CH 3 Biological Molecules (Biomolecules)

1. CH 3 Biological Molecules(Biomolecules)

2. Biochemistry Review • Elements are substances that cannot be broken down or converted into another substance • They are composed of atoms which are the smallest units of matter (recall the levels of organization)

3. Biochemistry Review • An atom is composed of a nucleus, an electron cloud, and 3 subatomic particles: • Protons (p+) • Neutrons (n0) • Electrons (e-) • Protons and neutrons are located in the nucleus of an atom and electrons in the electron cloud Electron cloud Nucleus p+ n0 e-

4. Section 3.1Carbon in Biomolecules

5. Carbon & Biomolecules • Molecules are particles composed of atoms (from elements) held together by chemical bonds • Classified as organic and inorganic • Organic molecules are important because they are general types of molecules that all living organisms synthesize and use; they are essential for life

6. Carbon & Biomolecules • The term “organic” describes molecules that contains the element carbon (C) and some hydrogen atoms • “Inorganic” molecules are all molecules that do not contain carbon, with the exception of carbon dioxide (CO2)

7. Carbon & Biomolecules • Although they have a common structure and function, the tremendous variety of organic molecules contributes to the diversity of structures within an individual organism and even individual cells • The reason for this? • Carbon’s structure is very versatile when it comes to forming bonds with other atoms

8. Carbon & Biomolecules • Macromolecules – large molecules composed of similar repeating units • There are 4 main groups of macromolecules that compose living things: • Carbohydrates • Lipids • Proteins • Nucleic Acids

9. Section 3.2 Synthesizing Organic Molecules

10. Modular Approach • The modular approach involves building organic molecules piece by piece (like a train with individual cars): • Monomer: individual subunits (car) • Polymer: long chains of monomers (train) • Mono- means “one” • Poly- means “many”

11. Biomolecules & Water • Biomolecules are joined together or broken apart by removing or adding water: • Water can break apart polymers (biomolecule), freeing up the monomers OR… • When polymers (biomolecules) are formed, water is often produced as a by-product

12. Biomolecules & Water • Dehydration synthesis reactions: when monomers are joined together by removing water to make biomolecules (polymers) • A H+ is removed from one monomer and an OH- from the other…they will form water • The spaces left open allow the monomers to bond together, creating a biomolecule (polymer)

13. Dehydration Synthesis

14. Biomolecules & Water • Hydrolysis reactions: when molecules are broken apart by water • Water is added to a molecule (polymer), causing it split back into the original monomers

15. CH 3.3What are Carbohydrates?

16. Carbohydrates

17. CH2OH O H H H OH H OH HO H OH Carbohydrates energymolecules

18. Carbohydrates-Sugars • Composed of carbon, hydrogen, and oxygen (1:2:1) • Overall function: used by organisms for short term energy and structural support

19. Monosaccharides • 1 sugar molecule (monomer) • Function: mainly used to form polymers or for cell activities • Most common: glucose C6H12O6 • Others: • Fructosefruits • Galactoselactose • RiboseRNA • DeoxyriboseDNA

20. Disaccharides • 2 sugar molecules linked together • Function: mainly used for short-term energy • Examples: • Sucroseglucose + fructose • Lactoseglucose + galactose • Maltoseglucose + glucose

21. Polysaccharides • Many sugar molecules linked together • Function: used for long-term energy storage • Examples: • Starch: found in plant seeds & roots (FYI: 1000 to ½ million glucose) • Glycogen (animals): found in animal muscles & liver (much smaller than starch) • Cellulose: found in plant cell walls • Animals can’t digest it, has to be broken down by microbes so its usually just roughage/fiber for us • Chitin: found in exoskeletons and fungi cell walls

22. Cellulose Structure & Location

23. Chitin Structure & Location

24. Section 3.4What are Lipids?

25. Lipids: Fats & Oils

26. Lipids energy storage

27. Lipids • Composed of mainly carbon and hydrogen • Have nonpolar regions that make them insoluble in water (meaning they won’t dissolve) • Types of lipids: • Fats • Oils • Waxes • Phospholipids • Steroids

28. Oils, Fats, and Waxes • Triglyceride: the chemical name of fats and oils • Difference between fats & oils: • Fats are solid, oils are liquid

29. Saturated Fats • Saturated fats are made of mainly hydrogen so the FA chains are “saturated” in hydrogen • Where we get them from: butter, bacon fat, steak; tends to come from animals

30. Unsaturated Fats • Unsaturated fats have a smaller amount of hydrogen in their FA chains • Where we get them from: the seeds of plants (they’re stored for the embryo) such as corn oil, peanut oil, etc.

31. FYI: Unsaturated fats • Unsaturated fats can be converted to a fat by breaking some of the double bonds and adding some hydrogens…this is known as a “hydrogenated oil” (allows margarine to be solid at room temp) • Partial hydrogenation creates trans fats which are also solid at room temperature • Read Health Watch: Cholesterol-Friend or Foe on pg. 45

32. FYI: Saturated & Unsaturated Fats Saturated Unsaturated

33. Waxes • Function: used as a waterproof covering for: • plant leaves and stems • mammalian fur • insect exoskeletons • to construct beehives • FYI: Chemically similar to fats, but they aren’t a food source because we and most other animals don’t have the enzymes necessary to break them down

34. Fats & Waxes

35. Phospholipids • Make up the plasma (cell) membrane • Head is hydrophilic or “water loving” • Tail is hydrophobic or “water fearing”

36. Steroids • Structurally different from all other lipids because it is a ring while the others were chains • Common steroid: cholesterol • Component of animal cell membranes

37. Section 3.5What are Proteins?

38. Proteins

39. Amino Acids and Proteins • Monomer: amino acids (AAs); there are 20 different AAs in all • Polymer: protein (chains of AAs) • Bond between the AAs when they are making polymers is known as a peptide bond

40. Amino Acids and Proteins • Peptide: short chains of AAs (FYI: 2-49 AAs) • Polypeptide: long chains, aka a protein (FYI: 50 or more AAs)

41. Protein Structure 1. Primary structure (1o)-the chain of AAs that make up the protein 2. Secondary structure (2o)- when the protein takes on a coiled or pleated shape

42. Primary/Secondary Level Primary Secondary

43. Protein Structure • Tertiary structure (3o)-the 3-D shape a polypeptide becomes (like balling up a piece of paper) • Quaternary structure (4o)-when polypeptide chains link together

44. Tertiary/Quaternary Levels Tertiary Quaternary

45. Types of Proteins • Can be classified as functional or structural • Functional: • Enzymes: proteins that speed up almost all chemical reactions that occur inside the cell • Albumin (egg white) & Casein (milk): provides AAs for developing young animals • Some hormones such as insulin & growth hormone • Antibodies

46. Types of Proteins • Structural • Elastin: gives skin its elasticity • Keratin: main protein found in hair, nails, horns, scales, and feathers • Gossamer: the silk protein in spiders and silk moth cocoons

47. Section 3.6What are Nucleic Acids?

48. Nucleic Acids Informationstorage

49. Nucleic Acids • Monomers: nucleotides • Polymers: nucleic acids (NAs) • 2 types of nucleic acids: • DNA-deoxyribonucleic acid • RNA-ribonucleic acid

50. Other Nucleotides • Not all nucleotides are part of NAs • Cyclic nucleotides: used as intracellular messengers • Adenosine triphosphate (ATP): energy molecule found in all organisms • Coenzymes: assist enzymes in promoting and chemical reactions