chemistry of life (chapter 2)

october 5, 2024; biology 1 honors

element

a pure substance made of only one type of atom.

neutron

 a neutral subatomic particle in the nucleus of an atom.

proton

a positively charged subatomic particle in the nucleus.

electron

a negatively charged subatomic particle that orbits the nucleus.

electron shell

an energy level around the nucleus where electrons are found.

atom

the smallest unit of matter that defines an element.

molecule

two or more atoms bonded together.

ion

an atom or molecule with a net electric charge due to electron loss or gain.

isotope

an atom of the same element with a different number of neutrons.

ionic bond

a bond formed by the transfer of electrons between atoms.

covalent bond

a bond where atoms share electrons.

hydrogen bond

 a weak bond between a hydrogen atom and an electronegative atom.

chemical reaction

a process that changes substances by breaking and forming chemical bonds.

activation energy

the minimum energy needed to start a chemical reaction.

carbohydrate

a molecule made of sugars, providing energy for cells (e.g., glucose).

lipid

a fat or oil molecule, used for long-term energy storage and cell structure.

cholesterol

a type of lipid important for cell membranes and hormone production.

protein

a molecule made of amino acids that performs many functions in the body, like structure and enzymes.

nucleic acid

molecules like dna or rna that store and transmit genetic information.

pH scale

 a scale (0-14) that measures how acidic or basic a substance is.

acid

a substance with a pH less than 7, releasing hydrogen ions (H⁺) in solution.

base

a substance with a pH greater than 7, releasing hydroxide ions (OH⁻) in solution.

organic

refers to compounds that contain carbon and are found in living organisms.

enzyme

a protein that speeds up chemical reactions in the body.

catalyst

a substance that increases the rate of a chemical reaction without being consumed.

amino acid

the building block of proteins.

peptide bond

the bond that links amino acids together in a protein.

hydrophobic

a substance that repels or does not mix with water.

hydrophilic

a substance that attracts or mixes well with water.

macromolecules

large molecules like proteins, nucleic acids, carbohydrates, and lipids.

compound

a substance made of two or more different elements chemically bonded.

substrate

the substance an enzyme acts upon in a reaction.

nucleotides

the building blocks of nucleic acids like dna and rna.

monosaccharide

a simple sugar molecule, like glucose.

polysaccharide

a carbohydrate made of many sugar units, like starch or glycogen.

dehydration synthesis

a chemical reaction in which two molecules are joined together by the removal of a water molecule. this process is commonly used to form larger molecules, such as polymers, from smaller monomers. it is essential in the formation of carbohydrates, proteins, and nucleic acids.

carbonyl group

a functional group characterized by a carbon atom double-bonded to an oxygen atom (C=O). found in aldehydes and ketones, polar, affecting the physical properties of compounds. involved in various chemical reactions, including nucleophilic addition. plays a crucial role in biological molecules like sugars and proteins.

carboxyl group

a functional group consisting of a carbon atom double-bonded to an oxygen atom and single-bonded to a hydroxyl group (-COOH). it is polar and hydrophilic, acts as an acid by donating a proton (H+). found in amino acids and fatty acids. contributes to the acidity of organic compounds.

hydroxyl group

a functional group consisting of an oxygen atom bonded to a hydrogen atom (-OH). polar due to the electronegativity of oxygen. increases solubility of compounds in water. found in alcohols and sugars. plays a key role in forming hydrogen bonds. essential in organic chemistry, influencing the properties and reactivity of molecules.

hydrolysis reaction

a chemical process in which water is used to break down a compound. involves the reaction of water with a substance. common in the breakdown of polymers into monomers (e.g., starch to glucose. often catalyzed by enzymes in biological systems. plays a crucial role in digestion and metabolism.

isomer

substances that have the same chemical formula but the atoms are arranged differently

monosaccharide formula

C₆H₁₂O₆

disaccharide formula

C₁₂H₂₂O₁₁

lipid formula

C₃H₈O₃

unsaturated fats

c=c double bonds in the fatty acids, plant and fish fats, vegetable oils, liquid at room temp

saturated fats

no c=c double bonds in the fatty acids, all c bonded to h, long straight chain, most animal fats, solid at room temp

cellulose

most abundant organic compound on earth

phospholipid

a class of lipids that are a major component of all cell membranes, can form micelles (bubbles) or form a bilayer that provides structure and flexibility for the cell membrane.

steroid

a type of lipid characterized by a molecular structure containing four fused carbon rings, often functioning as hormones or signaling molecules in biological systems.