Exam 1 Flashcards
A. cellulose B. chitin C. starch D. glycogen E. peptidoglycan \_\_\_\_ forms sheets that stiffen the cell wall of bacteria
____ composes the cell wall of fungi
____ refers to insoluble fiber on food packages
E
B
A
A. Non-polar covalent bond B. Polar covalent bond C. Ionic bond D. Hydrogen bond E. Van der Waal's force
The partial negative charge at one end of a water molecule is attracted to the partial positive charge of another water molecule. This attraction is called a(n) ____.
In a(n) ____, outer-shell electrons of one atom are transferred to fill the outer electron shell of another atom
A(n) ____ is when the atom is involved in the electron-sharing bond have the same electronegativity
In a DNA double helix, ____s form between the complementary nitrogenous bases.
D
C
A
D
Which of the following statements best distinguishes scientific hypotheses from scientific theories?
A. Hypotheses are generally supported by more evidence than theories.
B. Hypotheses are usually narrower in scope; theories have broader explanatory power
C. Hypotheses describe and theories explain
D. Hypotheses are used in experiments. Theories are not tested.
B
Why do chemical reactions tend to speed up when the concentration of the reactants is increased?
A. The reactants move faster
B. The reactants collide more often
C. The reactants have greater energy
D. All of the listed responses are correct.
D
Upon chemical analysis, a particular polypeptide was found to contain 100 amino acids. How many peptide bonds are present in this protein? A. 101 B. 100 C. 99 D. 98 E. 97
C
Compare proteins to nucleic acids. Which of the following is true?
A. Both have primary and secondary structure
B. Both contain sulfur
C. Both take on structural roles in a cell
D. Both have monomers, which contain phosphorus
A
A glycosidic linkage is analogous to which of the following proteins? A. an amino group B. a peptide bond C. a disulfide bond D. a beta-pleated sheet
B
How many electrons are involved in a single covalent bond? A. 1 B. 2 C. 3 D. 4
B
Complementary base pairing is possible only if two DNA strands align in antiparallel–instead of parallel–fashion. Which statement best explains why?
A. Only antiparallel strands create the geometry that allows complementary base pairs to form via Van der Waals interactions.
B. Only antiparallel strands contain the nitrogenous bases necessary to form complementary base pairs
C. Only antiparallel strands contain unusual backbone atoms which allow complementary base pairing
D. Only antiparallel strands create the geometry that allows complementary base pairs to form via hydrogen bonding.
D
In the process of science, which of these is tested? A. A conclusion B. An observation C. A result D. A control group E. A hypothesis
E
Proteins in biological systems ____.
A. Form a high-energy intermediates such as ATP
B. Catalyze reactions
C. Link with other proteins to form bilayers in cell membranes
D. Store genetic information
B
Why do researchers think the first self-replicating molecule was RNA?
A. Fossils evidence of such a molecule was recently discovered
B. RNA is the only type of molecule that can catalyze a chemical reaction
C. Self-replicating molecules of RNA exists today, in human cells
D. RNA can carry information and catalyze chemical reactions
D
Which of the following can vary among monosaccharides? A. The presence of hydroxyl groups B. The presence of sulfur groups C. The number of carbon atoms D. The presence of carbonyl groups
C
A friend of yours calls to say that his car would not start this morning. He asks for your help. You say that you think the battery must be dead. If so, then jump-staring the car from a good battery will solve the problem. In doing so, you are ____.
A. testing a theory for why the car will not start
B. making observations to inspire a theory for why the car will not start
C. stating a hypothesis and using that hypothesis to make a testable prediction
D. comparing multiple hypotheses for why the car will not start.
C
Why is carbon so important in biology?
A. It is a common element on Earth
B. It has very little electronegativity, making it a good electron donor
C. It bonds to only a few other elements
D. it can form a variety of carbon skeletons and host functional groups
D
You disrupt all hydrogen bonds in a protein. What level of structure will be preserved? A. Primary structure B. Secondary structure C. Tertiary structure D. Quaternary structure
A
DNAase is an enzyme that catalyzes the hydrolysis of the covalent bonds that join nucleotides together. What would first happen to DNA molecules treated with DNAase?
A. The two strands of the double helix would separate
B. The phosphodiester bonds between deoxyribose sugars would be broken.
C. The purines would be separated from the deoxyribose sugar
D. The pyrimidines would be separated from the deoxyribose sugars
E. All bases would be separated from the deoxyribose sugars.
A
Which of the following best explains why “carbs” (carbohydrates) are advertised by manufacturers of candy bars and sports drinks as a “quick energy boost”?
A. The energy in them can be stored as fat, which has high energy per unit weight
B. The carbon is carbohydrates are rich in energy because they are highly oxidized
C. Carbohydrates are reduced molecules that have high-energy electrons
D. This is an advertising gimmick that has no scientific evidence to support it
B
\_\_\_\_ atoms give organic molecules their overall shape; \_\_\_\_ atoms determine the overall chemical behavior of organic molecules. A. Carbon; H, N, and O B. Hydrogen; C, N, and O C. Carbon; H2O D. H, N, and O; carbon
A
The bonding of two amino acid molecules to form a larger molecule requires the ____.
A. Release of a water molecule
B. Release of a carbon dioxide molecule
C. Addition of a carbon dioxide molecule
D. Addition of a water molecule
E. Addition of a water molecule and a carbon dioxide molecule
A
If a DNA double helix contains 28% T nucleotides, then what is the percentage of A nucleotides?
A. 22
B. 28
C. 44
D. 56
E. It is impossible to tell from the information given
B
At which bond would water need to be added to achieve hydrolysis of the peptide, back to its component amino acids? A. A B. B C. C D. D E. E
C. in between O boned C-N bonded H
What is the structural feature that allows DNA to replicate?
A. Disulfide bonding (bridging) of the two helixes
B. Complementary pairing of the nitrogenous bases
C. Sugar-phosphate backbone
D. Three-component structure of the nucleotides
E. Twisting of the molecule to form an alpha-helix
B
You have two beakers. One contains pure water, the other contains pure methanol (wood alcohol). The covalent bonds of methanol molecules are nonpolar, so there are no hydrogen bonds among methanol molecules. You pour crystals of table salt (NaCl) into each beaker. Predict what will happen.
A. Equal amounts of NaCl crystals will dissolve in both water and methanol
B. NaCl crystals will not dissolve in either water or methanol.
C. NaCl crystals will dissolve readily in water but will not dissolve in methanol.
D. NaCl will dissolve readily in methanol but will not dissolve in water.
E. When the first crystals of NaCl are added to water or to methanol, the will not dissolve; but as more crystals are added, the crystals will begin to dissolve faster and faster.
C
