Specialized macromolecules that speed up chemical reactions
What happens in a dehydration reaction?
Monomers are connected by a reaction in which two molecules are covalently bonded to each other with the loss of a water molecule. One monomer provides a hydroxyl group (-OH) and the other provides a hydrogen (-H)
What process disassembles polymers into monomers?
The opposite of a dehydration reaction is:
Dehydration _________ a polymer while Hydrolysis ______ ____ a polymer
Dehydration Synthesizes a polymer while Hydrolysis BreaksDown a polymer
What are the simplest carbohydrates?
monosaccharides (simples sugars)
What are disaccharides?
Double sugars consisting of two monosaccharides joined by a covalent bond
What is the general molecular formula of monosaccharides?
Glucose C6H12O6 is the most common monosaccharide
Define glycosidic linkage:
a covalent bond formed between two monosaccharides by a dehydration reaction
Polymers with a few hundred to a few thousand monosaccharides joined by glycosidic linkages are known as
Plants store polysaccharides for later use in the form of what?
How can a plant withdraw sugars from its stored starch reserves?
Animals store polysaccharides for later use in the form of what?
What important trait do lipids have that groups them together?
The are all hydrophobic
What two kinds of smaller molecules compose fat?
Why are fats hydrophobic?
Because of the relatively non polar C-H bonds in their hydrocarbon chains
What does triacylglycerol consist of?
3 Fatty Acid molecules joined to glycerol by ester linkage
What is a saturated fatty acid?
A fatty acid in which there are no double bonds between carbon atoms in the hydrocarbon chain allowing maximum hydrogens to be bonded
What is the major function of fats?
Why are phospholipids essential to cells?
Because they make up the cell membrane
What is the molecular difference between phospholipids and fat molecules?
Phospholipids only have 2 fatty acids attached to a glycerol instead of 3 and have an additional phosphate and choline group
What happens when phospholipids are added to water?
They self assemble into double-layered structures called bilayers shielding their hydrophobic portions from water
What are steroids?
Lipids characterized by a carbon skeleton consisting of 4 fused rings
A high level of cholesterol in the blood may contribute to which disease?
Cholesterol is a crucial molecule in animals why?
Common component of animal cell membranes
It acts as the precursor from which other steroids are synthesized from
In vertebrates, what organ synthesizes cholesterol?
Enzymatic proteins regulate metabolism by acting as:
Chemical agents that selectively speed up chemical reactions without being consumed by the reaction
What are polypeptides?
Polymers of amino acids
A biologically functional molecule that consist of one or more polypeptides, each folded and coiled into a specific three dimensional structure
What is a polymer?
A long molecule consisting of many similar or identical monomers linked together by covalent bonds
What is a monomer?
The subunit that serves as the building blocks of polymers
Enzymatic Protein Function and Example:
Function: Selective acceleration of chemical reactions
Example: Digestive enzymes catalyze the hydrolysis of bonds in food molecules
Defensive Protein Function and Example:
Function: Protection against disease
Example: Antibodies inactivate and help destroy viruses and bacteria
Storage Protein Function and Example:
Function: Storage of amino acids
Example: Casein the protein of milk
Transport Protein Function and Example:
Function: Transport of substances
Example: Hemoglobin, the iron-containing protein of vertebrate blood that transports oxygen in red blood cells
Hormonal Protein Function and Example:
Function: Coordination of an organism's activities
Example: Insulin, a hormone released by the pancreas, causes tissues to take up glucose, thus regulating blood sugar concentrations
Receptor Protein Function and Example:
Function: Response of cell to chemical stimuli
Example: Receptors built into the membrane of a nerve cell
Contractile and Motor protein Function and Example:
Example: Motor proteins are responsible for the undulations of cilia and flagella.
Actin and myosin proteins are responsible for the contraction of muscles
Structural Protein Function and Example:
Example: Keratin and Collagen
What is an amino acid?
An organic molecule possessing both an amino group and a carboxyl group
Which two groups do ALL amino acids have?
The resulting covalent bond from a dehydration reaction of amino acids is formally known as: