Part 1: Definition of Concepts: Matter and Energy

Matter and Energy

Understanding matter and energy is foundational in Anatomy & Physiology, as all biological processes depend on their interactions.

• Matter: Anything that has mass and occupies space. It is the substance of the universe.

• Energy: The capacity to do work or cause change. Energy moves matter and is essential for physiological processes.

• Mass vs. Weight: Mass is the amount of matter in an object, while weight is the force exerted by gravity on that mass.

Elements and Atoms

Elements are pure substances consisting of only one type of atom. Atoms are the smallest units of elements that retain their properties.

• Major Elements of the Body: Four elements—carbon, hydrogen, oxygen, and nitrogen—make up most of the human body.

• Subatomic Particles: Atoms consist of protons (positive charge), neutrons (neutral), and electrons (negative charge).

• Atomic Number: Number of protons in the nucleus.

• Atomic Mass: Sum of protons and neutrons.

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

• Radioisotopes: Unstable isotopes that emit radiation.

Chemical Bonds

Types of Chemical Bonds

Chemical bonds hold atoms together to form molecules and compounds, which are essential for biological structure and function.

• Ionic Bonds: Formed when electrons are transferred from one atom to another, creating charged ions.

• Covalent Bonds: Formed when atoms share electrons.

• Hydrogen Bonds: Weak attractions between a hydrogen atom and an electronegative atom (such as oxygen or nitrogen).

Chemical Reactions

Chemical reactions involve the making and breaking of bonds, resulting in new substances.

• Factors Affecting Chemical Reactions: Temperature, concentration, particle size, and catalysts can influence reaction rates.

• Catalysts: Substances that increase the rate of a chemical reaction without being consumed.

Part 2: Biochemistry

Inorganic Compounds

Inorganic compounds such as water, salts, acids, and bases are vital for maintaining homeostasis in the body.

• Water: Most abundant inorganic compound; excellent solvent and involved in many physiological processes.

• Salts: Ionic compounds that dissociate in water to form electrolytes.

• Acids and Bases: Acids release hydrogen ions (H+), bases accept them. They help regulate pH in the body.

Organic Compounds

Organic compounds contain carbon and are the building blocks of life. They include carbohydrates, lipids, proteins, and nucleic acids.

• Carbohydrates: Provide an easily used energy source for the body. Examples include glucose and starch.

• Lipids: Insulate body organs, build cell membranes, and provide stored energy. Examples include fats and oils.

• Proteins: Basic structural material of the body; involved in many vital functions such as enzymes, hormones, and antibodies.

• Nucleic Acids: DNA and RNA store, transmit, and help express genetic information.

Formation and Breakdown of Organic Molecules

Organic molecules are formed and broken down by specific chemical reactions.

• Dehydration Synthesis: Joins molecules by removing water.

• Hydrolysis: Breaks molecules apart by adding water.

Enzymes

Enzymes are biological catalysts that speed up chemical reactions in the body.

• Characteristics: Highly specific, reusable, and sensitive to environmental conditions.

• Mechanism of Action: Lower the activation energy required for reactions.

ATP (Adenosine Triphosphate)

ATP is the primary energy carrier in cells, transferring energy to other compounds for cellular work.

• Role of ATP: Provides energy for muscle contraction, nerve impulse propagation, and chemical synthesis.

• ATP Formation: Produced during cellular respiration.

DNA and RNA

DNA and RNA are nucleic acids responsible for storing and transmitting genetic information.

• DNA: Stores genetic information; double-stranded helix.

• RNA: Transmits genetic information; single-stranded.

Summary Table: Major Organic Compounds and Their Functions

Key Equations

• Atomic Mass Calculation:

• Dehydration Synthesis (Generalized):

• Hydrolysis (Generalized):

Summary:

• Matter is the stuff of the universe and energy moves matter

• The properties of an element depend on the structure of its atom

• Atoms bound together form molecules; different molecules can make mixtures

• The three types of chemical bonds are ionic, covalent, and hydrogen

• Chemical reactions occur when electrons are shared, gained, or lost

• Inorganic compounds include water, salts, and many acids and bases

• Organic compounds are made by dehydration synthesis and broken down by hydrolysis

• Carbohydrates provide an easily used energy source for the body

• Lipids insulate body organs, build cell membranes, and provide stored energy

• Proteins are the body’s basic structural material and have many vital functions

• DNA and RNA store, transmit, and help express genetic information

• ATP transfers energy to other compounds

Additional info: Academic context and definitions have been expanded for clarity and completeness. The summary table and equations are inferred from standard Anatomy & Physiology curriculum.