AP Biology Ultimate Guide (copy)

The fundamental substances that make up all matter, consisting of atoms of the same atomic number.

Elements

Molecules made up of oxygen, carbon, hydrogen, and nitrogen used to build carbohydrates, proteins, lipids, and nucleic acids.

Biological molecules

Elements required by an organism in small quantities, including iron, iodine, and copper.

Trace elements

Compounds made up of oxygen, carbon, hydrogen, and nitrogen used to store energy in organisms.

Storage compounds

Basic unit of life, made up of oxygen, carbon, hydrogen, and nitrogen.

Cells

Substances made up of one type of atom, including oxygen, carbon, hydrogen, nitrogen, and others.

Elements

The unit of life and building blocks of the physical world.

Atoms

Positively charged (+) particles.

Protons

Uncharged particles.

Neutrons

Negatively charged (–) particles.

Electrons

Atoms with the same number of protons but different number of neutrons in the nucleus.

Isotopes

A substance consisting of two or more elements that are chemically bonded together.

Compounds

The force that holds two atoms together in a molecule.

Chemical bonds

Charged forms of atoms that are formed when one or more electrons are transferred from one atom to another.

Ions

A chemical bond formed between two atoms when one or more electrons are transferred from one atom to the other.

Ionic bond

A chemical bond formed when electrons are shared between atoms.

Covalent bond

A covalent bond where electrons are shared equally between the atoms.

Non-polar covalent bond

A covalent bond where electrons are shared unequally between the atoms.

Polar covalent bond

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

Acidic Solution

A solution that contains a lot of hydroxide ions (OH–).

Basic Solution

A scale used to measure the acidity or alkalinity of a solution, numbered from 1 to 14, with 7 considered neutral pH.

pH Scale

The concentration of hydrogen ions in a solution, which indicates whether it is acidic, basic, or neutral.

Hydrogen Ion Concentration

The formula used to calculate the pH of a solution, which is pH = –log [H+].

pH Formula

A scale in which each unit represents a tenfold change in hydrogen ion concentration on the pH scale.

Logarithmic Scale

Molecules with carbon atoms

Organic molecules

Molecules that do not contain carbon atoms

Inorganic compounds

A versatile atom that can bind with other carbons, nitrogen, oxygen, and hydrogen

Carbon

Chains of building blocks in macromolecules

Polymers

Individual building blocks of a polymer

Monomers

A reaction that forms polymers by losing a water molecule

Dehydration synthesis

A reaction that breaks down polymers into monomers by adding a water molecule

Hydrolysis

Four classes of organic compounds central to life on Earth

Carbohydrates, proteins, lipids, nucleic acids

Organic compounds containing carbon, hydrogen, and oxygen that are categorized as monosaccharides, disaccharides, or polysaccharides.

Carbohydrates

Simple sugars that are an energy source for cells and include glucose and fructose with a chemical formula of C6H12O6.

Monosaccharides

Sugars formed by joining two monosaccharides with a glycosidic linkage, such as maltose, and can be broken down into two monosaccharides by adding water.

Disaccharides

Complex carbohydrates made up of many repeated units of monosaccharides, such as starch, cellulose, and glycogen.

Polysaccharides

A polysaccharide that stores sugar in plants.

Starch

A polysaccharide made up of β-glucose and is a major part of the cell walls in plants, lending structural support.

Cellulose

A polysaccharide that stores sugar in animals.

Glycogen

A polymer of β-glucose molecules that serves as a structural molecule in the walls of fungus and in the exoskeletons of arthropods.

Chitin

Organic compounds formed by joining a group of amino acids together in a "string" through peptide bonds. Once they twist and fold on themselves, they form a 3D structure called a protein.

Polypeptides

Organic compounds consisting of carbon, hydrogen, and oxygen atoms. They function as structural components of cell membranes, sources of insulation, signalling molecules, and a means of energy storage.

Lipids

Lipids with two hydrophobic fatty acid tails and one hydrophilic phosphate head. They have both hydrophobic and hydrophilic properties, making them amphipathic molecules.

Phospholipids

A four-ringed molecule found in membranes that generally increases membrane fluidity, except at very high temperatures. It is also important for making certain types of hormones and for making vitamin D.

Cholesterol

Molecules made up of simple units called nucleotides that contain carbon, hydrogen, oxygen, nitrogen, and phosphorus. DNA contains the hereditary "blueprints" of all life, while RNA is essential for protein synthesis.

Nucleic Acids

The concept that as cells or organisms increase in size, their surface area-to-volume ratio decreases, leading to less efficient exchange of materials. Small organisms lose heat at much higher rates than larger organisms due to their efficient exchange of heat.

Surface Area-to-Volume Ratio

Cells that lack a nucleus and other membrane-bound organelles. They are typically smaller and simpler in structure than eukaryotic cells.

Prokaryotic Cells

Cells that contain a nucleus and other membrane-bound organelles. They are typically larger and more complex in structure than prokaryotic cells.

Eukaryotic Cells

A type of cell that is smaller and simpler than a eukaryotic cell, with no membrane-bound organelles. Bacteria and archaea are examples of prokaryotes.

Prokaryotic cell

A type of cell that is more complex than a prokaryotic cell and has many smaller structures called organelles. Fungi, protists, plants, and animals are examples of eukaryotes.

Eukaryotic cell

The outer envelope of the cell, made up of mostly phospholipids and proteins. It regulates the movement of substances into and out of the cell and is semipermeable.

Plasma membrane

The largest organelle in the cell that contains the cell's genetic material (DNA) and is responsible for directing the cell's activities and reproduction.

Nucleus

Sites of protein synthesis in the cell, composed of two subunits (large and small) made of ribosomal RNA (rRNA) and proteins. They can be free-floating or attached to the endoplasmic reticulum (ER).

Ribosomes

A continuous channel that extends into many regions of the cytoplasm and provides mechanical support and transportation. The rough ER compartmentalizes the cell, while the smooth ER makes lipids and breaks down toxic chemicals.

Endoplasmic reticulum (ER)

An organelle that modifies, processes, and sorts proteins synthesized by ribosomes on the rough ER. It packages the final products in vesicles for distribution outside of the cell.

Golgi complex

Organelles responsible for converting energy from organic molecules into ATP, the most common energy molecule in the cell. They have an inner and outer membrane, with the inner membrane forming folds called cristae.

Mitochondria

Organelles that contain digestive enzymes used to break down old, worn-out org

Lysosomes

Movement of molecules down a concentration gradient without the use of energy.

Passive Transport

Movement of small, hydrophobic molecules across the cell membrane without the assistance of proteins.

Simple Diffusion

Movement of molecules across the cell membrane with the assistance of channel-type proteins.

Facilitated Diffusion

Movement of water across a selectively permeable membrane from an area of high water potential to an area of low water potential.

Osmosis

The measure of osmotic pressure gradient between two solutions separated by a selectively permeable membrane.

Tonicity

Movement of molecules against a concentration gradient with the use of energy.

Active Transport

The process by which the cell membrane engulfs large molecules or particles to form a vacuole or vesicle.

Endocytosis

The one-way movement of fluids brought about by pressure.

Bulk Flow

The study of how cells obtain and use energy.

Bioenergetics

The study of energy transformation.

Thermodynamics

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

Enzyme

The ability of an enzyme to catalyze only one kind of reaction.

Enzyme Specificity

The temporary binding of an enzyme to one or more substrates.

Enzyme-Substrate Complex

The change in shape of an enzyme to accommodate the shape of its substrate.

Induced-fit

The control of enzymatic activity by regulating the conditions that influence the shape of the enzyme.

Enzyme Regulation

Adenosine triphosphate, a molecule that stores and releases energy.

ATP

The process of breaking down sugar to make ATP.

Cellular Respiration

The process by which light energy is converted to chemical energy.

Photosynthesis

The dark reactions that use ATP and NADPH produced in the light reactions to convert CO2 into carbohydrates in the stroma of the leaf.

Calvin-Benson Cycle

A strategy used by CAM plants to separate carbon fixation and the Calvin cycle by incorporating CO2 into organic acids at night and releasing it during the day.

Temporal Separation

A process used by C4 plants to fix CO2 in a different part of the leaf from the Calvin cycle, preventing photorespiration and producing a four-carbon molecule as the first product.

Carbon Fixation

The final stage of aerobic respiration where electrons from NADH and FADH2 are transported through a series of proteins to create a proton gradient that powers ATP synthesis.

Electron Transport Chain

The three-carbon molecule produced by the splitting of glucose in the first stage of glycolysis, which also results in the net production of two ATP and two NADH molecules.

Pyruvic Acid

The process by which cells of multi-celled organisms coordinate their activities by communicating with one another through cell-to-cell contact or cell signaling.

Cell communication

A type of cell signaling that affects cells throughout the organism, often done through signaling molecules called ligands that bind to receptors and trigger a response by changing the shape of the receptor protein.

Long-range signaling

The process by which an external signal is transmitted to the inside of a cell, usually involving three steps: a signaling molecule binding to a specific receptor, activation of a signal transduction pathway, and production of a cellular response.

Signal transduction

An integral membrane protein that transmits signals from the extracellular space into the cytoplasm, binding a particular molecule in a highly specific way. It is required for signaling molecules that cannot enter the cell.

Plasma membrane receptor

Membrane receptors that open or close an ion channel upon binding a particular ligand.

Ligand-gated ion channels

Membrane receptors that have an enzymatic active site on the cytoplasmic side of the membrane and are initiated by ligand binding at the extracellular surface.

Catalytic (enzyme-linked) receptors

Membrane receptors that bind a different version of a G-protein on the intracellular side when a ligand is bound extracellularly, causing activation of secondary messengers within the cell.

G-protein-linked receptor

Processes that amplify a signal in a cell.

Signal transduction cascades

The set of conditions under which living things can successfully survive.

Homeostasis

A feedback pathway that works by turning itself off using the end product of the pathway.

Negative feedback pathway

A feedback pathway that involves an end product playing a role and further stimulating the pathway instead of inhibiting it.

Positive feedback pathway

The period from the beginning of one cell division to the beginning of the next, divided into two periods: interphase and mitosis.

Cell Cycle

The growing phase of the cell cycle, divided into three stages: G1, S, G2. The S phase is the most important phase, where the cell replicates its genetic material.

Interphase

Identical strands of DNA that are duplicated during interphase and held together by a structure called the centromere.

Sister Chromatids

Control mechanisms that ensure proper cell division is happening in eukaryotic cells, regulated by proteins called cyclins and cyclin-dependent kinases (CDKs).

Cell Cycle Checkpoints

Mutated genes that can convert normal cells into cancerous cells, while tumour suppressor genes produce proteins that prevent the conversion of normal cells into cancer cells.

Oncogenes

The process of cellular division, occurring in four stages: prophase, metaphase, anaphase, and telophase.

Mitosis

Genetic material in its decondensed state, occurring during interphase once daughter cells are produced and the cell goes back to its original state.

Chromatin

Achieving the production of identical daughter cells and maintaining the proper number of chromosomes from generation to generation, for growth, repair, or asexual reproduction.

Purpose of Mitosis

The monk who discovered genetics and is known as the father of genetics.

Gregor Mendel