Unit 2 Biochemistry and the Molecules of Life

The nucleus of an atom is composed of

• protons

• neutrons

• protons and neutrons

• protons and electrons

The polymers with the most complex and diverse three-dimensional structures are

• proteins

• lipids

• carbohydrates

An ionic bond is a bond in which

• atoms share electrons

• a bond between hydrogens

• atoms of opposite charges attract each other

The elements or compounds that enter into a chemical reaction are called _.

• products

• catalysts

• active sites

• reactants

Which of the following is NOT an organic molecule found in living organisms.

• protein

• nucleic acid

• sodium chloride

• lipid

Which combination of particle and charge is correct?

• Proton: positive charge

• electron: positive charge

• neutron: negative charge

• electron: no charge

In which of the following ways do isotopes of the same element differ?

• in number of neutrons only

• in number of protons only

• in number of neutrons and protons

• in number of neutrons and in mass

The particle that has no charge is called:

• electron

• neutron

• proton

A covalent bond is formed by the

• transfer of electrons

• sharing of electrons

• gaining of electrons

• losing of electrons

When you shake sugar and sand together in a test tube, you cause them to form a

• compound

• mixture

• solution

• suspension