Chapter 3 The Molecules of Cells

1. Chapter 3The Molecules of Cells Carbohydrates Lipids Nucleic acids Proteins All of these molecules exist as small, single units generally called monomers, which can then be combined to form larger units called polymers

2. Chapter 3 The Molecules of Cells Molecules often have functional groups. Functional groups give different characteristics to molecules. R - NH2 – amino group R - OH – hydroxyl group R – COOH – carboxyl or carboxylic acid group R = the rest of the molecule As we look at molecules, which molecules have these functional groups???

3. Chapter 3 The Molecules of Cells R - NH2 – amino group R - OH – hydroxyl group R – COOH – carboxyl or carboxylic acid group R = the rest of the molecule

4. Chapter 3 The Molecules of Cells How do monomers become polymers? Amino acid (monomer) Amino acid (monomer) Polypeptide or protein polymer

5. Chapter 3 The Molecules of Cells How do monomers become polymers? Dehydration synthesis – Removal of a water molecule between two reacting molecules forming a new covalent bond in the process

6. Chapter 3 The Molecules of Cells How do polymers become monomers? Hydrolysis – Addition of a water molecule to a polymer to break a bond within a polymer to form the monomers

7. Chapter 3 The Molecules of Cells Molecule MonomerPolymer Carbohydrates Monosaccharide Polysaccharide or Carbohydrate Protein Amino Acid Polypeptide or Protein Nucleic Acid Nucleotide Nucleic Acid

8. Chapter 3 The Molecules of Cells CARBOHYDRATES Function: quick energy structural support Characteristics: H – C – OH ratio of hydrogen to oxygen atoms is 2:1 Monomer is the monosaccharide

9. Chapter 3 The Molecules of Cells

10. Chapter 3 The Molecules of Cells

11. Chapter 3 The Molecules of Cells What do these three carbohydrates have in common? What is different between them?

12. Chapter 3 The Molecules of Cells Starch is a polymer of glucose used for storage. It is found in plants. Cellulose is a polymer of glucose - used for storage. It is found in plants. We cannot digest cellulose!

13. Chapter 3 The Molecules of Cells Glycogen is a polymer of glucose used for storage. It is found in animals.

14. Chapter 3 The Molecules of Cells LIPIDS Function: long term energy storage insulation protective cushion forms cell membranes hormones Characteristics: do not dissolve in water no simple monomer structure Types Fats and Oils Phospholipids Steroids

15. Chapter 3 The Molecules of Cells LIPIDS – Fats and Oils Triglyceride What atoms are these molecules made of? Are these molecules hydrophobic or hydrophilic?

16. Chapter 3 The Molecules of Cells LIPIDS – Fats and Oils Triglyceride What atoms are these molecules made of? Are these molecules hydrophobic or hydrophilic?

17. Chapter 3 The Molecules of Cells LIPIDS – Triglycerides Saturated fats – no double bonds exist in the fatty acid tails Unsaturated fats – have at least one carbon – carbon double bond in any of their fatty acid tails What is the difference between oil and butter?

18. Chapter 3 The Molecules of Cells LIPIDS – Triglycerides Saturated fats – no double bonds exist in the fatty acid tails Unsaturated fats – have at least one carbon – carbon double bond in any of their fatty acid tails What is the difference between oil and butter?

19. Chapter 3 The Molecules of Cells LIPIDS – Phosopholipid Is this hydrophobic or hydrophilic? The phosopholipid is a critical member of the cell membrane because it has hydrophobic and hydrophilic regions.

20. Chapter 3 The Molecules of Cells LIPIDS – Phosopholipid

21. Chapter 3 The Molecules of Cells LIPIDS – Other Lipids Steroids are lipids which possess a “ringed” structure Cholesterol is a major component of the cell’s plasma membrane (structural function), but it is also the precursor for the key hormones testosterone & estrogen

22. Chapter 3 The Molecules of Cells LIPIDS – Other Lipids Is cholesterol always bad for you? Sources: Liver and Diet HDL – High Density Lipoprotein Carries cholesterol away from the cells and transports to liver LDL – Low Density Lipoprotein Carries cholesterol to the cells where needed If there is not enough HDL, then cholesterol does not get removed from the cells and excess builds up along the walls of arteries.

23. Chapter 3 The Molecules of Cells LIPIDS – Other Lipids Is cholesterol always bad for you? Average American: LDL to HDL ratio is 5:1 If you could lower this ratio to 3.5 to 1 you decrease your chance for heart disease by half!!

24. Chapter 3 The Molecules of Cells Nucleic Acids • Function: • make up genes which store all of the information about an organism • energy currency of the cell • Characteristics: • monomer is a nucleotide • 5- carbon sugar • phosphate group • 1 of 5 nitrogenous bases • (adenine, cytosine, thymine, guanine, or uracil)

25. Chapter 3 The Molecules of Cells Nucleic Acids

26. Chapter 3 The Molecules of Cells Nucleic Acids

27. Chapter 3 The Molecules of Cells Nucleic Acids

28. Chapter 3 The Molecules of Cells Nucleic Acids

29. Chapter 3 The Molecules of Cells Nucleic Acids A = T G = C

30. Chapter 3 The Molecules of Cells Nucleic Acids

31. Chapter 3 The Molecules of Cells Nucleic Acids Types of nucleic acids DNA – deoxyribonucleic acid Deoxyribose Phosphate group Adenine, guanine, thymine, cytosine Double-stranded structure (double helix) RNA – ribonucleic acid Ribose Phosphate group Adenine, guanine, uracil, cytosine Single-stranded linear structure

32. Chapter 3 The Molecules of Cells Nucleic Acids ATP – adenosine triphosphate Ribose 3 phosphate groups - the terminal or last phosphate is held on by a high energy but weak bond – when this bond is broken energy is released Adenine

33. Chapter 3 The Molecules of Cells Proteins Functions Structural – bones, muscles, collagen Enzymes – proteins which speed up chemical reactions Transportation – hemoglobin within your red blood cells transports oxygen to all parts of your body Protection – antibodies enable you to fight off infections MORE MORE MORE!

34. Chapter 3 The Molecules of Cells Proteins Characteristics There are 20 different amino acids based on their R groups The R group establish the distinctive properties of each amino acid

35. Chapter 3 The Molecules of Cells Proteins Characteristics The monomer form is called an an amino acid. A central or alpha carbon which is connected to the following: amino group carboxylic acid group hydrogen R-group

36. Chapter 3 The Molecules of Cells Proteins

37. Chapter 3 The Molecules of Cells Proteins

38. Chapter 3 The Molecules of Cells Proteins What process do you use to form a peptide bond? NCC – NCC – NCC- NCC - NCC

39. Chapter 3 The Molecules of Cells Proteins Levels of protein structure Primary - the sequence of amino acids Secondary – the coiling or folding due to hydrogen bonds Tertiary – overall shape of the polypeptide Quaternary – relationship among multiple polypeptides of a protein

40. Chapter 3 The Molecules of Cells Proteins

41. Chapter 3 The Molecules of Cells Proteins

42. Chapter 3 The Molecules of Cells Proteins

43. Chapter 3 The Molecules of Cells Proteins

44. Chapter 3 The Molecules of Cells Proteins

45. Chapter 3 The Molecules of Cells Proteins – example: Hemoglobin

46. Chapter 3 The Molecules of Cells Proteins

47. Chapter 3 The Molecules of Cells Proteins Enzymes are often proteins that speed up chemical reactions by providing a surface for molecules to react. You saw the enzyme peroxidase in lab!