Bio1151b
Chapter
4
Carbon and the Molecular Diversity of Life
Living organisms are made up of
compounds based mostly on the element
carbon.
which has
valence
electrons, and can form four covalent bonds with many
atoms.
Hydrocarbons such as
and
consist
of
only
and
.
are molecules with the same molecular
formula
but different
.
isomers differ in the covalent
arrangements
of their atoms.
isomers differ in
arrangements
around a
bond.
are
mirror
images of each other, centered around an
carbon.
groups are the chemically reactive groups of atoms that give
molecules distinctive
chemical
properties.
The
hydroxyl
group (–OH) is
, helping molecules such as ethanol and
carbohydrates
dissolve in
.
The
carbonyl
group (C=O) is slightly polar and can be either at the end of a carbon skeleton (
) or within the skeleton (
).
The
carboxyl
group (-COOH) is found in carboxylic acids. The hydrogen of this group can dissociate, making such molecules weak
.
The
amino
group (-NH
2
) can accept a proton (H
+
), thereby acting as a
.
The
sulfhydryl
group (-SH) helps stabilize the
structure
of some proteins.
The
phosphate
group (-OPO
3
2-
) can transfer energy between molecules.
Adenosine Tri-Phosphate (
) is an important source of energy for cellular processes.
Bio1151b
Chapter
5
The Structure and Function of Macromolecules
Macromolecules
are polymers that are made from linking building blocks (
) with
bonds
by
, and can
disassemble
by
.
Carbohydrates include
and serve as fuel and building material.
Monosaccharides
are sugar monomers and can be linked to form
.
such as
sucrose
, lactose, and
maltose
consist of two monosaccharides.
include
starch,
cellulose,
glycogen,
and
chitin.
are mostly neutral
and thus are
.
Fats
can be
with
no
double bonds, or
with double
bonds.
Two important classes of lipids in cells are
phospholipids
and
steroids.
Proteins
consist of one or more
chains, which are polymers of amino acids.
Amino
acids are linked by
bonds
to form the
structure
of
proteins.
Most proteins fold into a specific
defined by its
structure,
structure,
and
structure.
An
is a protein that acts as a
,
speeding
up chemical reactions.
Nucleic acid
polymers
called
are made of
monomers.
DNA is usually composed of two polynucleotide strands wound around each other in a
helix.