Chemistry Atoms and Molecules Quiz

Atoms and Elements

• Atoms are the fundamental building blocks of all matter, both living and nonliving.
• Atoms consist of a nucleus at the center, which contains protons (positive charge) and neutrons (no charge).
• Electrons (negative charge) revolve around the nucleus in outer orbits, called electron shells.
• Elements are pure substances consisting of a specific type of atom, with 118 known elements found in the Periodic Table.

Molecules, Monomers, and Polymers

• Compounds form when two or more elements chemically bond to create molecules (e.g., Sodium chloride or NaCl).
• Monomers are small molecules made of few elements; they serve as the building blocks for larger structures.
• Polymers, also known as macromolecules, are large molecules formed by linking many monomers through chemical reactions (polymerization).

Amino Acids and Proteins

• Amino acids are the monomers that combine to form proteins, consisting mainly of carbon, hydrogen, oxygen, and nitrogen.
• There are 20 essential amino acids needed by the human body to synthesize over 20,000 different proteins.
• Proteins serve critical functions such as providing structure, support, and facilitating biochemical reactions in cells.

Essential and Non-Essential Amino Acids

• Non-essential amino acids can be synthesized by the body; examples include alanine, arginine, and asparagine.
• Essential amino acids cannot be produced by the body and must be obtained from food; examples include histidine, isoleucine, and lysine.

Protein Structure and Functions

• Proteins are long chains of amino acids and can be described as polymers or macromolecules.
• Proteins play various roles including:
  • Antibodies: Help the body combat infections.
  • Enzymes: Accelerate biochemical reactions.
  • Hemoglobin: Carries oxygen in red blood cells.
  • Actin: Aids in muscle contraction.
  • Hormones: Regulate bodily functions.
  • Keratin: Provides structure in nails.

Protein Sources and Importance

• Dietary proteins are vital for providing essential amino acids that the body cannot produce.
• Sources of protein include meat, eggs, dairy, rice, and beans.
• After digestion, proteins are broken down into amino acids for the body to use in creating its own proteins.

Molecule Interactions with Water

• Molecules exhibit hydrophobic (water-repelling), hydrophilic (water-attracting), or amphipathic (having both properties) characteristics depending on their chemical structure.

Summary of Protein Functions

• Proteins are crucial for building and maintaining tissues, ensuring the proper function of organs, and supporting overall health.