Chemistry of Life

In the following chemical reaction, what is NaCl? NaOH + HCl → NaCl + H2O A. Water B. Product C. Reactant D. Acid

Product

Of the subatomic particles, which one is positively charged? A. Neutrons B. All subatomic particles are positively charged. C. Protons D. Electrons

Protons

Nuclear medicine uses ______ in medical diagnosis and treatment. A. X-rays B. colloids C. radioisotopes D. buffers

Radiosotopes

Determine the number of protons in an isotope of nitrogen with an atomic number of 7 and a mass number of 14. A. 10 B. 14 C. 7 D. 17

7

Which of the following increases the rate of a reaction? A. Increased reactant concentration B. Solid reactants C. Cold temperatures D. Absence of a catalyst

Increased reactant concentration

Atoms that satisfy the octet rule are said to be __________. A. inert B. reactive C. isotopes D. ions

Inert

Salts are held together by __________. A. nonpolar covalent bonds B. ionic bonds C. polar covalent bonds D. single covalent bonds

Ionic bonds

Anything that takes up space and has mass is known as: A. electron shells. B. particles. C. mass. D. matter.

Matter

What predicts the element to which an atom belongs? A. number of electrons in the first shell B. total number of protons C. total number of neutrons D. total number of electrons

Total number of protons

When blood pH rises above 7.45, the body systems suffer from _____. A. The blood is not affected by changes in pH. B. acidosis C. buffering D. alkalosis

alkalosis

The synthesis reactions that take place in the body are referred to as _____ reactions, whereas the decomposition reactions are referred to as ______ reactions. A. exchange; reversible B. exergonic; endergonic C. anabolic; catabolic D. catabolic; anabolic

anabolic; catabolic

A _______ forms when electrons are shared equally among the atoms in the bond. A. ionic bond B. nonpolar covalent bond C. hydrogen bond D. polar covalent bond

nonpolar covalent bond

The group of polymers that contribute the smallest mass to the human body but are the most important because they are responsible for the storage and execution of the genetic code, are the: A. lipids. B. nucleic acids. C. carbohydrates. D. proteins.

nucleic acids.

The atomic number for each element on the periodic table represents the: A. the number of protons plus the number of neutrons in the atom. B. the number of electrons in the atom. C. number of protons in the atom. D. the number of neutrons in the atom.

number of protons in the atom.

What type of chemical bond forms when electrons are shared unequally between two atoms? A. An ionic bond B. A nonpolar covalent bond C. A hydrogen bond D. A polar covalent bond

A polar covalent bond

Which of the following represents an exchange reaction? A. AB → A + B B. AB + CD → BA + DC C. AB + CD → AD + BC D. A + B → AB

AB + CD → AD + BC

_____ is the main source of chemical energy that drives all cellular work and belongs to the class of organic molecules known as _______. A. Triglycerides; lipids B. Glucose; carbohydrates C. ATP; nucleic acids D. Collagen; proteins

ATP; nucleic acids

Which two functional groups are always found in amino acids? A. Hydroxyl and carboxylic acid B. Amino and carbonyl C. Amino and carboxylic acid D. Carbonyl and phosphate

Amino and carboxylic acid

The formation of a cation and an anion is indicative of __________. A. a polar bond B. an ionic bond C. a nonpolar bond D. a covalent bond

An ionic bond

Which of the following is the same among isotopes of the same element? A. Atomic number B. Mass number C. Both the number of neutrons and the mass number D. Number of neutrons

Atomic number

A hydrogen acceptor in a solution is called a: A. buffer. B. acid. C. salt. D. base.

Base

What chemical binds free hydrogen ions in solution? A. Water B. Salt C. Base D. Acid

Base

Which of the following terms is not defined as one of the three basic types of mixtures? A. Suspensions B. Colloids C. Solutions D. Buffers

Buffers

What is the function of a buffer? A. Buffers lower the activation energy of a chemical reaction. B. Buffers act as a lubricant between two adjacent surfaces. C. Buffers absorb heat without changing temperature themselves. D. Buffers prevent large swings in pH when an acid or base is added to a solution.

Buffers prevent large swings in pH when an acid or base is added to a solution.

When the electrons located in the outermost electron shells of atoms interact, _________ are formed. A. chemical bonds B. isomers C. solutions D. isotopes

Chemical bonds

______ is what occurs when a protein's structure and function is lost because of exposure to extreme heat or chemical factors. A. Synthesis B. Denaturation C. Renaturation D. Oxidation

Denaturation

When two electron pairs are shared between atoms, a _______ is formed. A. double bond B. triple bond C. ionic bond D. single bond

Double bond

Which subatomic particle carries a negative charge? A. Nucleus B. Electron C. Proton D. Neutron

Electron

What happens in oxidation-reduction (redox) reactions? A. Energy is used because these are endergonic reactions. B. Electron exchange occurs. C. Energy is used since these are endergonic reactions. D. Larger molecules are built from smaller subunits.

Electron exchange occurs.

What type of reaction is A + B + energy → AB? A. Catabolic reaction B. Equilibrium reaction C. Endergonic reaction D. Exergonic reaction

Endergonic reaction

All of the following properties are associated with enzymes except: A. nzymes are not permanently altered in the reaction. B. enzymes alter the chemical reaction. C. enzymes speed up reactions by lowering the activation energy. D. enzymes are highly specific for individual substrates.

Enzymes alter the chemical reaction

Which statement best describes enzyme function? A. enzymes chemically alter both the reactants and products. B. one enzyme can work on thousands of different substrates. C. enzymes can perform catabolic reactions only. D. enzymes speed chemical reactions by lowering the activation energy.

Enzymes speed chemical reactions by lowering the activation energy.

All of the following are basic types of chemical reactions in the body except: A. exchange reactions. B. catabolic reactions. C. anabolic reactions. D. homeostatic reactions.

Homeostatic reactions.

Of the 92 naturally occurring elements, the four major elements that make up 96% of all living things are: A. hydrogen, oxygen, nitrogen, and carbon. B. oxygen, carbon, sodium, and calcium. C. hydrogen, oxygen, sulfur, and phosphorus. D. carbon, sodium, phosphorus, and oxygen.

Hydrogen, oxygen, nitrogen, and carbon.

Which two organ systems work to maintain pH balance in the body? A. Respiratory and urinary B. Urinary and endocrine C. Endocrine and nervous D. Digestive and respiratory

Respiratory and urinary

Which of the following organic compounds is not found in the human body? A. Glycogen B. Cholesterol C. Starch D. Hemoglobin

Starch

Which of the following statements concerning protein structure is incorrect? A. The quaternary structure is present in all proteins and consists of the combination of several polypeptide chains. B. The secondary structure consist of a twisting or folding peptide chain. C. The primary structure of a chain consists of amino acids joined by peptide bonds. D. The tertiary structure refers to the three-dimensional shape of the protein.

The quaternary structure is present in all proteins and consists of the combination of several polypeptide chains.

Ionic bonds result from __________. A. unequal sharing of electrons between nonmetals B. equal sharing of electrons between nonmetals C. the transfer of electrons from a metal to a nonmetal D. weak attractions between polar molecules

The transfer of electrons from a metal to a nonmetal

What determines how an atom interacts with other atoms and whether it will form bonds with specific atoms? A. Protons B. Valence shell C. Neutrons D. Valence electrons

Valence electrons

The four nitrogenous bases found in DNA are: A. adenine, guanine, cytosine, and thymine. B. adenine, thymine, uracil, and guanine C. adenine, thymine, cytosine, and uracil. D. guanine, cytosine uracil, and adenine.

adenine, guanine, cytosine, and thymine.

In DNA, an adenine base will form two hydrogen bonds with ____ A. a cytosine base B. a phosphate group C. a deoxyribose sugar D. a thymine base

a thymine base

Saturated, monounsaturated, and polyunsaturated fats differ in the: A. presence or absence of ester linkages. B. absence or number of double covalent bonds present. C. number of carboxyl groups. D. number of carbon atoms.

absence or number of double covalent bonds present.

The more hydrogen ions present in a solution, the more _____ the solution. A. alkaline B. acidic C. neutral D. basic

acidic

When an atom loses an electron it is called a(n) _____; when an atom gains an electron it is called a(n) ______. A. cation; anion B. anion; cation C. polar; nonpolar D. nonpolar; polar

cation; anion

Water has more structure than other liquids because of its ability to form hydrogen bonds. Because of this phenomena, water expresses a relatively high __________, which allows it to cushion and protect the body's structures. A. heat capacity B. density C. surface tension D. solvency

density

Which of the following molecules is not considered a polymer? A. nucleic acid B. protein C. fatty acid D. polysaccharide

fatty acid

A ______ reaction involves the addition of water to break down large molecules into smaller molecules. A. anabolic B. hydrolysis C. exchange D. dehydration synthesis

hydrolysis

A ______ reaction involves the addition of water to break down large molecules into smaller molecules. A. hydrolysis B. anabolic C. dehydration synthesis D. exchange

hydrolysis

Molecules or compounds that will not dissolve easily in water are _____. A. hydrophilic B. hydrophobic C. ionic D. polar

hydrophobic

Organic and inorganic compounds differ in that: A. inorganic compounds usually lack carbon. B. inorganic molecules are usually large and complex. C. inorganic compounds usually contain carbon. D. inorganic molecules are used by the body to perform complex functions.

inorganic compounds usually lack carbon.

Atoms with the same atomic number but different mass numbers are called _____. A. isotopes B. ions C. isomers D. inert

isotopes

DNA contains all of the following structural features except: A. it contains uracil. B. it contains deoxyribose sugar. C. it forms hydrogen bonds between bases. D. it forms a double helix.

it contains uracil.

All of the following properties are associated with water except: A. it is an organic molecule. B. it has a high heat capacity. C. it is a solvent. D. it is involved in synthesis and hydrolysis reactions.

it is an organic molecule.

Building blocks of organic molecules are known as __________. A. monomers B. polymers C. enzymes D. electrolytes

monomers

The monomer of the carbohydrates is __________. A. fatty acid B. nucleotide C. amino acid D. monosaccharide

monosaccharide

The four most common elements, comprising 96% of the body's mass, are __________. A. oxygen, nitrogen, hydrogen, and carbon B. oxygen, potassium, iron, and copper C. carbon, sodium, phosphorus, and sulfur D. chlorine, sodium, magnesium, and potassium

oxygen, nitrogen, hydrogen, and carbon

On the pH scale, which number has the highest concentration of hydrogen ions? A. pH 10 B. pH 5 C. pH 1 D. pH 7

pH 1

A _____ is a polar covalent bond that joins two amino acids together through a synthesis reaction. A. ester linkage B. phosphodiester bond C. glycosidic linkage D. peptide bond

peptide bond

The primary lipid in cell membranes is: A. triglyceride. B. cholesterol. C. phospholipid. D. steroid.

phospholipid

A fatty acid that contains two or more double covalent bonds is __________. A. hydrogenated B. polyunsaturated C. saturated D. monounsaturated

polyunsaturated

Amino acids are the monomers for __________. A. carbohydrates B. lipids C. nucleic acids D. proteins

proteins

The atomic number represents the number of __________. A. protons and neutrons in the nucleus of an atom B. electrons in an atom C. protons in an atom D. neutrons in an atom

protons in an atom

The mass number of an atom is determined by the number of: A. neutrons plus electrons. B. protons plus electrons. C. protons plus neutrons. D. electrons.

protons plus neutrons.

Energy in the human body takes on all of the following forms except: A. chemical energy. B. mechanical energy. C. radiant energy. D. electrical energy.

radiant energy

A _____ is a mixture that generally consists of a liquid mixed with a solid. A. colloid B. buffer C. suspension D. solution

suspension