Bio-Chemistry

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Bio-Chemistry

  1. 1. Bio-chemistryStructures / Functions of BiomoleculesT- 1-855-694-8886Email- info@iTutor.comBy iTutor.com
  2. 2. MacroMoleculesMacro = largeMolecules = 2 or more atomscovalently bondedUsually referred to as polymersLike a chainMade from several repeating subunitsThe repeated subunits are calledmonomers.Like links in a chain© iTutor. 2000-2013. All Rights Reserved
  3. 3. Types of MacromoleculesThere are four of them.1. Carbohydrates2. Lipids3. Proteins4. Nucleic acids© iTutor. 2000-2013. All Rights Reserved
  4. 4. • Monomer – monosaccharide• Chemical formula: (CH2O)n• Carbon chains or rings with H’s, OH groups and a C=Oor carbonyl group. Depending on the placement ofthe carbonyl group they may be aldoses or ketoses.Carbohydrate Structure© iTutor. 2000-2013. All Rights Reserved
  5. 5. Carbohydrate Structure© iTutor. 2000-2013. All Rights Reserved
  6. 6. • Most monosaccharides have 3, 5, or 6 carbons.– 3 carbons = triose– 5 carbons = pentose– 6 carbons = hexose• Different placement of the OH groups creates severaldifferent monosaccharides with the same chemicalformula.Carbohydrate Structure© iTutor. 2000-2013. All Rights Reserved
  7. 7. Carbohydrate Structure© iTutor. 2000-2013. All Rights Reserved
  8. 8. • Polysaccharides consist of many monosaccharidesjoined together by glycosidic bonds.• One function of polysaccharides is energy storage– it is hydrolyzed as needed.• Other polysaccharides serve as building materials forthe cell or whole organism.• Common polysaccharides:-StarchGlycogenCellulose ChitinCarbohydrate Structure© iTutor. 2000-2013. All Rights Reserved
  9. 9. • Starch is a storage polysaccharide composed entirelyof glucose monomers– Great big chain of glucose moleculesCarbohydrate Structure© iTutor. 2000-2013. All Rights Reserved
  10. 10. Biological Uses of Polysaccharides• Plants store starch within plastids, includingchloroplasts.• Plants can store surplus glucose in starch andwithdraw it when needed for energy or carbon.• Animals that feed on plants, especially parts rich instarch, can also access this starch to support theirown metabolism.© iTutor. 2000-2013. All Rights Reserved
  11. 11. © iTutor. 2000-2013. All Rights Reserved
  12. 12. Functions of Carbohydrates• Energy production (glucose and fructose) andstorage (glycogen and starch).• Cell identity markers – carbohydrate chains attachedto cell membrane proteins identify the type of cell.• Building blocks for other molecules such as, DNAand RNA, amino acids and lipids.• Structural - cellulose, chitin, peptidoglycans.© iTutor. 2000-2013. All Rights Reserved
  13. 13. Lipids• Lipids are an exception among macromoleculesbecause they do not have polymers.– Though lipid structure is easily recognized• Lipids all have little or no affinity for water.• Lipids are highly diverse in form and function.© iTutor. 2000-2013. All Rights Reserved
  14. 14. Lipids - DiverseHydrophobic Molecules1. Fats store large amounts of energy.2. Phospholipids are major components of cellmembranes.3. Steroids include cholesterol and certain hormones.© iTutor. 2000-2013. All Rights Reserved
  15. 15. 1. Fats store large amounts of energy• Although fats are not strictly polymers, they are largemolecules assembled from smaller molecules bydehydration reactions.• A fat is constructed from two kinds of smallermolecules, glycerol and fatty acids.Structures and functions lipids© iTutor. 2000-2013. All Rights Reserved
  16. 16. • Glycerol consists of a three carbon skeleton with ahydroxyl group attached to each.• A fatty acid consists of a carboxyl group attached toa long carbon skeleton, often 16 to 18 carbons long.Structures and functions lipids© iTutor. 2000-2013. All Rights Reserved
  17. 17. • The many nonpolar C-H bonds in the longhydrocarbon skeleton make fats hydrophobic.• In a fat, three fatty acids are joined to glycerol by anester linkage, creating a triacylglycerol.Structures and functions lipids© iTutor. 2000-2013. All Rights Reserved
  18. 18. • The three fatty acids in a fat can be the same or different.• Fatty acids may vary in length (number of carbons) and inthe number and locations of double bonds.• If there are no carbon-carbon double bonds,then the molecule is asaturated fatty acid - ahydrogen at everypossible position.Structures and functions lipids© iTutor. 2000-2013. All Rights Reserved
  19. 19. • If there are one or more carbon-carbon doublebonds, then the molecule is an unsaturated fattyacid - formed by the removal of hydrogen atomsfrom the carbon skeleton.• Saturated fatty acids arestraight chains, butunsaturated fatty acidshave a kink whereverthere is a double bondStructures and functions lipids© iTutor. 2000-2013. All Rights Reserved
  20. 20. Saturated vs. Unsaturated• Fats with saturated fatty acids are saturated fats.– Most animal fats– solid at room temperature.– A diet rich in saturated fats may contribute to cardiovasculardisease (atherosclerosis) through plaque deposits.• Fats with unsaturated fatty acids are unsaturatedfats.– Plant and fish fats, known as oils– Liquid are room temperature.© iTutor. 2000-2013. All Rights Reserved
  21. 21. 2. Phospholipids are major components of cellmembranes• Phospholipids have two fatty acids attachedto glycerol and a phosphate group at the thirdposition.• The “head” likes water• The “tail” hates waterStructures and functions lipids© iTutor. 2000-2013. All Rights Reserved
  22. 22. • The interaction of phospholipids with water is complex.– The fatty acid tails are hydrophobic, but the phosphate groupand its attachments form a hydrophilic head.Structures and functions lipids© iTutor. 2000-2013. All Rights Reserved
  23. 23. • At the surface of a cell phospholipids are arranged asa bilayer.– the hydrophilic heads are on the outside in contact with the aqueoussolution and the hydrophobic tails form the core.– The phospholipid bilayer forms a barrier between the cell and theexternal environment.• They are the major component of cell membranes.Structures and functions lipids© iTutor. 2000-2013. All Rights Reserved
  24. 24. 3. Steroids include cholesterol and certain hormones.• Steroids are lipids with a carbon skeletonconsisting of four fused carbon rings.– Different steroids are created by varying functional groupsattached to the rings.Structures and functions lipids© iTutor. 2000-2013. All Rights Reserved
  25. 25. • Proteins are instrumental in about everything that anorganism does.– structural support,– storage– transport of other substances– intercellular signaling– movement– defense against foreign substances– Proteins are the main enzymes in a cell and regulatemetabolism by selectively accelerating chemical reactions.• Humans have tens of thousands of different proteins,each with their own structure and function.Proteins© iTutor. 2000-2013. All Rights Reserved
  26. 26. Proteins1. A polypeptide is a polymer of amino acidsconnected to a specific sequence .2. A protein’s function depends on its specificconformation.Many Structures, Many Functions© iTutor. 2000-2013. All Rights Reserved
  27. 27. • Proteins are the most structurally complex moleculesknown.– Each type of protein has a complex three-dimensional shape or conformation.• All protein polymers are constructed from the sameset of 20 monomers, called amino acids.• Polymers of proteins are called polypeptides.• A protein consists of one or more polypeptidesfolded and coiled into a specific conformationProteins© iTutor. 2000-2013. All Rights Reserved
  28. 28. A polypeptide is a polymer of amino acidsconnected in a specific sequence• Amino acids consist of four components attachedto a central carbon, the alpha carbon.• These components include a hydrogen atom, acarboxyl group, an amino group, and a side chain.• Polypeptides are made of amino acids– Amino acids CONTAIN NITROGEN (N)Proteins© iTutor. 2000-2013. All Rights Reserved
  29. 29. Proteins© iTutor. 2000-2013. All Rights Reserved
  30. 30. • The repeated sequence (N-C-C) is the polypeptidebackbone.• Attached to the backbone are the various R groups.• Polypeptides range in size from a few monomers tothousands.Proteins© iTutor. 2000-2013. All Rights Reserved
  31. 31. Proteins© iTutor. 2000-2013. All Rights Reserved
  32. 32. Nucleic Acids• Contain genetic information– Provides instructions for making polypeptides• Each monomer is a nucleotide• Nucleotides are composed of1. 5 carbon sugar Deoxyribose ribose2. Phosphate group3. Nitrogenous base Adenine (A) Thymine (T) in DNA, Uracil (U) in RNA Guanine (G) cytosine© iTutor. 2000-2013. All Rights Reserved
  33. 33. • Deoxyribonucleic acid (DNA)– Sugar is deoxyribose– Shape is a double helix• Ribonucleic acid (RNA)– Sugar is ribose– Uses a different nitrogenous base– Uracil (U) instead of thymine (T)– Shape may be a single or double helixNucleic Acids© iTutor. 2000-2013. All Rights Reserved
  34. 34. THE ENDCall us for moreInformation:www.iTutor.com1-855-694-8886Visit

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