The Chemistry of Life – Foundations for Anatomy & Physiology

The Chemistry of Life

Introduction to Chemistry in Anatomy & Physiology

Chemistry is fundamental to understanding the structure and function of living organisms. In Anatomy & Physiology, chemical principles explain how biological molecules interact and how energy is transferred within the body.

• Chemistry: The study of matter, including its composition, structure, properties, and transformations.

• Inorganic Chemistry: Focuses on compounds not based on carbon.

• Organic Chemistry: Studies compounds based on carbon.

• Biochemistry: Examines chemical reactions and interactions within living organisms.

Matter and Energy

Forms and Properties of Matter and Energy

All living things are composed of matter and require energy to function. Understanding these concepts is essential for studying physiological processes.

• Energy: The ability to do work.

• Two main types of energy:

  • Kinetic energy: Energy of motion.

  • Potential energy: Stored energy due to position or structure.

• Forms of energy include mechanical, nuclear, electrical, radiant, chemical, and magnetic.

• Matter: Anything that has mass. Note: Mass is not the same as weight.

Elements

Elements and Their Role in the Human Body

Elements are the building blocks of matter. The human body is primarily composed of a small number of elements, each with specific roles in physiological processes.

• Elements: Substances that cannot be broken down into simpler substances by ordinary chemical methods.

• Four elements make up 96% of the body:

  • Carbon (C)

  • Oxygen (O)

  • Hydrogen (H)

  • Nitrogen (N)

• 9 elements make up 3.9% of the body.

• 11 elements make up less than 0.01% of the body.

• The periodic table lists all known elements.

Atoms

Structure and Properties of Atoms

Atoms are the smallest units of elements that retain their chemical properties. Their structure determines how they interact in chemical reactions.

• Atom: Once thought to be indivisible; the term comes from the Greek "atomos" meaning "uncuttable" or "indivisible".

• Scale analogy: Atom : Apple :: Apple : Planet Earth.

Atomic Structure

Atoms consist of a dense nucleus surrounded by electrons.

• Nucleus: Contains protons and neutrons.

• Protons: Positively charged particles.

• Neutrons: Neutral particles with no charge.

• Electrons: Negatively charged particles that "orbit" the nucleus.

• Example: Boron atom (atomic number 5) has a nucleus of 5 protons and 5 neutrons, with 5 electrons orbiting the nucleus.

Subatomic Particles and Atomic Properties

The number and arrangement of subatomic particles determine the identity and behavior of atoms.

• Proton count: Determines the atomic number and the element.

• Neutron count: Determines the isotope of an atom.

• Electron count: Determines the chemical properties of an atom.

Key Terms

• Atomic number: Number of protons in the nucleus.

• Isotope: Atoms of the same element with different numbers of neutrons.

• Chemical properties: Determined by the arrangement of electrons.

Additional info: Atoms interact through chemical bonds to form molecules, which are essential for the structure and function of cells and tissues in the human body.