Samenvatting Biology Campbell H5
Biological Macromolecules and Lipids
Concept 5.1 Macromolecules are polymers built from monomers
Macromolecules: large carbohydrates, proteins, and nucleic acids, these are
chain molecules
Polymer: long molecule consisting of many similar of identical building blocks
linked by covalent bonds
Monomers: building blocks of a polymer,
when repeatedly serve a polymer
Enzymes: specialize macromolecules that
speed up chemical reactions.
Condensation reaction: a monomer
connects to another monomer/polymer, in
with a loss of a small molecule
Dehydration reaction: a condensation
reaction where a water molecule is lost.
Hydrolysis: dissembling of a polymer, the
reverse of the dehydration reaction, the
bond between monomers is broken by the
addition of a water molecule, with a
hydrogen from water attaching to one monomer and the hydroxyl group
attaching to the other.
Concept 5.2 Carbohydrates serve as fuel and building material
Carbohydrates: polymers called polysaccharides, composed of many sugars
building blocks
Monosaccharides: molecular formulas that are some multiple of the unit
CnH2nOn
Disaccharides: two monosaccharides joined by a glycosidic linkage; a covalent
bond formed between the two monosaccharides by a dehydration reaction
, Polysaccharides: macromolecules, polymers with a few hundred to a few
thousand monosaccharides joined by glycosidic linkages.
Both plants and animals store sugars for later use in the form of storage
polysaccharides.
Starch: plants store starch, a polymer of glucose monomers as granules within
cellular structures known as plastids.
Glycogen: animals store these polysaccharides, a polymer of glucose that is like
amylopectin but more extensively branched.
Cellulose: a polysaccharide and a major component of the tough walls that
enclose plant cells.
Chitin: a polysaccharide and the carbohydrate used by arthropods (insects,
spiders, crustaceans, and related animals) to build their exoskeletons
Concept 5.3 lipids are a diverse group of hydrophobic molecules
Lipids: large biological molecules that does not include true polymers, and they
are generally not big enough to be considered macromolecules, hydrophobic:
because of their molecular structure.
Fats: large molecules assembled from
smaller ones by dehydration reactions, are
not polymers, consists of a glycerol molecule
joined to three fatty acids.
Fatty acid: long carbon skeleton, the carbon
at one end of the skeleton is part of a
carboxyl group, which gives these molecules
the name fatty acid. The rest of the skeleton
consists of a hydrocarbon chain. The
relatively nonpolar C—H bonds in the
hydrocarbon chains of fatty acids are the
reason fats are hydrophobic. Fats separate
from water because the water molecules
hydrogen-bond to one another and exclude
the fats.
Saturated fatty acid: no double bonds
between carbon atoms composing a chain
Unsaturated fatty acid: one or more
double bonds, with one fewer hydrogen
atom on each double-bonded carbon