Biology Chapter on Energy and Matter

Matter and Energy

• All living organisms are composed of matter and require a continuous supply of energy to grow and function.
• Energy exists in various forms: chemical, electrical, mechanical, and radiant.

Key Principles of Energy

• Energy is conserved; it cannot be created or destroyed.
• Energy conversion occurs but is inefficient, leading to energy loss during the process.

Chemical Energy

• Chemical energy is stored in the bonds between molecules through anabolic processes and released via catabolic processes.
• Food, adenosine triphosphate (ATP), and nerve energy are examples of how chemical energy is utilized in forms like electrical energy and heat.

Basic Building Blocks of Matter

• Matter is defined as anything that occupies space and has mass (weight), existing in solid, liquid, or gas states.
• Elements are unique substances that cannot be broken down further by ordinary chemical means, with 118 identified and 92 found in nature (e.g., oxygen, carbon, iron).

Atomic Structure

• Atoms are the smallest indivisible units of matter, composed of protons, neutrons, and electrons.
• Protons carry a positive charge and are heavy (1 AMU), while neutrons are neutral and also heavy. Electrons carry a negative charge and have virtually no mass.

Atomic Number and Mass

• The atomic number indicates the number of protons in an atom (e.g., carbon has 6 protons).
• The atomic mass is the sum of protons and neutrons in the nucleus.

Isotopes and Subatomic Particles

• Isotopes are variations of elements with the same number of protons but different numbers of neutrons, resulting in different weights.
• The orbital model illustrates the arrangement of subatomic particles, with protons and neutrons in the nucleus and electrons in electron clouds surrounding it.

Electron Distribution

• Electrons occupy layers called shells around the nucleus, with the first layer holding a maximum of 2 electrons.
• The outermost shell, known as the valence shell, determines chemical behavior; if it has 8 electrons, the atom is inert, otherwise, it will react to achieve stability.

Inorganic Compounds: Water

• Water (H2O) is the most abundant inorganic compound in the body, comprising 2/3 of body weight and possessing vital functions such as high heat capacity and solvent properties.

Inorganic Compounds: Salts and Acids/Bases

• Salts form through the donation or acceptance of electrons (ions).
• Acids release H+ into solution (proton donors) and can be classified as strong or weak based on their ionization in water.
• Bases release OH- and act as proton acceptors.

Organic Compounds: DNA and RNA

• DNA (deoxyribonucleic acid) is organized into a double helix, essential for replication and providing instructions for protein synthesis.
• RNA (ribonucleic acid) operates primarily outside the nucleus, carrying out DNA's orders and containing varieties such as mRNA, rRNA, and tRNA.

Adenosine Triphosphate (ATP)

• ATP serves as the primary energy carrier in cells, storing energy in its chemical bonds, vital for life processes and cellular work.

This quiz covers essential concepts from biology related to energy release from food, the principles of energy in creation and destruction, and the chemical bonds involved in energy transformation. Additionally, it touches on the composition of living organisms and the definition of elements. Perfect for revising key biological processes!