Chapter five: Biological macromolecules and Lipids
5.1
A polymer is a long molecule consisting of many similar or identical monomers linked
together by covalent bonds. E.g. large carbohydrates, proteins, nucleic acids.
A monomer is a small molecule; a subunit that serves as the building block of a polymer.
In the cell polymers are formed by enzymes: a (specialized) macromolecule serving as
catalyst, a chemical reagent that increases the rate of a reaction without being consumed by
the reaction. Most enzymes are proteins (eiwitten).
Connecting monomers is an example of a dehydration reaction: a reaction in which two
molecules are covalently bonded to each other with the loss of a water molecule. One
monomer provides a hydroxyl- group (-OH) as the other molecule provides a hydrogen atom
(-H). The two molecules are connected to the oxygen-atom (-O-) from the
molecule that has given away it’s hydrogen atom. As this process proceeds more
monomers are connected forming a polymer. This process is called
polymerization.
Polymers can be disassembled to monomers by hydrolysis, a process where water
is used to break the covalent bond between two molecules. Both molecules then
have a hydroxyl- group. E.g. digestion: enzymes attack the polymers so that the
monomers can go into our system.
The diversity in life’s polymers lies in the arrangement (particular linear sequence
that the units follow).
5.2
Carbohydrates (koolhydraat) include sugars and polymers of sugars (disaccharides
or polysaccharides).
Monosaccharide is the simplest saccharide, active alone or serving as a monomer
for a disaccharide or polysaccharide. They’re also called simple sugars,
monosaccharides generally have a molecular formula that are generally some
multiple of CnH2nOn. they have a carboxyl group (>C=O) and multiple hydroxyl
groups (-OH).
Depending on the position of the carboxyl group the sugar molecule is a ketose or
an aldose. Ketose has the carboxyl group within the carbon skeleton. An aldose has the
carboxyl group at the end of the carbon skeleton.
Examples of simple sugars (monosaccharide):
Glucose and fructose have six carbons; they’re called
hexoses. Trioses (three carbon sugars) and pentoses
(five carbon sugars) are also common.
Sugar monomers are also able to differ in structure, as
they are isomers. Glucose and galactose, for example,
differ in one asymmetrical placement of parts around
carbon atom.
In aqueous conditions five and six carbon sugars form
rings, because that’s when they are most stable.
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5.1
A polymer is a long molecule consisting of many similar or identical monomers linked
together by covalent bonds. E.g. large carbohydrates, proteins, nucleic acids.
A monomer is a small molecule; a subunit that serves as the building block of a polymer.
In the cell polymers are formed by enzymes: a (specialized) macromolecule serving as
catalyst, a chemical reagent that increases the rate of a reaction without being consumed by
the reaction. Most enzymes are proteins (eiwitten).
Connecting monomers is an example of a dehydration reaction: a reaction in which two
molecules are covalently bonded to each other with the loss of a water molecule. One
monomer provides a hydroxyl- group (-OH) as the other molecule provides a hydrogen atom
(-H). The two molecules are connected to the oxygen-atom (-O-) from the
molecule that has given away it’s hydrogen atom. As this process proceeds more
monomers are connected forming a polymer. This process is called
polymerization.
Polymers can be disassembled to monomers by hydrolysis, a process where water
is used to break the covalent bond between two molecules. Both molecules then
have a hydroxyl- group. E.g. digestion: enzymes attack the polymers so that the
monomers can go into our system.
The diversity in life’s polymers lies in the arrangement (particular linear sequence
that the units follow).
5.2
Carbohydrates (koolhydraat) include sugars and polymers of sugars (disaccharides
or polysaccharides).
Monosaccharide is the simplest saccharide, active alone or serving as a monomer
for a disaccharide or polysaccharide. They’re also called simple sugars,
monosaccharides generally have a molecular formula that are generally some
multiple of CnH2nOn. they have a carboxyl group (>C=O) and multiple hydroxyl
groups (-OH).
Depending on the position of the carboxyl group the sugar molecule is a ketose or
an aldose. Ketose has the carboxyl group within the carbon skeleton. An aldose has the
carboxyl group at the end of the carbon skeleton.
Examples of simple sugars (monosaccharide):
Glucose and fructose have six carbons; they’re called
hexoses. Trioses (three carbon sugars) and pentoses
(five carbon sugars) are also common.
Sugar monomers are also able to differ in structure, as
they are isomers. Glucose and galactose, for example,
differ in one asymmetrical placement of parts around
carbon atom.
In aqueous conditions five and six carbon sugars form
rings, because that’s when they are most stable.
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