CHAPTER 2 - study questions

A&P

Atoms of the same element that contain the same number of protons and electrons, but different numbers of

neutrons are called

a. ions. c. isotopes.

b. isomers. d. bonds.

c. isotopes.

A chemical bond formed by the sharing of electrons between two atoms is called a(n)

a. ionic bond. c. covalent bond.

b. hydrogen bond. d. none of the above.

c. covalent bond.

The electrons in the covalent bonds of water are not equally shared between oxygen and hydrogen. As a result, the water molecule has two distinct ends, each with a partial electrical charge. Because of this imbalance in charges, water is said to be

a. liquid. c. neutral.

b. solvent. d. polar.

d. polar.

Hydrochloric acid is labeled an acid because it

a. is a proton donor c. it releases hydrogen ions.

b. it has a pH below 7.0 d. all of the above are correct.

d. all of the above are correct.

As the pH of a solution increases the hydrogen ion concentration

a. increases. c. stays the same.

b. decreases. d. is unknown.

b. decreases.

The most important monosaccharide in the body is

a. fructose. c. glucose.

b. galactose. d. sucrose.

c. glucose.

Proteins are made up of a long chain of

a. glucose molecules. c. nucleotides.

b. fats. d. amino acids.

d. amino acids.

Which of the following compounds would not be classified as a lipid?

a. triglyceride c. cholesterol

b. steroid d. polysaccharide

d. polysaccharide

______________ refers to all the chemical reactions that occur in the cells of the body.

a. Anabolism c. Catabolism

b. Metabolism d. ATP

b. Metabolism

Adenosine triphosphate (ATP)

a. is a polysaccharide.

b. provides enzymes for metabolism.

c. is the form of energy that cells use.

d. has a double helical structure.

c. is the form of energy that cells use.

The negatively charged small subatomic particles that move around the nucleus of an atom are the

____________.

a. protons c. quarks

b. neutrons d. electrons

d. electrons

___________ bonds hold together the sodium and chloride ions in table salt.

a. Hydrogen c. Polar covalent

b. Ionic d. Nonpolar covalent

b. Ionic

A solution with a pH of 7.4 is

a. acidic. c. neutral.

b. alkaline. d. normal.

b. alkaline.

Glycogen is a storage form of sugar and is a _________________________.

a. monosaccharide c. trisaccharide

b. disaccharide d. polysaccharide

d. polysaccharide

_____________ is the molecule which contains the genetic information necessary to regulate cells.

a. Ribonucleic acid (RNA) c. Protein

b. Deoxyribonucleic acid (DNA) d. Adenosine triphosphate

b. Deoxyribonucleic acid (DNA)

The functions of DNA are ___________________________.

to store hereditary materials, guide the formation of protein and activities of the cell

When a protein denatures, it ____________________________.

unfolds or loses it three-dimensional structure

Cholesterol is used to synthesize _________________________.

steroid hormones and bile salts

Phospholipids are important in ___________________________.

formation of plasma membranes

Protein function is determined by _________________________.

its three-dimensional structure

A saturated fatty acid _______________________________.

contains no double bonds.

Peptide bonds are _____________________________________.

covalent bonds between amino acids

Lipids are soluble in __________________________________.

lipids

The functions of RNA are ________________________.

to provide instructions for making proteins (mRNA), transport amino acids to ribosomes (tRNA),and components of ribosomes (rRNA); RNA is involved in protein synthesis

Three examples of polysaccharides are ________, __________, and_______.

glycogen, starch, cellulose/fiber

The building blocks of proteins are ________________________.

amino acids

Four groups of organic substances in cells are _________, __________, __________ and __________.

carbohydrates, proteins, lipids, nucleic acids

Buffers are ___________________________.

compounds that prevent large fluctuations in pH; pH stabilizers

Two major types of nucleic acids are ______________ and _____________.

DNA (deoxyribonucleic acid), RNA (ribonucleic acid)

A hydrogen bond is _______________________.

weak bond between a slightly positive hydrogen atom and a slightly negative oxygen or nitrogen atom; helps stabilize interactions within a molecule or between molecules

The part of a phospholipid molecule that is insoluble in water is ________________.

hydrophobic, fatty acid and glycerol portion (fatty acid tails)

A(n) _____________ bond is formed by atoms sharing electrons.

covalent

An important example of a polar molecule is ________________.

water

The building blocks of nucleic acids are ____________________.

nucleotides

An important steroid found in all body cells is ________________.

cholesterol

A covalent bond forms when _______________________.

electrons are shared between atoms

Three examples of lipids are _________, _________, and __________.

triglycerides, phospholipids, steroids, waxes

Three examples of monosaccharides are ________, __________ and ________.

glucose, fructose, ribose, deoxyribose, galactose

Acids are _____________________________.

compounds that increase hydrogen ion concentration in a solution, proton or hydrogen ion donors

If an atom gains an electron, it becomes _____________ charged.

negatively

A(n) ___________ bond forms between polar compounds.

hydrogen

The part of a phospholipid molecule that is soluble in water is the ___________.

hydrophilic or phosphate group or polar head

The pH scale is _________________________.

a measurement of hydrogen ion concentration in a solution

Isotopes are ___________________________.

atoms that contain the same number of protons and electrons but different numbers of neutrons

Several amino acids bonded together will produce a __________.

polypeptide or protein

Lipids are insoluble in _______________________.

water

Bases are _________________________.

compounds that decrease hydrogen ion concentration in a solution, proton acceptors or hydrogen ion acceptors

An ionic bond forms when ____________________.

ions with opposite charges are electrically attracted to each other

If an atom loses an electron, it becomes _____________ charged.

positively

Ions are ______________________.

atoms that have gained or lost electrons, atoms with a charge

Atoms lose, gain, or share electrons to _________________________________

become stable, fill their outermost energy level with electrons

 ________ is/are building blocks of carbohydrates.

 Monosaccharides

________ is/are building blocks of fat.

Fatty acids, Glycerol 

________ is/are building blocks of protein.

Amino acids

________ is/are building blocks of nucleic acids.

Nucleotides

________ are the most important fuel source for body cells.

Monosaccharides

________ is/are not soluble in water.

Lipids (fats), Fatty acids, Glycerol

________ is/are used to insulate the body and are found in cell membranes.

Lipids (fats) 

Cholesterol is included in the group of macromolecules known as _________.

Lipids (fats) 

Hemoglobin and enzymes are included in the group of macromolecules known as __________.

Proteins

________ is/are soluble in water.

 Amino acids, Carbohydrates, Nucleotides, Monosaccharides, Proteins

an attraction that occurs between atoms that have opposite charges

ionic bond

a measurement of the hydrogen ion concentration of a solution

 pH

a connection that occurs due to the equal sharing of electrons between two atoms

nonpolar covalent bond

a protein that works as a biological catalyst

enzyme

an attraction that occurs between polar molecules

hydrogen bond

the compounds that are the result of an enzymatic reaction

product

a compound that can donate a hydrogen ion to a solution

acid

the compound or molecule that binds to the active site of an enzyme

 substrate

a connection that occurs due to the unequal sharing of electrons between two atoms

polar covalent bond

a compound that can bind or accept a hydrogen ion

base

a connections that occurs due to the sharing of electrons between two atoms

covalent bond

the area of an enzyme where the substrate attaches

active site