Brooklyn College – BIOL 1010 Chapter 2 Questions

The atomic number of an element is: A. the mass of one atom, in atomic mass units (amu). B. the number of neutrons in the nucleus of one atom. C. the number of electrons in the nucleus of one atom. D. the number of protons in the nucleus of one atom. E. the total number of particles in the nucleus of one atom.

The four most abundant elements in living organisms are: A. carbon, nitrogen, oxygen, and calcium. B. sodium, nitrogen, carbon, and silicon. C. carbon, nitrogen, helium, and oxygen. D. carbon, hydrogen, nitrogen, and phosphorus. E. hydrogen, nitrogen, oxygen, and carbon.

An atom can be changed into an ion by adding or removing: A. either a proton or an electron. B. either a neutron or a proton. C. a neutron. D. a proton. E. an electron.

In an uncharged atom, the number of protons and ___________ must be equal. A. ions B. electrons C. neutrons D. particles E. neurons

Ionic bonds form _______, while covalent bonds form ________. A. molecules; compounds B. atoms; molecules C. compounds; molecules D. isotopes; molecules E. molecules; atoms

The pH scale is a direct measure of: A. the concentration of salt in a solution. B. the concentration of hydroxide ions in a solution. C. the concentration of buffers in a solution. D. the concentration of hydrogen ions in a solution. E. the concentration of hydrogen atoms in a solution.

The tendency of water molecules to stick together is called: A. transpiration. B. evaporation. C. surface tension. D. adhesion. E. cohesion.

Hydrogen bonding among water molecules gives water all of the following important properties, EXCEPT: A. lower density as a solid than as a liquid. B. strong cohesion among the individual water molecules. C. high heat capacity. D. a transparent color. E. the capacity to serve as a solvent to many other molecules.

A chemical compound that releases H+ into a solution is called: A. a buffer. B. an acid. C. a base. D. an aqueous solution. E. a hydrogen ion.

Which of the following accurately describes a buffer? A. chemicals that can neutralize added H+ or OH- with minimal changes in pH B. chemicals that maintain a neutral pH when acid or base is added C. solutions with pH of 7 D. chemicals that maintain a relatively constant pH when acid or base is added E. Only choices A and D are correct.

Which carbohydrate is of most importance to living organisms? A. maltose B. fructose C. galactose D. cellulose E. glucose

Which of the following foods is NOT a significant source of complex carbohydrates? A. fresh fruits B. pasta C. rice D. oatmeal E. All of the above are significant sources of complex carbohydrates.

What is "carbo-loading"? A. It is a dietary modification characterized by increasing the ratio of complex carbohydrates to monosaccharides. B. It is a method of increasing the hemoglobin concentration in red blood cells and is believed to increase the efficiency of oxygen delivery to muscles, thereby improving athletic performance. C. It is a weight-loss strategy characterized by the depletion of fats from body cells as they are replaced by dietary sugars with a low glycemic index. D. It is a method of saturating the carbon molecules of an oil with hydrogen, increasing the energy released when the oil is metabolized. E. It is a method by which athletes can increase the usual amount of glycogen that is stored in their muscles and liver, increasing the amount of fuel available for extended exertion and delaying the onset of fatigue during an endurance event.

A complex polymer built of monosaccharides is called a: A. polypeptide. B. protein. C. nucleic acid. D. polysaccharide. E. nucleotide.

Unlike humans, termites are able to extract energy from wood because: A. they have sharp teeth which are able to break the bonds linking the simple sugars together. B. they carry genes that contain the instructions for the production of cellulose-digesting enzymes. C. they have some microorganisms living in their gut that are able to break down cellulose. D. they consume cellulose-free species of plants only. E. the cellulose in wood contains bonds easily broken down by animal enzymes.

Long-term energy storage and insulation, membrane formation, and creation of sex hormones are characteristics of which of the following? A. proteins B. carbohydrates C. amino acids D. lipids E. sugars

An unsaturated fatty acid is one in which: A. no carbon-carbon double bonds are present in the hydrocarbon chain. B. the hydrocarbon chain has an odd number of carbons. C. not all of the carbons in the hydrocarbon chain are bonded to hydrogen atoms. D. carbon-carbon double bonds are present in the hydrocarbon chain. E. the hydrocarbon chain has an even number of carbons.

Saturated fatty acids have _________________ than unsaturated fatty acids, which is why they exist as a ____________ at room temperature. A. more glycerol molecules; liquid B. fewer double bonds; solid C. more carbon atoms; solid D. fewer hydrogen atoms; gel E. more double bonds; gel

Unsaturated fatty acid chains in membrane phospholipids help to maintain fluidity because: A. they are less likely to pack tightly at lower temperatures. B. they have no valence electrons to donate to neighboring lipids. C. they have kinks induced by extra carbon-carbon double bonds. D. they are positively charged and attract electrolytes. E. Both A and C are correct.

In a phospholipid, the head is _____, and the fatty acid is _____. A. unsaturated, saturated B. hydrophobic, hydrophobic C. hydrophobic, hydrophilic D. hydrophilic, hydrophilic E. hydrophilic, hydrophobic

A protein is a polymer of: A. amino acids. B. oligosaccharides. C. lipids. D. nucleic acids. E. polypeptides.

Proteins are an essential component of a healthy diet for humans (and other animals). Their most common purpose is to serve as: A. raw material for growth. B. inorganic precursors for enzyme construction. C. long-term energy storage. D. organic precursors for membrane construction. E. fuel for running the body.

Dietary proteins: A. can be obtained from animal sources but not plant sources. B. are considered "complete" only if they contain the eight essential amino acids required by humans. C. are nutritionally identical, since all are broken down into their constituent amino acids in the digestive system. D. are considered "complete" only if they contain the 12 non-essential amino acids required by humans. E. consist of all 20 amino acids required in the human body.

One consequence of protein denaturation is: A. the protein performs better than before. B. the protein loses its functionality. C. the protein adds another protein to its folded shape. D. the protein becomes more tightly folded. E. the protein forms covalent sulfur-sulfur bonds.

Which of the following statements about enzymes is NOT true? A. Enzymes lower the activation energy of chemical reactions. B. Enzymes reduce the energy difference between reactants and products. C. Enzymes often induce conformational changes in the substrates to which they bind. D. Enzymes are biological catalysts. E. Enzymes speed up chemical reactions.

What are the essential components of all nucleotides? A. Only a phosphate group, a sugar molecule, a nitrogen-containing molecule, and three methyl groups. B. Only a phosphate group and a sugar molecule. C. Only a phosphate group, a sugar molecule, and a nitrogen-containing molecule. D. Only a phosphate group, a sugar molecule, and an acid. E. Only a phosphate group, a nitrogen-containing molecule, and three methyl groups.

RNA differs from DNA with regards to the use of the nitrogenous base __ instead of __. A. uracil, thymine B. cytosine, guanine C. adenine, cytosine D. uracil, guanine E. adenine, uracil

There are ____ nucleotides in DNA, _____________. A. twenty; tryptophan, alanine, glycine, and methionine are examples B. three; glucose, fructose, and lactose C. four; A, C, T, and G D. four; A, C, U, and G E. two; saturated and unsaturated

Which type of macromolecule contains an organism's genetic information? A. Phospholipid B. fatty acid C. polysaccharide D. monosaccharide E. DNA

All of the following are features of RNA except: A. a sugar-phosphate-sugar-phosphate backbone. B. a different type of base than is found in DNA. C. a different type of sugar than is found in DNA. D. a coiled double-stranded structure. E. an ability to direct protein production.