Celbiologie
Chapter 5 Biological Molecules and
Lipids
Concept 5.1 Macromolecules are polymers made of
monomers
A polymer is a long molecule built out of monomers → linked together by
covalent bonds.
The 4 most important ones are carbohydrates, proteins, nucleic acids
and lipids.
Synthesis and Breakdown of a Polymer
The breakdown and synthesis of a polymer is catalized by enzymes, which
speed up the reaction.
Dehydration reaction → building a polymer by taking water
Hydrolysis → Breaking a polymer by adding water
Every individual produces differend polymers. Between siblings lie the
smallest difference, because their DNA is most similar.
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, There are 40 common monomers which are used to create a polymer.
Concept 5.2 Carbohydrates
Carbohydrates include sugars and polymers of sugars.
The simplest carbohydrates are monosaccharides → disaccharides are
2 monosaccharides joined by glycosidic linkages, which is a covalent
bond.
Sugars
Monosaccharides have a molecular formula that are multiples of CH2O.
Glucose is the most common monosaccharide → C6H12O6.
A sugar consists of carbonyl groups (C=O) and hydroxyl groups (-OH) and
is usually between 3 and 7 carbon molecules long.
Ketose → carbonyl group lies in the middle
Aldose → carbonyl group lies at the end
Glucose and galactose are mostly the same, only 1 -OH group is located on
the other side in glucose compaired to galactose
Most 5- or 6- carbon sugars form a ring, because this is the most stable form
under different physiological conditions.
Plants transport carbohydrates in the form of sucrose, which is glucose +
frustose.
Lactose is a disaccharide of glucose + galactose. If someone is lactose
intolerant → it misses the enzyme lactase, which breaks down lactose
Polysaccharides
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