Presentation on theme: "Carbohydrates, Lipids, Proteins, and Nucleic Acids"— Presentation transcript:
1Carbohydrates, Lipids, Proteins, and Nucleic Acids The Molecules of LifeCarbohydrates, Lipids, Proteins, and Nucleic Acids
2What 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 diversityCan be categorized by structure and function
3Major Categories of bio-molecules Carbohydrates – think sugars like glucoseLipids – think fats and oilsProteins – think muscle and amino acidsNucleic Acids – think DNA and RNA
4Other 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
5Carbohydrates Include sugars and polymers of sugars Commonly form ring structuresFunction in energy storage and structural supportMonosaccharide – a single carbohydrateDisaccharide – two covalently bound carbohydratesPolysaccharide – a polymer of carbohydrates
15Look in the Book!Find two polysaccharides used by animals and state their name and functions.
16Lipids Includes triglycerides, steroids, phospholipids Lipids are defined as non-polar moleculesThey don’t dissolve in waterTend to coalesce (stick together) when placed in an aqueous solutionFunction as energy storage, membranes, and hormones
22Phospholipid Primary molecule used to create membranes Typically found in bi-layersConsists of a polar ‘head’ region, a glycerol neck, and a non-polar fatty acid ‘tail’Head region is hydrophilic – likes waterTail region is hydrophobic – fears water
28Proteins Proteins are polymers of amino acids They have more functions than all other bio-molecules combinedThey can be used for catalyzing reactions, structural support, chemical messengers, and much more.If you don’t understand proteins you don’t understand how life works.
29Proteins cont’dThere are about 20 different types of amino acids used in most living organismsBut 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.
30Amino AcidsContains an amine group (NH2), a carboxyl group (COOH), and a side group (R)The R-group is the variable part which distinguishes one amino acid from another
31Peptide bonds are formed by condensation reactions
41Quaternary StructureThe combination of 2 or more protein subunits to create a fully functional proteinA protein composed of two identical subunits is known as a dimer
42The Effects of Temperature on proteins High temperatures break hydrogen bondsmolecules have too much kinetic energy and do not remain still long enough to attract one another.Protein subunits separate and unfoldProteins lose their structure and thus cannot functionKnown as denaturation
43The Effects of pH on Proteins Proteins function optimally at specific pH levelsIncreasing or decreasing [H+] may alter protein functionWhy do you think ion concentration effects protein function?