Biological Molecules Flashcards
What is a hydrogen bond?
A weak interaction that can occur whenever molecules contain a slightly positive charged atom bonded to a slightly negative charged atom.
What is a hydrolysis reaction?
A reaction that occurs when a molecule is split into two smaller molecules with the addition of water.
What is a monomer?
A small molecule which binds to many other identical molecules to form a polymer.
What is a polymer?
A large molecule made up of monomers.
Why is a water molecule polar?
oxygen has a greater number of positive protons in its nucleus so that it exerts a greater attraction for shared electrons making it slightly negative and the hydrogen atoms become slightly positive
Why is a hydrogen bond weaker than a covalent bond?
A hydrogen bond is a weak interaction between slightly positive and slightly negative molecules whereas covalent bonds are the sharing of electrons to gain a full outer shell.
What are carbohydrates?
A group of molecules containing carbon, hydrogen and oxygen.
What is a condensation reaction?
A reaction that occurs when two molecules join together with the removal of water.
What is a glycosidic bond?
A bond formed between two monosaccharides by a hydrolysis reaction.
What is the function of carbohydrates?
To act as a source of energy(glucose), a store of energy(starch and glycogen), and as structural units(cellulose in plants).
What are the three main groups of carbohydrates?
Monosaccharides, disaccharides and polysaccharides.
What are monosaccharides?
The simplest carbohydrates. Good source of energy because of large number a carbon to hydrogen bonds. Soluble in water and insoluble in non- polar solvents.
What are disaccharides?
Sweet and soluble.
Most common is maltose.
Give an example of a reducing sugar?
Maltose and lactose.
Give an example of a non-reducing sugar?
Sucrose.
How are disaccharides made?
When two monosaccharides join.
What makes maltose?
Alpha-glucose + alpha-glucose.
What makes sucrose?
Alpha-glucose + fructose.
What makes lactose?
Beta-galactose + alpha-glucose.
What makes cellobiose?
Beta-glucose + beta-glucose.
What happens when monosaccharides join.
A condensation reaction and a glycosidic reaction.