Macromolecules
Polymers are long molecules built by linking repeating units
covalently. A single unit of a polymer is a monomer. The four main
types of macromolecules are carbohydrates, lipids, proteins, and
nucleic acids.
CarbohydratesThere are three types of carbohydrates:
monosaccharides,
disaccharides, and polysaccharides. Monosaccharides consist of 1
monomer, disaccharides are made of 2 monosaccharides, and
polysaccharides are composed of more than 2 monosaccharides.
Carbohydrates are made of Carbon, Hydrogen, and Oxygen. The two
functional groups are aldose (carbonyl group at the end of the
molecules) and ketose (carbonyl group in the center of the
molecule). Carbohydrates give immediate energy, store energy, and
provide raw and structural materials. Polysaccharides can
either be branched or linear. Branched polysaccharides have
several end for glucose to be released quickly, while linear
polysaccharides do not. Structural polysaccharides such as
cellulose and chitin form cell walls. If the carbohydrate has an
alpha configuration, it is folded in loops and is easier to digest.
Beta configuration carbohydrates are formed in pleated sheets and
are more difficult to digest.
LipidsLipids are composed of Carbon, Hydrogen, and Oxygen, but
mostly hydrocarbons.
Lipids include fats, waxes, steroids, pigments, and
phospholipids. Lipids only form in their monomers, fatty acids.
Lipids store energy, provide structure to cells, insulate the body,
and
fusion organs. Phospholipids have hydrophobic tails made of
saturated and unsaturated fats and hydrophilic heads. They form the
cell membranes by arranging in a bilayer with heads on the outside
and tails on the inside. Saturated fats only have single bonds
between carbon atoms and are solid at room temperature. The single
bonds allow them to form straight lines and pack tightly together.
Unsaturated fats have one or more double bonds between carbon atoms
and which causes a bend in the structure so they can't pack as
tightly
together, causing them to be liquid at room temperature.
ProteinsAmino acids are the monomers of proteins and
polypeptides are the polymers of proteins. Proteins consist of a
sequence of the same 20 amino acids held together
by peptide bonds. The levels of structure are primary (sequence
of amino acids), secondary (folding in alpha or beta helix),
tertiary (interactions between r-groups), and quaternary (joining
of polypeptide chains). Proteins can be unfolded, or denatured, due
to physical or chemical changes to the environment. Chaperonins
create an isolated are for proteins to re-fold. Proteins can be
used in chemical reactions, structure, transport, signaling,
receptors, motor, and defense.
Nucleic AcidsNucleic acids store and transmit hereditary
information throughout cells. The monomers of nucleic acids are
nucleotides. Nucleotides are made of a nitrogen-containing base, a
pentose sugar, and a phosphate group. The nucleotide bases are
divided into the pyrimidine and purine groups. The pyrimidine group
contains Cytosine, Thymine, and Uracil and the purine group
contains Adenine and Guanine. DNA had two strands of deoxyribose
sugar with nitrogenous bases Adenine and Thymine, and Cytosine and
Guanine connected to each other in the middle. RNA has a single
strand of ribose sugar with nitrogenous bases Adenine, Guanine,
Cytosine, and Uracil. DNA uses a dividing and replication process
to form RNA, which then forms proteins.
Standards: 4.A.1:a1-4,b1-3
