Lecture 2, 3 and 4; Chapter 2 and 4 Biology
14C is an isotope of carbon that possesses: A.6 protons, 8 neutrons, and 6 electrons. B.6 protons, 6 neutrons, and 2 electrons. C.6 protons, 8 neutrons, and 2 electrons. D.8 protons, 6 neutrons, and 2 electrons. E.6 protons, 2 neutrons, and 6 electrons.
A
Secondary structures are stabilized by which type of interaction? Please choose the correct answer from the following choices, and then select the submit answer button. A.hydrogen bonding B.van der Waals forces C.hydrophobic clustering D.disulfide linkages E.ionic bonding
A
Stanley Miller's research provided insight into how the first proteins may have appeared on Earth. Please choose the correct answer from the following choices, and then select the submit answer button. A.true B.false
A
The age of the Earth is 4.6 billion years. For what percentage of this time is Earth thought to have been anaerobic? Please choose the correct answer from the following choices, and then select the submit answer button. A.44% B.27% C.99.3 D.68% E.0.1%
A
When a peptide bond is created between two amino acids: A.the carboxyl group of the first amino acid is joined to the amino group of the second. B.the carboxyl group of the first amino acid is joined to the carboxyl group of the second. C.the amino group of the first amino acid is joined to the amino group of the second. D.the amino group of the first amino acid is joined to the carboxyl group of the second.
A
Which of the following gases did Stanley Miller not use in his experiment to recapitulate the Earth's early atmosphere? Please choose the correct answer from the following choices, and then select the submit answer button. A.oxygen gas (O2) B.water vapor (H2O) C.ammonia (NH3) D.hydrogen gas (H2) E.methane (CH4)
A
As part of their normal function, many proteins bind to DNA briefly and then release it again. Which types of bonds might be involved in these transient protein-DNA interactions? (Select all that apply.) A.ionic B.covalent C.hydrogen D.van der Waals forces
A,C,D
Carbohydrates and proteins are two types of macromolecules. Which functional characteristic of proteins distinguishes them from carbohydrates? A.None of the other answer options is correct. B.ability to catalyze biochemical reactions C.efficient storage of usable chemical energy D.large amount of stored information E.tendency to make cell membranes hydrophobic
B
Helicase is an enzyme that separates the double helix of the DNA into two separate strands. How do you think helicase does this? A.by breaking ionic bonds B.by breaking hydrogen bonds C.by breaking phosphodiester bonds D.by breaking peptide bonds
B
Of the following types of bonds between atoms, which is the STRONGEST? A.hydrogen bond B.covalent bond C.van der Waals forces D.ionic bond
B
The structural diversity of carbon-based molecules is determined by which of the following properties? A.the ability of those bonds to rotate freely B.All of these choices are correct. C.the orientation of those bonds in the form of a tetrahedron D.the ability of carbon to form four covalent bonds
B
Triacylglycerols are used primarily for: A.movement. B.energy storage. C.cell membrane biosynthesis. D.biological catalysis. E.information storage.
B
Which of the following statements are true regarding nucleic acids? Please choose the correct answer from the following choices, and then select the submit answer button. A.Nucleic acids cannot form spontaneously; the first nucleic acids were most likely "built" by early proteins. B.Nucleic acids can form spontaneously, provided that there are an adequate number of available nucleotides. C.Early nucleic acids were likely formed spontaneously and could not have formed complementary strands. D.None of the other answer options is correct.
B
Which of the following statements is true regarding a basic amino acid? Please choose the correct answer from the following choices, and then select the submit answer button. A.The hydrophilic R group of a basic amino acid will be located in the interior of a protein. B.The positively charged R group of a basic amino acid could bind DNA. C.The R group of a basic amino acid would only be able to form covalent bonds with other molecules. D.A basic amino acid would be considered both polar and hydrophobic. E.All of these choices are correct.
B
A 1,4-glycosidic linkage would refer to which one of the following? Please choose the correct answer from the following choices, and then select the submit answer button. A.the covalent bond between amino acid 1 in one protein and amino acid 4 in a second protein B.the covalent bond between the 1' carbon of one nucleotide and the 4' carbon of a second nucleotide C.the covalent bond between carbon 1 of one monosaccharide and carbon 4 of a second monosaccharide D.hydrogen bonding between carbon 1 and carbon 4 within a monosaccharide E.hydrogen bonding among the four bases in double-stranded DNA
C
Using the structures of amino acids in figure 4.2, determine which one of the following amino acids is MOST likely to participate in hydrogen bonding with water? A.alanine B.leucine C.asparagine D.phenylalanine E.valine
C
Which of the following statements is true regarding glycine? Please choose the correct answer from the following choices, and then select the submit answer button. A.Glycine is an asymmetric amino acid. B.Glycine is a large, polar amino acid. C.Glycine increases the flexibility of the peptide backbone. D.Glycine is similar to tyrosine in terms of structure and chemical properties. E.Glycine is special because it contains a -SH group important in protein folding.
C
Which of the following are covalent bonds? A.peptide bonds B.glycosidic bonds C.phosphodiester bonds D.All of these choices are correct.
D
Which one of the following components of an amino acid differs from one amino acid to another? A.the hydrogen atom opposite the R group B.the carboxyl group C.the α-carbon atom D.the side chain E.the amino group
D
Which one of the following interactions is NOT a stabilizing force at the tertiary level of protein organization? A.hydrophobic clustering of nonpolar R groups in the interior of a protein B.van der Waals interactions between R groups in close proximity C.hydrogen bonding between polar R groups in the same polypeptide chain D.disulfide linkages between cysteine residues in different polypeptide chains E.an ionic bond between a positively charged R group and a negatively charged R group
D
α helices are coils with how many amino acids per complete turn? Please choose the correct answer from the following choices, and then select the submit answer button A.10 B.20 C.4.8 D.3.6 E.2.5
D
What do double bonds do in gylcerols?
Decrease the melting point
In general, colder temperatures reduce the fluidity of the membrane, so cells will produce different molecules to maintain the proper degree of fluidity. How would the membrane change in response to colder temperatures? A.The amount of saturated triacylglycerols would decrease. B.The amount of saturated triacylglycerols would increase. C.The length of the fatty acid side chains in the phospholipids would increase. D.The amount of unsaturated fatty acids would decrease. E.The amount of unsaturated fatty acids would increase.
E
Which one of the following is NOT a component of an amino acid? A.α carbon B.amino group C.carboxyl group D.R group E.triphosphate group
E
Unsaturated fatty acids have what?
double bonds
Saturated fatty acids have what?
no double bonds
