뒤로Anatomy & Physiology: Chemistry of Life and Organic Molecules
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이 집합의 용어 (21)
Matter is anything that has mass and occupies space; it exists in three states: solid, liquid, or gas.
Protons (positively charged, in nucleus), neutrons (neutral, in nucleus), and electrons (negatively charged, outside nucleus).
An element is a substance that cannot be broken down chemically and is defined by its atomic number, the number of protons in its nucleus.
An isotope is an atom with the same number of protons but a different number of neutrons, resulting in a different mass number.
Hydrogen, Oxygen, Carbon, and Nitrogen.
A chemical bond is an energy relationship or attractive force between atoms, not a physical structure.
The octet rule states that atoms are most stable when they have 8 electrons in their valence shell.
An ionic bond forms when electrons are transferred from a metal atom to a nonmetal atom, creating cations and anions attracted to each other.
A covalent bond is the sharing of one or more pairs of electrons between two nonmetal atoms.
Polar covalent bonds share electrons unequally due to different electronegativities; nonpolar covalent bonds share electrons equally.
Hydrogen bonds are weak attractions between the partially positive end of one dipole and the partially negative end of another, important for water's surface tension.
A mixture is a physical combination of substances; types include suspensions (large particles, settle out), colloids (small particles, do not settle), and solutions (very small particles, do not settle).
A molecule is two or more atoms of the same element bonded; a compound is atoms of different elements bonded.
Adenosine triphosphate (ATP) is the main chemical energy source in the body, composed of adenine, ribose, and three phosphate groups.
Primary (amino acid sequence), Secondary (alpha helix or beta-pleated sheet), Tertiary (3D folding), and Quaternary (multiple polypeptide chains).
Fibrous proteins are long, rope-like, mostly nonpolar, providing strength; globular proteins are spherical, mostly polar, functioning as enzymes and messengers.
Carbohydrates are composed of carbon, hydrogen, and oxygen; their monomers are monosaccharides like glucose and fructose.
Triglycerides are storage lipids made of three fatty acids linked to glycerol by dehydration synthesis.
Phospholipids have a glycerol backbone, two fatty acid tails (nonpolar), and a phosphate head (polar), making them amphiphilic and vital for cell membranes.
Nucleotides consist of a nitrogenous base, a five-carbon sugar (ribose or deoxyribose), and a phosphate group.
DNA is double-stranded with deoxyribose sugar and thymine; RNA is single-stranded with ribose sugar and uracil instead of thymine.