Basic Biochemistry for Anatomy & Physiology: Matter, Atoms, and Atomic Structure

Basic Biochemistry for Anatomy & Physiology

Introduction

This study guide covers foundational concepts in chemistry that are essential for understanding biochemistry in the context of Anatomy & Physiology. Topics include the nature of matter, atomic structure, and the properties of atoms and their subatomic particles.

Matter and Atoms

Matter

Matter is defined as anything that has mass and occupies space. All substances in the universe, including those that make up the human body, are forms of matter.

• Mass: The quantity of matter in an object.

• Volume: The amount of space an object occupies.

There are three most common states of matter:

• Solid: Definite shape and volume. Particles are closely packed in a fixed arrangement.

• Liquid: Indefinite shape (takes the shape of its container), but definite volume. Particles are close together but can move past one another.

• Gas: Indefinite shape and volume. Particles are far apart and move freely.

Example: Water can exist as ice (solid), liquid water, or water vapor (gas), as shown in the diagram with molecular arrangements for each state.

Atoms

Atoms are the smallest units of matter that retain the properties of an element. All matter is composed of atoms.

• Atoms are made up of three main subatomic particles:

  • Proton (p+): Relatively large, positively charged particle found in the nucleus.

  • Neutron (n): Relatively large, electrically neutral particle found in the nucleus.

  • Electron (e-): Very small (about 1/1800 the mass of a proton), negatively charged particle found outside the nucleus.

Example: A hydrogen atom consists of one proton and one electron; most hydrogen atoms have no neutrons.

Atomic Structure

The structure of an atom is determined by the arrangement of its subatomic particles.

• Nucleus: The central core of the atom, containing protons and neutrons. Most of the atom's mass is concentrated here.

• Electron Cloud: The region surrounding the nucleus where electrons are likely to be found. Electrons occupy specific energy levels or shells.

• Energy Levels: Electrons in the electron cloud have different amounts of energy, and their arrangement determines the atom's chemical properties and reactivity.

Key Point: The number of protons in the nucleus (atomic number) defines the identity of the element.

Additional info: Understanding atomic structure is fundamental for grasping how atoms interact to form molecules, which is essential for studying biochemistry and physiological processes in the human body.