Chapter 2 Chemistry Comes to Life

A substance consists of weak acids or bases designed to maintain a specific pH of a solution within a cell or a biological system. Which of the following describes this substance? A) buffer B) catalyst C) pH D) acids

A) buffer

Saturated fatty acids are so named because they are saturated with ________. A) hydrogen B) nitrogen C) carbon D) oxygen

A) hydrogen

Water has very special properties that not all chemicals share. Which of the following is not a property of water? A) is nonpolar B) prevents wide temperature fluctuations C) requires a lot of energy to evaporate it D) interacts with lots of different substances

A) is nonpolar

A molecule consists of a long chain of glucose monomers linked by covalent bonds and serves as an energy source for plants and animals. Which of the following would describe this molecule? A) polysaccharide B) oligosaccharide C) monosaccharide D) sucrose

A) polysaccharide

You received your genetic material from your parents in the form of DNA. Your DNA provides your cells with instruction for making ________. A) lipids B) proteins C) polysaccharides D) cholesterol

B) proteins

Alteration of the ________ structure of a protein can transform the protein into an infectious agent known as a prion. A) primary B) secondary C) tertiary D) quaternary

B) secondary

A neutral atom must contain ________. A) an equal number of protons and neutrons B) an equal number of protons, neutrons, and electrons C) an equal number of protons and electrons D) an equal number of neutrons and electrons

C) an equal number of protons and electrons

Triglycerides ________. A) are fatty acids bonded to glycerol through hydrolysis B) have solid unsaturated forms at room temperature, such as butter C) can provide twice the energy per gram than proteins D) All of the above are true.

C) can provide twice the energy per gram than proteins

Which of the following carbohydrates is made by plants and is not digested by humans? A) lactose B) starch C) cellulose D) glycogen

C) cellulose

An element with more or fewer neutrons than the same element as it appears on the periodic table is known as which of the following? A) ion B) buffer C) isotope D) isomer

C) isotope

These lipids have a hydrophobic part and a hydrophilic part. A) triglycerides B) carotenoids C) phospholipids D) steroids

C) phospholipids

A substance in which other substances are dissolved is known as a(n) ________. A) solute B) acid C) solvent D) buffer

C) solvent

The hydrogen, ionic, and covalent bonds that stabilize the shape of a protein contribute to which level of structure of a protein? A) primary B) quaternary C) secondary D) tertiary

D) tertiary

________ is the process of using water to break down polymers to their monomer subunits.

Hydrolysis

When an electron moves from the outer shell of one element to the outer shell of another element, a(n) ________ bond has been created.

Ionic

________ refers to a structure of a protein in which two or more polypeptide chains bind together to form a functional protein.

Quaternary

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

isotopes

A molecule with hydrophobic properties and polar molecular attributes would be called a(n) ________.

lipid

The ________ can be used to measure whether a substance is an acid or a base.

pH scale

A(n) ________ consists of many monomer subunits bonded together in order to produce a large molecule.

polymer

A(n) ________ is a type of polymer that helps in support, transport, and movement in the body.

protein

A polysaccharide that is made by plants and can usually be digested by humans is ________.

starch

Partially hydrogenated fats are also referred to as ________ fats.

trans

This nucleotide is found in RNA but not in DNA: ________.

uracil

In what ways are hydrogen bonds and ionic bonds similar? A) Both are based on attraction between atoms that carry differences in electrical charge. B) Both are based on attraction between two atoms that carry negative charges. C) Both are based on repulsion between atoms that carry differences in electrical charge. D) Both involve an even sharing of electrons between atoms. E) Both are based on attraction between two atoms that carry positive charges.

A) Both are based on attraction between atoms that carry differences in electrical charge.

Dipeptidase is an enzyme found in your small intestine that helps break polypeptides down. What would its most likely products be? A) amino acids B) proteins C) triglycerides D) oligosaccharides

A) amino acids

Your roommate is experiencing heartburn and asks you to purchase her an antacid. Chemically speaking, how do you know that the antacid will help eliminate her pain? A) It is a buffer and will prevent the pH in her digestive tract from changing. B) It has a higher OH- concentration to increase the pH in her digestive tract. C) It is probably high in H+. D) It has a low pH to balance the acidity in her digestive tract.

B) It has a higher OH- concentration to increase the pH in her digestive tract.

You have information about a particle that contains 7 protons, 8 neutrons, and 8 electrons. Which of the following statements would be true? A) It has an atomic weight of 23. B) It is an ion. C) It has 8 electrons in its outermost shell. D) It has an atomic number of 15.

B) It is an ion.

By analyzing the chemical formulas, you can determine that this molecule, CH3CH(NH2)COOH, is a(n) ________, whereas the molecule C5H10O5 is a(n) ________. A) cholesterol; amino acid B) amino acid; sugar C) nucleotide; glycerol D) fatty acid; sugar

B) amino acid; sugar

The pH scale measures ________. A) OH- concentration B) buffer concentration C) H+ concentration D) All of the above are true.

C) H+ concentration

A researcher suspects that the food in an ecosystem has been contaminated with radioactive phosphates over a period of months. Which of the following substances could be examined for radioactive phosphate to test the hypothesis? A) the amino acids within proteins produced by organisms living in the area B) the starch produced by plants in the area C) the DNA of the organisms in the area D) All of the above are true.

C) the DNA of the organisms in the area

The Cl- ion has a single negative charge and the atomic number of 17. How many electrons are on its innermost shell? A) 18 B) 17 C) 9 D) 2

D) 2

Oxygen, with an atomic number of 8, is a neutral atom and has ________ electrons in the first electron shell and ________ electrons in the second electron shell. A) 1; 7 B) 5; 3 C) 4; 4 D) 2; 6 E) 3; 5

D) 2; 6

If I tested your intestinal fluid and found that it was basic, which of the pH values listed would best describe this solution? A) 6.8 B) 3.2 C) 1.2 D) 8.0

D) 8.0

Which of the following is not found in ATP? A) a nitrogen-containing base B) a sugar C) a phosphate group D) All of these are found in ATP.

D) All of these are found in ATP.

Which of the following monomers is not paired correctly? A) glucose-carbohydrates B) amino acids-proteins C) nucleotides-nucleic acids D) All of these are paired properly.

D) All of these are paired properly.

What is the difference between covalent and ionic bonds? A) Covalent bonds involve the sharing of electrons, whereas ionic bonds involve the sharing of protons. B) Covalent bonds involve the attraction between slightly charged molecules, whereas ionic bonds involve the attraction between two fully charged ions. C) Covalent bonds involve the sharing of neutrons, whereas ionic bonds involve the attraction of slightly charged atoms. D) Covalent bonds involve the sharing of electrons, whereas ionic bonds involve the transfer of electrons from one atom to another.

D) Covalent bonds involve the sharing of electrons, whereas ionic bonds involve the transfer of electrons from one atom to another.

An organic compound that provides instructions for the synthesis or production of polypeptide chains is referred to as which of the following? A) nucleotide B) lipids C) ATP D) DNA

D) DNA

Any substance that when dissolved in water will give off H+ ions is referred to as a(n) ________. A) pH B) buffer C) catalyst D) acid

D) acid

The interaction between two polar molecules would involve ________. A) ionic bonds B) peptide bonds C) covalent bonds D) hydrogen bonds

D) hydrogen bonds

The compound magnesium chloride (MgCl2) turns into one Mg2+ and two Cl- when placed in water. You can guess that the Mg and Cl atoms are held together normally by a(n) ________ bond. A) covalent B) electronegative C) hydrogen D) ionic

D) ionic

A substance that, when dissociated in water, will give off hydrogen ions is referred to as a(n) ________.

acid

A(n) ________ is a substance that accepts hydrogen ions or, when it dissociates in water, will give off hydroxide ions.

base

A(n) ________ is a nonprotein substance that aids in forming the enzyme-substrate complex in metabolic reactions.

cofactor

A protein that speeds up chemical reactions without being consumed in the process is called a(n) ________.

enzyme

The energy-storing polysaccharide that can be found mainly in liver and muscle cells is called ________.

glycogen