Chapter 2

Oxygen

Oxygen is used by cellular organelles to release energy from glucose. (TRUE)

A+B→AB

A __(synthesis)__ reaction is symbolized as A+B→AB.

A chemical reaction

A chemical reaction in which pairs of two of different molecules trade positions with one another is a(an) (. Exchange reaction)

covalent bond

A covalent bond is formed by two atoms that exchange electrons. (FALSE)

molecular formula

A molecular formula represents the numbers and ypes of atoms in a olecule. (TRUE)

molecule of a compound

A molecule of a compound always contains definite kinds and numbers of (Atoms)

A solution

A solution that contains more hydroxide ions than hydrogen ions is (Basic) A solution that contains more hydrogen ions than hydroxide ions is __(acidic)_.

ionizes in water

An __(electrolyte)__ is defined as a substance that ionizes in water.

An acid

An acid is defined as an electrolyte that releases hydroxyl ions (OH-) in water and an example is sodium hydroxide. (FALSE)

compounds that release ions

As a group, compounds that release ions when they dissolve in water are called (Electrolytes)

hydrogen ion

As hydrogen ion concentration increases the pH number (Gets smaller) A substance that releases hydrogen ions in water is a base. (FALSE) __(pH)_ measures hydrogen ion concentration.

90 naturally occurring

At present, there are 90 naturally occurring __(elements)__.

Buffers

Buffers combine with hydrogen ions when they are in excess or they donate hydroxide ions when they are depleted. (FALSE)

Carbon dioxide

Carbon dioxide is (A waste product of metabolic processes and exhaled from the lungs)

Chemicals

Chemicals that resist changes in pH are called (Buffers)

Cholesterol

Cholesterol is a protein that is used by the body to make sex hormones. (FALSE)

whole number

Each whole number on the pH scale represents a _(10 fold )_ difference in hydrogen ion concentration.

Elements

Elements are composed of tiny particles called _(atoms)__. Which of the following substances is not an element? (ATP) An element with an atomic number of 6 contains 12 protons. (FALSE)

reactant molecule

If the bonds within a reactant molecule break so that simpler molecules, atoms or ions form, the reaction is an exchange reaction. (FALSE)

electrons

If two pairs of electrons are shared, the resulting bond is called a double covalent bond. (TRUE) The electrons of an atom occupy one or more areas of space called? (Shells)

Inorganic substances

Inorganic substances dissociate in water to release ions. (TRUE) Which of the following chemicals is not an inorganic substance? (Carbon)

Sodium and chloride ions

Sodium and chloride ions combine readily because they both tend to lose or gain _(electrons)_.

atom

The __(atomic weight)_ of an atom of an element equals the number of protons and neutrons in its nucleus. An atom that has gained or lost electrons is called an ion. (TRUE)\ Atoms that gain or lose electrons become electrically charged and are called __(ions)__. The electrons of an atom occupy one or more areas of space called? (Shells) The atoms of the isotopes of a particular element vary in the number of (Neutrons) When two or more atoms bond, they form a new kind of particle called a molecule. (TRUE) When atoms combine with other atoms, interactions occur between their _(electrons)_. The atomic weight of an atom of an element equals the number of neutrons in its nucleus. (FALSE) A __(structural formulas)__ shows how atoms are joined and arranged in various molecules.

atomic weight

The atomic weight of an atom of an element equals the number of neutrons in its nucleus. (FALSE)

positive hydrogen end of a polar molecule

The attraction of the positive hydrogen end of a polar molecule to the negative nitrogen or oxygen end of another polar molecule is called a(an) (Hydrogen bond)

building blocks

The building blocks of proteins are amino acids. (TRUE) The building blocks of fat molecules are amino acids. (FALSE) ____(nucleotides)__ are the building blocks of nucleic acids.

carbohydrates

The different types of carbohydrates do not include (Proteins)

The first electron shell

The first electron shell of an atom can hold a maximum of (2 electrons )

electron shell

The first electron shell of an atom can hold a maximum of (2 electrons)

protons in the atoms

The number of protons in the atoms of a particular element is called the element's __(atomic number)__.

protons

The number of protons in the atoms of a particular element is called the element's ___(atomic number)_.

chemical bond

The type of chemical bond formed when atoms share electrons is called __(covalent bond)_.

pH

The value called pH measures the hydrogen ion concentration in solutions such as body fluids. (TRUE) A person has alkalosis if the blood pH (Rises above 7.45) _(buffers)__ are chemicals that resist changes in pH. A pH of __(7)__ is the midpoint of the pH scale and contains equal numbers of hydrogen and hydroxide ions. Each whole number on the pH scale represents a __(10 fold)_ difference in hydrogen ion concentration. The pH scale ranges from __(0-14)___. A solution that has a pH of 6 has ten times the hydrogen ion concentration of a solution with a pH of (7)

chemistry

Understanding chemistry is essential for understanding anatomy and physiology because body structures and functions result from ___(chemical changes)__.

Water

Water is an example of a compound. (TRUE)

organic substance

Which of the following is not an organic substance? (Carbon dioxide)

95% of the human body

Which of the following substances comprise 95% of the human body? (Carbon, hydrogen, oxygen, nitrogen)

cellular activities

_(fats)_ are used primarily to store energy for cellular activities.

DNA and RNA

__(nucleic acids)__ include the molecules known as DNA and RNA.