active transport ✔✔movement of molecules across a cell membrane from a region of lower concentration to a region of higher concentration—against the concentration gradient. Active transport requires cellular energy to achieve this movement. passive transport ✔✔Requires NO energy, movement of molecules from high to low concentration, moves with the concentration gradient covalent bond ✔✔A chemical bond that involves sharing a pair of electrons between atoms in a molecule ionic bond ✔✔Linkage formed from the electrostatic attraction between oppositely charged ions in a chemical compound. Such a bond forms when the valence (outermost) electrons of one atom are transferred permanently to another atom. allosteric bond ✔✔The regulation of an enzyme by binding an effector molecule at a site other than the enzyme's active site. Substrate ✔✔reactant of an enzyme-catalyzed reaction substrate-enzyme complex ✔✔The substrate connects to the enzyme to perform chemical reactions. It connects to the enzyme at the active site. substrate enzyme inhibition ✔✔the substrate or product of an enzyme reaction inhibit the enzyme's activity. Carbohydrates ✔✔Are sugar molecules- our body breaks down carbohydrates into glucose. Glucose, or blood sugar, is the main source of energy for your body's cells, tissues, and organs. Proteins ✔✔Chains of amino acids Lipids ✔✔Energy-rich organic compounds, such as fats, oils, and waxes, that are made of carbon, hydrogen, and oxygen. nucleic acids ✔✔Nucleic acids are naturally occurring chemical compounds that serve as the primary information-carrying molecules in cells. The two main classes of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Lysosomes ✔✔An organelle containing digestive enzymes Vacuole ✔✔Cell organelle that stores materials such as water, salts, proteins, and carbohydrates Mitochondria ✔✔Powerhouse of the cell, organelle that is the site of ATP (energy) production Ribosomes ✔✔a cellular particle made of RNA and protein that serves as the site for protein synthesis in the cell. Smooth Endoplasmic Reticulum ✔✔An endomembrane system where lipids are synthesized, calcium levels are regulated, and toxic substances are broken down. Rough Endoplasmic Reticulum ✔✔System of internal membranes within the cytoplasm. Membranes are rough due to the presence of ribosomes. functions in transport of substances such as proteins within the cytoplasm Golgi apparatus ✔✔stack of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum