Zellbiologie

Cellulose: The major structural component of plants. It is a long polymer made of cellobiose (a disaccharide
made of two glucose molecules). Humans can’t digest cellulose because we don’t have the enzyme cellulase.

cellobiose: glucose-β-1,4-glucose

Lactose: It is made up of galactose linked to glucose. The galactose can be converted to glucose by the human
body only if the enzyme lactase is present.

lactose: galactose β 1,4 glucose

Sucrose: A very common natural sweetener made up of glucose and fructose. Our body can synthesise all the
different sugars needed from glucose and it can also produce the glucose itself in many different ways.

sucrose: glucose α 1,2 fructose

Glycogen: Branched polysaccharide which is used for energy storage (in humans/animals)

Carbohydrates
Used as energy source (glucose), energy storage (glycogen, starch), carbon source (pyruvate), for structure and
protection (chitin, cellulose, connective tissue) and for recognition/signaling (antibodies). Their names usually
and with “–ose”.

first C double connection with O

second C double connection with O

Hexose sind Monosaccharide, deren Kohlenstoffgrundgerüst sechs Kohlenstoff-Atome enthält.

maltose: glucose α 1,4 glucose

• storage molecules for energy (adipose tissue)
• structural components of cellular membranes
• protective molecules (waxes)
• hormones and vitamins
• intracellular messengers
• pigments

• very important biomolecules
• insoluble in water
• soluble in organic sovents and other lipids

There are four main classes of which the first three have the basic structure of fatty acids:
- Triacylglyverols (TAGs): Storage lipids --> the fatty acids are linked through an ester
bondage to glycerol. non polar
- Phosphoacylglycerols: Membrane structural lipids. polar
- Sphingolipids: Membrance structural lipids (polar)
- Non saponifiable lipids: Steroids, hormons, cholesteros --> based on a fused
ring structure rather than fatty acids

Common Fatty Acids: A carboxylic acid with a long hydrocarbon tail which can be either saturated (no double
bonds) or unsaturated (one or more double bonds)

All amino acids have the
same basic structure (an organic molecule with at least one carboxyl group (organic acid) and at
least one amino group (organic base) --> they only differ in their side chain).

There 20 naturally occurring amino acids which can be linked together by peptide bonds. The
bond is mace between the amide-nitrogen and the carbonyl oxygen.

Zwitterions: Positive and negative charge on the same molecule. Amino acids exist in this form at physiological
pH ( about 7.4)

There 20 naturally occurring amino acids which can be linked together by peptide bonds. The
bond is mace between the amide-nitrogen and the carbonyl oxygen.

Only one way to link amino acids together – peptide bond

Amino acids/proteins act as: enzymes (catalysts), metabolic
intermediates, carriers of energy and waste products and hormones.