Exam 2: A: The Chemical Basis of Life

Inorganic compounds do not play an important role in living systems.

Oxygen has 8 electrons,but only 6 of them are in its outermost energy level.

Sodium chloride is an example of an ionic bond.

Synthesis reactions release energy for use by the cell.

According to the general formula,in decomposition reactions,the number of reactants is usually greater than the number of products.

Glycogen and starch are both examples of polysaccharides.

Because oxygen has 8 electrons,it has achieved its octet and will not react with other elements.

If an atom has an atomic number of 12 and an atomic mass of 25,it must have 13 neutrons.

A molecule can be an element or a compound.

When ATP is in short supply,muscles can use creatine phosphate for extra energy.

There are a total of 21 essential amino acids.

Nonessential amino acids are rarely used in the making of proteins in the human body.

The number of protons in the nucleus of an atom determines its atomic mass.

The atomic number of an atom determines its identity.

Two shared pairs of electrons represent a single covalent bond.

An atom is chemically inert if its outermost shell has two pairs of electrons.

A triglyceride is composed of a glycerol molecule and three of the same type of fatty acid.

The idea that electrons are found in areas of probability distribution around the nucleus was first proposed by Niels Bohr.

During catabolic reactions,some of the energy is released as heat to help keep the body warm.

Enzymes are proteins that function by the lock-and-key theory.