MCB 150 Practice Exam I Spring 2016 1 Using the strictest definition of an organelle ribosomes would not be classified as organelles because A B C D E 2 Which one of the following chemical formulas would most likely represent an oligosaccharide of six hexose sugars A B C D E 3 they did not originate from the endomembrane system organelles are singular structures and cells have multiple ribosomes they are not separated from the rest of the cell by a biological membrane the function they carry out is not essential for cell function they exist as separate subunits until they are directly participating in protein synthesis C36H67O31 C30H48O24 C36H60O30 C30H50O25 C36H62O31 All of the following stabilizing forces are known to contribute to the quaternary structure of multi subunit proteins although not every multi subunit protein has all of these forces Which one of these forces would be least likely to contribute to the association of a peripheral membrane protein with an integral membrane protein A B C D E Hydrogen bonding Ionic bonding van der Waals forces Disulfide linkages All of the above forces are equally likely to contribute to the association of a peripheral membrane protein with an integral membrane protein 1 MCB 150 Practice Exam I Spring 2016 4 Consider the following two statements about lipids 1 Transverse diffusion of phospholipids requires the involvement of an enzyme to occur at a biologically relevant rate 2 Because sphingomyelin does not have glycerol providing its three carbon backbone it cannot precisely be classified as a phospholipid Determine which one of the options below is correct A B C D 5 Identify the condition s of natural selection A B C D E 6 Individuals within a population vary in characteristics that are heritable In a particular environment certain versions of heritable traits help survive or reproduce better than do other versions Changes in populations occur when humans select certain individuals to produce the most offspring A and B A B and C Which of the following statements about enzymes is correct A B C D E 7 Statement 1 and statement 2 are both true Statement 1 and statement 2 are both false Statement 1 is true statement 2 is false Statement 1 is false statement 2 is true Enzymes lower the activation energy for the forward reaction but not the reverse reaction Enzymes alter the equilibrium of a reaction in favor of the exergonic reaction Enzymes lose their activity very gradually when the temperature is raised higher than the enzyme s optimal temperature Enzymes have pH optima that are always at neutral pH 7 None of the above statements about enzymes are correct True or False Phosphatidyl choline can be converted to phosphatidyl ethanolamine by converting unsaturated fatty acids to saturated fatty acids A B True False 2 MCB 150 Practice Exam I Spring 2016 8 Which of the following does not accurately describe a function or feature of a plasma membrane A B C D E Has molecules that are responsible for binding and adhering to adjacent cells Acts as a freely permeable barrier to allow import and export of materials Allows cells to maintain a constant internal environment Is an interface for cells where information is received from adjacent cells and extracellular signals All of the above accurately describe a function or feature of a plasma membrane The figure below represents the straight chain form of a common monosaccharide Use the figure to answer the next three 3 questions 9 OH O H OH OH OH H C C C C C C 1 H 2 OH H H H 4 5 3 H 6 Which of the labeled carbons would be designated Carbon 1 C1 A B C D E 1 2 3 5 6 10 Which pair of labeled carbons directly participate in the circularization of this monosaccharide A B C D E 1 and 6 3 and 6 2 and 5 1 and 5 2 and 6 3 MCB 150 Practice Exam I Spring 2016 11 Identify the biologically relevant functional group s that is are found in the molecule A B C D E Hydroxyl Carbonyl Ketone B and C A B and C 12 Consider the following two statements about protein synthesis 1 Ribosomes are structured in such a way that the carboxy terminus of an incoming amino acid interacts with the amino terminus of the amino acid that was previously at the end of the polypeptide chain 2 Polyribosome formation is possible in all domains of life Determine which one of the options below is correct A B C D Statement 1 and statement 2 are both true Statement 1 and statement 2 are both false Statement 1 is true statement 2 is false Statement 1 is false statement 2 is true 13 Which of the following is not a common function for a membrane protein A B C D E Attachment to the cytoskeleton and extracellular matrix Cell cell recognition Signal transduction Enzymatic activity All of the above are common functions of membrane proteins 4 MCB 150 Practice Exam I Spring 2016 14 You are studying the evolutionary relatedness among three different organisms species A species B and species C You identify a gene for ribosomal RNA rRNA from all three species and determine its nucleotide sequence After analyzing the data you conclude that the sequence of the rRNA gene from species A differs from the sequence of the rRNA gene from species C at 5 different bases Furthermore you determine that the sequence of the rRNA gene from species A differs from the sequence of the rRNA gene from species B at 20 different bases Which one of the following conclusions would you most likely draw from this sequence data A B C D E Species B and species C are identical organisms Species B shares a more recent common ancestor with species C than it does with species A Species A shares a more recent common ancestor with species C than it does with species B Species A is a bacteria species B is an animal and species C is a plant None of the above conclusions would logically be drawn from the sequence data 5 MCB 150 Practice Exam I Spring 2016 The following figure depicts a section of a polypeptide The ellipses indicate that the polypeptide continues on beyond the depicted region in both directions Use the figure to answer the next two 2 questions 15 If another amino acid was to be added to this polypeptide it would be added closest to the side labeled A B C B The end of the polypeptide to which another amino acid would be added cannot be determined from the information in this figure 16 How many of the side chains shown in the figure would be able to directly participate in the formation of an helix A B C D E 0 1 2 3 4 6 MCB 150 Practice Exam I Spring 2016 17 Which statement