1. Introduction to Biochemistry
“Chemistry of Life”

2. Basic Chemistry Terms Atom = basic unit of matter
Element = substance consisting entirely of one type of atom.
Helium Atom

4. Basic Chemistry Terms Molecule = smallest unit of most compounds
Compound = Chemical combination of more than one element, in a definite ratio.

5. Compounds

6. Chemical Bonding Bonds Strength
Covalent bond > Ionic bond > Hydrogen bond
Organic molecule= a carbon containing molecule (C-C or C-H)
Ion = an atom that has gained or lost an electron, thus acquiring a charge

7. Covalent bonds =
Strongest chemical bond in which two atoms share valence electron(s)
Octet rule
Ex. Water H2O
Ex. Glucose C6H12O6

8. Ionic bonds
Strong bond that results from the attraction between charged atoms.
Electrons are given up.
Bond dissolves in water creating ions
Ex. NaCl (salts)
Ex. CaCl2

9. Hydrogen bonds Weak bonds between hydrogen and other atoms.
Result from polarity, electronegatvity.
Very important in protein’s 3 dimensional structure.
Ex. Water H2O
Ex: Protein structure

10. Hydrogen bonds hold water together

11. Radioactive Isotopes Uses: Treat cancer Determine age of fossils
Isotopes have different number of neutrons
Nucleus of atom breaks down over time
Carbon 12 Normal (6 neutrons + 6 protons)
Carbon 14 Radioactive (8 neutrons + 6 protons)
Uses:
Treat cancer
Determine age of fossils
“tracers” in medical imaging

12. Chemical Reactions
Occur when chemical bonds are broken, rearranged or formed.
The sum of all chemical reactions in the body is known as metabolism.
All systems tend to go toward entropy  disorder

13. Synthesis Reactions A + B AB Energy is required to form bonds
Amino Acids
Protein
energy
A + B AB
Energy is required to form bonds
Reactions are energy absorbing
Anabolic (Constructive) reactions
Monomers join to form polymers

14. Decomposition Reactions
Glycogen
Glucose molecules AB
A + B +
energy
Energy is released to break bonds
Reactions release energy
Catabolic (destructive reactions)
Complex nutrients are broken down

15. Electrolytes and Salts
Made of cations/anions
Disassociate in water
Calcium phosphates makes bones and teeth hard
Na+ & K+ help transmit nerve impulses and muscle contractions
Kidneys maintain water level to keep ions concentrations in balance

16. Acids and Bases Each jump up in the pH scale is a ten fold increase
taste sour
pH <7
HCL  H+ + CL-
Release H+ ions
Proton donors
H2SO4, HC2H3O2
Bases
Taste bitter
pH >7
Proton acceptor
NaOH  Na+ + OH-
HCO3-, NH3
Each jump up in the pH scale is a ten fold increase
pH 5  7 = 100x H+ ions
H2O is a weak acid

17. Buffers Acidosis- pH < 7.35 Alkalosis- pH > 7.45 Buffers
Resist sharp swings in pH
Blood must stay within
Biological molecules function at optimum pHs
Acids and bases neutralize each other
Acidosis- pH < 7.35
Alkalosis- pH > 7.45

18. Properties of Water

19. Water’s structure matches function
Water is a polar molecule because the electrons from H are unequally shared. + +
- -

20. Traits of water? Cohesion Surface Tension Adhesion Imbibition
Universal Solvent
The fact that water is polar allows for these traits

22. Universal Solvent Many substances will dissolve in water.
Especially those found in organisms (blood).

23. Additional traits of water
High Specific Heat
High Heat of Vaporization
Provides cushioning for body organs
Solution for Biochemical reactions

24. High Specific Heat
Water can absorb a lot of energy before its temperature changes.
The large amount of water in living things prevent sudden changes in temp. in response to external or internal factors.
In blood water keeps temperature homeostasis in tissues.

25. High Heat of Vaporization
Water absorbs a lot of energy (540 cal/g) to change states…thus sweat cools us.
When we lose 1 gram of water in sweat we lose 540 calories of heat

26. Cushions Organs Protects organs from physical trauma
Cerebrospinal fluid protects the brain

27. Medium for Biochemical Rxns
Biochemical reaction will only occur in solution.
Dehydration Synthesis
Removing water to form new molecules
Hydrolysis
Adding water to break bonds.