1 / 43

Carbohydrates and Their Functions in Biological Molecules

This article explores the importance of carbohydrates in biological molecules. It discusses the different types of organic molecules, the synthesis of organic molecules, and the role of carbohydrates in energy storage and structural support. The article also touches on lipids, proteins, and nucleic acids.

vivianwilliamson
Télécharger la présentation

Carbohydrates and Their Functions in Biological Molecules

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Day 3 Carbohydrates Adapted from

  2. 3.1 Why Is Carbon So Important in Biological Molecules? • Organic/inorganic molecules • Organic - molecules containing a carbon skeleton bonded to hydrogen atoms • Inorganic - carbon dioxide and all molecules without carbon

  3. 3.2 How Are Organic Molecules Synthesized? • Small organic molecules (called monomers) are joined to form longer molecules (called polymers)

  4. Author Animation: Monomers and Polymers

  5. 3.2 How Are Organic Molecules Synthesized? • All biological molecules fall into one of four categories • Carbohydrates • Lipids • Proteins • Nucleotides/nucleic acids

  6. 3.3 What Are Carbohydrates? • Carbohydrate molecules are composed of C, H, and O in the ratio of 1:2:1 (CH2O)n “hydrated” carbon • monosaccharide – consists of a single sugar molecule (C6H12O6) • Disaccharide - 2 linked monosaccharides • Polysaccharide - a polymer of many monosaccharides

  7. 3.3 What Are Carbohydrates? • Glucose (C6H12O6) is the most common monosaccharide in living organisms Fig. 3-3

  8. 3.3 What Are Carbohydrates? • Additional monosaccharides are: • Fructose (“fruit sugar” found in fruits, corn syrup, and honey) • Galactose (“milk sugar” found in lactose) • Ribose and deoxyribose (found in RNA and DNA, respectively)

  9. 3.3 What Are Carbohydrates? • Examples of disaccharides include: • Sucrose (table sugar) = glucose + fructose • Lactose (milk sugar) = glucose + galactose • Maltose (malt sugar) = glucose + glucose

  10. 3.3 What Are Carbohydrates? • Examples of polysaccharides include • Starch • Glycogen • Cellulose • Chitin • All 4 made of glucose/modified glucose monomers

  11. 3.3 What Are Carbohydrates? • Functions: • Energy source/storage (sugar, starch, glycogen) • Structural molecule (cellulose, chitin)

  12. Testing for Carbohydrates • Test for simple sugar – glucose test strips • Test for starch - iodine

  13. Day 4 Lipids, Proteins, and Nucleic Acids Adapted from

  14. 3.4 What Are Lipids? • Lipids are a diverse group of molecules • All lipids contain large chains of nonpolar hydrocarbons (hydrogen and carbon) • Most lipids are therefore hydrophobic and water insoluble

  15. Author Animation: Lipids

  16. 3.4 What Are Lipids? • Functions • Energy storage (fats, oils) • Waterproof coverings on plant and animal bodies (waxes) • Primary component of cellular membranes (phospholipids) • Many hormones (steroids)

  17. 3.6 What Are Nucleic Acids? • Nucleotides are the monomers of nucleic acid chains • Nucleotides act as energy carriers and intracellular messengers • Made of a sugar (deoxyribose or ribose), a phosphate group (contains phosphorus), and a nitrogenous base (contains nitrogen and differs among nucleotides)

  18. 3.6 What Are Nucleic Acids? • Adenosine triphosphate (ATP) is a deoxyribose nucleotide with three phosphate functional groups • Functions as an energy carrier

  19. 3.6 What Are Nucleic Acids? • DNA and RNA, the molecules of heredity, are nucleic acids • There are two types of polymers of nucleotides called nucleic acids • DNA(deoxyribonucleic acid) is found in chromosomes and carries genetic information needed for protein construction • RNA (ribonucleic acid) makes copies of DNA and is used directly in the synthesis of proteins

  20. 3.5 What Are Proteins? • Proteins are formed from chains of amino acids joined by peptide bonds • Monomer = ?

  21. 3.5 What Are Proteins? • The sequence of amino acids in a protein dictates its function • Covalent bond linking the amino acids is a peptide bond • Chain of two amino acids is a peptide • Long chains of amino acids are polypeptides, or just proteins

  22. 3.5 What Are Proteins? • Proteins exhibit up to four levels of structure • Primary structure is the sequence of amino acids linked together in a protein • Secondary structure is a helix, or a pleated sheet • Tertiary structure refers to complex foldings of the protein chain held together by disulfide bridges, hydrophobic/hydrophilic interactions, and other bonds • Quaternary structure occurs where multiple protein chains are linked together

  23. The Four Levels of Protein Structure (b) Secondary structure: Usually maintained by hydrogen bonds, which shape this helix (a) Primary structure: The sequence of amino acids linked by peptide bonds leu val heme group lys lys gly his hydrogen bond ala lys val (d) Quaternary structure: Individual polypeptides are linked to one another by hydrogen bonds or disulfide bridges (c) Tertiary structure: Folding of the helix results from hydrogen bonds with surrounding water molecules and disulfide bridges between cysteine amino acids lys helix pro Fig. 3-20

  24. 3.5 What Are Proteins? • The functions of proteins are linked to their three-dimensional structures • If proteins lose their structure (become denatured), they lose their function

  25. 3.5 What Are Proteins? • Functions of proteins • Catalytic - enzymes promote chemical reactions • Structural - make up physical structure of organisms

  26. 6.4 How Do Enzymes Promote Biochemical Reactions? • At body temperatures, spontaneous reactions proceed too slowly to sustain life • Reaction speed is determined by the activation energy required  how much energy is required to start the process • low activation energies  proceed rapidly at body temp. • high activation energies  move very slowly at body temp.

  27. 6.4 How Do Enzymes Promote Biochemical Reactions? • Enzymes catalyze (speed up) chemical reactions by lowering the activation energy • Enzymes are biological catalysts and regulate all the reactions in living cells • They are very specific – dependent on enzyme’s 3-D structure • Not used up in chemical reactions

  28. Author Animation: Activation Energy

  29. Catalysts Such As Enzymes Lower Activation Energy high Activation energy without catalyst Activation energy with catalyst energy content of molecules reactants products low Fig. 6-10 progress of reaction

  30. The Cycle of Enzyme-Substrate Interactions substrates active site of enzyme enzyme 1 Substrates enter the active site in a specific orientation The substrates and active site change shape, promoting a reaction between the substrates 3 2 The substrates, bonded together, leave the enzyme; the enzyme is ready for a new set of substrates Fig. 6-11

  31. Liver Magic! • Let’s test it!

  32. Day 5 Central Dogma of Molecular Biology and Energy Production Adapted from

  33. Central Dogma of Molecular Biology Replication Transcription Translation DNA RNA Protein

  34. ATP and Energy • Most organisms are powered by the breakdown of glucose • Energy in glucose cannot be used directly by our cells • Energy in glucose must first be transferred to an energy-carrier molecule (ATP) Glucose ATP Cell Process

  35. ATP and Energy • ATP stores energy within its bonds • Phosphate groups negatively charged and don’t like being crowded together Base Sugar P P P High-energy bond

  36. ATP and Energy • When bond is broken in ATP products are ADP (Adenosine Diphosphate), a phosphate group, and energy

  37. ATP and Energy • Putting ATP back together again requires energy • Comes from breaking down glucose energy P P P  P P P ATP phosphate ADP

  38. What’s Earth’s ULTIMATE source of energy?

  39. How do WE get that energy?

  40. How do WE get that energy? • Eat sugar  now what? • Remember, sugar’s the gold bar! • Cellular Respiration Glucose + Oxygen  Carbon dioxide + Water + ATP (+ heat) C6H12O6 + 6 O2 6 CO2 + 6 H2O + ATP (+ heat)

  41. How does OUR FOOD get that energy? • Animals  they eat too! • Plants, Algae? • Photosynthesis Carbon dioxide + Water + Light Energy  Sugar + Oxygen 6 CO2 + 6 H2O + Light Energy  C6H12O6 + 6 O2

  42. Author Animation: Overview: Photosynthesis and Respiration

More Related