Today’s topics

1. Today’s topics -cell building blocks (proteins, lipids, nucleic acids, carbohydrates) -cell structure (plant vs. animal) -cells and herbivory

3. Building Blocks of Life • Protons (positive charge), electrons (negative charge), & neutrons (neutral charge) are building blocks of atoms • Atoms are building blocks of elements (the most basic “substances”) • Atoms = smallest part of a element that retains the element’s traits • 92 natural elements • Living organisms mostly: C,O,H,N,P,K,Ca,Mg,S, with lesser amounts of Fe,Cl, Mn, Zn, B, Cu, Mo, etc. • Atoms held together with chemical bonds • E.g., covalent, ionic, hydrogen • Elements are building blocks of molecules (made from one or more atoms) and compounds (made from one or more elements)

6. Figure 1.7

7. Figure 1.8a

8. Figure 1.8b

9. The processes of life are based on the chemical nature and interactions of: • Carbohydrates • Lipids • Proteins • Nucleic acids • Secondary metabolites/compounds

10. Carbohydrates • Comprised mostly of carbon (C), hydrogen (H), and oxygen (O), in the proportion (CH2O)n (where n = 3-7 for simple sugars) • Many functions; e.g., fuel, storage, structural, signaling • Simple sugars (e.g., glucose, fructose = monosaccharides) to complex macromolecules (cellulose, glycogen, starch = polysaccharides)

11. Figure 1.9

14. Lipids • Comprised mostly of C & H (so often called hydrocarbons) • Insoluble in water • Several major classes (fats & oils = triglycerides; phospholipids; fatty acids; sterols, e.g. cholesterol; waxes) • Many functions (e.g., energy/storage, structural, signaling/hormones)

23. Proteins • Comprised of amino acids (AAs) • Chain of amino acids = oligo- or poly-peptide, cause amino acids held together by covalent peptide bonds • Polypeptides (one or more) make proteins/enzymes; oligo-peptides common signaling molecules • AAs built from C,H,O,N, and sometimes S • 20 common AAs used for most proteins

25. Figure 1.10

27. Figure 1.11

28. Nucleic Acids • Comprised of nucleotide building blocks containing C,H,O,N,P • Nucleotides contain a sugar (ribose, for RNA, or deoxyribose for DNA), phosphate (PO4), and nitrogenous base (5 kinds) • Arranged in long chains in DNA (double helix) and some RNA (single chain), or in other shapes • Major function is storage and expression of genetic code (DNA,RNA) and energy (ATP)

33. Figure 1.13

34. All living organisms share certain characteristics • growth and reproduction • ability to respond • ability to evolve and adapt • metabolism • organized structure • organic composition

35. Cell theory • Cell is basic unit of life • Organisms are composed of cells • Cells arise from pre-existing cells

36. Figure 27.1  The three major lineages of life Nucleus Membrane-bound organelles

37. Have a nuclear envelope DNA double-stranded Have 2+ chromosomes Have membrane-bound organelles Have asexual reprdn by mitosis Have sex by fusion No nuclear envelope Have single strand of DNA No chromosomes No organelles Asexual reproduction by fission No sexual reproduction Types of cellseukaryotes vs. prokaryotes

42. Figure 2-6

43. Fig. 5.10a

44. Fig. 19.1

45. Mitosis in a plant cell

46. Mitosis in an onion root

47. Cytokinesis in animal and plant cells

49. Fig. 5.22