22 Secondary Structure The secondary structure occurs when the amino acid chain folds and coils in a helix or pleated sheet Figure 2.15 23 Tertiary Structure The tertiary structure occurs when the helix or pleated sheet folds irregularly, forming disulfide bridges, hydrogen bonds, and ionic bonds between amino acids in the chain Figure 2.15 24 Quaternary Structure The quaternary structure consists of two or more polypeptide chains bound to each other Figure 2.15 25 Lipids Made of carbons, hydrogens and oxygens Consist of subunits (building blocks) called triglycerides Primary components of cell membranes Classes of lipids: 1. Simple Lipids 2. Complex Lipids 3. Steroids & Sterols 26 Simple Lipids AKA fats (or triglycerides) Triglycerides contain 1 glycerol (in yellow) and 3 fatty acid chains (in green) that are linked together by a covalent bond (called an ester bond) via dehydration synthesis Figure 2.9 c 27 Simple Lipid Types Saturated Fats vs Unsaturated Fats  Saturated Fatty Acids  No double bonds in the fatty acids (only have single bonds)  Unsaturated Fatty Acids  One or more double bonds in the fatty acids Key Function  Alternative source of energy when carbs are not available 28 Complex Lipids Cell membranes are made of complex lipids called phospholipids Phospholipid contains: 1 glycerol, 2 fatty acid chains & 1 phosphate group Phospholipids have polar regions (polar head) and nonpolar regions (nonpolar fatty acid tails) Figure 2.10 Polar = charged Non-polar = uncharged 29 Complex Lipids Key Functions:  Structural components - form the phospholipid bilayer of the cell membrane  Regulation of transport - controls what enters & leaves the cell and leads to homeostasis Examples  Waxes  Glycolipids (lipids with carbohydrates attached to them)  Mycolic Acid - waxy lipid material present in cell wall of the bacterium Mycobacterium tuberculosis 30 Steroids & Sterols Steroid - forms when three 6-carbon rings (A, B, C) attach to one 5-carbon ring (D) When an “-OH” group attaches to one of the 6-carbon rings it is called a Sterol Figure 2.11 31 Steroids & Sterols Examples of steroids Cholesterol Hormones Some vitamins Key Functions: Structural component of the cell membrane of Eukaryotic cells  Cholesterol - a sterol found in animal cell membranes  Phytosterol - a sterol found in plant cell membranes  Ergosterol - a sterol found in fungi cell membranes 32 Nucleic Acids Made of C, H, O, N Examples - DNA and RNA; also ATP Consist of subunits (building blocks) called nucleotides that are are linked together by a covalent bond (called a phosphodiester bond) via dehydration synthesis 33 Nucleotide Nucleotides consists of: 1. Sugar = 5-carbon pentose sugar 2. Phosphate group 3. Base = a nitrogen-containing base that comes from either the Purine family or Pyrimidine family Purine bases = A, G A = Adenine G = Guanine Pyrimidine bases = C, U, T C = Cytosine U = Uracil T = Thymine 34 DNA vs RNA DNA Double-stranded molecule (double helix) Sugar-Phosphate backbone A-T and C-G base pairing through hydrogen bonds Function - stores genetic information RNA Usually single-stranded molecule Sugar-Phosphate backbone No base pairing 3 kinds of RNA:  mRNA, tRNA, rRNA Function - for protein synthesis 35 RNA vs DNA 36 ATP Adenosine Triphosphate Adenosine is attached to 3 phosphate groups Is a nucleic acid but remains as a “single nucleotide” High energy compound Stored chemical energy is release by hydrolysis/breaking of bonds connecting phosphate groups Figure 2.18 37