Topic 2 - Molecular Biology

4 groups of organic compounds

1. Proteins
2. Carbonhydrates
3. Fat (lipids)
4. Nucleic acids

Proteins

Polypeptide - a chain of amino acids joined together by peptide bonds

Carbonhydrates

Any of the group of organic compounds consisting of carbon, hydrogen, and oxygen:

* Monosaccarides
* Disaccarides
* Polysaccides

Lipids

A fatty or waxy organic compound that is readily soluble in a nonpolar solvent but not in a polar solvent, consisting of carbon, hydrogen, oxygen

* Triglycerides
* Steroids
* Phospholipids

Nucleid acids

Long chainlike molecules composed of a series of nearly identical building blocks called nucleotides

* DNA (Deoxyribonucleic acid)
* RNA (Ribonucleic acid)
* ATP (Adenosine triphosphate)

Carbon

* Simplest organic compound
* Consists of 6 electrons and 6 protons
* 4 valance electrons that make 4 covalent bonds

Biochemistry

A branch of organic chemistry (chemistry of life)

Metabolism

The web of all enzyme catalyzed reactions in a cell or an organism

* Provide sources of energy for cellular processing
* Synthesis/assimilation of new material

Anabolism

“Build up” - Synthesis of larger molecules from simples molecules through condensation reaction

Catabolism

“Break down” - Break down of larger molecules into simpler molecules through hydrolysis reaction

Monosaccharides

Smallest sugar unit made up of one sugar monomer

* Glucose


* Galactose
* Fructose
* Ribose/sugars

An energy form

Disaccharides

Substance that is composed of two molecules of simple sugars (monosaccharides) linked together by condensation reactions

* Lactose
* Maltose
* Sucrose/sugars

A transport form

Polysaccharides

Chain of monosaccharide monomers joined together through condensation reaction

* Starch
* Glycogen
* Cellulose
* Chitin

A storage form

Cellulose

Type of polysaccharide:

* Plant cell wall
* Subunit: B-glucose
* Bonds: 1-4
* Branches: No

Starch

Product of photosynthesis

* A D-glucose

**Amylose:**

* Bonds: 1-4
* Branche: Yes

**Amylopectin:**

* Bonds: 1-4, 1-6
* Branches: Yes

Glycogen

Glucose storage in animals

* A-D-glucose
* Bonds: 1-4, 1-6
* Branches: Yes

Triglycerids

One glycerid, three fatty acids

* Saturated fatty acids
* Unsaturated fatty acids
* Mono-unsaturated fattu acids
* Poly-unsaturated fatty acids

Saturated fatty acid

* No double bonds in carbon chain
* Bad

Triglycerides structure

* Glycerol
* 3 fatty acids
* Methyl group (CH3-)
* Carbon chain
* Carboxyl group (COOH)

Unsaturated fatty acid

Fatty acid with double bonds

Mono unsaturated fatty acids

One double bond in the carbon chain

Poly unsaturated fatty acids

Many double bonds

Cis unsaturated fatty acid

Hydrogen on the same side

* good fat

Trans unsaturated fatty acid

Hydrogen on opposite sides

* Bad fatty acid

Hydrolysis

Splitting with the help of water

Ex. Dissacharide + H2O → monosaccharides

Condensation

Molecules joined with loss of water

Ex. Monosaccharides - H2O → Disaccharides

D-ribose

* Pentose - 5 carbon sugar
* C5H10O5

Deoxyribose

Found in DNA

Alpha-D-Glucose

Glucose type: Starch and glycogen

Beta-D-Glucose

Glucose type: Cellulose

Generalized amino acid

* Amine group
* R group
* Carboxyl group

R-group

Radical group: Different in different amino acids

Amino acid

Molecules that are linked together by condensation reaction to form polypepties (proteins)

Dipeptide

Two amino acids linked together with a peptide bond, by condensation reaction