AP BIO UNIT 1-5 VOCAB

Element

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

Trace Elements

Elements required by an organism only in very small quantities, including iron (Fe), iodine (I), and copper (Cu).

Atom

The unit of life and the building blocks of the physical world, consisting of protons, neutrons, and electrons.

Proton

Positively charged particle within an atom.

Neutron

Uncharged particle within an atom.

Electron

Negatively charged particle within an atom.

Isotope

Atoms that have the same number of protons but differ in the number of neutrons.

Compound

Consists of two or more elements held together by chemical bonds.

Ionic Bond

A bond formed when one or more electrons are transferred from one atom to another.

Covalent Bond

A bond formed when electrons are shared between atoms.

Water Cohesion

The tendency of water molecules to stick together due to hydrogen bonding.

Adhesion

The tendency of water molecules to stick to other substances.

Capillary Action

The ability of water to rise up through narrow spaces due to cohesion and adhesion.

Acidic Solution

A solution containing a lot of hydrogen ions (H+).

Basic Solution

A solution that releases hydroxide ions (OH–) in water.

pH Scale

A scale measuring acidity or alkalinity, ranging from 1 to 14.

Organic Molecules

Molecules that contain carbon; include carbohydrates, proteins, lipids, and nucleic acids.

Polymers

Chains of building blocks in macromolecules formed through dehydration synthesis.

Monomers

The individual building blocks of a polymer.

Carbohydrates

Organic compounds that contain carbon, hydrogen, and oxygen, typically in a 1:2:1 ratio.

Monosaccharides

The simplest form of carbohydrates, serving as energy sources for cells.

Disaccharides

Carbohydrates formed by the joining of two monosaccharides.

Polysaccharides

Carbohydrates made up of many repeated units of monosaccharides.

Proteins

Important macromolecules made of amino acids that are essential for structure, function, and regulation of organs.

Amino Acids

The building blocks of proteins, containing carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur.

Peptide Bond

The bond that links amino acids together in a protein.

Polypeptide

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

Lipids

Hydrophobic organic molecules that are important for energy storage and membrane structure.

Phospholipids

Lipids that consist of two fatty acid tails and a phosphate head, essential for cell membranes.

Cholesterol

A four-ringed molecule found in cell membranes that contributes to membrane fluidity.

Nucleic Acids

Macromolecules made of nucleotides; include DNA and RNA.

Cell Theory

The theory that all living things are composed of cells and that cells are the basic units of life.

Prokaryotic Cell

Simpler, smaller cells without membrane-bound organelles, such as bacteria.

Eukaryotic Cell

More complex cells with membrane-bound organelles, including plants, animals, and fungi.

Plasma Membrane

The semipermeable membrane surrounding the cytoplasm of a cell, composed mainly of phospholipids and proteins.

Cytoskeleton

A network of protein fibers in a cell that provides structure and facilitates movement.

Enzyme

A biological catalyst that speeds up reactions by lowering activation energy.

Catalyst

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

Bioenergetics

The study of how cells manage energy and energy transformations.

Glycolysis

The metabolic pathway that converts glucose into pyruvate, producing ATP and NADH.

Krebs Cycle

A series of chemical reactions used by aerobic organisms to generate energy through the oxidation of acetyl-CoA.

Electron Transport Chain

A series of protein complexes that transfer electrons to form ATP.

Fermentation

A metabolic process that converts sugar to acids, gases, or alcohol in the absence of oxygen.

Meiosis

The process of cell division that produces gametes with half the number of chromosomes.

Mitosis

The process of cell division that results in two identical daughter cells.

Phenotype

The observable traits of an organism, influenced by its genotype.

Genotype

The genetic makeup of an organism, determined by its alleles.

Homozygous

An organism with two identical alleles for a specific trait.

Heterozygous

An organism with two different alleles for a specific trait.

Dominant Allele

An allele that masks the effect of a recessive allele in heterozygous individuals.

Recessive Allele

An allele that is masked by the presence of a dominant allele.

Punnett Square

A diagram used to predict the genetic outcomes of a cross between individuals.

Incomplete Dominance

A genetic scenario where neither allele is fully dominant, resulting in a blended phenotype.

Codominance

A genetic scenario where both alleles are expressed equally in the phenotype.

Pedigree

A family tree that shows the occurrence of traits across generations.

Chromatids

The two identical halves of a duplicated chromosome.

Centromere

The region where two sister chromatids are joined.

Crossing Over

The exchange of genetic material between homologous chromosomes during meiosis.

Barr Body

The inactivated X chromosome in a female cell.

Oncogenes

Mutated genes that can lead to cancer.

Tumor Suppressor Genes

Genes that help regulate cell division and prevent cancer.

Signal Transduction

The process by which a cell responds to external signals by activating specific pathways.