Download They do NOT like water!

Macromolecules
Carbohydrates
Proteins
Lipids
Nucleic Acids
Carbohydrates
Function: fuel and building material; made of C +
H2O.
– Monosaccharides (simple or single sugars).
Ex: glucose, galactose, fructose
– Disaccharides (double sugars).
– Ex: sucrose, fructose, maltose
– Polysaccharides are
long chains of
monosaccharides.
– Ex: cellulose (starch in flour)
– glycogen (in animals)
Carbohydrates
Monosaccharides have molecular formulas that
are some multiple of CH2O. Ex: glucose and galactose
C6H12O6.
– Most names for sugars end in –ose: glucose, ribose.
Monosaccharides form disaccharides by
dehydration. (chemical reaction)
SEE NEXT TWO SLIDES
Carbohydrates
Polysaccharides are polymers of hundreds
to thousands of monosaccharides.
1) Function in energy storage (used as
needed).
Ex: starch (in plants) and glycogen (in animals’
livers)
2) Function as strong building materials. Ex: cellulose
Lipids
Lipids are hydrophobic: They do NOT like water!
– In a triglyceride, 3 fatty acids (same or different)
are joined to glycerol.
glycerol
3 fatty
acids
Lipids
• A saturated fat has no carbon-carbon double bonds,
and it is straight. They pack together – solid at room
temperature.
• Unsaturated fats have one or more carbon-carbon double
bonds, and they bend. They can’t get close to each other, so
they are liquid at room temperature.
Lipids
Saturated fats come from animal products.
– Ex: butter, lard
– A diet rich in saturated fats may contribute to
cardiovascular disease (heart attack, stroke)
through plaque deposits in arteries; obesity,
diabetes.
Lipids
Unsaturated fats come from plant & fish
products.
– Ex: olive oil, corn oil, safflower oil, fish oils.
– Generally considered healthier for the heart.
Lipids
Functions of lipids
– Nutrition: 1g of fat contains twice as much energy
as 1g of carbohydrate.
– Protection: cushions vital organs and insulates
them.
• This subcutaneous layer is especially thick in whales,
seals and most other marine mammals.
Lipids
Functions of lipids
– Phospholipids: MAJOR components of cell
membranes.
• Have two fatty acids attached to glycerol and a
phosphate group at the third position.
Lipids
Functions of lipids
– Waxes reduce water loss by plants.
• Carnauba wax
– Steroids
• Cholesterol is a component in animal cell membranes.
• Many steroids are hormones.
Nucleic acids
All molecules of the body are programmed by a
genetic code in the organism’s DNA, a polymer
of nucleic acids.
– Nucleic acids store and
transmit hereditary information.
A nucleic acid
Nucleic acids
There are two types of nucleic acid polymers:
• Ribonucleic acid (RNA)
– Single-stranded.
– Contains adenine,
guanine, cytosine,
and uracil.
– Sugar is ribose.
• Deoxyribonucleic
(DNA)
– Double stranded.
– Contains adenine, guanine, cytosine, and thymine.
– Sugar is deoxyribose.
acid
Proteins
Humans have at least 30,000 different proteins,
each with a unique structure and function.
– Functions include structural support, storage,
transport of materials, intercellular signaling,
movement, and defense.
– Enzymes are one class of proteins that regulate
metabolism by moderating chemical reactions.
– All proteins are structurally complex in 3 dimensions.
– All are constructed from the same set of 20
monomers, called amino acids.
Proteins
Amino acids are joined by
dehydration; the resulting
covalent bond is called a
peptide bond.
• Polymers of amino acids
are called polypeptides.
Proteins
A protein’s function depends on
its precise twisting, folding, and
coiling into a unique shape.
– The order of amino acids
determines what the threedimensional shape will be.
– Folding of a protein occurs
spontaneously: an emergent
property resulting from its
specific molecular order.
Proteins
In individuals with sickle cell disease, abnormal
hemoglobins develop because of a single
amino acid substitution.
Proteins
Fibrous proteins are long, insoluble molecules .
– For movement (muscle fibers);
– For structure and support.
• Collagen in skin.
• Cartilage connects tissues.
Keratin is found
in hair, horns,
wool, nails, and
feathers.
Proteins
Globular proteins are soluble and form compact
spheroidal molecules in water.
– Transport proteins and
receptor proteins are
globular.
– Enzymes are globular
proteins that are involved in chemical
reactions (enzymes
generally end in –ase).
– Antibodies
Hemoglobin – transport of oxygen
Proteins
Transport proteins and receptor proteins in the cell
membrane capture chemicals in the blood and may
move them into the cell.
Proteins
A protein’s shape can change in response to changes in pH, salt
concentration, temperature. These forces disrupt the bonds
that maintain the protein’s shape. This is called denaturation.
Then the protein won’t work right.