Biological Molecules - Fall River Public Schools
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Transcript Biological Molecules - Fall River Public Schools
The building block of life.
All
living and once-living things are
made up of the element carbon
Carbon is unique because it can make up
to four strong covalent bonds
• Bonds can be single, double, or triple bonds
Carbon
compounds form 3 main shapes:
A
single chain or ring is called a
monomer
Many monomers can join together to
make a large “macromolecule” called a
polymer
A reaction that combines two or
monomers is called a condensation
reaction
• H2O is also produced through condensation
reactions
• Also called dehydration synthesis
The
opposite of dehydration synthesis is
hydrolysis
• Water (H2O) is added to a polymer and breaks
the bonds linking two monomers together
• http://www.biotopics.co.uk/as/disaccharidehyd
rolysis.html
Carbohydrates
are compounds made of
carbon, hydrogen, and oxygen in a 1:2:1
ratio (example: CH2O, C6H12O6)
All living things use carbs as their main
source of energy
• Plants use starch
• Animals use glycogen
Carbohydrates
cells
are also used for structure in
• Plants have cellulose in their cell walls
• Fungi have chitin in their cell wall and insects have
chitin in their exoskeletons
Carbohydrates
are sugars, or
saccharides
A single sugar molecule is called a
monosaccharide
• Glucose is a very important monosaccharide
and makes up many more complex sugars
• Other examples of monosaccharides include:
Sucrose – table sugar
Lactose, found in milk
Fructose, found in most fruits
Many
monosaccharides linked together
are called polysaccharides
• Starch, glycogen are long chains of glucose
molecules
• Cellulose and chitin are also polysaccharides
Proteins
are made up of the elements
carbon, hydrogen, oxygen, nitrogen, and
sulfur
Proteins are polymers of molecules
called amino acids
• More than 20 different amino acids exist in
nature
http://www.biotopics.co.uk/as/aminocon.html
Proteins
have four main shapes
• Straight chain of amino acids
• Chain with twisted amino acids
• Twisted and folded chain
• Knotted chain
Protein
chains are connected by two
bonded sulfur atoms, called disulfide
bridges
Proteins
control the rates of reactions and
regulate cell processes (enzymes)
Proteins also provide structure within living
things
Examples:
• Collagen makes up cartilage, tendons (muscles),
skin, and bones
• Keratin makes up horns, feathers, hair, and finger
nails
• Enzymes increase reaction rates
Carbonic anhydrase quickly removes carbon dioxide from
the bloodstream
Lactase breaks down lactose
Lipids
are made up of carbon, hydrogen,
oxygen, and phosphorous
Lipids are fats, oils, waxes, and steroids
Lipids are made up of a glycerol
backbone and fatty acid chains
GLYCEROL
FATTY ACIDS
A saturated fatty acid is a
fatty acid chain where all
carbons are linked by
single bonds
• Saturated fats are solids at
room temperature
An unsaturated fatty acid is
a fatty acid chain where
there is at least one double
bond between two carbon
atoms
• The fatty acid chains are
bent where there are double
bonds
• Unsaturated fats are liquids
at room temperature
Lipids
are used for long-term energy
storage
• Fats are used for energy storage
Lipids
are also used in cell membranes
and to deliver chemical messages
• Phospholipids make up cell membranes
• Steroids include hormones, which deliver
chemical messages, and cholesterol
• Waxes include ear wax, beeswax, and the
waterproof wax coating on plant stems and
leaves
Nucleic
acids are made up of carbon,
hydrogen, oxygen, phosphorous, and
nitrogen
Nucleic acids are made up of nucleotides
Nucleotides are made up of
• 5-Carbon sugar – deoxyribose (DNA) or ribose
(RNA)
• Nitrogen base – A, T, G, C, or U
• Phosphate group
Nucleic
Acids store genetic information
(DNA) or synthesize, or put together,
proteins (RNA)
The order of the nitrogen base pairs
determine genetic code
• DNA has adenine (A), guanine (G), thymine (T),
and cytosine (C)
• RNA has A, G, C, and uracil (U) instead of T
• A always joins T or U and G always joins C
DNA HAS A DOUBLE HELIX
SHAPE
RNA HAS A SINGLE HELIX
SHAPE