AP Biology Terms you Might Forget!

Condensation/Dehydration Synthesis

The chemical reaction that joins monomers into polymers by the removal of water between the monomers. The process creates a covalent bond between the now-connected atoms and produces a water molecule as a byproduct

Hydrolysis

The chemical reaction that separates a polymer into monomers by the addition of a water molecule. The addition breaks a bond within the polymer, forcing it to split

Carbon, hydrogen, and oxygen. The general formula for this macromolecule is CH2O

The elements that create carbohydrates

Carbon, hydrogen, oxygen. The general formula for this macromolecule is not generalized

The elements that create lipids (+phosphorus for phospholipids)

Carbon, hydrogen, oxygen, and nitrogen (sometimes sulfur)

The elements that create protein

Carbon + COOH, NH2, H, R-group

The required structure of an amino acid

Primary Structure

The level of protein formation that involves the sequence of amino acids in a polypeptide chain

Secondary Structure

The level of protein formation that involves the hydrogen bonding between parts of the peptide backbone

Tertiary Structure

The level of protein structure that involves the bonding of the R-groups that distinguish the protein

Quaternary Structure

The level of protein formation that involves two or more folded polypeptides united

Carbon, hydrogen, oxygen, nitrogen, and phosphorus

Elements that create nucleic acids

Plasma (Cell) membrane, cytosol, ribosomes, DNA

All cells contain these features

Endosymbiotic Theory

Some organelles that have their own DNA, ribosomes, and reproduce independently (like mitochondria and chloroplasts) prove this theory that certain organelles originated from prokaryotic cells engulfed by ancestral eukaryotic cells.

Ribosomes

These are made by the nucleolus and their cellular function is to synthesize proteins during RNA translation

Nucleus

Contains a eukaryotic cell’s genetic information

Endoplasmic Reticulum

Can be smooth (without ribosomes) or rough (with ribosomes) and its main functions are to synthesize lipids, store carbs, and detoxify poisons, OR to create secretory proteins

Golgi Apparatus

Cellular function is to correctly fold and chemically modify proteins and package secretory proteins in vesicles for transporation

Lysosomes

These components are made by the Golgi and function to break down cellular materials (like during apoptosis)

Mitochondria

Organelles that produce ATP through cellular respiration and are known as the powerhouse of the cell.

Glucose

A molecule that doesn’t dissolve in water due to covalent bonds and has a ionization number of 1

Isotonic

In osmosis, when the solute concentration is equal to the water concentration

Hypotonic

In osmosis, when the solute concentration is less than the water concentration (strained cell)

Hypertonic

In osmosis, when the solute concentration is greater than the water concentration (dried out cell)

Sodium-Potassium Pump

A vital membrane protein that (carrier-mediated) transports sodium ions (3) out of and potassium ions (2) into cells against their concentration gradients, using ATP for energy.

Catabolic Pathways

Metabolic pathways that break down molecules, releasing energy.

Anabolic Pathways

Metabolic pathways that build complex molecules and consume energy in the process

Feedback Inhibition

A regulatory mechanism in which an enzyme's activity is inhibited by the end product of the pathway it controls, preventing overproduction.

Exergonic Reaction

A reaction that have a net release of energy

Endergonic Reaction

Reactions that absorb free energy from the environment

The allosteric site

A specific location on an enzyme where a molecule can bind, resulting in a change in the enzyme's activity or active site

The active site

Where a substrate binds to an enzyme

Secondary Messengers

Small, water-soluble, non-protein molecules or ions that pass on an intracellular signal

• Cyclic AMP (cAMP)

• Ca2+

Protein Ligands

Ligands that trigger responses in the cytosol of a cell

Lipid Ligands

Ligands that trigger responses that change gene expression

Structural Order

The separation of enzymes and metabolic pathways in time or space to control the functions

Noncompetitive Inhibitor

A substance that alters enzymatic activity by binding to its allosteric site, altering the shape of its active site

Competitive Inhibitor

A molecule with fundamentally the same shape/ability to bind to an enzyme’s active site, preventing the correct ligand from bonding

Hydrogen Pump

A bulk and co-transport pump that uses a proton pump and sucrose cotransporter to diffuse large amount of Hydrogen ions across the cell membrane

Protein Kinase

A common relay protein that amplifies a ligand’s signal in a cell during the transduction phase by adding phosphate groups to specific amino acids in target proteins, thereby changing their activity

G1

The cell cycle phase where the cell grows while carrying out regular functions

Synthesis (S)

The cell cycle phase where DNA is replicated

G2

The cell cycle phase where organelles are duplicated and the cell prepares for division

Prophase (Mitosis)

The cell cycle phase where chromatin condenses into chromosomes and the nuclear envelope breaks down

Metaphase (Mitosis)

The cell cycle phase where chromosomes line up down the metaphase plate and spindle fibers/centrioles are fully developed

Anaphase (Mitosis)

The cell cycle phase when centromeres split and sister chromatids are pulled apart to opposite poles of the cell.

Telophase (Mitosis)

The cell cycle phase when chromosomes relax back into chromatids and the nuclear envelope reforms

Cytokinesis

The cell cycle phase when the cytoplasm divides

Cyclin Dependent Kinase (CDK)

A kinase protein that is inactive unless bound with cyclin

M-Phase Promoting Factor (MPF)

A regulator formed when CDK and cyclin bind, which stimulates the progression through the cell cycle, particularly the transition from G2 to M phase

Prophase 1

When the chromatids of homologous chromosomes crisscross to form chiasmata to exchange genetic material (crossing over)

Metaphase 1

At the metaphase plate, PAIRED homologous chromosomes are randomly lined up (some paternal on one side, maternal on the other, etc.) (INDEPENDENT ASSORTMENT)

Anaphase 1

Homologous chromosomes trade sections of DNA and are moved to opposite poles of the cell

Random fertilization, independent assortment, and crossing over

The three key features of meiosis that promote genetic diversity

Barr Body

An inactive X chromosome in a female somatic cell, ensuring dosage compensation between males and females.

Extranuclear Inheritence

The transmission of genetic information outside the nucleus, often involving mitochondrial or chloroplastic DNA (from the mother). This type of inheritance can influence traits that are not linked to nuclear genes.

Linkage Map

A diagram that shows the relative positions of genes on a chromosome and the distances between them based on recombination frequency (1% = 1 map unit) (50%> = different chromosomes)

Chi-Square Rejection/Acceptance

If the CHI-SQUARE value is greater than the CRITICAL VALUE, then null hypothesis is rejected (vice-versa)

TATA Box

A short segment of Thymine and Adenine that acts as a recognition site for transcription factors to bind to DNA

AUG

The ‘start code’ for RNA transcription that codes for methionine (MET)

Introns

Portions of transcribed RNA that are unnecessary and removed

Exons

Portions of transcribed RNA that are retained and translated into protein

GTP Cap

An RNA modification that helps with ribosomal recognition and protection

Poly-A Tail

An RNA modification that helps with the stability and protection of mRNA

A-P-E

The order that ribosomal sites are involved in protein synthesis

Lac Operon

A set of genes involved in the metabolism of lactose in bacteria, that is INDUCIBLE (substrate will denature the repressor protein)

Trp Operon

A set of genes involved in the metabolism of tryptophan in bacteria, that is REPRESSIBLE (the protein activates a repressor protein)

Acetylation

The addition of acetyl groups to amino acid groups in histones allows DNA to be more accessible for transcription

Methylation

The addition of methyl groups to DNA bases prevents DNA transcription

Hox Genes

Master regulatory genes that control placement of body parts

Non-Disjunction

The failure of homologous chromosomes or sister chromatids to separate properly during cell division, leading to an abnormal distribution of chromosomes in daughter cells.

Habitat Isolation

A prezygotic reproductive barrier that occurs when two species live in different habitats and do not meet to mate

Temporal Isolation

A prezygotic reproductive barrier that occurs when two species breed at different times of the day or year

Behavioral Isolation

A prezygotic reproductive barrier that prevents mating due to differences in mating behaviors or rituals between species

Mechanical Isolation

A prezygotic reproductive barrier that occurs when physical differences prevent successful mating between species

Gametic Isolation

A reproductive barrier that occurs when sperm and egg from different species are incompatible, preventing fertilization

Hybrid Inviability

A postzygotic reproductive barrier where hybrid offspring fail to develop properly or die before reaching reproductive maturity.

Hybrid Sterility

A postzygotic reproductive barrier in which hybrid offspring are sterile and cannot reproduce, preventing gene flow between parent species.

Hybrid Breakdown

A postzygotic reproductive barrier where the first generation of hybrids are viable and fertile, but subsequent generations are inviable or sterile and fail to compete with other, similar species