Biochemistry

Carbon

• Helped contribute to the great diversity of life due to it’s ability to form large complex molecules

• All compounds are either:– Organic – Inorganic

Organic Compounds

• Made of carbon atoms• Most matter in living things besides

water is made up of organic compounds.

• Carbon can form:– Straight chains– Branched carbon chains– Carbon rings

Bonding• When 2 atoms share a pair of

electrons a covalent bond is formed

• “Single Bond” – single line, 1 pair• “Double Bond” – two parallel lines,

2 pairs• “Triple Bond” – 3 parallel lines, 3

pairs

Large Carbon Molecules

• Monomers: small, simple molecules that build many carbon compounds

• Polymers: repeated, linked units of monomers

• Macromolecules: larger polymers

– Carbohydrates, lipids, proteins & nucleic acids

Condensation Reaction

• Monomers link to form polymers

• Type of chemical reaction

• A water molecule is released each time a monomer is added

Hydrolysis

• Reverse of condensation reaction

• Breaks down macromolecules (polymers) by adding water molecules

• Bond is broken between monomers

Energy for Life

• Adenosine Triphosphate (ATP)

• Compound that stores a large amount of energy in it’s structure

• Phosphate groups are attached via covalent bonds (very unstable)

• Every time a bond is broken energy is released.

Four Main Classes of Organic Compounds

• Carbohydrates

• Lipids

• Proteins

• Nucleic Acids

Carbohydrates

• Made up of carbon, hydrogen, & oxygen• Source of energy and/or structural materials

• Monosaccharides: simple sugar, ratio 1:2:1

(CH2O)n

• Common Examples:– Glucose, Fructose, & Galactose

More Carbs…

• Disaccharides: two monos in living things combine via a condensation reaction.

Fructose + Glucose Disaccharide Sucrose

Polysaccharides: 3 or more monosaccharides

Examples: Glycogen, starch, cellulose

Lipids

• Large, nonpolar organic molecules

• Do not dissolve in water

• Store more energy per gram then other compounds due to large number of C-H bonds

Examples of Lipids• Fatty Acids: unbranched C chains,

carboxyl group attached at one end & is polar

– Hydrophilic: attracted to water– Hydrophobic: water fearing– Saturated: Carbon atom is covalently bonded to 4 atoms– Unsaturated: form double bonds with carbon chain due to not being bonded to 4 atoms.

Steroid (the lone lipid)• Composed of 4 fused carbon rings with

various functional groups attached to them

• Example: *Testosterone is a steroid compound *Cholesterol is also very

famous!!

• Three classes of lipids contain fatty acids:

• Triglycerides (1 alcohol glycerol joined to 3 fatty acids)

• Phospholipids (1 glycerol joined to 2 fatty acids, phosphate group attached to 3rd carbon of glycerol)

• Waxes (long fatty acid chain joined to a long alcohol chain)

Nucleic Acids• Large complex organic molecules that store

& transfer important info in the cell.

• Two types: DNA (Deoxyribonucleic acid) RNA (Ribonucleic acid)

Both consist of thousands of linked monomers called nucleotides

Proteins• Organic compounds made of:

– Carbon, Hydrogen, Oxygen & Nitrogen

Amino Acids: *monomers that link to make proteins

* 20 different ones that share the same basic structure

Examples: Hair, Horns, Skin, Muscles

Proteins Continued…

• Dipeptide: when 2 amino acids form a covalent bond via a condensation reaction.

•THE BOND IS CALLED A PEPTIDE BOND!!

•Polypeptidesare very long chains of amino acids

Enzymes• RNA or protein molecules that act as biological

catalysts• Necessary for any cell to function

• Substrate: reactant being catalyzed• Active site: area that allows substrate to fit in

• The environment can effect the enzyme drastically

– Examples: Temperature & pH

Activation Energy

• Chemical substances that reduce the amount of activation energy needed for a reaction to take place are known as catalysts

• A reaction in the presence of the correct catalyst will proceed spontaneously or with only a little energy added