Ch.5: Macromolecules Flashcards
Living things are made up of four classes of macromolecules:
Carbohydrates, lipids, protein, and nucleic acid
are large molecules composed of thousands of covalently connected atoms
macromolecules
is a long molecule consisting of many building blocks
Monomers
polymers
Three of the four classes of life’s organic molecules are polymers:
Carbohydrates, proteins and nucleic acid
Monomers are bonded together via a
condensation reaction/ dehydration reaction
Polymers are disassembled into monomers by XXXX a reaction that is essentially the reverse of the dehydration reaction
Hydrolysis
Description of Carbohydrates:
monosachrides and disaccharides and polysaccharide glucose, sucrose, starch simple sugar major fuel for cells raw material for building molecules
storage and structure
polysaccharide
a storage polysaccharide of plants, consists entirely of glucose monomers
starch
is a storage polysaccharide in animals
glycogen
is a major component of the tough wall of plant cells
XXXX is not easily digested
XXXXX in human food passes through the digestive tract as insoluble fiber
Starch and XXXXX are both polymers of glucose, but their bonds differ.
Cellulose
another structural polysaccharide, is found in the exoskeleton of arthropods
XXXXX also provides structural support for the cell walls of many fungi
Chitin
Describe Lipids:
do not form polymers
have little or no affinity for water
Nonpolar
The most biologically important lipids are fats, phospholipids, and steroids*
are actually alcohols but alcohols behave like lipids
Steroids
Fats are constructed from two types of smaller molecules
glycerol and fatty acids
a three-carbon alcohol with a hydroxyl group attached to each carbon
Glycerol
consists of a carboxyl group attached to a long carbon skeleton
fatty acids
Saturated fatty acids have
no double bonds
the maximum number of hydrogen atoms possible
Unsaturated fatty acids have
one or more double bonds
The major function of fats is
to store energy
two fatty acids and a phosphate group are attached to glycerol
The two fatty acid tails are hydrophobic
The phosphate group and its attachments form a hydrophilic head
These properties make it a wonderful material to form membranes
phospholipid
lipids characterized by a carbon skeleton consisting of four rings
steroids
an important component in animal cell membranes
Maintains correct membrane fluidity
However, high levels in the blood may contribute to cardiovascular disease
cholesterol
Describe protein:
account for more than 50% of the dry mass of most cells
Function:
support, storage, transport, cellular communications, movement, and defense against foreign substances