2 Chemistry Comes Alive

Which of the following is not an example of matter? Blood plasma Air we breathe A hand bone Energy Answer: d. Energy © 2013 Pearson Education, Inc.

Chemical energy is __________. a form of kinetic energy energy stored in bonds between atoms a form of potential energy both b and c Answer: d. both b and c © 2013 Pearson Education, Inc.

Which of the following is an example of the conversion of potential energy into kinetic energy? Synthesis of ATP from glucose ATP hydrolysis to drive muscle contraction Digestion of protein in the stomach Pumping ions across a cell membrane Answer: b. ATP hydrolysis to drive muscle contraction © 2013 Pearson Education, Inc.

The four elements that comprise 96% of living matter are __________. carbon, sodium, nitrogen, oxygen carbon, hydrogen, sodium, oxygen carbon, hydrogen, nitrogen, sodium carbon, hydrogen, nitrogen, oxygen Answer: d. carbon, hydrogen, nitrogen, oxygen © 2013 Pearson Education, Inc.

An atom's nucleus contains __________. protons neutrons electrons protons and neutrons Answer: d. protons and neutrons © 2013 Pearson Education, Inc.

The element lithium has 3 protons and 4 neutrons in its nucleus The element lithium has 3 protons and 4 neutrons in its nucleus. Its mass number is __________. 3 4 7 12 Answer: c. 7 © 2013 Pearson Education, Inc.

When atoms of two different elements bind together, they form a(n) __________. compound mixture element solution Answer: a. compound © 2013 Pearson Education, Inc.

Which of the following mixture(s) are homogeneous? Colloids Solutions Suspensions Both colloids and suspensions Answer: b. Solutions © 2013 Pearson Education, Inc.

The most important determinant of an atom's bonding behavior is __________. the number of protons in the nucleus the total number of electrons the number of valence shell electrons the number of neutrons in the nucleus Answer: c. the number of valence shell electrons © 2013 Pearson Education, Inc.

When atoms gain electrons, __________. the atoms become electrically neutral the atoms become positively charged their atomic mass significantly increases the atoms become negatively charged Answer: d. the atoms become negatively charged © 2013 Pearson Education, Inc.

Ionic bonds connect atoms together by __________. overlap of valence shells charge attractions overlap of the nucleus attractions between dipoles Answer: b. charge attractions © 2013 Pearson Education, Inc.

Covalent bonds occur when __________. electrons are shared between atoms electrons are transferred between atoms electrons are lost opposite charges attract atoms together Answer: a. electrons are shared between atoms © 2013 Pearson Education, Inc.

An atom will tend to be electronegative if __________. it lacks only 1–2 electrons in the valence shell it easily donates electrons it only has 1–2 electrons in the valence shell it is negatively charged Answer: a. it lacks only 1–2 electrons in the valence shell © 2013 Pearson Education, Inc.

Water, H2O, is a polar molecule Water, H2O, is a polar molecule. Oxygen is electronegative and hydrogen is electropositive. This means that __________. each hydrogen pulls electrons away from oxygen and becomes more negative the electrons are shared equally the oxygen pulls electrons away from hydrogen and becomes more negative the oxygen pulls electrons away from hydrogen and becomes more positive Answer: c. the oxygen pulls electrons away from hydrogen and becomes more negative © 2013 Pearson Education, Inc.

Hydrogen bonds are similar to ionic bonds because __________. they both are due to opposite charge attractions they both occur between like charged atoms they both form molecules they are both very strong bonds Answer: a. they both are due to opposite charge attractions © 2013 Pearson Education, Inc.

In a chemical reaction, ___________ join to form __________. products; reactants molecules; atoms formulas; products reactants; products Answer: d. reactants; products © 2013 Pearson Education, Inc.

Water's unique properties like high heat capacity, high heat of vaporization, and universal solvent can be attributed to its __________. oxygen atom ability to form hydrogen bonds hydrogen atoms small size Answer: b. ability to form hydrogen bonds © 2013 Pearson Education, Inc.

When chemical equilibrium is reached, __________. no further net change in the amounts of reactants and products occurs more reactants are converted to products in the forward direction the chemical reaction no longer occurs more products are converted to reactants in the reverse direction Answer: a. no further net change in the amounts of reactants and products occurs © 2013 Pearson Education, Inc.

What will be the effect on a chemical reaction if the concentration of reactants is increased? The speed of the reaction will slow. The speed of the reaction will increase. The speed of the reaction will remain unchanged. The reaction will now require a catalyst. Answer: b. The speed of the reaction will increase. © 2013 Pearson Education, Inc.

A substance that is very acidic may have a pH of 1 or 2 A substance that is very acidic may have a pH of 1 or 2. This means that the acidic substance __________. has a high concentration of OH– ions has an equal concentration of OH– and H+ ions has a low concentration of H+ ions has a high concentration of H+ ions Answer: d. has a high concentration of H+ ions © 2013 Pearson Education, Inc.

A buffer will release H+ ions if the blood pH __________. rises (becomes more basic) falls (becomes more acidic) stays the same becomes neutral Answer: a. rises (becomes more basic) © 2013 Pearson Education, Inc.

The four major organic compounds that comprise our bodies are __________. water, salt, carbon, oxygen proteins, carbohydrates, lipids, nucleic acids amino acids, fats, sugars, DNA carbon, hydrogen, oxygen, nitrogen Answer: b. proteins, carbohydrates, lipids, nucleic acids © 2013 Pearson Education, Inc.

The major function of carbohydrates in the body is __________. protein synthesis as cellular fuel being a genetic blueprint forming the basis of the cell membrane bilayer Answer: b. as cellular fuel © 2013 Pearson Education, Inc.

Which type of reaction occurs when biological molecules are broken down? Hydrolysis Anabolic Dehydration synthesis Endergonic Answer: a. Hydrolysis © 2013 Pearson Education, Inc.

The three major subclasses of lipids include phospholipids, steroids, and __________. fatty acids glycerols triglycerides oils Answer: c. triglycerides © 2013 Pearson Education, Inc.

The major building blocks for proteins are __________. amino acids monosaccharides triglycerides nucleotides Answer: a. amino acids © 2013 Pearson Education, Inc.

Functions of proteins do not include acting as __________. membrane receptors genes enzymes muscle cell components Answer: b. genes © 2013 Pearson Education, Inc.

The quaternary level of protein structure involves __________. individual amino acids aggregations of polypeptides forming a complex protein alpha-helices hydrogen bonds between adjacent amino acids Answer: b. aggregations of polypeptides forming a complex protein © 2013 Pearson Education, Inc.

An enzyme's ____________ is the molecule upon which an enzyme acts. active site substrate inhibitor catalyst Answer: b. substrate © 2013 Pearson Education, Inc.

Increasing the concentration of an enzyme's substrate (up to a point) would ___________ the reaction. slow down speed up inhibit destroy Answer: b. speed up © 2013 Pearson Education, Inc.

The major building blocks of nucleic acids are __________. amino acids DNA and RNA nucleotides sugars Answer: c. nucleotides © 2013 Pearson Education, Inc.

The four DNA nucleotides are __________. carbon, hydrogen, nitrogen, oxygen protein, lipid, nucleic acid, carbohydrate primary, secondary, tertiary, quaternary adenine, thymine, cytosine, guanine Answer: d. adenine, thymine, cytosine, guanine © 2013 Pearson Education, Inc.

Which of the following is not a metabolic function of ATP? Providing energy for anabolic reactions Providing energy to transport substances across membranes Providing energy for diffusion Providing energy for muscles to shorten Answer: c. Providing energy for diffusion © 2013 Pearson Education, Inc.