Transcript Biological Chemistry and Macromolecules

Organic Chemistry
 Molecules made up of
carbon and hydrogen are
called organic compounds.
 Oxygen and Nitrogen are
common atoms found in
organic compounds as
well.
 In many molecules, atoms
are arranged in special
clusters called functional
groups.
Common Functional Groups
Macromolecules
 A macromolecule is a
large molecule made up
of smaller subunits often
with many functional
groups.
 The four major groups of
macromolecules are:
carbohydrates, lipids,
proteins and nucleic
acids.
Carbohydrates
 Contain carbon, hydrogen
and oxygen.
 Used mostly for energy.
 Produced by plants in
photosynthesis.
 Broken down into energy
by animals in cellular
respiration.
Carbohydrates
 Monosaccharides are
“simple sugars” and have
a sweet taste. The most
common one is glucose
C6H12O6.
 Disaccharides occur
when two
monosaccharides join
together (i.e. glucose +
fructose = sucrose, which
is table sugar).
Carbohydrates
 Long chains of simple
sugars combine to form
polysaccharides.
 These are called “complex
carbohydrates”.
 They are used for energy
storage like starch in plants
and glycogen in animals
OR used for structural
support like cellulose in
plant cell walls and chitin
in insect exoskeletons
(contact lenses and
stitches as well).
Good Sources of Carbohydrates
Lipids
 Made up of C, H and O
as well, but with more H.
 They store more energy
than carbohydrates, but
harder to get the energy
out of.
 Four classes of lipids: oils
and fats, waxes,
phospholipids and
steroids.
Fats and Oils
 Each of these is known as a triglyceride, contain three
fatty acids attached to a glycerol molecule.
Fats and Oils
 If the fatty acids are straight, they are known as
saturated fatty acids and the substance is a fat (i.e. lard,
butter, animal fat).
• Can lead to coronary
artery disease if over
eaten.
Fats and Oils
 If they are bent, they are called unsaturated fatty acids
and the substance is an oil (peanut oil, canola oil, plant
oils).
Phospholipids
 Main component of cell
membranes.
 Head part is hydrophilic
(loves water) while tail is
hydrophobic (hates
water).
 They are like fats and
oils, but have a
phosphate group instead
of one of the fatty acids.
Steroids
 Made up of four fused
carbon rings.
 All are derivatives of
cholesterol.
 Cholesterol is a big
reason cell membranes
are flexible and fluid.
 All our sex hormones are
natural steroids.
Waxes
 They are used by animals and plants as
waterproofing agents.
 Basically they are steroids with long side
chains coming off of them.
 Examples: beeswax, cutin on leaves…
Good Sources of Lipids
Proteins
 Most diverse and
important molecules in
living organisms.
 Made up of small
subunits called amino
acids that are held
together by peptide
bonds.
 Protein making is called
protein synthesis and
happens on ribosomes.
Proteins
 Enzymes are special proteins that are used to speed up
chemical reactions without getting used up themselves.
 If an enzyme loses its shape, it is said to be denatured
and does not work anymore.
 This happens if the temperature or pH changes.
Good Sources of Protein
Nucleic Acids
 Made up of nucleotides
that contain a sugar, a
phosphate group and a
nitrogen base.
 The two main nucleic
acids are DNA and RNA.
 DNA contains hereditary
information, whereas
RNA is used in protein
making.
Nucleic Acids
 DNA has one of four
nitrogen bases in its
nucleotides, Adenine,
Thymine, Cytosine and
Guanine.
 It is a double-stranded
molecule where A binds
to T and C binds to G.
 RNA is a single strand
and has Uracil instead of
Thymine.
Homework
1) Where in your digestive system would the
macromolecules we have discussed be broken down?
2) What other things do we need in our diets besides
the macromolecules discussed today?
3) From Austin Powers, Fat Bastard says he went on the
Atkins Diet in which “Carbs are the enemy”! Is this a
safe thing to do, eliminate carbohydrates? Why or
why not?