Savvas Biology 2.3 and 2.4 - The Chemistry of Life

atom

the building blocks of matter; contains subatomic particles: neutrons, electrons, and protons

nucleus

located at the center of the atom, consists of protons and neutrons

proton

positively charged particle located in the center of an atom

electron

negatively charged particle located outside the nucleus

neutron

particle with no charge located in the center of an atom

element

A pure substance composed of only one type of atom. A pure substance that cannot be broken down into other substances by physical or chemical means

compound

a pure substance with unique properties formed whern two or more different elements combine

covalent bond

chemical bond which forms when two atoms share electrons

molecule

a compound in which the atoms are held together by covalent bonds

ion

atom that is negatively or positively charged because it has lost or gained one or more electrons

ionic bond

an electrical attraction between two oppositely charged atoms or groups of atoms

van der Waals forces

the attractive force between the positive and negative regions of different molecules

chemical reaction

energy requiring process by which atoms or groups of atoms are changed into different substances

reactants

substance that exists before a chemical reaction starts

products

the substances formed during the chemical reaction

activation energy

the minimum amount of energy needed for the reactants to form products in a chemical reaction

catalyst

substance that speeds up a chemical reaction by reducing the needed amount of activation energy

polar molecules

molecule with oppositely charged regions

hydrogen bond

weak electrostatic bond formed by the attraction of opposite charges between a hydrogen atom and oxygen, flourine, or nitrogen atom

solution

a homogeneous mixture formed when a substance is dissolved in a another substance

solvent

the substance in which another substance is dissolved

solute

the substance that is dissolved in the solvent

pH

the measure of the concentration of hydrogen ions present in a solution

acids

substances that release hydrogen ions when dissolved in water

buffers

mixtures that can react with acids or based to keep pH within a particular range

exothermic

Chemical Reaction in which energy is primarily given off in the form of heat

endothermic

(of a chemical reaction or compound) occurring or formed with absorption of heat

0-7

pH of acids

7-14

pH of bases

7

neutral pH

Macromolecules

carbohydrates, lipids, proteins, nucleic acids

carbohydrates

immediate energy and structural support

lipids

Store energy and provide barriers

proteins

Transport substances, speed reactions, support and make hormones.

nucleic Acids

store and transmit genetic information

monosaccharide

simple sugar molecule

disaccharide

A double sugar, consisting of two monosaccharides

polysaccharide

large macromolecule formed from monosaccharides

lipids

fats and oils

saturated fat

A lipid made from fatty acids that have no double bonds between carbon atoms

unsaturated fat

A lipid made from fatty acids that have at least one double bond between carbon atoms.

Amino Acids

monomers of proteins

Nucleotides

make up a nucleic acid that consist of a pentose, phosphate group, and nitrogenous base.

DNA

deoxyribonucleic acid

RNA

ribonucleic acid

What distinguishes organic compounds from inorganic compounds?

Organic compounds contain multiple carbon atoms bonded to each other, while inorganic compounds do not contain carbon atoms, with few exceptions like CO2.

Why is carbon considered an ideal building block for organic molecules?

Carbon has 4 valence electrons, allowing it to form covalent bonds with other atoms, resulting in diverse structures like chains and rings.

What are functional groups in organic chemistry?

Functional groups are groups of atoms attached to carbon skeletons that give molecules specific shapes and are directly involved in chemical reactions.

What is a macromolecule?

A macromolecule is a giant molecule formed by the joining of smaller molecules, typically through polymerization.

What is polymerization?

Polymerization is a reaction in which monomers are joined together to form polymers, often through condensation reactions.

What is the process of condensation in macromolecule formation?

Condensation is when two molecules are covalently bonded through the loss of a water molecule, requiring energy and an enzyme.

What is hydrolysis?

Hydrolysis is the process of breaking down polymers into monomers using water, essentially the reverse of condensation.

What is the general formula for carbohydrates?

Carbohydrates are made up of carbon, hydrogen, and oxygen in a 1:2:1 ratio, represented as CxHyOz.

What are monosaccharides?

Monosaccharides are simple sugars that consist of one sugar molecule and are the monomers of carbohydrates.

What are disaccharides?

Disaccharides are carbohydrates made of two simple sugars covalently bonded together through a condensation reaction.

What are polysaccharides?

Polysaccharides are carbohydrates made up of three or more monosaccharides linked together.

Name three common polysaccharides.

Glycogen, cellulose, and starch.

What are lipids?

Lipids are large, nonpolar organic molecules, including fats, waxes, and oils, that are not soluble in water.

What are the two types of fatty acids?

Saturated fatty acids, which have no double bonds, and unsaturated fatty acids, which have at least one double bond.

What are triglycerides?

Triglycerides are a type of lipid formed from glycerol and three fatty acids.

What are proteins made of?

Proteins are macromolecules made up of carbon, oxygen, hydrogen, and nitrogen, with amino acids as their monomers.

What is the basic structure of an amino acid?

An amino acid consists of a central carbon, a hydrogen atom, an amino group, a carboxyl group, and a unique 'R' group.

What is a dipeptide?

A dipeptide is formed when two amino acids are linked together by a condensation reaction.

What role do enzymes play in biological reactions?

Enzymes are proteins that speed up chemical reactions without being consumed in the process.

What are nucleic acids?

Nucleic acids are macromolecules that contain carbon, hydrogen, oxygen, nitrogen, and phosphorus, and include DNA and RNA.

What is the function of DNA?

DNA stores genetic information that determines the characteristics of an organism and directs cell activities.

What is the role of RNA?

RNA transfers information from DNA in the nucleus to ribosomes in the cytoplasm for protein synthesis.

What is the enzyme-substrate complex?

The enzyme-substrate complex is formed when a substrate molecule binds to the active site of an enzyme.

What are the two models of enzyme action?

The Lock and Key model and the Induced Fit model.

How do heat and pH affect enzymes?

Heat and pH can affect the shape and function of enzymes, potentially denaturing them and altering their activity.

Matter

Anything that occupies space and has mass.

Mass

A measure of the amount of matter in an object.

Weight

The force produced by gravity acting on an object.

Element

Pure substance composed of all the same type of atom.

Atom

The smallest particle of an element that retains all of the properties of that element.

Protons

Positively charged subatomic particles found in the nucleus of an atom.

Neutrons

Subatomic particles that have no charge.

Atomic Number

The number of protons contained in the nucleus of an atom.

Mass Number

The combined total of protons and neutrons in the nucleus of an atom.

Electrons

Small, negatively charged subatomic particles that move about the nucleus at very high speeds and are located in orbitals.

Orbital

The three-dimensional region around the nucleus of an atom that indicates the probable location of an electron.

Isotopes

Atoms of the same element that have different numbers of neutrons.

Compound

A substance composed of atoms of two or more elements in a fixed proportion.

Chemical Bonds

The attractive forces that hold atoms together in compounds.

Covalent Bond

A bond that is formed when two atoms share one or more pairs of electrons.

Molecule

The simplest unit of a compound that retains all of the properties of that substance.

Ion

An atom or molecule that has lost or gained one or more electrons resulting in an atom or molecule with an electrical charge.

Ionic Bond

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

Energy

The ability to do work.

Chemical Reaction

A process that changes one set of chemicals into another set of chemicals.

Reactants

The elements or compounds that enter into a chemical reaction.

Products

The elements or compounds produced by a chemical reaction.

Metabolism

The sum total of all of the chemical reactions occurring within a cell.

Activation Energy

The amount of energy required to start a reaction.

Catalyst

Inorganic substance that speeds up a chemical reaction by lowering the amount of activation energy needed for the reaction to occur.

Polar Molecule

A molecule in which electrons are shared unequally between the atoms, resulting in a molecule that has poles. Part of the molecule is negative and part of the molecule is positive.

Hydrogen Bond

A weak molecular bond formed between the hydrogen atom of one molecule and a highly electronegative atom of another molecule.

Cohesion

The attraction between molecules of the same substance.

Adhesion

The attraction between molecules of different substances.

Capillary Action

The tendency of water to rise in a thin tube due to cohesion and adhesion.