1. Chemistry Of Life

2. Chemistry of Life
What are some of the basic physical and chemical processes that allow energy to be stored and utilized by living things?

3. Chemistry of Life Atom – composed of Nucleus
Proton – positive charge
Neutron – neutral charge
Electrons – orbiting nucleus, negative charge

5. Chemistry of Life
Element – a substance consisting entirely of one type of atom.
Molecule – two or more atoms joined together by a chemical bond.
Chemical compounds – two or more elements joined together (can be the same or different type of element)

6. Types of Chemical Bonds
Chemical bonds – how atoms are held together. Energy is stored in the bonds!
Types of Chemical Bonds
Ionic bonds: electrons are transferred
one atom (or compound) loses electron; becomes positive
one atom (or compound) gains electron; becomes negative

7. Basic Elements Carbon Hydrogen Oxygen Nitrogen Potassium Phosphate
Calcium
Iron

8. Salt: NaCl  Na Cl-
Example of Ionic Bond

9. Covalent bonds: electrons are shared between atoms to form molecules
(not as strong as ion bonds! )
Water: H2O Each hydrogen atom bonds with the Oxygen atom

10. Hydrogen Bonding
Special type of bonding / attraction between water molecules.
It is the reason water will “beads up” (cohesion) or climbs up sides of graduated cylinder (adhesion) to form the meniscus.

11. Chemical Bonds
Van der Waals Forces - not as strong as ionic or covalent but are responsible for the Gecko’s ability to climb up a glass window

12. Chemical Equations Reactants – appear before the arrow
Substances being changed
Products– appear after the arrow
Substances being made

13. Chemical Equations 6O2+ C6H12O6 6CO2 + 6H2O
LAW OF CONVSERVATION OF MASS All chemical reactions must be balanced
Whatever goes into the reaction must come out
Notice 18 oxygen on both sides, 12 Hydrogen and 6 Carbon

14. Energy from Bonds
In order for reactants to change into products, the bonds of the reactants must break and new bonds must form in the products
Bond Energy – the amount of energy it takes to break a bond between two atoms

15. Activation Energy
The amount of energy that is needed for a chemical reaction to start

16. Endothermic reaction
A chemical reaction that absorbs more energy that it releases
Takes in energy/heat
Ex) photosynthesis

17. Exothermic Reaction
Chemical reaction that gives off more energy than it takes in
Energy/heat exits
Ex) cellular respiration

18. ACIDS, BASES, BUFFERS
pH – measurement the concentration of the H+ (hydrogen ions) in solution.
pH equal to 7: The Solution is Neutral

19. ACIDS, BASES, BUFFERS Acids: pH is less than 7
Release hydrogen ions H+ in solution
Has positive charge,
Juices, vinegar
Taste sour

20. ACIDS, BASES, BUFFERS Base pH greater than 7
Releases hydroxide ions OH- in solution
Ex. are ammonia, some soaps, lye
Taste bitter, feel slimey
___________________

21. pH Scale

22. Buffers
Buffers: solutions that react with acids or bases and prevent sudden changes in pH, for example bicarbonate of soda, Tums

23. Organic Chemistry Organic Inorganic Compounds containing carbon
Lacking Carbon

24. Macromolecules
Large molecules formed by joining smaller organic molecules

25. Carbohydrates
CH2O
1 carbon
2 Hydrogen
1 Oxygen

26. Carbohydrate Examples
Glucose
Important for energy source of living things

27. Carbohydrate Examples
Sucrose
Or as you call it Table Sugar

28. Carbohydrate Examples
Celluose
Structural support in cell walls