What are the four main classes of important molecules of all living things?
- Carbohydrates
- Lipids
- Proteins
- Nucleic acids
These classes encompass the essential biological macromolecules.
What is a polymer?
A long molecule consisting of many similar building blocks called monomers.
Polymers are formed through the linking of monomers.
What occurs during a dehydration reaction?
Two monomers bond together through the loss of a water molecule.
An -OH is removed from one monomer and an -H from another, forming H2O.
What is hydrolysis?
The process of disassembling polymers to monomers by adding water.
It is the reverse of dehydration reaction.
What role do carbohydrates serve in living organisms?
They serve as fuel and building material.
Carbohydrates include sugars and polymers of sugars.
What are the simplest carbohydrates called?
Monosaccharides.
These are the basic building blocks of carbohydrates.
What are polysaccharides?
Polymers composed of many sugar building blocks.
They are formed by the linkage of monosaccharides.
What is the most common monosaccharide?
Glucose (C6H12O6).
Glucose is a primary source of energy for cells.
What is starch?
A storage polysaccharide of plants.
Starch serves as an energy reserve for plants.
What is cellulose?
A major component of the tough cell walls of plant cells.
Cellulose provides structural support to plants.
What is glycogen?
A storage polysaccharide in animals.
Glycogen serves as a form of energy storage in animal cells.
What is chitin?
Chitin is a structural polysaccharide found in the exoskeleton of arthropods and the walls of fungi.
Do lipids form true polymers?
No, lipids do not form true polymers.
Why are lipids hydrophobic?
Lipids are hydrophobic because they consist mostly of hydrocarbons, which form nonpolar bonds.
What are the two smaller molecules that fats are constructed from?
Fats are constructed from glycerol and fatty acids.
How is triacylglycerol formed?
Triacylglycerol is formed by the joining of three fatty acids to a glycerol backbone in a dehydration reaction.
What is released during the formation of triacylglycerol?
Three molecules of water are released in the process.
How do fatty acids vary?
Fatty acids vary in length (number of carbons) and in the number and locations of double bonds.
What are saturated fatty acids?
Saturated fatty acids have the maximum number of hydrogen atoms possible and no double bonds.
What are fats made from saturated fatty acids called?
Fats made from saturated fatty acids are called saturated fats and are solid at room temperature.
What are unsaturated fatty acids?
Unsaturated fatty acids have one or more double bonds.
What is the major function of fats?
The major function of fats is energy storage.
What is a phospholipid?
A phospholipid consists of two fatty acids and a phosphate group attached to glycerol.
What are the properties of the fatty acid tails in a phospholipid?
The two fatty acid tails are hydrophobic, but the phosphate group is hydrophilic.
