AP Biology - Unit 1: Chemistry of Life All Topics

What is matter?

Anything that takes up space and has mass.

What is an element?

A substance that cannot be broken down into other substances by chemical reactions.

How many naturally occurring elements are there?

92 elements.

What is a compound?

A substance consisting of two or more different elements combined in a fixed ratio.

What percentage of essential elements are required for survival and reproduction?

20-25% of the 92 naturally occurring elements.

What elements make up 96% of living matter?

Carbon, Hydrogen, Oxygen, Phosphorus, and Nitrogen (CHOPN).

What are trace elements?

Elements required by an organism in very small quantities.

What does atomic number represent?

The number of protons in an atom.

What is atomic mass?

The number of protons plus neutrons averaged over all isotopes.

What do elements in the same vertical column of the periodic table have in common?

They have the same number of valence electrons.

What do elements in the same horizontal row of the periodic table have in common?

They have the same total number of electron shells.

What is the octet rule?

Elements will gain, lose, or share electrons to complete their valence shell and become stable.

What are chemical bonds?

An attraction between two atoms, resulting from the sharing or transferring of valence electrons.

What is electronegativity?

The measure of an atom's ability to attract electrons to itself.

What is a covalent bond?

A bond formed when two or more atoms share electrons.

What is a polar covalent bond?

A bond where electrons are not shared equally between two atoms.

What is an ionic bond?

The attraction between oppositely charged atoms (ions), usually between a metal and a nonmetal.

What is a hydrogen bond?

An attraction between a partially positive hydrogen atom in one polar covalent molecule and an electronegative atom in another.

What is cohesion?

The attraction of molecules for other molecules of the same kind.

What is adhesion?

The attraction to other molecules that are polar or have charge.

What is capillary action?

The upward movement of water due to the forces of cohesion, adhesion, and surface tension.

What is high specific heat?

The ability of water to resist changes in temperature.

What is evaporative cooling?

The process where water molecules evaporate, cooling the surface they evaporate from.

Why does ice float on water?

As water solidifies, it expands and becomes less dense due to hydrogen bonds.

What is a solvent?

The dissolving agent in a solution.

What is pH?

A measure of how acidic or basic (alkaline) a solution is.

What is a buffer?

A solution that resists changes in pH when an acid or base is added.

What is organic chemistry?

The study of compounds with covalently bonded carbon.

What are organic compounds?

Compounds that contain carbon and hydrogen.

How many valence electrons does carbon have?

Four valence electrons.

What types of covalent bonds can carbon form?

Single, double, or triple covalent bonds.

What is a hydrocarbon?

An organic molecule consisting only of carbon and hydrogen.

What affects the length and shape of carbon chains?

The type and number of covalent bonds carbon forms with other atoms.

What are functional groups?

Chemical groups attached to the carbon skeleton that participate in chemical reactions.

What are the four classes of macromolecules?

Carbohydrates, Proteins, Nucleic acids, and Lipids.

What is a polymer?

Chain-like macromolecules of similar or identical repeating units that are covalently bonded together.

What are monomers?

The repeating units that make up polymers.

What is a dehydration reaction?

A reaction that covalently bonds two monomers with the loss of H2O.

What is hydrolysis?

A reaction that breaks the covalent bonds in a polymer by adding H2O.

How many water molecules are needed to hydrolyze a polymer with 300 monomers?

299 water molecules.

What role does nitrogen play in macromolecules?

Nitrogen is important for building proteins and nucleic acids.

What role does phosphorus play in macromolecules?

Phosphorus is important for building nucleic acids and some lipids.

What role does sulfur play in macromolecules?

Sulfur is used in the building of proteins.

What is polymerization?

The connection of many monomers to form a polymer.

What are the variations in carbon skeletons responsible for?

Molecular diversity.

What is the significance of carbon's ability to form long chains?

It allows for the formation of complex organic molecules.

What is the relationship between carbon and silicon in the periodic table?

Silicon is in the same group as carbon, indicating similar properties.

What are the four main types of biological macromolecules?

Carbohydrates, Lipids, Nucleic Acids, Proteins

What are carbohydrates primarily composed of?

Carbon (C), Hydrogen (H), and Oxygen (O)

What are monosaccharides?

Simple sugars that are the building blocks of carbohydrates, with molecular formulas that are multiples of CH2O.

What is the most common monosaccharide?

Glucose

What is a disaccharide?

A carbohydrate formed from two monosaccharides joined by covalent bonds.

What is the most common disaccharide?

Sucrose, which is composed of glucose and fructose.

What are polysaccharides?

Polymers of many sugars joined via dehydration reactions.

What is starch?

A storage polysaccharide in plants, composed of glucose monomers.

What is glycogen?

A storage polysaccharide in animals, primarily stored in liver and muscle cells.

What is cellulose?

A structural polysaccharide that forms plant cell walls.

What are lipids?

A class of molecules that are generally small, nonpolar, and hydrophobic, not true polymers.

What are the major functions of fats?

Energy storage, support cell function, and provide insulation.

What are phospholipids?

Major components of cell membranes, consisting of two fatty acids attached to glycerol and a phosphate group.

What is the structure of steroids?

Hormones with four fused rings, with unique groups attached that determine the type of steroid.

What are nucleic acids?

Polymers made of nucleotide monomers that store, transmit, and express hereditary information.

What are the two forms of nucleic acids?

Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).

What are the three components of a nucleotide?

A nitrogenous base, a five-carbon sugar (pentose), and a phosphate group.

What are the two types of nitrogenous bases?

Pyrimidines (Cytosine, Thymine, Uracil) and Purines (Adenine, Guanine).

What is the difference between DNA and RNA sugars?

DNA contains deoxyribose, while RNA contains ribose.

What is a polypeptide?

A chain of amino acids linked by peptide bonds.

What determines the 3D shape of a protein?

The sequence of amino acids and interactions between their side chains.

What are the four levels of protein structure?

Primary, Secondary, Tertiary, and Quaternary.

What is the primary structure of a protein?

A linear chain of amino acids determined by genes.

What is the secondary structure of a protein?

Coils and folds formed due to hydrogen bonding within the polypeptide backbone.

What is the tertiary structure of a protein?

The 3D folding due to interactions between side chains of amino acids.

What is the quaternary structure of a protein?

The association of two or more polypeptides, found in some proteins.

What role do enzymes play in proteins?

They carry out chemical reactions or assist in creating new molecules.

What is the significance of the shape of a protein?

The shape determines the protein's function.