Chemistry of Life - Full Review

A comprehensive set of vocabulary flashcards covering key terms about atoms, bonds, water properties, organic molecules, macromolecules, and origins of life from the provided notes.

Matter

Anything that has mass and occupies space; all living things are composed of matter.

Element

A substance that cannot be broken down into simpler substances by chemical means.

Oxygen (O)

One of the essential elements; makes up about 96% of the mass of living things along with C, H, and N.

Carbon (C)

A key essential element; versatile atom that bonds with many elements to form organic compounds.

Hydrogen (H)

A major element in living things; part of the 1:2:1 CH2O ratio in carbohydrates.

Nitrogen (N)

A major element essential for living organisms; a key component of amino acids and nucleic acids.

Trace elements

Elements required in very small amounts (e.g., Fe, I, Cu) for living organisms.

Atom

The smallest unit of an element that retains its properties; building block of matter.

Nucleus

Central region of an atom where protons and neutrons are located.

Protons

Positively charged particles in the nucleus.

Neutrons

Uncharged particles in the nucleus.

Electrons

Negatively charged particles that orbit the nucleus; mass is negligible for many purposes.

Isotopes

Atoms of the same element with the same number of protons but different numbers of neutrons.

Carbon-14

A radioactive isotope used in radiometric dating to determine the age of artifacts.

Radiometric dating

Dating objects by measuring the decay rate of radioactive isotopes (e.g., carbon-14).

Ions

Atoms that carry a net electric charge due to loss or gain of electrons.

Ionic bond

Bond formed by transfer of electrons resulting in oppositely charged ions that attract.

Covalent bond

Bond formed by sharing electrons between atoms; can be nonpolar or polar.

Nonpolar covalent

Covalent bond where electrons are shared equally between atoms.

Polar covalent

Covalent bond where electrons are shared unequally, creating partial charges.

Water

A polar molecule (H2O) that acts as a universal solvent and forms hydrogen bonds.

Polar molecule

Molecule with partial positive and partial negative charges due to unequal electron distribution.

Hydrogen bond

Weak attraction between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom.

Cohesion

Water molecules sticking to each other, contributing to surface tension and transport in plants.

Adhesion

Water molecules sticking to other substances, aiding capillary action.

Surface tension

Tension at the surface of water due to cohesive forces among water molecules.

Capillary action

Movement of water up narrow tubes as a result of cohesion and adhesion.

pH

A scale measuring how acidic or basic (alkaline) a solution is; 1–14 with 7 neutral.

Acid

Substance that increases H+ concentration in water; lowers pH.

Base (alkaline)

Substance that increases OH- concentration in water; raises pH.

Neutral

A solution with a pH of 7; equal H+ and OH- concentrations.

Organic compounds

Compounds that contain carbon and hydrogen (often with other elements).

Inorganic compounds

Compounds that do not contain both carbon and hydrogen.

Polymer

A large molecule made by linking many monomers.

Monomer

A building block that links to form polymers.

Carbohydrates

Organic compounds with C, H, O in about a 1:2:1 ratio; CH2O; include sugars and starches.

Monosaccharide

A single sugar (e.g., glucose, fructose); the simplest carbohydrate.

Glucose

A common six-carbon monosaccharide; a primary energy source in cells.

Fructose

A six-carbon monosaccharide commonly found in fruits.

Disaccharide

A carbohydrate formed by two monosaccharides; example maltose (two glucose units).

Maltose

Disaccharide composed of two glucose molecules.

Polysaccharide

Polymers composed of many monosaccharides (e.g., starch, glycogen, cellulose, chitin).

Starch

Polysaccharide used by plants to store glucose.

Glycogen

Polysaccharide used by animals to store glucose.

Cellulose

Polysaccharide of beta-glucose; provides structural support in plant cell walls.

Chitin

Polysaccharide of beta-glucose; forms fungal cell walls and arthropod exoskeletons.

Amino acids

Building blocks of proteins; contain amino group, carboxyl group, hydrogen, and an R group.

Amino group

NH2 group found on amino acids.

Carboxyl group

COOH group found on amino acids.

R group (side chain)

Variable group attached to the central carbon that defines each amino acid.

Dipeptide

Two amino acids linked by a peptide bond via dehydration synthesis.

Peptide bond

Bond linking amino acids in a protein; formed by dehydration synthesis.

Polypeptide

A chain of many amino acids that folds into a protein.

Protein

A macromolecule formed from one or more polypeptides folded into a functional 3D structure.

Primary structure

Linear sequence of amino acids in a protein.

Secondary structure

Local folding of polypeptide into alpha helices or beta-pleated sheets via hydrogen bonds.

Alpha helix

Coiled secondary structure of a protein.

Beta-pleated sheet

Sheet-like secondary structure formed by hydrogen bonds between strands.

Tertiary structure

3D folding of a protein due to interactions among R groups; can include disulfide bonds.

Disulfide bond

Covalent bond between cysteine residues that stabilizes tertiary structure.

Chaperone proteins

Helper proteins that assist in correct protein folding.

Lipids

Hydrophobic biomolecules (mostly C, H, O) including triglycerides, phospholipids, and steroids.

Triglycerides

Fat storage molecules made of glycerol + three fatty acids linked by ester bonds.

Phospholipids

Lipids with two fatty acid tails and a negatively charged phosphate head; amphipathic.

Steroids

Lipids with four-ring structure (e.g., cholesterol); can regulate membranes and hormones.

Glycerol

Backbone of triglycerides to which fatty acids attach via ester linkages.

Ester linkage

Bond formed between glycerol and fatty acids during fat formation.

Saturated

Fatty acids with no double bonds between carbon atoms; fully hydrogenated.

Unsaturated

Fatty acids with one or more double bonds; kinks prevent tight packing.

Polyunsaturated

Fatty acids with multiple double bonds.

Hydrophobic

Water-fearing; nonpolar substances tend to avoid water.

Hydrophilic

Water-loving; polar or charged substances interact well with water.

Amphipathic

Molecule having both hydrophobic and hydrophilic regions (e.g., phospholipids).

Cholesterol

A four-ring lipid that modulates membrane fluidity and is a hormone/ vitamin D precursor.

Nucleic acids

Biomolecules (DNA and RNA) made of nucleotides; store and express genetic information.

Nucleotides

Monomers of nucleic acids; contain a sugar, phosphate group, and a nitrogenous base.

DNA

Deoxyribonucleic acid; stores hereditary information; uses deoxyribose sugar.

RNA

Ribonucleic acid; essential for protein synthesis; uses ribose sugar.

RNA-world hypothesis

Hypothesis that RNA molecules may have been the first self-replicating life-form before DNA/proteins.

Oparin

Proposed that early Earth's atmosphere contained methane, ammonia, hydrogen, and water leading to organic molecules.

Haldane

Co-proposer of the idea that primitive atmospheres could yield organic compounds.

Miller-Urey

Experiment simulating early Earth conditions that produced amino acids and other organics.

Heterotrophs

Organisms that obtain energy by consuming organic molecules (consumers).

Autotrophs

Organisms capable of making their own organic molecules (producers) via photosynthesis.