Uracil in RNA,thymine in DNA

The DNA-language consists of the ”letters” (bases) A, T, G og C

The bases in DNA (A) and RNA (B) are coupled to each other via deoxyribose (DNA) and ribose (RNA), and with phosphate

A

B

The structure of DNA (one strand shown) and RNA

Note that the strands are antiparallel and have a 5’ (5-merket) and a 3’ (3-merket) ende

Most DNA molecules are right-handed twisted

DNA-molecules can be visualized by elektron microscopy, here illustrated by a particularly small molecule (plasmid, see later)

DNA can replicate itself by the help of numerous proteins. This is perhaps the most important characteristic of life! Life anywhere (in the universe!)without copying is difficult to envision

Proteins consist 20 different amino acids (R varies)

Covalent sulfur bridges can occur in proteins. This can have a major effect on protein 3D structures and therebye functionality

The acid-base properties of amino acids have a big effect on protein functionality

The amino acids in proteins are held together by covalent peptide bonds.Note that this defines the carboxyterminal and amino-terminal ends of proteins. Polymerization occurs such that the amino acid at the amino terminal end is the first to become incorporated.

The penta-peptide Ser-Gly-Tyr-Ala-Leu (SGYAL)

Monosaccharides are aldoses or ketoses

Many monosaccharides are epimers of each other

The monosaccharides can (and will) also be found in ring form

Monosaccharides can be linked to each other and become carbohydratestorages (starch) or have structural functions (cellulose, chitin etc.)

The stiff ”skeleton” of this insect contains a lot of chitin, also in shrimps, crabs etc

Fungi can ”eat” the cellulose, which is a major component of wood. Cotton is almost pure cellulose. What would happen if no organism could utilize cellulose (like humans)?

Lipids typically have long chains of carbon atoms, but exist in many forms, also linked to polysaccharides (lipopolysacchariders), phosphate (phospholipids) and as triglycerides. They are typically found in cell membranesand as stored fat (do you see it on yourself?). Candle-lights are composed of long chain fatty acids

Different triglycerides (note the double bonds, which are interesting in relation to human health)

storage of genetic informationDNA

RNA

Proteins

carrier of genetic information

carry out the functions of the cell

Central Dogma

genetic information in DNA is passedto next generation (heredity)

This is probably the most important of all slides in the course!

An alternative way of illustrating the central dogma