Chemistry

The group of organic compounds containing carbon, hydrogen, and oxygen in a near 1:2:1 ratio is likely a

carbohydrate

Which has the greater concentration of hydrogen ions - a substance with a pH of 5 or a substance with a pH of 4?

pH of 4

Fructose

	is a hexose (6C).
	is an isomer of glucose.
	is found in fruits.
	all of the above

Carbohydrate molecules

are the body's most readily available source of energy.

Which of the following is the symbol for an amino group?

-NH₂

Ionic bonds are formed when

electrons are completely transferred from one atom to another.

The chemical behavior of an atom is determined by

the outermost electron shell

Magnesium atoms have two electrons in their outermost shells and chlorine atoms have seven. The compound magnesium chloride would contain

1 magnesium and 2 chlorine

The mass of an atom is largely determined by the number of ________ it has.

protons+neutrons

A molecule with a long hydrocarbon chain and a carboxyl group at the end is a(an)

fatty acid

An ion differs from its parent atom by the number of

electrons

The “A” portion of the molecule

	is a functional group.
	is present in all amino acids.
	can react with a carboxyl group to form a peptide bond.
	is termed an amino group.
	all the above

Radioactive isotopes are:

often used in the diagnosis and treatment of cancer.

In hydrolysis reactions, compounds react with

water, causing decomposition

The molecule H₂ is known as

hydrogen

The molecule O₂ is known as

oxygen

Molecules that store and process genetic information are the

nucleic acids

Of the list below, which has the highest concentration of hydrogen ions?

pH 1

The sugar added to water is called the:

solute.

An example of an organic substance is

sucrose.

A side chain on an amino acid is sometimes called

an R group

Interaction between two or more polypeptide chains to form a protein complex is __ structure

quaternary

The above diagram in its entirety represents a (an):

amino acid

Identify the product formed from the addition of a phosphate group to ADP

adenosine triphosphate

Disaccharides are:

2 monosaccharide units linked with loss of water.

Carbohydrates, lipids, and proteins are

organic molecules.

Choose the answer below which is not true about oxidation

Oxidation is the gain of electrons by an atom during a chemical reaction.

The atomic number of an atom is determined by the number of ________ it has.

protons

A dust particle floating on a water surface illustrates

surface tension

According to the rules of complementary base pairing in nucleic acids, cytosine would pair with the base

guanine

A functional group is best described as groups of

atoms that greatly influence the chemical properties of molecules they are part of

When placed in water, an inorganic compound dissociates 99 percent, forming hydrogen ions and anions that are not OH-. This compound would be

a strong acid.

Each amino acid differs from another in the

nature of the side chain

One foot in the English system equals how many centimeters in the metric system?

30

If one pair of electrons is unequally shared between two atoms, a(n) ________ occurs.

polar covalent bond

Lipids

	form essential structural components of cells.
	provide roughly twice the energy as carbohydrates.
	help insulate the body.
	cushion organs against shocks.
	all of the above.

The innermost electron shell in an atom holds up to ________ electrons.

2

Substrate molecules bind to enzymes at the ________ sites.

active

A solution containing equal numbers of hydrogen ions and hydroxide ions is

neutral.

In dehydration synthesis reactions

water is a product.

Each of the following is an example of an inorganic compound, except

proteins

The most important metabolic fuel molecule in the body is

glucose.

The mass number represents the number of

protons + neutrons.

If an isotope of oxygen has 8 protons, 10 neutrons, and 8 electrons, its mass number is

18

Isotopes of an element differ in the number of

 neutrons in the nucleus.

In a molecule of oxygen, two pairs of electrons are shared equally by two oxygen atoms. The type of bond that is formed is an example of a(n)

nonpolar covalent bond.

The smallest stable units of matter are

atoms

The maximum rate of an enzyme reaction occurs at

saturation limit.

Hydrophilic molecules readily associate with

water molecules

Compounds that are ionically bonded:

dissociate into electrolytes in water.

You would expect a peptide bond to link

two amino acid

In a chemical reaction, enzymes control:

the speed of the reaction

An amino acid is to a protein as ____________ is to a nucleic acid

a nucleotide

Molecules that have the same molecular formula but different structural formulas are called

isomers

An important buffer in body fluids is

NaHCO₃

Adding one phosphate group to adenosine forms

AMP

Magnesium atoms have two electrons in the outermost shell. As a result, you would expect magnesium to form ions with a charge of

+2.

When electrons are transferred from one atom to another,

 an ionic bond is formed.

Which pH is closest to normal blood pH?

pH 7.4

Which of the following is not a cation?

Cl^-

The reaction A + B + energy → AB is an example of a(n)

endergonic reaction.

Lipids that are produced by nearly every tissue in the body and that act as local regulators of cell activities are the

 prostaglandins.

An example of an inorganic substance is (are)

water.

The nucleus of an atom consists of

protons + neutrons.

If an element is composed of atoms with an atomic number of 6 and a mass number of 14, then the nucleus of a neutral atom of this element contains

6 protons and 8 neutrons.

A shortage of cholesterol in the body could interfere with the formation of

sex hormones.

AB → A + B is to decomposition as A + B → AB is to

synthesis.

Which of the following is/are needed to form a triglyceride molecule?

1 glycerol + 3 fatty acid molecules

In an aqueous solution, sodium ions would move toward

a negative terminal

A fatty acid that contains multiple double covalent bonds is said to be

polyunsaturated

A polysaccharide that is formed in liver and muscle cells to store glucose is

glycogen

Elements that have atoms with full outer shells of electrons

are inert gases.

Nonpolar organic molecules are good examples of

hydrophobic compounds

Which of the following substances would be most acidic?

stomach secretions, pH = 1

By weight, which element is the most plentiful in the human body?

oxygen

Hydrogen bonds

	are responsible for some of the properties of water.
	can occur within a single large molecule.
	can form between neighboring molecules.
	are important for holding large molecules together.
	all of the above

When two monosaccharides undergo a dehydration synthesis

a disaccharide is formed.

By weight, which element is the second most abundant in the human body

carbon

Chemical reactions that yield energy, such as heat, are said to be

 exergonic

A nucleotide consists of

a five-carbon sugar, a nitrogenous base, and a phosphate group

Buffer pairs function to:

prevent large changes in pH

The term ________ means each enzyme catalyzes only one type of reaction

 specificity

A(n)________ releases hydrogen ions and a(n) ________ accepts hydrogen ions.

acid; base

A potato is eaten and then broken down into glucose. This process is called

digestion.

The alpha-helix and pleated sheet are examples of ________ protein structure.

secondary

The most abundant high-energy compound in cells is

ATP

In chemical notation, the symbol Ca²⁺ means ________.

a calcium ion that has lost two electrons

Ions with a + charge are called

cations

A translucent, heterogeneous mixture with particles that do not settle out is a

colloid.

A lipid made of a glycerol molecule with two fatty acids attached to one side and a phosphate group connecting a non-lipid group attached to the other

phospholipids

The reaction N₂ + 3 H₂ → 2 NH₃ is an example of a(n)

 synthesis reaction.

Elements that have atoms with full outer shells of electrons

are inert gases

A solution containing equal numbers of hydrogen ions and hydroxide ions is

neutral.

Carbohydrate molecules

are the body's most readily available source of energy.

In chemical notation, the symbol Ca²⁺ means ________.

a calcium ion that has lost two electrons

The molecule H₂ is known as

 hydrogen.

A fatty acid that contains multiple double covalent bonds is said to be

polyunsaturated.