Key Topics for Chapter 2:CHEMISTRY OF LIFE
• The difference between matter, elements, and compounds
• The main elements in the human body
• The structure of atoms
• Chemical bonds
• Energy, metabolism, and chemical reactions
• Characteristics of water and the roles of water in the body
• The difference between compounds and mixtures
• Acids, bases, and pH
• Types of carbohydrates and their roles in the body
• Types of lipids and their roles in the body
• The structure of protein
• Nucleic acids and ATP
Page 1
, Elements
1. Elements are the simplest chemicals, which make up all matter.
2. Carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur, and calcium make up 99%
of the human body.
3. Elements combine in many ways to form molecules.
Atoms
1. Atoms are the smallest part of an element that still retains the characteristics of the
element.
2. Atoms consist of positively and negatively charged particles and neutral (or
uncharged) particles.
• Protons have a positive charge and are found in
the nucleus of the atom.
• Neutrons have no charge and are found in the
nucleus of the atom.
• Electrons have a negative charge and orbit the
nucleus.
3. The number and arrangement of electrons give an
atom its bonding capabilities.
Chemical Bonds
1. An ionic bond involves the loss of electrons by one atom and the gain of these
electrons by another atom: Ions are formed that attract one another .
• Cations are ions with positive charges: Na, Ca
• Anions are ions with negative charges: Cl, HCO .
Page 2
• The difference between matter, elements, and compounds
• The main elements in the human body
• The structure of atoms
• Chemical bonds
• Energy, metabolism, and chemical reactions
• Characteristics of water and the roles of water in the body
• The difference between compounds and mixtures
• Acids, bases, and pH
• Types of carbohydrates and their roles in the body
• Types of lipids and their roles in the body
• The structure of protein
• Nucleic acids and ATP
Page 1
, Elements
1. Elements are the simplest chemicals, which make up all matter.
2. Carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur, and calcium make up 99%
of the human body.
3. Elements combine in many ways to form molecules.
Atoms
1. Atoms are the smallest part of an element that still retains the characteristics of the
element.
2. Atoms consist of positively and negatively charged particles and neutral (or
uncharged) particles.
• Protons have a positive charge and are found in
the nucleus of the atom.
• Neutrons have no charge and are found in the
nucleus of the atom.
• Electrons have a negative charge and orbit the
nucleus.
3. The number and arrangement of electrons give an
atom its bonding capabilities.
Chemical Bonds
1. An ionic bond involves the loss of electrons by one atom and the gain of these
electrons by another atom: Ions are formed that attract one another .
• Cations are ions with positive charges: Na, Ca
• Anions are ions with negative charges: Cl, HCO .
Page 2
