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Carbohydrates, Lipids, Proteins, and Nucleic Acids Slide 2 What is a molecule? A collection of atoms bound together by covalent bonds. Can be very small, 2 atoms, or very large, millions of atoms. Exist in great diversity Can be categorized by structure and function Slide 3 Major Categories of bio-molecules Carbohydrates think sugars like glucose Lipids think fats and oils Proteins think muscle and amino acids Nucleic Acids think DNA and RNA Slide 4 Other key terms Polymer a long molecule consisting of many similar or identical building blocks (monomers) Condensation Reaction (dehydration synthesis) the formation of a covalent bond between molecules, produces water as a byproduct Hydrolysis the breaking up of a covalent bond, uses water molecules Slide 5 Carbohydrates Include sugars and polymers of sugars Commonly form ring structures Function in energy storage and structural support Monosaccharide a single carbohydrate Disaccharide two covalently bound carbohydrates Polysaccharide a polymer of carbohydrates Slide 6 Monomers and Polymers Slide 7 Glucose: monosaccharide, energy storage Slide 8 Ribose: monosaccharide, part of DNA and RNA Ribose has 5 carbons, glucose has 6 Sugars differ in number of carbons, location of double bonds, and hydroxide groups. Slide 9 More monosaccharides Slide 10 Formation of a disaccharide Slide 11 Breaking of a Disaccharide What is this process called? Why is water necessary for this reaction? Is this reaction the same for other types of bio-molecules? Slide 12 Slide 13 Starch and Cellulose Starch is used as an energy storage molecule in plants Cellulose is used for structural support creating the cell wall of plants Both are polysaccharides Slide 14 Slide 15 Look in the Book! Find two polysaccharides used by animals and state their name and functions. Slide 16 Lipids Includes triglycerides, steroids, phospholipids Lipids are defined as non-polar molecules They dont dissolve in water Tend to coalesce (stick together) when placed in an aqueous solution Function as energy storage, membranes, and hormones Slide 17 Some types of lipids Slide 18 Triglycerides: also known as FAT A molecule used to store energy Energy is stored as potential energy within chemical bonds Made up of two parts glycerol molecule three fatty acids Slide 19 Glycerol a 3-carbon molecule Fatty acid chains attach here Slide 20 Fatty Acid: long non-polar chains of carbon Slide 21 Glycerol + Fatty acid = Triglyceride Slide 22 Phospholipid Primary molecule used to create membranes Typically found in bi-layers Consists of a polar head region, a glycerol neck, and a non-polar fatty acid tail Head region is hydrophilic likes water Tail region is hydrophobic fears water Slide 23 Phospholipid structure Slide 24 Phospholipid Bi-layer Non-polar, hydrophobic tails turn inward Polar, hydrophilic heads point outward This creates a membrane that can separate two environments Slide 25 Cell Membrane Slide 26 Steroids Multiple ring shaped molecules Function to increase or decrease fluidity of membranes, depending upon temperature. Also used as hormones, chemical messengers sent through the blood stream Slide 27 Common Steroids Slide 28 Proteins Proteins are polymers of amino acids They have more functions than all other bio-molecules combined They can be used for catalyzing reactions, structural support, chemical messengers, and much more. If you dont understand proteins you dont understand how life works. Slide 29 Proteins contd There are about 20 different types of amino acids used in most living organisms But combining these monomers into long chains it is possible to create an immense variety of polypeptides (proteins) The function of protein is determined by its shape, which is determined by its amino acid sequence, which is determined by a DNA sequence. Slide 30 Amino Acids Contains an amine group (NH 2 ), a carboxyl group (COOH), and a side group (R) The R-group is the variable part which distinguishes one amino acid from another Slide 31 Peptide bonds are formed by condensation reactions Slide 32 A di-peptide is a two amino acid molecule Slide 33 Proteins have four levels of structure Slide 34 Primary Structure Primary structure is the actual amino acid sequence produced from the DNA code. Peptide bonds are the only bonds involved in the primary structure of a proteins Slide 35 Secondary Structure Created by hydrogen bonding between the amino and carboxyl groups of the amino acid backbones Results in two distinct structures Alpha helix Beta pleated sheet Slide 36 Alpha Helix Slide 37 Beta Pleated Sheet Slide 38 Tertiary Structure Bending and folding of protein chain based upon R-group interactions Can be hydrogen bonds, ionic bonds, or covalent bonds Slide 39 Slide 40 Slide 41 Quaternary Structure The combination of 2 or more protein subunits to create a fully functional protein A protein composed of two identical subunits is known as a dimer Slide 42 The Effects of Temperature on proteins High temperatures break hydrogen bonds molecules have too much kinetic energy and do not remain still long enough to attract one another. Protein subunits separate and unfold Proteins lose their structure and thus cannot function Known as denaturation Slide 43 The Effects of pH on Proteins Proteins function optimally at specific pH levels Increasing or decreasing [H+] may alter protein function Why do you think ion concentration effects protein function? Slide 44 The effect of pH on the activity of enzymes