1. Big Campbell ~ Ch 2-5 Baby Campbell ~ Ch 2-3
UNIT II - BIOCHEMISTRY
Big Campbell ~ Ch 2-5
Baby Campbell ~ Ch 2-3

2. I. CHEMICAL BASIS OF LIFE
Elements
Cannot be broken down without losing characteristic properties
Six elements in greatest concentration in living things are
Defined by

3. I. CHEMICAL BASIS OF LIFE, cont
Atoms
Smallest unit of matter that retains properties of that element
Atomic Mass
Isotopes

4. I. CHEMICAL BASIS OF LIFE, cont
Chemical Bonds
Chemical behavior of atom determined by valence electrons
Atoms interact with other atoms to complete their valence shells, either by transferring or sharing electrons

5. I. CHEMICAL BASIS OF LIFE, cont
Types of Chemical Bonds
Ionic – Results when one atom has a much stronger attraction for electrons than another; one atom has a greater electronegativity. Electron(s) are transferred resulting in formation of ions. Bond forms due to charge attraction. Strength is dependent on environment

6. I. CHEMICAL BASIS OF LIFE, cont
Covalent Bonds – More stable; results from sharing a pair of valence electrons. Forms a molecule. One pair of electrons shared = single covalent bond; two pair of electrons shared = double covalent bond.
Non-polar covalent bond – formed when electronegativity of atoms is the same
Polar covalent bond – formed when one atom is more electronegative; unequal sharing of electrons results in slight charges at either end of molecule

7. II. WATER Properties of Water Due to its Polarity Hydrogen “bonds”
“Stickiness”
Cohesion
Surface Tension
Adhesion
Capillary Action

8. II. WATER, cont Regulation of Temperature High specific heat
High heat of vaporization
Density of “solid” water ____ density of liquid water
Solvent of Life
“Water-loving”
Polar molecules “pull apart” ionic compounds & other polar molecules
“Water-hating”
Non-ionic and non-polar substances are repelled by water

9. II. WATER, cont Dissociation of Water Rare, but measurable phenomenon
(2)H2O → H3O+ + OH- → H+ + OH-
In aqueous solution at 25˚C, total conc of [H+] [OH-] = 1x10-14
Neutral solution → [H+] = [OH-]; therefore [H+] =
pH = Provides a means for a compressed measurement of [H+]
-log10[H+]
Acid – Substance that dissolves in water to ____________ [H+]
[H+] ____ 1 x 10-7; pH ____ 7
Base - Substance that dissolves in water to ____________ [H+]
pH of Water =

10. II. WATER, cont
Buffers
Maintain a constant pH by donating, accepting H+
Bicarbonate Buffer System
Very important buffer system in blood
pH of blood = _________

11. III. ORGANIC CHEMISTRY – THE STUDY OF CARBON
Atomic Structure of C
Atomic Number of C =
_____ valence electrons
Hydrocarbon
Isomer

12. III. ORGANIC CHEMISTRY, cont
Functional Group
Structure
Characteristics
Hydroxyl
Very polar; forms “ –ols”
Carbonyl
Carboxyl
Acts as an acid; donates H+ to solution
Amino
Acts as a base; removes H+ from solution

13. III. ORGANIC CHEMISTRY, cont
Functional Group
Structure
Characteristics
Sulfhydryl
Important in stabilizing protein structure; forms disulfide bridges
Phosphate
Gives molecule negative charge; react with water to release energy
Methyl
Affects the expression of DNA

14. IV. THE BIOMOLECULES
Most are polymers made up of single units called monomers
Four Main Groups

15. IV. BIOMOLECULES, cont Dehydration Synthesis
Also called ________________________
Reaction that occurs to build polymers
Forms ________________ bond between 2 monomers
____________lost as waste product
Requires energy input, enzymes

16. IV. BIOMOLECULES, cont Hydrolysis “________________________”
Covalent bonds between monomers broken Releases energy; reaction accelerated with enzymes

17. V. CARBOHYDRATES Provide fuel, act as building material
Generally, formula is a multiple of CH2O
Contain carbonyl group & multiple hydroxyl groups
Monomer = monosaccharides
Monosaccharides – usually found as ringed structures
Pentoses
Ribose
Deoxyribose

18. V. CARBOHYDRATES, cont
Hexoses
Glucose
Fructose
Galactose

19. V. CARBOHYDRATES, cont Disaccharides
2 monosaccharides covalently bonded together through dehydration synthesis
Example
Sucrose
Lactose
Maltose

20. V. CARBOHYDRATES, cont Polysaccharides
Many monosaccharides covalently bonded together through dehydration synthesis
Two main groups
Energy Storage Polysaccharides
Starch – Plants store glucose as starch in cell structures called plastids. Humans have enzymes to hydrolyze starch to glucose monomers.
Glycogen – Storage form of glucose in animals. More highly-branched than starch. In humans, found mainly in liver, muscle cells

21. V. CARBOHYDRATES, cont Structural polysaccharides
Cellulose – polymer of glucose. Every other glucose is upside down – forms parallel strands of glucose molecules held together with H-bonds
Chitin – found in arthropod exoskeleton, cell walls of fungi

22. VI. LIPIDS Very diverse group Non-polar, hydrophobic molecules
Not true polymers
Four groups

23. VI. LIPIDS, cont Fats& Oils Composed of glycerol + 3 fatty acids
Glycerol = 3-C alcohol
Fatty acids – long hydrocarbon chains ending with carboxyl group
AKA triglycerides
Used for energy storage

24. VI. LIPIDS, cont
Saturated fats – “Saturated with hydrogens”; contain all single bonds. Typically from animal source, solid at room temp. Associated with greater health risk.
Unsaturated fats – Contain double bonds, fewer H-atoms. Results in “kinked” hydrocarbon chain. Typically from plant source, liquid at room temp.

25. VI. LIPIDS, cont Phospholipids
2 fatty acids attached first 2-carboxyl groups of glycerol.
Negatively-charged phosphate group is attached to 3rd carboxyl
Partially polar and partially non-polar
Found in all cell membranes.

26. VI. LIPIDS, cont
Waxes – One fatty acid attached to an alcohol. Very hydrophobic. Used as coating, lubricant
Steroids – Consist of 4-rings with different functional groups attached.
Cholesterol – steroid found in animal cell membranes; precursor for sex hormones

27. VII. PROTEINS
Important part of virtually all cell structures, processes, reactions
Amino Acids – Proteins are large polymers made up of amino acid monomers. All amino acids have the same basic structure:
Amino group
Carboxyl group
Carbon, known as alpha carbon
R group → variable component; gives each amino acid its unique properties. Determines whether amino acid is classified as polar, non-polar, acidic, or basic.

28. VII. PROTEINS, cont

29. VII. PROTEINS, cont

30. VII. PROTEINS, cont

31. VII. PROTEINS, cont Amino Acid → Protein
Dehydration synthesis results in formation of a peptide bond
Polypeptide – many amino acids covalently bonded together

32. VII. PROTEINS, cont Protein Conformation
Protein’s shape is related to its function. Generally, a protein must recognize/bind to another molecule to carry out its function.
Denaturation - A change in a protein’s shape. Results in a loss of protein’s ability to carry out function.
Four levels of protein structure
Primary
Secondary
Tertiary
Quaternary

33. VII. PROTEINS, cont
Primary – Sequence of amino acids

34. VII. PROTEINS, cont
Secondary – Coiling of polypeptide chain due to formation of H-bonds between H of amino end of one aa and OH of carboxyl end of another aa
Alpha helix – created from H-bonds forming within one pp chain
Beta pleated sheet – H-bonds form between aa in parallel pp chains

35. VII. PROTEINS, cont
Tertiary - Involves interactions between R groups of amino acids. Helps to give each protein its unique shape.

36. VII. PROTEINS, cont
Quaternary – Proteins that are formed from interactions between 2 or more polypeptide chains folded together. Examples include hemoglobin, collagen, chlorophyll

37. VII. PROTEINS, cont Enzymes
Biological catalysts that act by lowering activation energy; that is, the amount of energy needed to get the reaction going
Only catalyze reactions that would normally occur
Recycled – not used up or changed by the reaction
Temperature and pH sensitive
Substrate specific

38. VII. PROTEINS, cont
Induced fit – As enzyme envelops substrate, a slight change takes place in bond angles, orientation of atoms. Allows chemical rxns to occur more readily
Inhibition of Enzyme Function
Competitive inhibitor – mimics normal substrate
Non-competitive inhibitor – attaches to another part of enzyme; changes shape of active site

39. VII. PROTEINS, cont Regulation of enzyme function
Allosteric Regulation – binding of a molecule to enzyme that affects function of protein at another site
Feedback Inhibition – as end product is synthesized and accumulates, enzyme is inactivated → switches off metabolic pathway

40. VIII. NUCLEIC ACIDS Nucleic acid group includes DNA, RNA, ATP
Monomers = __________________
Composed of
Pentose
Phosphate group
Nitrogen base
Polymers formed through ____________________________
Phosphate group of one nucleotide covalently binds to sugar of next

41. VIII. NUCLEIC ACIDS, cont
Nitrogen Bases
Pyrimidines – Single-ringed structure
Purines – Double-ringed structure

42. VIII. NUCLEIC ACIDS, cont
DNA