1. Chemistry Basics

2. Elements, Molecules and Compounds

3. matter any object around us is made of tiny particles called atoms atoms are made of protons, neutrons, and electrons

4. every element has its own type of atoms ex. carbon ex. hydrogen

5. isotopes are atoms of the same element that have different number of neutrons, ex.

6. Pet scans: radioisotopes Unstable isotopes are radioactive and are called radioisotopes

7. When atoms join together they can form molecules

8. molecules combinations of atoms held together by strong chemical forces of attraction (covalent bonds) molecules that contain atoms of the same element are called molecular elements, ex. O 2 molecules that contain atoms of different elements are called compounds, ex. H 2 O

9. The elements of life living things are mostly (98%) made of 6 elements: C – carbon H – hydrogen O – oxygen P – phosphorus N – nitrogen S – sulphur -each element makes a specific number of bonds with other elements

10. Carbon: 4 bonds Hydrogen: 1 bond Oxygen: 2 bonds Phosphorus: 3 bonds Nitrogen: 3 bonds Sulphur: 2 bonds

11. Biochemistry Field that bridges chemistry and biology Deals with properties and interactions of biologically important molecules

12. Many of the molecules of life are organic: contain carbon and hydrogen

13. Life on Earth involves water…

14. SO WHAT'S SO SPECIAL ABOUT WATER? 1) two-thirds of Earth are covered by it (97% of that is sea water) 2) ours is the only planet in the Solar System where water can exist in its liquid state 3) all life is water-based: we are 75% water!

15. Structure of Water 1) water has a very slight charge to it, where the O is more negative and the H is more positive 2) this slight charge difference makes water polar 3) Polar molecules can form hydrogen bonds with other polar molecules

16. Intramolecular bonds: bonds within a molecule, ex. covalent, ionic Intermolecular interactions: bonds between molecules, ex. hydrogen bonding and hydrophobic/hydrophilic interactions

17. Polarity of water:

19. Since water is polar it can dissolve other charged or polar substances (ex. salt) but not uncharged or nonpolar substances, ex. Oil [remember: like dissolves like]

20. hydrophilic molecules -like water, can be dissolved in it -are polar hydrophobic molecules -don’t like water, can’t be dissolved in it -are non-polar - the natural clumping of non-polar molecules in water plays a key role in how biologically important molecules are shaped!

22. Ions in biological systems an atom can obtain a stable valence shell by losing or gaining electrons, rather than sharing:

23. when an atoms gains/loses an electron it becomes charged, and forms an ion

25. cation: a positive ion anion: a negative ion

26. substances that form ions (ionic compounds) are almost always considered in terms of ions, since they are in an aqueous environment

27. So… In biology STRUCTURE DICTATES FUNCTION Since molecules will come together depending on how hydrophobic/hydrophilic hydrogen bonding will determine the function of many large biological molecules: MACROMOLECULES