U1 AP BIO test review

Which four elements are primarily used to build biological molecules?

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

What are trace elements?

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

What are atoms?

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

What are isotopes?

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

What are compounds?

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

What is an ionic bond?

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

What is a covalent bond?

A bond formed when electrons are shared between atoms.

What is the difference between polar and non-polar covalent bonds?

Polar covalent bonds share electrons unequally, while non-polar covalent bonds share electrons equally.

What are hydrogen bonds?

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

What is capillary action?

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

What defines an acidic solution?

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

What defines a basic solution?

A solution that releases a lot of hydroxide ions (OH-) when added to water.

What are organic molecules?

Molecules that contain carbon.

What are polymers?

Chains of building blocks in macromolecules.

What are monomers?

The individual building blocks of a polymer.

What is dehydration synthesis?

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

What is hydrolysis?

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

What are carbohydrates?

Organic compounds containing carbon, hydrogen, and oxygen in a ratio of approximately 1:2:1.

What are monosaccharides?

The simplest form of carbohydrates, serving as an energy source for cells.

What is a glycosidic linkage?

The bond formed when two monosaccharides are joined together.

What is maltose?

The disaccharide formed from two glucose molecules.

What is the process to break down a disaccharide into two monosaccharides?

Add water.

What are polysaccharides made of?

Many repeated units of monosaccharides.

Name three important polysaccharides.

Starch, cellulose, and glycogen.

What is the function of glycogen?

It stores sugar in animals.

What is the function of starch?

It stores sugar in plants.

What is cellulose made of and what is its function?

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

What is chitin and where is it found?

A polymer of β-glucose; found in fungal cell walls and arthropod exoskeletons.

What are proteins important for?

Structure, function, and regulation of tissues and organs.

What are the building blocks of proteins?

Amino acids.

How many different amino acids are there?

20 different amino acids.

What are the four important parts of an amino acid?

An amino group (-NH2), a carboxyl group (-COOH), a hydrogen, and an R-group.

What determines the properties of an amino acid?

The R-group, or side chain.

What are the three broad categories of amino acids based on polarity?

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

Which amino acids donate a proton and become negatively charged?

Glutamic acid and aspartic acid.

Which amino acids accept a proton and become positively charged?

Lysine and arginine.

What is a dipeptide?

A molecule formed when two amino acids join.

What type of bond forms between two amino acids?

Peptide bond.

What is a polypeptide?

A chain of amino acids linked together.

What is the primary structure of a protein?

The linear sequence of amino acids.

What are the secondary structures of proteins?

Alpha helix and beta-pleated sheets.

What is the tertiary structure of a protein?

The overall 3D shape formed by interactions among amino acids.

What is the quaternary structure of a protein?

When different polypeptide chains interact with each other.

What is the role of cholesterol in membranes?

It increases membrane fluidity and is important for hormone production.

What are the main components of lipids?

Carbon, hydrogen, and oxygen atoms.

What are triglycerides made of?

A glycerol molecule and three fatty acid chains.

What distinguishes saturated from unsaturated fatty acids?

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

What are phospholipids composed of?

Two fatty acid tails and one negatively charged phosphate head.

What property makes phospholipids amphipathic?

They have both hydrophilic (water-attracting) and hydrophobic (water-repelling) regions.

What are nucleic acids made of?

Carbon, hydrogen, oxygen, nitrogen, and phosphorus.

What is the primary function of DNA?

To contain the hereditary blueprints of all life.

What is the role of RNA in cells?

Essential for protein synthesis.