AP Bio Unit 1 Review

Elements

Substances that cannot be broken down into simpler substances by chemical means.

Name the four primary elements used to build biological molecules.

Oxygen (O), carbon (C), hydrogen (H), and nitrogen (N).

trace elements

Elements required by an organism only in very small quantities, such as iron (Fe), iodine (I), and copper (Cu).

atoms

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

protons

Positively charged particles found in an atom.

neutrons

Uncharged particles found in an atom.

electrons

Negatively charged particles found in an atom.

isotopes

Atoms that have the same number of protons but differ in the number of neutrons.

compound

A substance consisting of two or more elements held together by chemical bonds.

ionic bond

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

ions

Charged forms of atoms that result from ionic bonding.

covalent bond

A bond formed when electrons are shared between atoms.

hydrogen bonds

Weak chemical bonds that form when a hydrogen atom covalently bonded to one atom is attracted to another atom.

cohesion

The tendency of water molecules to stick together due to hydrogen bonding.

adhesion

The tendency of water molecules to stick to other substances.

capillary action

The ability of water to rise up through roots, trunks, and branches of trees due to cohesion and adhesion.

surface tension

The tension at the surface of water caused by the cohesive forces among water molecules.

organic molecules

Molecules that contain carbon.

polymers

Chains of building blocks in macromolecules.

monomers

The individual building blocks of a polymer.

dehydration synthesis

A reaction where a water molecule is lost, forming a larger compound from monomers.

hydrolysis

A reaction where water breaks the bond between two monomers, breaking down a polymer.

Name the four classes of organic compounds central to life.

Carbohydrates, proteins, lipids, and nucleic acids.

general formula ratio for carbohydrates

Approximately 1:2:1 for carbon, hydrogen, and oxygen.

monosaccharides

Single sugar molecules that serve as an energy source for cells.

glycosidic linkage

The bond formed when two monosaccharides are joined to create a disaccharide.

polysaccharides

Many repeated units of monosaccharides.

three important polysaccharides

Starch, cellulose, and glycogen

It stores sugar.

What is the function of glycogen in animals?

It stores sugar

What is the function of starch in plants?

Made of β-glucose; provides structural support in plant cell walls.

What is cellulose made of and what is its function?

A polymer of β-glucose; found in the walls of fungi and exoskeletons of arthropods.

What is chitin and where is it found?

Structure, function, and regulation of tissues and organs.

What are proteins important for?

amino acids

building blocks of proteins

The R-group, or side chain.

What determines the properties of an amino acid?

Hydrophobic (non-polar), hydrophilic (polar), and ionic (polar and charged).

How are amino acids categorized based on polarity?

A molecule formed when two amino acids join together.

What is a dipeptide?

The bond between two amino acids.

What is a peptide bond?

The linear sequence of amino acids

What is the primary structure of a protein?

Alpha helices and beta-pleated sheets.

What are the secondary structures of proteins?

The 3D shape formed when secondary structures interact.

What is the tertiary structure of a protein?

Formed when different polypeptide chains interact.

What is a quaternary structure in proteins?

It increases membrane fluidity and is important for hormone production.

What is the role of cholesterol in cell membranes?

Carbon, hydrogen, and oxygen atoms.

What are the main components of lipids?

One glycerol molecule and three fatty acid chains

What are triglycerides made of?

Saturated fatty acids have no double bonds; unsaturated fatty acids contain one or more double bonds.

What distinguishes saturated from unsaturated fatty acids?

Two fatty acid tails and one negatively charged phosphate head.

What is the structure of phospholipids?

They have both hydrophilic and hydrophobic regions

What property makes phospholipids amphipathic?

Carbon, hydrogen, oxygen, nitrogen, and phosphorus.

What are nucleic acids made of?

Contains the hereditary blueprints of all life.

What is the function of DNA?

Essential for protein synthesis.

What is the role of RNA?