AP Biology Complete Vocab

Element

Element

Substance that cannot be broken down to other substances by chemical reactions

Compound

Substance containing 2 or more elements combined

Trace Elements

Elements required by an organism in very small quantities

Proton

Positively charged subatomic particle

Neutron

Neutrally charged subatomic particle

Electron

Negatively charged subatomic particle

Atomic Number

Number of protons in an atom

Atomic Mass

Sum of neutrons and protons in an atom

Isotope

Atoms with the same number of protons but different number of neutrons

Potential Energy

Energy that is stored due to position or structure

Valence Shell

Outermost electron shell with electron capacity (2,8,8)

Valence Electron

Electrons in the outermost shell of an atom

Valence Number

Number of unpaired electrons in the outer shell

Electronegativity

Atom's attraction for electrons

Nonpolar

Equal sharing of electrons in a covalent bond

Polar

Unequal sharing of electrons in a covalent bond

Ionic bond

Bond formed by transfer of electrons between atoms

Anion

Negatively charged ion

Cation

Positively charged ion

Hydrogen bonds

Weak attractions between polar molecules

Equilibrium

State where forward and reverse reactions occur at the same rate

Hydrophobic

Substances that repel water

Hydrophilic

Substances that attract water

Hydrocarbons

Molecules composed of carbon-hydrogen chains

Hydroxyl

Functional group (-OH) found in alcohols

Carbonyl

Functional group (-C=O) found in sugars

Carboxyl

Functional group (-COOH) found in carboxylic acids

Amino

Functional group (-NH2) found in amines

Sulfhydryl

Functional group (-SH) found in thiols

Phosphate

Functional group (-OPO3) found in phosphates

Polymer

Long molecule made of repeating monomers

Monomer

Building block of a polymer

Dehydration synthesis

Process that joins monomers by removing water

Hydrolysis

Process that breaks polymers by adding water

Polypeptides

Chains of amino acids forming proteins

Peptide Bonds

Bonds between amino acids in a polypeptide

Primary Structure

Sequence of amino acids in a protein

Secondary Structure

Coils and folds in a protein due to hydrogen bonding

Tertiary Structure

Overall 3D shape of a protein

Quaternary Structure

Structure formed by multiple protein subunits

Chaperonins

Proteins that assist in protein folding

Protein Denaturation

Loss of protein's shape and function

Monosaccharides

Simple sugars with CH2O formula

Carbohydrates

Molecules containing sugars and their polymers

Disaccharides

Double sugars like sucrose

Starch

Plant energy storage polysaccharide

Glycogen

Animal energy storage polysaccharide

Cellulose

Polysaccharide used in plant cell walls

Lipids

Hydrophobic molecules including fats

Fats (triacylglycerol)

Glycerol and fatty acids linked by ester bonds

G1 Checkpoint

Decision point in the cell cycle where the cell can proceed to divide, enter G0 phase, or stop

MPF (M phase promoting factor)

Cyclin CDK complex that triggers cell passage past the G2 checkpoint

Growth Factor

Protein released by cells triggering other cells to divide

Density Dependent Inhibition

Mechanism where crowded cells stop dividing

Anchorage Dependence

Requirement for cells to be attached to divide

Transformation (cancer)

Process where a single cell becomes a cancer cell

Tumor

Mass of cells originating from a transformed cell

Benign Tumor

Non-invasive tumor remaining in the original site

Malignant Tumor

Invasive tumor impairing healthy tissue, leading to cancer

Metastasis

Spread of cancer cells to other body parts

Radiation

Targeted cancer treatment

Chemotherapy

Treatment using toxic drugs targeting rapidly dividing cells

Gene

DNA segment coding for a specific trait

Haploid Cell

Cell with one set of chromosomes

Diploid Cell

Cell with two sets of chromosomes

Sex Chromosomes

Chromosome pair #23 determining sex

Autosomes

Chromosomes pairs #1-#22 excluding sex chromosomes

Homologous Chromosomes

Chromosome pairs with genes for the same traits

Interphase (meiosis)

Phase where DNA replication occurs

Meiosis 1

Division of diploid cells into two haploid cells with double chromosomes

Meiosis 2

Division of haploid cells into four haploid cells with single chromosomes

Crossing Over

Exchange of genetic material between non-sister chromatids

Independent Assortment of Chromosomes

Random distribution of chromosomes into gametes

Random Fertilization

Fusion of gametes leading to over 70 trillion possible zygotes

Parasitism

Relationship where the parasite benefits by getting nourishment from the host, which is harmed

Autotroph

Organism that produces its own food by capturing physical or chemical energy

Protosynthetic Autotroph

Autotrophs that use light to produce food

Chemosynthetic Autotroph

Autotrophs that use energy from chemical reactions to make food

Heterotroph

Organism that obtains energy from other organisms

Biodiversity

The variety of species present in an ecosystem

Keystone Species

Species that have a significant impact due to their ecological niche, not their abundance

Invasive Species

Species that cause ecological or economic harm in a new environment where they are not native

Trophic Cascade

Effect where changes in one part of a trophic pyramid influence other, sometimes unrelated parts

Succession

Process where the structure of a biological community changes over time

Primary succession

Colonization of newly exposed rock for the first time

Secondary succession

Recolonization of an area with living things after a disturbance

Primary productivity

Rate at which autotrophs produce organic compounds

Gross Primary productivity

Total amount of organic compounds produced

Net Primary productivity

Amount of organic compounds remaining after plants use what they need

Trophic efficiency

Percentage of biomass/energy transferred from one trophic level to the next (about 10%)

Nitrogen fixation

Conversion of N2 to nitrogen compounds

Saturated Fats

all single bonds, maximum hydrogens, linear (solid at room temperature) (source: animal fats)

Unsaturated Fats

At least 1 double bond, less than maximum hydrogens, bent (liquid at room temperature) (source: plants and fish oils)

Phospholipids

one phosphate, on glycerol, two fatty acids (polar head and nonpolar tail)

Cholesterol

helps with membrane stability (not too fluid, not too viscous) 

Amphipathic Molecule

has both a hydrophobic and hydrophilic region

Selective Permeability

 some substances are allowed to cross the membrane; others are not

Membrane Fluidity

held together by hydrophobic interactions

Integral Proteins

extend into the hydrophobic interactions

Transmembrane Proteins

Cross the entire membrane