Water and Life Quiz

Which atom in a molecule of water has a slightly negative charge?

• hydrogen

• oxygen

Why do the biochemical reactions of living things depend on water?

• Water may be a reactant or a product.

• Water can dissolve many substances.

• Water must be present for many biochemical reactions to take place.

• Water holds energy needed for many reactions.

A hydration reaction combines molecules to form a single, larger molecule and a water molecule.

• TRUE

• FALSE

When table salt dissociates, it forms two charged ions. These charges are attracted to the charges in a water molecule, allowing the salt to dissolve. This attraction of charges to water can dissolve many substances. This occurs because

• water is a polar molecule.

• salt is a polar molecule.

• water dissociates into hydrogen and hydroxide ions.

• salt binds to water molecules.

Cells use the energy in sunlight to combine carbon dioxide and water to synthesize glucose and oxygen during the process of ____________________.

In cellular respiration, cells break down glucose to release energy, water, and carbon dioxide. What is another reactant required for this process?

• hydrogen

• oxygen

• nitrogen

• carbon

What are hydrogen bonds?

• Weak bonds between the oxygen atom of one water molecule and a hydrogen atom of another.

• Weak bonds between the hydrogen atoms of water molecules.

• Strong bonds between the oxygen atom of one water molecule and a hydrogen atom of another.

• Strong bonds between the hydrogen atoms of water molecules.

How does the strength of intramolecular bonds within a water molecule compare to the strength of intermolecular bonds between water molecules?

• The intramolecular bonds within a water molecule are stronger than the intermolecular bonds between water molecules.

• The intermolecular bonds between water molecules are stronger than the intramolecular bonds within a water molecule.

• The strength of both intramolecular and intermolecular water bonds of water molecules is the same.

• While water molecules are held together by intramolecular bonds, there are no intermolecular bonds between water molecules.

The _______ charge around a hydrogen atom in a water molecule is attracted to the ________ charge around a neighboring oxygen atom.

• positive, negative

• negative, positive

• negative, negative

• positive, positive

Many substances dissolve in water. This allows them to quickly and easily travel throughout the body. What allows this to happen?

• This is possible because water is a polar molecule.

• This is possible because water is a liquid.

• This is possible because water has a neutral pH.

• This is possible because the body is mostly water.