Oils, fats and waxes

1. Oils, fats and waxes • Waxes: • Composed by long Carbon and Hydrogen chains that are highly hidrophobic. • They are saturated. • Are found in: hair, insect skeletons, leaves, stems and beehives.

2. FIGURE 3-12bLipids. Bees build their homes with wax hexagons.

3. Phospholipids - Are found in cell membranes. Structure: 2 fatty acids + glycerol + phosphate group + 1 functional polar group

4. Columna vertebral de glicerol Cabeza polar (hidrofílica) Colas de ácido graso (hidrofóbica) FIGURE 3-15 Phospholipids.

5. Phospholipids • They have hydrophobic and hydrophilic portions. • Polar “heads”: water soluble. • Non polar “tails”: not water soluble. • Hydrophilic = lipophobic • Hydrophobic = lipophilic

6. Steroids • They consist in 4 fusioned carbon rings. • Examples: • Cholesterol • Found in animal cell membranes. • Masculine and Femenine hormones.

7. Estrogen Cholesterol Testosterone

8. What are proteins? Functions : • They are formed with amino acid chains. • Aminoacids join to form chains by dehydration synthesis. • A protein can have 1,2,3 or 4 structure levels. • Enzimes catalize (speed up or accelerate) reactions. • Elastin provides suport.

9. FIGURE 3-17aStructural proteins. Exaples: queratin, found in: a) hair b) horns c) spider silk.

12. Proteins´s functions

13. Proteins • Proteins are composed of amino acids. • Aminoacids are proteins´s main units. • They all have amino and carboxyl groups. • They all have an “R” group: • Some are hydrophobic. • Some are hydrophilic.

14. “R” group Amino group Carboxyl group Hydrogen FIGURE 3-18 Amino acids structure.

15. FIGURE 3-19aAmino acid diversity.

18. Amino acids • The amino acid sequence determines the properties and functions of every protein.

19. Dehydration synthesis • Process by which amino acids join to form chains. • The covalent bond that is formed between the C and the N is called peptide bond. • The long amino acid chains are called polypeptides or proteins.

20. FIGURE 3-20 Protein synthesis.

21. 4structure levels The primary structure is the amino acid sequence that forms the protein. The secondary structure is composed of helix and chains that fold. The tertiary structure consists in one complex peptidic chain that holds the structure with different links. The quaternary structure is found where several proteic chains link.

22. Structure example: hemoglobin.

23. Hydrogen Links Folded plate This folded plate is an example of the secondary proteic structure.

24. queratin FIGURE 3-23Queratin structure.

25. Tridimensional structures • The kind, position and number of amino acids determine the protein´s function. • If bonds or links break, that causes the denaturing of the protein and lost of its biological functions.

26. FIGURE 3-24 Desoxyrribose nucleotide.

27. There are 2 kinds of nucleotides: • Ribose nucleotides: • The ones that contain: Adenine, Guanine, Cytosine, Uracil. They are found in RNA. • Deoxyrribose nucleotides: • The ones that contain:Adenine, Guanine, Cytosine, Thymine. They are found in DNA.

28. Inheritance molecules • DNA • It spells the genetic info necesary to build proteins. • RNA • Are DNA copies or replicas used at the protein synthesis.

29. base sugar phosphate FIGURE 3-25 Nucleotide chain.

30. Hydrogen links

31. Other nucleotides • AMP carries chemical signals inside the cell. • ATP carries energy. • NAD+ and FAD carry electrons.

32. ATP