Biochemistry
Organic Chemistry All living things are mostly composed of 4 elements: H, O, N, C honk Compounds are broken down into 2 general categories: Inorganic Compounds: Do not contain carbon Organic compounds Contain significant amounts of carbon. Often found with common "functional groups"
Carbon: The Swiss Army Knife of Chemistry. Carbon is essential to life for several reasons: It can form strong stable (usually non-polar) covalent bonds It can form up to 4 chemical bonds It can form multiple bonds
Organic Compounds Organic Compounds often form Polymers Long chains of smaller molecules (not atoms) called monomers, bind to form huge Macromolecules 4 Types: Carbohydrates, Lipids, Proteins & Nucleic acids
Carbohydrates Includes: Sugars, starches, cellulose & glycogen Made of Carbon ( C ), Hydrogen ( H ), and Oxygen (O ) Following ratio of elements C n H 2n O n Sugars: Provide immediate energy for cells Simple sugars include Glucose & Fructose since these are made of only 1 Carbohydrate molecule they are known as Monosaccharides Glucose: A Monosaccharide
Dehydration Synthesis Monosaccharides can be linked together through the process of Dehydration Synthesis Water is removed from 2 monosaccharides - resulting in a covalent bond between the 2 molecules Sucrose (table sugar) is made of 2 sugars linked together and these are called Disaccharides Require some digestion to be used by cells
Hydrolysis Dehydration synthesis is a reversible process Called Hydrolysis. A water molecule is inserted where the monomers join. Breaking their bonds.
Dehydration Synthesis Simplified
Hydrolysis Simplified
Polysaccharides Starches are many monosaccharides linked together in a single chain. These are called Polysaccharides. Plants use Starch for energy storage e.g. Potatoes Two types of starches Amylose - Long straight unbranched chains Pectins - many linked short Amylose chains What do humans use it for? Starch
Cellulose Cellulose is made of long polysaccharide chains Plants use this for structure (e.g. Wood) - not very digestible Due to the reverse orientation of the monosaccharide subunits, digestive enzymes cannot hydrolyze the bonds between them What do humans use it for? Cellulose
Glycogen Glycogen is a moderately branched polysaccharide Animals use this for short-term energy storage. Mostly stored in the human liver until converted to fat Glycogen
Lipids Lipids are macromolecules including Fats, Waxes and Oils. Primary function is energy storage. Energy is stored in C-H bonds. More efficient in storing energy Lipids are made of 2 parts Glycerol - an alcohol - Serves as backbone of the molecule 3 Fatty acids - Long hydrocarbon chains
Dehydration Synthesis of a Lipid
Hydrolysis of a Lipid
Types of fats Saturated fats have long chains with no double-bonds Unsaturated fats have double bonds Polyunsaturated fats have many double bonds Each time a double bond is encountered, the molecule "Bends" slightly, resulting in a lower density of the lipid. This makes the molecule more likely to remain liquid at room or body temperatures. And thus, less likely to clog cardiac arteries.
Other Lipids 4 Other types of biologically important Lipids Phospholipids - Important for membrane structure Steroids - eg. Cholesterol & testosterone. Provide membrane support / serve as hormones Terpenes - serve as important components of pigments Prostaglandins - appear to act like localized hormones to induce cellular/tissue responses
Proteins Proteins are made of Amino Acids There are 20 different amino acids. Each having a similar general structure - Differ only in their R groups
Peptide Bonds Amino acids form proteins via dehydration synthesis forming peptide bonds Two amino acids linked together are called dipeptides More than 2 linked together are called polypeptides - polypeptides can be thousands of amino acids long
Dehydration synthesis of a protein
Hydrolysis of a Protein
Protein Structure Protein types include globular proteins which are usually enzymes and Fibrous proteins which usually serve for structure (eg. Hair) Proteins Exhibit 4 levels of structure.
Primary Structure Primary Structure of a protein is it s sequence of amino acids Primary Structure dictates all further levels of protein structure
Secondary Structure The Sequence (primary structure) causes parts of a protein molecule to fold into sheets or bend into helix shapes - this is a protein s Secondary Structure.
Tertiary Structure The protein then can compact and twist on itself to form a mass called it s Tertiary Structure
Quaternary Structure Several Proteins then can can combine and form a protein s Quaternary Structure Various conformations are usually caused by the formation of hydrogen or disulfide bonds. PH, changes or heat can disrupt these bonds, permanently denaturing the protein.
Nucleic Acids Two types of Nucleic acids DNA Deoxyribonucleic Acid) RNA (Ribonucleic acid) DNA is Formed of in a "Double Helix" - like a spiral staircase.
Nucleotides DNA is formed from Nucleotides These are made of 3 components A 5-Carbon Sugar A Nitrogenous base A Phosphate group Nucleotides form a backbone through linkages from the OH group of the 3 rd carbon to a phosphate group of the adjoining nucleotide. These are called Phosphodiester bonds
Types of Nucleotides For DNA There are 4 different Nucleotides categorized as either Purines (double ring) or Pyramidines (single ringed). These are usually represented by a letter. These Are: Adenine (A) Cytosine (C) Guanine (G) Thymine (T)
Base Pairing Rules Each "Rung" of the DNA "staircase" is formed by the linking of 2 Nucleotides through Hydrogen Bonds. These Hydrogen bonds form only between specific Nucleotides. This is known as Base Pairing. The rules are as follows: Adenine (A) will ONLY bond to Thymine (T) Cytosine (C) will ONLY bond to Guanine (G)
Summary of DNA Structure
RNA AKA ribonucleic acid RNA differs from DNA in several important ways. It is much smaller It is single-stranded It does NOT contain Thymine, but rather a new nucleotide called Uracil which will bind to Adenine.
ATP Short for Adenosine Tri-Phosphate. ATP is closely related to nucleic acids. Composed of Ribose, Adenine & a phosphate group Phosphate group has ability to bind/release additional phosphate group allowing it to store or release energy