Biology: Chemistry Terms

• Atomic Number: Determines the element, based on the number of protons in an atom's nucleus.
• Atomic Weight (Atomic Mass): The total mass of an atom, calculated by summing the number of protons and neutrons.
• Valence Shell: The outermost electron shell in an atom, determining how the atom bonds with others.
• Inert Gases (Noble Gases): Elements in group 18 of the periodic table, including helium, neon, and argon, are chemically stable and rarely react.
• Ion: An atom or molecule that has gained or lost one or more electrons, resulting in a positive or negative charge.
• Isomers: Molecules that share the same chemical formula but have different structures.
• Isotopes: Atoms of the same element with varying numbers of neutrons, resulting in different atomic masses.

Chemistry in Biology

• Solute: A substance dissolved in a solution, for example, salt in water.
• Solvent: A substance that dissolves a solute, such as water.
• Tonicity: The ability of a solution to affect a cell's shape by altering its water content, described as hypertonic, hypotonic, or isotonic.

Biology and Cell Structure

• Hypothesis: A testable prediction or explanation for a phenomenon.
• Biology: The scientific study of life and living organisms.
• Eukaryote: Organisms whose cells contain a nucleus and other membrane-bound organelles, such as plants, animals, and fungi.
• Prokaryote: Single-celled organisms lacking a nucleus or membrane-bound organelles, for example, bacteria.
• Nucleus (of a cell): The membrane-bound organelle containing the cell's genetic material (DNA).
• Nucleus (of an atom): The dense, positively charged center of an atom, consisting of protons and neutrons.
• Mitochondrion: The organelle that generates energy for the cell in the form of ATP and is known as the powerhouse of the cell.
• Plasma Membrane: The flexible boundary around a cell that controls the movement of substances in and out.
• Cell Wall: A rigid structure external to the plasma membrane in plant cells, fungi, and certain bacteria, providing shape and support.
• Golgi Complex/Apparatus: An organelle that modifies, sorts, and packages proteins and lipids for transport.
• Ribosome: Small organelles responsible for synthesizing proteins by translating messenger RNA (mRNA).
• Endoplasmic Reticulum (ER): A network of membranes involved in protein and lipid synthesis; rough ER has ribosomes, while smooth ER does not.
• Lysosome: Organelles containing digestive enzymes used to break down waste and cellular debris.
• Chloroplast: Organelles found in plant cells that capture light energy to produce food through photosynthesis.

Biochemistry

• Enzyme: A protein that catalyzes and accelerates chemical reactions.
• Substrate: The substance upon which an enzyme acts.
• Active Site: The region on an enzyme where the substrate binds.
• Energy of Activation: The energy required to initiate a chemical reaction.
• Kinetic Energy: The energy of motion.
• Potential Energy: Stored energy, often based on an object's position.
• ATP (Adenosine Triphosphate): The primary energy carrier in cells.

Transport and Energy in Cells

• Osmosis: The diffusion of water across a semi-permeable membrane.
• Diffusion: The movement of particles from an area of high concentration to an area of low concentration.
• Facilitated Diffusion: The movement of molecules across a membrane via transport proteins along the concentration gradient that does not require energy.
• Active Transport: The movement of molecules across a membrane against the concentration gradient that requires energy.
• Passive Transport: The movement of molecules across a membrane without energy, down the concentration gradient.
• Concentration Gradient: The difference in the concentration of molecules in two regions.

Macromolecules and Chemical Reactions

• Dehydration Synthesis: A chemical reaction in which two molecules are joined by removing a water molecule.
• Hydrolysis: A chemical reaction in which a water molecule is added to break bonds between molecules.
• Monomer: A small molecule that can combine with others to form a polymer.
• Polymer: A large molecule made up of repeating units known as monomers.
• Saturated: A type of fat molecule lacking double bonds between carbon atoms, solid at room temperature.
• Endergonic: A reaction requiring energy input to proceed.
• Exergonic: A reaction that releases energy.
• Conservation of Energy: The principle stating that energy cannot be created or destroyed, only transformed.
• Selective Permeability: A membrane property allowing some substances to pass through while blocking others.

Additional Review Questions

• An atom with an atomic number of 6 and an atomic mass of 13 is Carbon, it has 6 protons, 6 electrons, 4 valence electrons, and 7 neutrons.
• The three domains are Bacteria, Archaea, and Eukarya.
• Hierarchy from atom to biosphere: Atom → Molecule → Cell → Tissue → Organ → Organ System → Organism → Population → Community → Ecosystem → Biosphere
• Types of Bonds:
  • Covalent Bond: A bond between H and O within a water molecule.
  • Hydrogen Bond: A bond between H of one water molecule and the O of another.
  • Ionic Bond: A bond between a positive ion and a negative ion.
  • Peptide Bond: A bond between the carboxyl group of one amino acid and the amino group of another.
• The elements found in all organic molecules are carbon, hydrogen, oxygen, and nitrogen.
• Organic molecules with the formula C6H12O6 are Carbohydrates (Glucose).
• What happens to a red blood cell in different solutions:
  • Hypertonic solution: Shrinks
  • Hypotonic solution: Swells and may burst
  • Isotonic solution: No change
• The plasma membrane is a phospholipid bilayer with embedded proteins, cholesterol, and carbohydrate chains, controlling the movement of substances in and out of the cell.

Prefixes and Suffixes

• More: -er, -more
• Less: -less
• Same: Iso-
• Many: Poly-
• Sugar: -ose
• Enzyme: -ase
• Water: Hydro-
• Break down: -lysis
• Cell: -cyte

Periodic Table

• Columns: Elements with similar properties (groups) are indicated.
• Rows: The number of electron shells around the nucleus is indicated.