Chemistry
Macromolecules
Metabolism
Cells
Membranes
200
Why are hydrocarbons insoluable in water?
A. the majority of their bonds are ionic bonds between carbon atoms B. the majority of their bonds are nonpolar covalent carbon to carbon or carbon to hydrogen linkages C. they are hydrophilic D. they are polar molecules with unequal sharing of electrons in the bonds between carbon and hydrogen E. they are less dense than water
200
The tertiary structure of a protein is the...
A. Bonding together of several polypeptide chains by weak bonds B. Order in which amino acids are joined in a polypeptide chain. C. Unique three dimensional shape of the fully folded polypeptide. D. Organization of a polypeptide chain into an alpha-hexix or beta-pleated sheet. E. Overall protein structure resulting from the aggregation of two or more polypeptide subunits.
200
Which of the following is TRUE for catabolic pathways?
A. they do not depend on enzymes B. they release energy as they degrade polymers to monomers C. they are usually highly spontaneous chemical reactions D. they only occur if steroids are the catalyst E. they consume energy to build up polymers from monomers
200
Which of the following do only plant cells have?
a. chloroplasts, cell wall b. mitochondria, ribosomes c. cell wall, rough and smooth ER d. chloroplasts, central vacuole
200
Proteins associated with the cell membrane can be involved in all the following activities, EXCEPT…
A. simple diffusion B. facilitated diffusion C. attatchment of the cytoskeleton D. cell recognition E. active transport
300
Which of the following statements CORRECTLY describes geometric isomers?
A. they have different arrangement around a double bond B. they have an asymmetric carbon that results in mirror images C. they have identical chemical properties D. they have different molecular formulas E. they have different atoms in their structure
300
Polysaccharids, lipids, and proteins are all similar in that they…
A. are synthesized from monomers by the process of hydrolysis B. are synthesized as a result of peptide bond formation between monomers C. are broken into their subunits by dehydration reactions D. all contain the same monomer building blocks E. are synthesized from monomers by dehydration reactions
300
Using the image showing the reaction of A + B -> C + D, which arrow corresponds to the activation energy required for the enzyme-catalyzed reaction?
A. a B. b C. c D. d E. e
300
All of the following can be found in bacterial archaean, and plant cell EXCEPT…
A. ribosomes B. nucleic acids C. endoplasmic reticulum D. polypeptides E. phospholipids
300
When a plant cell such as one from a peony stem, is submerged in a very hypotonic solution, what is likely to occur?
A. the cell will burst B. the cell membrane will lyse C. plasmolysis will shrink the interior D. the cell will become flaccid E. the cell will become turgid
400
The element _________ is a major component of a plant’s cells and is found in ________.
A. nitrogen ; carbohydrates B. potassium ; lipids C. magnesium ; amino acids D. idodine ; nucleic acids E. carbon ; proteins
400
The molecular formula for glucose is C6H12O6. What would be the molecular formula for a molecule made by linking three glucose molecules together by dehydration reactions?
A. C18H36O18 B. C18H32O16 C. C6H10O5 D. C18H10O15 E. C3H6O3
400
Which of the following statements about enzyme-catalyzed reactions is TRUE?
A. the reaction occurs faster than the same reaction without the enzyme B. the free energy change of the reaction is greater when an enzyme is used C. the reaction is not affected by the presence of an inhibitor D. the activation energy is increased when an enzyme is used E. enzymes slow down the reaction so there is time for it to occur
400
Which of the following conditions would produce a cell with lots of free ribosomes (not associated with the endoplasmic reticulum)?
A. a cell that is secreting proteins B. a cell that is producing cytoplasmic enzymes C. a cell that is constructing its cell wall or extracellular matrix D. a cell that is digesting food particles E. a cell that is enlarging its vacuole
400
The solution in the arms of the U-tube shown are separated at the bottom of the tube by a selectively permeable membrane. The membrane is not permeable to glucose. Initially side A is filled with a solution of 2 M glucose while side B is filled with 1 M NaCl and the volume in both arms is the same. After the solutions in the two arms come to equilibrium…
A. side A will be hypertonic to side B B. side B will be hypertonic to side A C. side B will be lower than side A D. side A will be lower than side B E. there will be no change seen in the liquid levels
500
Research indicates that Albuterol, a drug used to relax bronchial muscles, improving airflow and thus offering relief from asthma, consists only of one enantiomer, the R-form. Why is it important for this drug to consist of only one enantiomeric form, rather than a mixture of enantiomers?
A. Different enantiomers may have different or opposite physiological effects. B. It is impossible to synthesize mixtures of enantiomers. C. It is much less expensive to synthesize one enantiomer at a time. D. Albuterol is an example of a compound for which only one enantiomer exists. E. Only the R-form of Albuterol has been studied; until more information is available, physicians prefer to use the pure R-form.
500
If hundreds of this molecule were linked together, the polysaccharide that would result would be…
A. cholesterol B. cellulose C. glucose D. lipid E. starch
500
A competitive inhibitor decreases the rate of an enzyme reaction by…
A. acting as a coenzyme for the reaction B. changing the shape of the enzyme’s activation site C. changing the free energy change of the reaction D. binding at the active site of the enzyme E. decreasing the activation energy of the reaction
500
When a potassium ion (K+) moves from the soil into the vacuole of a cell of a plant root, it must pass through several cellular structures. Which of the following describes the order in which K+ will cross these structure (from outside to inside)?
A. plasma membrane -> cell wall -> cytoplasm -> vacuole B. cell wall -> plasma membrane -> smooth ER -> nucleus C. cell wall -> plasma membrane -> cytoplasm -> vacuole D. soil -> cytoplasm -> plasma membrane -> vacuole E. plasma membrane -> cell wall -> nucleus -> vacuole
500
The presence of cholesterol in the plasma membranes of some animals…
A. enables the membrane to stay fluid more easily when cell temperature drops B. enables the animal to remove hydrogen atoms from saturated phospholipids C. enables the animal to add hydrogen atoms to unsaturated phospholipids D. makes the membrane less flexible, allowing it to sustain greater pressure from within the cell E. makes the animal more susceptible to circulatory disorders
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