Lecture 4 Basic Chemistry refresher & Macromolecules of all sorts

1. Lecture 4Basic Chemistry refresher &Macromolecules of all sorts

2. Latest model of an atom 02_01_atom.jpg

3. 02_02_atomic number.jpg Hydrogen -the simplest and smallest of all atoms Atomic number is the number of proton found in the nucleus

4. 02_03_mole.jpg

5. The most abundant element in the human body is hydrogen Why? The most abundant element making the planet is oxygen Why? 02_04_element abundance.jpg

6. 02_05_chemical reactivity.jpg

7. 02_06_stable arrangement.jpg Sharing bond Giving bond

8. Periodic Table of universal elements 02_07_periodic table.jpg

9. Ionic bond between two elements 02_08_ionic bond.jpg

10. The stability of a covalent bond. Remember that one needs to supply energy to get the two atoms close together in the first place 02_09_covalent bond.jpg

11. Properties of the most common bioelements 02_10_geometries.jpg Hydrogen Just one

12. A single bond allows rotation of the atoms either side, whereas a double bond does not 02_11_C-C double bonds.jpg

13. The angle of the bond is very important 02_12_polar covalent.jpg It may make a molecule polar, or… …non-polar

14. Proteins rely very heavily on this molecular polarity (as well as other Forces) to function correctly 02_13_Proteins bind.jpg

15. Atoms can be on the move constantly… 02_14_Protons on move.jpg

16. What is life made of… ATOMS MOLECULES SPECIAL MOLECULES 02_15_organic molecules.jpg These are the four organic classes of molecules

17. Glucose has this structure 02_16_glucose structure.jpg

18. Life systems are constantly making and breaking bonds 02_17_disaccharide.jpg

19. Macromolecules • Macro = huge • Amino acids can build into huge molecules • So can carbohydrates • So may nucleic acids • There is theoretical limit to the size of these

20. There are three major types of biological macromolecules in mammalian systems. 1. Carbohydrates 2. Nucleic acids 3. Proteins Our tasty friends, fats, do not make the grade because they do not form these immense complexes

21. FATS • Here are some important facts about fats…

22. Saturated & Unsaturated Fats • Fact: we all need fats. • Fats helps nutrient absorption, nerve transmission, maintaining cell membrane integrity etc. • However, when consumed in excess amount, fats contribute to weight gain, heart disease and certain types of cancer. • Fats are not created equal. • Some fats promote our health positively while some increase our risks of heart disease and other ailments.

23. Bad Fats

24. Bad Fats 2

25. Good Fat

26. Good Fat 2

27. 02_18_Fatty acids.jpg

28. 02_19_fatty side chains.jpg

29. 02_20_lipid membranes.jpg

30. 02_21_Alanine.jpg

31. 02_22_peptide bonds.jpg

32. Nucleotides DNA and RNA are the two nucleic acids that come to mind first However, there are many other uses for these important compounds….

33. ATP - Adenosine Triphosphate - made of ribose sugar This is the most important molecule for ready energy storage - it can be considered to be the cells’ battery 02_23_ATP.jpg

34. 02_24_energy carrier.jpg

35. 02_25_nucleotide residues.jpg

36. By weight 25% of total bacterial cell contents are macromolecules. They are essential in dictating the character of the cell type, ie. E.coli, Salmonella, heart cells, liver cells, brain cells, etc.

37. Irrespective of the type of biological macromolecule being made they have a common construction theme: A subunit is added one at a time by a repetitive enzymatic process 02_27_monomeric subunits.jpg However, unlike a bottle factory, where the same robot performs the identical function, with these biological systems the subunits have to be added in a set sequence because we have more than one flavour! 4 subunits in NA; 20 subunits in P’; many many in polysaccarides

38. Revision Question - What is this process called? 02_28_adding subunits.jpg By design, macromolecule construction occurs by the addition of the incoming subunit to just one end of the growing molecule, ie. DNA growth only takes place at the 3’OH end of an existing DNA strand. These processes are common to the construction of all these macromolecules. YOU MUST REMEMBER THEM!

39. WOW! • Due to these differencing subunits there is the potential to make many many alternative polymers. Consider: • Proteins • A protein of just 200 amino acids • We have 20 amino acids to choose from each time • There are then possible 20200 possible combinations! • DNA • 10,000 base DNA molecule • We have just 4 different base types to choose from • There are then possible 410000 possible combinations

40. More molecular interactions We learnt that there are 3 types of atomic interactions between atoms. ACTUALLY there are other forces too; van der Waals attractions - weaker than hydrogen bonds attraction between closely located atoms Hydrophobic interactions - weakest of all 3 dimensional structure of water forces hydrophobic groups together Oil in water

41. Most P’s and RNA molecules have a stable confirmation which they adopt readily and it is dictated by their primary sequence.

42. 02_32_Noncovalent bonds.jpg E.g. immunoglobulins (Abs). Heavy chain and light chain are made in various locations and combine readily together.

43. 02_33_macro complexes.jpg

44. Study Requirements • At the end of each chapter there are two resources: • Essential Concepts • You are required to learn each of these facts for every chapter that we cover (These concepts are essential!) • Key Terms • You are required to know the definition of each of these regardless of the fact that they did or did not appear on my PowerPoint slides (one needs to be familiar with these terms for subsequent courses)