The Chemistry of Life
Organic Chemistry
Organic Chemistry is the chemistry of Carbon!
Organic Chemistry vs. Inorganic Chemistry
C, H, N, O, P, S All Elements
Large # of Atoms Small # of Atoms
Associated with Life Associated with Environment
NaCl
Organic Chemistry
Carbon can form many bonds! Valence=4
Can store/release lots of energy
Carbon can build large and diverse molecules
Carbon
Functional GroupsGroups of atoms that bond to the “carbon skeleton”
Determine the properties of organic molecules
Behave consistently from one carbon-based molecule to another
Functional Groups
Hydroxyl
-OH
Alcohols, carbohydrates
Polar
Hydrophilic
Carbonyl (Aldehyde)
-C=O
At the end of the carbon skeleton
Carbohydrates (Aldose sugars)
Polar
Hydrophilic
Carbonyl (Ketone)
-C=O
On an inside carbon of the carbon skeleton
Carbohydrates (Ketose sugars)
Polar
Hydrophilic
Carboxyl-COOH
Carbon double bonded to oxygen and also attached to a hydroxyl
Lipids and Proteins
Polar
Hydrophilic
Called carboxylic acid because they tend to dissociate to release H+
Phosphate-OPO3
2-
Phosphorus atom surrounded by O
Lipids and Nucleic Acids, ATP
Polar
Hydrophilic
Amino
-NH2
Amino acids/proteins
Polar
Hydrophilic
Can act as a base by accepting a H+ to form –NH3
+
Most organic molecules are macromolecules (Really Big!)
Macromolecules are formed by a process called polymerization
Biological Macromolecules
Large compounds are constructed by joining together many smaller units….
Small Units: Monomers (Basic Unit)
Polymerization
Large Units: Polymers (Many Units)
Polymerization
Monomers Polymers
Process called Dehydration SynthesisMany bonds formed by removing water
Energy Stored
Animation
Dehydration Synthesis
Polymers Monomers
Process called HydrolysisBonds broken by adding water
Energy is released!
Animation
Hydrolysis
The compounds of life are all carbon based organic compounds!
There are 4 groups of organic biomolecules found in all living things:
• Carbohydrates
• Lipids
• Proteins
• Nucleic Acids
Organic Biomolecules
Carbohydrates
Contain Carbon, Hydrogen, and Oxygen in a 1:2:1 ratio
Building blocks (monomers) are Monosaccharides
MonosaccharidesCommonly called “sugars”
General formula is (CH2O)n
Contain 2 or more Hydroxyl groups, and a Carbonyl groupAldehyde = aldose sugarsKetone = ketose sugars
Very polar, hydrophilic
Straight chains or rings
Examples:
GlucoseFructoseGalactoseMannose
All C6H12O6
Monosaccharides
Isomers
Molecules that have the same chemical formula but different structure
Disaccharides
Two monosaccharides joined by dehydration synthesis
Strong covalent bond called Glycosidic Linkage
Example:
Sucrose C12H22O11
PolysaccharidesLarge complex carbohydrates
Made up of many repeating monosaccharides
Functions:
Energy storage
Structural molecules used to build cells/tissues
Energy Storage Polysaccharides
Plant Cells Animal Cells
Starch Glycogen
Structural Polysaccharides
Plant Cells Animal Cells
Cellulose Chitin
Lipids
Contain many Carbon and Hydrogen atoms and few Oxygen
Commonly called “fats”, “oils”, or “waxes”
All lipids are nonpolar and hydrophobic
Lipids
Lipids: Triglycerides (fat)
Building blocks include:
1 Glycerol a 3 carbon molecule
3 Fatty Acids long chains of Carbon with a single carboxyl group
Lipids: Triglycerides (fat)
Fatty Acids:
Saturated fatty acids contain carbon to carbon single bonds and the maximum number of H atoms
Unsaturated fatty acids contain 1 or more carbon to carbon double bonds and fewer than the maximum number of H atoms
Lipids: Triglycerides (fat)
Lipids: Triglycerides (fat)
3 fatty acids are joined to glycerol by dehydration synthesis
Strong covalent bond called ester linkage
Fats store concentrated energy in the many C-H bonds
Also provide insulation against cold, protect internal organs, provide waterproofing
Lipids: PhospholipidsGlycerol
2 Fatty acids
Phosphate group
Nonpolar tails, polar head (amphipathic)
Form bilayers that make cell membranes
Lipids: Phospholipids
Lipids: Steroids
Hormones that regulate cellular activities
Ring-shaped, not like triglycerides
ProteinMost abundant and diverse molecules in living cells
Contains C, H, O, and N
Carboxyl group
Amino group
Building blocks are called amino acidsPolymers of amino acids are called Polypeptides
Protein: Amino Acids
Amino Acids:
• Building blocks of proteins
• Central carbon atom
• Hydrogen atom
• Amino group
• Carboxyl group
• R group (variable structure)
There are 20 different amino acids
Diversity of R groups
Varied chemical properties and interactions
Protein: Peptide Bonds
Two amino acids joined together by dehydration synthesis
Strong covalent bond called peptide bond
Bond forms between C of carboxyl group and N of the amino group
Two amino acids joined together are called a dipeptide
Formation of a Polypeptide
Protein: Polypeptide
Many amino acids joined by peptide bonds
Primary structure (sequence of amino acids) is determined by genetic code
Tertiary structure results from amino acid chain folding back on itself. Results in globular, 3 dimensional molecule
Protein function is determined by its molecular shape (tertiary structure)
Structure in organisms: collagen, connective tissue, keratin
Hormones: regulate body functions
Movement: major role in muscle contraction
Transport: through cell membrane, and O2 in blood
Enzymes: catalysts that speed up chemical reactions
Protein: Functions
All complex proteins can be denatured!
Change in pH or temperature
Shape is lost
Function is lost
Function can be restored if conditions are restored!
Protein: Denaturing
Contain C, H, O, N and P atoms
The primary function of nucleic acids is to store and transmit genetic information!
Found in the nucleus of eukaryotic cells and in the nucleoid region of prokaryotic cells
Nucleic Acids
The building blocks of nucleic acids are called nucleotides
Nucleotides contain 3 parts:
1. 5 carbon sugar (pentose)2. Phosphate group3. Nitrogenous base
Nucleic Acids: Nucleotides
Two nucleotides are joined together by dehydration synthesis
Strong covalent bond called phosphodiester linkages link the phosphate of one nucleotide to the sugar of the next nucleotide.
This polynucleotide creates the “sugar-phosphate backbone”
Nucleic Acids: Nitrogenous BasesRing-shaped carbon and nitrogen molecules
Purines are double rings: Adenine and Guanine
Pyrimidines are single rings: Thymine, Cytosine, and Uracil (RNA)
DNA
Deoxyribonucleic Acid
Deoxyribose sugar
Bases: (A and T) (C and G)
Double Stranded
Stores genetic information in nucleus
Nucleic Acids: Polymers
RNARibonucleic Acid
Ribose Sugar
Bases: (A and U) (C and G)
Single stranded
Carries genetic code to ribosomes for protein synthesis
The Special Chemicals of Life