1 Ribosomal subunits come together into a functioning ribosome to synthesize a polypeptide MCB 150 Practice Exam I Fall 2011 nucleus in the region most accurately referred to as the A B cytoplasm C nucleoid region D extracellular space E nucleolus 2 Which one of the following accurately describes a feature that lactose cellobiose maltose and sucrose all have in common A They are each synthesized with a single glycosidic linkage B They are each composed exclusively of glucose C The monomers of each are all in the beta configuration D They are each found in the cell walls of plants E None of the above statements accurately describe features that lactose cellobiose maltose and sucrose all have in common 1 MCB 150 Practice Exam I Fall 2011 The following figure shows a common biological reaction Dotted arrows indicate specific regions of the molecules not additional participants in the reaction Use the figure to answer the next five 5 questions 3 Which one of the following statements about the reaction shown above is incorrect A The reaction would have a positive G B The reaction is endergonic C A molecule of water would be released during the reaction D The product of this reaction would be at a higher energy level than the substrates E The reaction is catabolic The side chain of Amino Acid X is hydrophobic while at physiological pH the side chain of Amino Acid Y carries a net positive charge Using the table of amino acid side chains provided in this exam packet if necessary determine how many possible products there are for this reaction A 20 B 30 C 50 D 100 400 E 4 2 MCB 150 Practice Exam I Fall 2011 5 A collection of cellular machines found working together to produce multiple copies of the molecule shown above is most accurately referred to as a polysome A B a polypeptide C a riboarray D a protein cluster E a ribosome 6 At which of the labeled regions in the figure above would you expect to find the chemical group shown below A B C D E E only C only D only A and C B and E 7 True or False If a third amino acid was added to the product of the reaction shown it would be attached to the end of the molecule labeled E A True B False 8 Which one of the following would be considered an integral membrane protein A A transport channel which spans the membrane 7 times B An extracellular protein linked to a membrane phospholipid C An extracellular protein held to a transmembrane protein via hydrogen bonds and D E ionic bonds A and B A B and C 3 MCB 150 Practice Exam I Fall 2011 9 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 Species B and species C are identical organisms B Species B shares a more recent common ancestor with species C than it does with C Species A is a bacteria species B is an animal and species C is a plant D Species A shares a more recent common ancestor with species C than it does E None of the above conclusions would logically be drawn from the sequence data with species B species A 10 A fold or crease in a protein created by a region of beta sheet followed by an alpha helix followed by another beta sheet is an example of a motif A B a subunit C a domain D a chaperone E an active site 4 MCB 150 Practice Exam I Fall 2011 11 A planar phospholipid bilayer was formed across a small hole in a partition that separates two aqueous compartments as shown in the figure below A mixture of two molecules A and B was added to one of the compartments and the fate of both molecules was followed over time 120 minutes later molecule A was evenly distributed between the two aqueous compartments while the distribution of molecule B was unchanged What is the most likely identity of molecules A and B A Molecule A is oxygen O2 molecule B is nitrogen N2 B Molecule A is chloride ion Cl molecule B is magnesium Mg2 C Molecule A is carbon dioxide CO2 molecule B is calcium Ca D Molecule A is lysine molecule B is sodium ion Na E None of the above identities are likely for molecules A and B 12 Which one of the following properties of biological membranes is demonstrated by the experiment described in the previous question A Hydrophobicity B Asymmetry C Fluidity D Selective permeability E Amphipathicity 5 MCB 150 Practice Exam I Fall 2011 13 The best evidence for the evolutionary timing in which the human genome has acquired DNA via horizontal gene transfer comes from sequencing of small subunit ribosomal RNA molecules A B comparing versions of transposons C monitoring the activity of DNA replication machinery D examining changes in membrane permeability as a function of changes in transport E protein composition studying genomic changes in bacterial cells over thousands of generations and directly extrapolating those results to the human genome 14 You are conducting an in vitro denaturation experiment on a protein of interest to you and your lab group You have verified that your purified protein is fully denatured but you are disappointed to find that upon removing the denaturing agent your protein is unable to fold properly and resume normal activity The addition of which one of the following to your in vitro system would most likely allow your protein to resume normal activity A Ribosomes B Mitochondria C Chaperones D Glycogen E Cholesterol 15 During the synthesis of an RNA chain during the process of transcription in a human cell the next incoming monomer to be added to the macromolecule would prior to being utilized in the synthesis reaction most specifically be referred to as a n dNTP A B ribonucleoside diphosphate C nucleoside D nucleoside monophosphate E None of the above accurately describe the next monomer to be added to the existing macromolecule 16 The process described in the previous question would be taking place in a region of the cell separated from the cytoplasm by how many leaflets A 0 B 1 C 2 D 3 E 4 6 MCB 150 Practice Exam I Fall 2011 17 In which of the molecules listed below does the molecule shown play