뒤로Anatomy & Physiology: Chemistry of Life
02:13
이 집합의 용어 (28)
Matter is anything that has mass and occupies space.
An atom is the smallest unit of matter retaining its properties. An element is a substance made of identical atoms and cannot be broken down chemically.
Protons (positive, in nucleus), neutrons (neutral, in nucleus), and electrons (negative, orbiting nucleus).
Because the number of protons equals the number of electrons.
The number of protons in the atomic nucleus defines the atomic number.
Oxygen (65%), Carbon (18%), Hydrogen (10%), and Nitrogen (3%).
An isotope is an atom with the same number of protons but different numbers of neutrons.
Radioisotopes are unstable isotopes that emit radiation; used in nuclear medicine for diagnosis and treatment.
A mixture is a physical combination of substances; a molecule is two or more atoms chemically bonded.
Suspensions (large particles settle), colloids (small particles dispersed), and solutions (solute dissolved in solvent).
An energy relationship or attractive force between atoms forming molecules or compounds.
Atoms are most stable with 8 electrons in their valence shell, except those with 5 or fewer electrons which follow the Duet Rule (2 electrons).
An ionic bond forms when electrons transfer between a metal and a nonmetal, creating charged ions attracted to each other.
Covalent bonds share electrons between two or more nonmetal atoms; can be single, double, or triple bonds.
Nonpolar bonds share electrons equally; polar bonds share electrons unequally, creating partial charges (dipoles).
Hydrogen bonds are weak attractions between partially positive hydrogen atoms and partially negative atoms in polar molecules.
Surface tension results from hydrogen bonds between water molecules forming a 'web' at air-water interfaces.
A process where chemical bonds are formed, broken, or rearranged, involving reactants and products.
Endergonic reactions require energy input; exergonic reactions release energy.
Enzymes are biological catalysts that lower activation energy and speed up chemical reactions without being consumed.
Activation energy is the energy needed to start a chemical reaction by overcoming electron repulsion.
The pH scale measures hydrogen ion concentration; 7 is neutral, below 7 acidic, above 7 basic.
Buffers resist pH changes by neutralizing added acids or bases, maintaining homeostasis.
Carbohydrates are made of carbon, hydrogen, and oxygen; monomers are monosaccharides like glucose.
Lipids are hydrophobic molecules including fatty acids, triglycerides, phospholipids, and steroids.
Proteins are polymers of amino acids with four structural levels: primary, secondary, tertiary, and quaternary.
Adenosine triphosphate (ATP) is the main energy currency of the cell, providing energy for cellular processes.
DNA stores genetic information; RNA carries instructions from DNA to make proteins.