biochem session 4 rl
DESCRIPTION
Biochem Session 4 RLTRANSCRIPT
Biological Chemistry
Session 4
Squamish The Chief
Functional Groups in Organic Compounds
v Most organic compounds are chains or rings of carbon and hydrogen
v What makes organic molecules different from each other are their functional groups
v “R” is a general symbol used to represent the functional group (also known as a radical group)
1. Alcohols
l General formula: OH
l Group called hydroxyl group
l General name: ends in “ol”
l OH group is polar (.:water soluble)
l Can have more than one OH group
l Examples: v ethanol (drinking alcohol), cholesterol, glycerol
l Many are toxic v eg. methanol (wood alcohol), can cause blindness
2. Aldehydes
l General formula: CHO
l General name: ends in “al”
l The C = O group is called the carbonyl group
v Polar (.:water soluble)
l Examples:
v formaldehyde (methanal): embalming fluid
v acetaldehyde (ethanal): smog
3. Ketones
l General formula: (on board)
l General name: ends in “one”
l Polar carbonyl group ∴ water soluble
l Often used as solvents
l Examples: v Acetone
v Cortisone
v Progesterone
4. Organic Acids/ Carboxylic Acids
l General formula: COOH
l General name: ends in “(o)ic acid”
l Called carboxyl group
l Acidic: R—COOH → R—COO- + H+
l If chain is short → water soluble
l If have long hydrocarbon chains → fatty acids
l Examples:
v acetic acid, vinegar
v formic acid, ant/bee stings
5. Amines
l General formula: NH2
l Group is called amino group
l General name: ends in “amine”
l Water soluble
l Weak bases: R-NH2 + H+ → R-NH3+
l Example:
v amino acid
6. Ethers
l General formula: O
l General name: ends in “ether”
l Examples:
v diethyl ether, decongestant
7. Esters
l General formula: (on board)
l General name: ends in “(o)ate”
l Responsible for flavour/odor of many foods
l Fats and oils are esters
l Examples:
v ethyl formate, rum
v pentyl acetate, banana
v octyl acetate, orange
Chemical “Food” Artificial Strawberry Flavour
Source: Fast Food Nation, Eric Schlosser, page 125-126
8. Amides l General formula: (see board)
l General name: ends in “amide”
l Examples:
v eg. proteins and nylon
9. Sulfhydryls
l General formula: SH
l Group called thiol group
l General name: ends in “thiol”
l Small thiols produce foul odors
l Examples:
v butenethiol: skunks
v propanethiol: onions/garlic
10. Disulfides
l General formula: S S
l Thiols in proteins form disulfide bridges
l Important in determining the characteristic shape of proteins
11. Phosphates l General formula: (see board diagram)
l Group called phosphate group
l Present in ATP (adenosine triphosphate)
• Assignment #3 • Work on it for remainder of class • Hand in today if done • Hand in next class if need more
time • Homework
• Review Chapter 10 • Next class
• Chapters 12, 13, 14