CHAPTER 2 MICRO
Compared to a solution of pH 9, a solution of pH 7 is A. 20 times more basic. B. 2 times more acidic. C. 100 times more acidic. D. 100 times more basic. E. 20 times more acidic.
. 100 times more acidic.
Burning coal produces sulfur dioxide in the atmosphere. When combined with rain that falls into bodies of water, this leads to A. a greater concentration of OHions in the water. B. a decrease in the pH level of the water. C. an increase in pH level of the water. D. no change in the pH level of the water.
. a decrease in the pH level of the water.
1.Polar molecules are composed of covalently bonded A. carbon atoms. B. ions. C. identical atoms. D. atoms of identical electronegativity. E. atoms of different electronegativity.
. atoms of different electronegativity.
The subatomic particles that surround the nucleus are the ______. A. protons and neutrons B. neutrons C. electrons D. protons E. protons and electrons .
. electrons
The purine ______ always hydrogen bonds with the pyrimidine ______ in double-stranded DNA. A. cytosine; guanine B. thymine; guanine C. guanine; cytosine D. adenine; guanine
. guanine; cytosine
1.Ionic bonds A. result from like charge attraction. B. result from transferring electrons. C. are the weakest chemical bonds. D. always involve carbon. E. result from sharing electrons.
. result from transferring electrons.
1.What is the maximum number of electrons in the first energy shell of an atom? A. 2 B. 4 C. 8 D. 18 E. 32
2
What is the maximum number of electrons in the second energy shell of an atom? A. 2 B. 4 C. 8 D. 18 E. 32
8
1.Which of the following represents a synthesis reaction? A. AB A + B B. A + B AB C. AB + XY AY + XB D. AB + XY AY + XB
A + B AB
An amino acid contains all of the following except a/n ______. A. phosphate B. carbon C. carboxyl group D. variable R group E. amino group
A. phosphate
1.Which of the following represents a reversible reaction? A. A + B AB B. AB A + B C. AB + XY<--> AY + XB D. AB + XY--> AY + XB
AB + XY <-->AY + XB
Which of the following is not a pyrimidine? A. Adenine B. Thymine C. Cytosine D. Uracil
Adenine
Characteristics shared by all cells include A. a membrane serving as a cell boundary. B. the possession of genetic information. C. the presence of cellular fluid. D. All of the choices are correct.
All of the choices are correct.
One nucleotide contains one A. phosphate. B. pentose sugar. C. nitrogen base. D. All of the choices are correct.
All of the choices are correct.
NASA has published a list of criteria for identifying fossil bacteria in samples from Mars, as part of a search for evidence of life. Which of the following is good evidence for the presence of bacterial cells? A. Three-dimensional organization of cells in a starburst pattern B. No evidence of water in the surrounding mineral C. Cell size of 0.5 to 2 microns D. Absence of carbon in the material
Cell size of 0.5 to 2 microns
Which pertains to DNA but not to RNA? A. Contains ribose B. Contains nucleotides C. Contains thymine D. Contains adenine
Contains thymine
1.The valence number is the A. number of protons. B. atomic weight .C. number of neutrons .D. number of electrons in the innermost orbital. E. number of electrons in the outermost orbital.
E. number of electrons in the outermost orbital.
Which of the following is not true about enzymes? A. Enzymes are found in all cells .B. Enzymes can be denaturated by heat and other agents. C. Enzymes participate in the cell's chemical reactions. D. Enzymes have high-energy bonds between phosphates. E. Enzymes are catalysts.
Enzymes have high-energy bonds between phosphates.
A new organism was identified that contained arsenic in place of phosphate in its DNA double helix structure. Based upon this information alone, it can be determined that this change will greatly alter the information encoded by this genetic material. TRUE FALSE
FALSE
Nucleic acids have primary, secondary, tertiary, and quaternary levels of organization. TRUE FALSE
FALSE
Water molecules are nonpolar molecules. TRUE FALSE
FALSE
Electrons that participate in chemical bonding are typically located closest to the nucleus. FALSE TRUE
False
What part of a phospholipid comprises the hydrophobic tail? A. Alcohol B. Hydroxyl C. Phosphate D. Glycerol E. Fatty acids
Fatty acids
Select the statement that most accurately reflects the process of plant material digestion in humans. A. It requires the action of enzymes called kinases. B. It is linked to the digestion of glycogen. C. It is a process that is dependent upon enzyme (cellulase) production by gut microbiota. D. It is a very efficient process the produces very little undigested material in feces.
It is a process that is dependent upon enzyme (cellulase) production by gut microbiota.
A student forgot to label a beaker containing a DNA solution and a beaker containing a glucose solution. If chemical analysis was performed to identify the contents of each beaker, which of the following would be found in the beaker of DNA but not in the beaker with glucose? A. Nitrogen and phosphorus B. Carbon atoms C. Hydrogen and oxygen atoms D. Fatty acidsE. Amino acids
Nitrogen and phosphorus
What type of bond is formed by dehydration synthesis between two amino acids? A. Ester B. Peptide C. Phosphate D. Disulfide E. Glycosidic
Peptide
Which of the following functional groups is mismatched to the organic compound in which it is typically found? A. Carboxyl - fatty acids B. Amino - proteins C. Hydroxyl - alcohols D. Sulfhydryl - proteins E. Phosphate - carbohydrates
Phosphate - carbohydrates
Which of the following would have glycosidic bonds? A. Monosaccharides B. Polypeptides C. Triglycerides D. ATP E. Polysaccharides
Polysaccharides
Which of the following is a correct description of a component of the ATP molecule? A. Sugar: deoxyribose B. Sugar: ribose C. Nitrogenous base: alanine D. High energy bond: peptide bond E. High energy bond: glycosidic bond
Sugar: ribose
the most important outcome of polypeptide intrachain bonding and folding is the unique shape of the protein. TRUE FALSE
TRUE
Which of the following statements is incorrect regarding protein structure? A. Proteins, such as antibodies that are comprised of multiple polypeptide chains, have quaternary structure. B. The folding of a protein to form its active site creates its tertiary structure. C. Beta-pleated sheets are a type of protein secondary structure. D. The sequence of nucleotides determines the primary structure of a protein.
The sequence of nucleotides determines the primary structure of a protein.
In what way would life be different if the element carbon was absent? A. There would be no organic compounds. B. There would be no inorganic compounds. C. Life would not exist in any shape or form. D. The concept of pH would not exist.
There would be no organic compounds.
1.C6H12O6 + C6H12O6 C12 H22O11 + H2O represents A. the formation of a polysaccharide. B. the formation of a peptide bond. C. a decomposition reaction. D. a denaturation reaction. E. a dehydration synthesis.
a dehydration synthesis.
A capillary tube is used to acquire a small blood sample for CBC (complete blood count) analysis. Suction is not required to transfer the blood from the fingertip prick to the tube in part due to A. covalent bonding between the water molecules. B. cohesive forces between the glass particles of the tube and the water molecules. C. ionic bonding between the water molecules. D. adhesive forces between the water molecules and the glass particles of the tube.
adhesive forces between the water molecules and the glass particles of the tube.
The electrons of an atom are A. used to determine the atomic weight. B. always equal to the number of protons. C. carrying a positive charge. D. always in full orbitals. E. used to determine the atomic number.
always equal to the number of protons.
The building blocks of an enzyme are ______. A. nucleotides B. monosaccharides C. amino acids D. glycerol and fatty acids E. phosphate, glycerol, and fatty acids
amino acids
Starch is the primary storage food for all of the following except ______. A. algae B. some fungi C. green plants D. animals
animals
1.Ionic compounds A. are basic in solution. B. are acidic in solution. C. are hydrophobic. D. are hydrophilic. E. always form salts in solution.
are hydrophilic.
1.What would be the valence number of electrons in the sulfur (S) atom? Its atomic number is 16. A. 2 B. 6 C. 8 D. 16 E. 32
b.6
1.Cations are A. atoms without protons. B. charged subatomic particles. C. atoms that have gained electrons. D. capable of forming ionic bonds with anions. E. atoms that have gained neutrons.
capable of forming ionic bonds with anions.
1.Organic chemicals always have a basic framework of the element _____ bonded to other atoms. A. oxygen B. phosphorous C. nitrogen D. hydrogen E. carbon
carbon
1. Substances that release ions when dissolved in water and conduct electricity are ______. A. covalent B. solvents C. nonpolar D. electrons E. electrolytes
electrolytes
. A covalent bond is formed between an anion and a cation. true false
false
All proteins are enzymes. true false
false
The concentration of a solution expresses the amount of solvent present. true false
false
All of the following are monosaccharides except ______. A. glycogen B. fructose C. glucose D. deoxyribose
glycogen
All of the following pertain to the atom Carbon-14 except it A. has 14 neutrons . B. is an isotope of carbon. C. has 6 protons. D. has 6 electrons.
has 14 neutrons.
Compared to a solution of pH 9, a solution of pH 7 A. is more basic. B. has more H+ ions. C. has a higher pH. D. has no OHions.
has more H+ ions.
1.Polar molecules A. always contain carbon. B. have an equal charge distribution. C. have an unequal charge distribution .D. always involve oxygen. E. are insoluble in water.
have an unequal charge distribution.
1.Atoms that gain or lose electrons become charged particles called ______. A. ions B. isotopes C. anions D. cations
ions
39. One technique for staining bacteria for viewing under the microscope is called the Gram stain. In this technique, alcohol is used as a decolorizer because it degrades the outer membrane found in some bacteria. What chemical component of the cell does alcohol affect? A. Protein B. Lipid C. Nucleic acids D. Carbohydrate
lipid
Anything that occupies space and has mass is called ______. A. matter B. energy C. living D. space E. atomic
matter
1.Two or more atoms bonded together are called a(n) ______. A. molecule B. isotope C. ion D. electrolyte E. element
molecule
The electrons of an atom are A. moving in pathways called orbitals. B. used to determine atomic number. C. positively charged. D. always equal to the number of neutrons in an atom. E. found in the nucleus.
moving in pathways called orbitals.
Purines and pyrimidines are components in the building block units of all ______. A. amino acids B. polysaccharides C. carbohydrates D. enzymes E. nucleic acids
nucleic acids
Protons and neutrons make up the atom's central core, which is referred to as its ______. A. isotope B. center of gravity C. valence number D. nucleus
nucleus
1.A reaction where an electron is lost is called ______. A. oxidation B. reduction C. ionization D. decomposition E. dissolution
oxidation
An example of an amphipathic molecule found in living cells is ______. A. phospholipid B. nucleic acid C. protein D. ATP E. glucose
phospholipid
The lipid group that is the major component of cell membranes is the ______. A. waxes B. steroids C. prostaglandins D. triglycerides E. phospholipids
phospholipids
An atom has gained an electron; it has been ______. A. ionized B. oxidized C. neutralized D. reduced E. deionized
reduced
Most biochemical macromolecules are polymers, which are chains of ______. A. hydrophobic molecules B. hydrogen bonds C. repeating carbohydrates D. electrolytic molecules E. repeating monomers
repeating monomers
1.Hydrogen bonds A. result from attractive forces between molecules with polar covalent bonds. B. are the strongest bonds between molecules. C. result from attractive forces between molecules with polar ionic bonds. D. result from attractive forces between molecules with nonpolar ionic bonds. E. result from attractive forces between molecules with nonpolar covalent bonds.
result from attractive forces between molecules with polar covalent bonds.
1.Covalent bonds A. result from gaining electrons. B. are always nonpolar. C. result from losing electrons .D. are always polar. E. result from sharing electrons.
result from sharing electrons.
All cells contain A. uracil in their DNA .B. ribosomes for protein synthesis. C. cell walls made of cellulose .D. organelles for compartmentalization. E. mitochondria to generate ATP.
ribosomes for protein synthesis.
A fat is called _____ if all carbons of the fatty acid chain are single-bonded to 2 other carbons and 2 hydrogens. A. monounsaturated B. unsaturated C. polyunsaturated D. saturated
saturated
The alpha () helix is a type of _____ protein structure. A. primary B. secondary C. tertiary D. quaternary
secondary
In the cell cytoplasm, molecules of ATP are a ______. A. solute B. solvent
solute
All of the following are lipids except ______. A. wax B. cholesterol C. phospholipid D. starch E. triglyceride
starch
All of the following are polysaccharides except A. dextran in some bacterial slime layers. B. agar used to make solid culture media. C. cellulose in certain cell walls. D. sterols in cell membranes. E. a cell's glycocalyx.
sterols in cell membranes.
ATP differs from the nucleotides found in DNA in the A. use of phosphate instead of sulfate in the backbone. B. use of phosphorus in the nitrogenous base portion of the molecule. C. sugar portion of the molecule. D. use of uracil in the nitrogenous base portion of the molecule. E. use of adenosine instead of adenine.
sugar portion of the molecule.
ATP is best described as A. a double helix. B. the energy molecule of cells. C. an electron carrier. D. an enzyme.
the energy molecule of cells.
The lipid group that serves as energy storage molecules is the ______. A. triglycerides B. prostaglandins C. steroids D. phospholipids E. waxes
triglycerides
. If solution A has a lower pH compared to solution B, then solution A is more acidic than solution B. true false
true
Polar molecules have more reactivity compared to nonpolar molecules. true False
true
The only part of an amino acid that differs from other amino acids is its R group. TRUE
true
The important solvent associated with living things is ______. A. benzene B. sodium chloride C. water D. carbon dioxide E. ethyl alcohol
water