Midterm Exam BIO105K NAME

Transcription

1 Midterm Exam BIO105K NAME You can write your name here, but you don t need to. Please write your name using a pencil on the bubble sheet (last name, then first) and fill in the circles below your name.

2 1) Where in a cell are proteins synthesized? A) peroxisomes B) riboosomes C) lysosomes D) chromosomes E) membranes 2) When we say an Aquaporin molecule looks like a donut, we are referring to the: A) tertiary structure B) secondary structure C) quaternary structure D) primary structure E) denatured structure 3) The solution outside the artificial cell in the beaker above is: A) isotonic B) hypertonic C) catatonic D) hypotonic E) ionic 4) Which of the following is not destroyed when a protein gets denatured? A) primary structure B) secondary structure C) tertiary structure D) quaternary structure E) all of the above are destroyed 5) Which of the following has the correct rank from smallest to largest. A) cholesterol, LDL, eukaryotic cell, coated vesicle B) cholesterol, coated vesicle, LDL, eukaryotic cell C) coated vesicle, cholesterol, LDL, eukaryotic cell D) cholesterol, LDL, coated vesicle, eukaryotic cell E) LDL, cholesterol, eukaryotic cell, coated vesicle 6) One theme our textbook s author likes but our instructor doesn t like is: A) organisms inherit information B) the whole is greater than the sum of its parts C) structure relates to function D) all life is composed of cells

3 E) feedback mechanisms are important 7) Gretchen s presentation was about how in some neurodegenerative diseases denatured proteins block the function of which organelle? A) smooth ER B) rough ER C) lysosome D) nucleus E) peroxisome 8) After our white blood cell macrophages phagocytose bacteria, the vesicle containing the bacteria fuses with: A) peroxisome B) lysosome C) mitochondria D) cytoskeleton E) smooth endoplasmic reticulum 9) What do lamins do for a cell? A) give the nucleus its round shape B) help the cell change shape C) move chromosomes D) help with osmosis E) all of the above 10) How many protons are in the atom of sodium shown above? A) 1 B) 10 C) 11 D) 12 E) 23 11) How many electrons are in the atom of sodium shown above? A) 1 B) 10 C) 11 D) 12 E) 23 12) Why would the 11 rarely be written next to Na as shown above? A) because it is a unstable isotope B) because if it wasn t 11, it wouldn t be Na C) because it changes when Na is dissolved in water D) because it is affected by temperature

4 E) because the Grateful Dead own the copyright to the number 11 13) On the drawing above, #1 is where LDL protein is synthesized so this organelle must be the: A) smooth ER B) rough ER C) nucleus D) Golgi apparatus E) lysosome 14) On the drawing above, #2 is where cholesterol is synthesized so this organelle must be the: A) smooth ER B) rough ER C) nucleus D) Golgi apparatus E) lysosome 15) On the drawing above, #3 shows how LDL leaves the liver cell by: A) receptor-mediated endocytosis B) pinocytosis C) exocytosis D) phagocytosis E) budding 16) On the drawing above, #4 shows LDL in the blood. What part of the LDL will bind to the LDL receptor? A) cholesterol B) phospholipid C) protein D) glucose E) fatty acid 17) On the drawing above, #5 is next to a coated vesicle. Coated vesicles are coated with: A) clathrin B) LDL protein C) cholesterol D) LDL receptor

5 E) proton pumps 18) On the drawing above, which number is next to the location where testosterone or estrogen is synthesized? A) #1 B) #2 C) #5 D) #6 E) #7 19) The last step on the drawing above involves LDL receptor returning to the gonad cell surface by: A) receptor-mediated endocytosis B) pinocytosis C) exocytosis D) phagocytosis E) budding 20) Which of the following function like railroad tracks that vesicles move around inside cells? A) mycobacteria B) microtubules C) mitochondria D) centromeres E) microfilaments 21) Which of the following affect radioactivity? A) electrons B) neutrons C) ions D) protons E) atomic number 22) How many grams of ribose would be in 2 liters of a 0.5 M solution of ribose? (the molecular weight of ribose is 150) A) 75 B) 150 C) 300 D) 450 E) need more information 23) What type of bond joins amino acids together in the primary structure of a protein? A) hydrogen bond B) London Dispersion C) peptide bond D) van der Waals E) salt bridge

6 24) In the above graph, which letter is next to the transition state for the reaction in the absence of enzyme? A B C D E 25) In the above graph, which letter is next to value that determines the final equilibrium of the reaction? A B C D E 26) In the above graph, which letter is next to the activation energy in the presence of enzyme? A B C D E 27) In the above graph, what is the change in free energy (ΔG) in the absence of enzyme? A) +4 kcal/mole B) - 7 kcal/mole C) +11 kcal/mole D) - 11 kcal/mole E) - 4 kcal/mole 28) In the above graph, what is the activation energy of the reaction in the absence of enzyme? A) + 7 kcal/mole B) - 7 kcal/mole C) + 4 kcal/mole D) - 11 kcal/mole

7 E) - 4 kcal/mole 29) The above structure shows the first four amino acids in a protein as it is being made by a ribosome. Which is a hydrophobic amino acid? A) #A B) #B C) #C D) #D E) more than one of the above 30) The above structure shows the first four amino acids in a protein as it is being made by a ribosome. Which is a hydrophilic amino acid? A) #A B) #B C) #C D) #D E) more than one of the above 31) The above structure shows the first four amino acids in a protein as it is being made by a ribosome. Which is amino acid number three in the protein? A) #A B) #B C) #C D) #D E) more than one of the above 32) The above structure shows the first four amino acids in a protein as it is being made by a ribosome. Which amino acid side chain could NOT form hydrogen bonds with other amino acids? A) #A B) #B C) #C D) #D E) all of them can form hydrogen bonds with other amino acids

8 33) What will happen to the artificial cell in the beaker shown above over time? A) water will flow both ways but more will flow in than out. B) water will flow both ways but more will flow out than in C) water will only flow inward D) water will only flow outward E) water will flow both ways equally 34) What will happen to the sugars over time? A) glucose will flow inward B) glucose will flow outward C) sucrose will flow inward D) sucrose will flow outward E) nothing 35) The human clathrin gene and the cow clathrin gene are: A) paralogs B) alleles C) orthologs D) mutations E) analogues 36) The human aquaporin-0 and aquaporin-5 genes are: A) paralogs B) alleles C) orthologs D) mutations E) analogues 37) The valence shell of which of these elements has six electrons: A) H B) B C) C D) N E) O 38) How many electrons would a sodium (Na) atom have if the atom had an equal number of electrons and protons and no net charge? A) 1 B) 3 C) 8 D) 11

9 E) 17 39) The hormone vasopressin causes water retention in kidneys by: A) fusion of vesicles to the cell membrane B) pumping water C) muscle contraction D) closing channels E) pinocytosis 40) Which of the following do not have a phospholipid bilayer? A) liver cells B) extremophiles C) plants D) archaea E) all have it 41) In Kevin s presentation, we learned the hard exoskeleton of lobsters is composed primarily of: A) microfilaments B) chitin C) phospholipids D) mycoplasm E) calcium 42) The fluid mosaic model describes: A) water chemistry B) cell membranes C) protein structure D) feedback inhibition E) exergonic reactions 43) A protein could have many possible conformations because covalent bonds can: A) bend B) rotate D) stretch D) all of the above E) none of the above

10 44) If one of your cells was the size of the Boston metropolitan area, about how big would a typical protein be? A) the size of a shoe B) the size of a big truck C) the size of a shopping mall D) the size of a town like Wayland (Yay, Wayland!) E) the size of Massachusetts 45) What is the main difference between passive transport and active transport: A) passive transport increases membrane potential B) passive transport uses no energy C) passive transport requires ATP D) passive transport creates concentration gradients E) passive transport does work 46) Before they are released by exocytosis, neurotransmitters are held inside: A) vesicles B) ribosomes C) proteins D) smooth ER E) liver cells 47) Which of the following correctly lists atoms in order from the one that prefers to make the fewest covalent bonds to the one that makes the most: A) O, C, H, N B) O, H, N, S C) H, O, N, C D) N, C, O, S E) H, C, O, N 48) If a person has trouble with osmosis in their eye cells but not their kidney cells, their problem is most likely: A) increased unsaturated phospholipids B) decreased cholesterol C) decreased ionophores D) mutated aquaporin paralog E) passive diffusion 49) Which of the following can pass through an artificial membrane composed of a phospholipid bilayer? A) ions B) big molecules C) proteins D) water E) sugars

11 50) Which of the following is the most important method scientists use to study extremophiles? A) radioactive dating B) growth in sterile dishes C) competition D) electron microscopy E) direct DNA sequencing 51) Most enzymes are: A) kinases B) bound to the membrane C) proteins D) signaling factors E) hormones 52) Which of the following is not a transmembrane protein: A) LDL receptor B) aquaporin C) clathrin D) proton pump E) Na+-K+ pump 53) The rate of a chemical reaction is determined by: A) the activation energy B) the increase in entropy C) the decrease in free energy D) the electronegativity E) the final equilibrium 54) Which of the following organelles has a strongly acidic ph? A) nucleus B) Golgi apparatus C) rough endoplasmic reticulum D) lysosome E) smooth endoplasmic reticulum 55) Which of the following are polymers of actin? A) microtubules B) intermediate filaments C) mitotic spindles D) microfilaments E) plasmid filaments 56) Different elements have different numbers of: A) protons B) neutrons C) electrons D) ions E) orbitals

12 57) Which of the following would increase a cell s surface area? A) phagocytosis B) exocytosis C) pinocytosis D) endocytosis E) receptor-mediated endocytosis 58) Vesicles are moved by molecular motors that bind to: A) microtubules B) phospholipids C) microfilaments D) clathrin E) intermediate filaments 59) Enzymes: A) are almost always proteins B) are biological catalysts C) have specific substrates D) lower the activation energy E) all of the above 60) Cell membrane proteins become modified in the: A) Golgi apparatus B) nucleus C) smooth endoplasmic reticulum D) rough endoplasmic reticulum E) nucleolus 61) If the clathrin in a cell was defective, what would probably happen? A) LDL receptors wouldn t cluster together when LDL binds to them B) LDL wouldn t bind to the LDL receptors C) cholesterol levels would decrease in the blood D) the cell would respond by making less of the LDL receptor E) the rate of exocytosis would increase 62) What does a Sodium-Potassium Pump need to do its job? A) starch B) ribosomes C) ATP D) sugar E) DNA 63) Water passing across the cell membrane through aquaporin is an example of: A) passive transport B) gated pumping C) phagocytosis D) ion channels E) cotransport

13 64) If acid rain has a ph of 4.0, what is the hydrogen ion concentration of the rain? A) 4.0 M B) M C) 10-4 M D) 10 4 M E) 10 M 65) What type of chemical reaction is occurring when proteins are digested apart into individual amino acids? A) electrophilic B) dehydration C) condensation D) hydrolysis E) reduction 66) Which pair of terms correctly completes this sentence: Catabolism is to anabolism as is to. A) exergonic; spontaneous B) exergonic; endergonic C) free energy; entropy D) work; energy E) entropy; enthalpy 67) Since the electronegativity of oxygen and hydrogen atoms are different, the covalent bonds in a water molecule are: A) ionic B) polar C) nonpolar D) hydrogen bonds E) isotopes 68) If ATP synthesis requires 7.3 kcal/mole, an enzyme could couple hydrolysis of molecule A with synthesis of ATP if the ΔG for hydrolysis of A is: A) +7.3 kcal/mole B) +10 kcal/mole C) 10 kcal/mole D) 5 kcal/mole E) 0 kcal/mole 69) When we say a chemical reaction has a negative ΔG, it means: A) the reaction will occur spontaneously B) the reaction cannot be used to do work C) the products have higher free energy than the substrates D) the reactants have lower potential energy than the products E) all of the above

14 70) Each element has a unique, which refers to the number of protons in its nucleus. A) isotope number B) mass number C) atomic number D) molecular weight E) charge number 71) Our text describes the cause of cystic fibrosis as: A) broken chloride ion channels B) broken aquaporins in the lung C) broken aquaporins in sweat glands D) broken sodium ion channels E) broken mucus transport 72) The atoms within one ethanol molecule are held together by: A) covalent bonds B) London dispersion forces C) hydrogen bonds D) ionic interactions E) all of the above 73) The functional group in alcohols is: A) a hydroxyl B) an amino C) a carboxyl D) a carbonyl E) a sulfhydryl 74) Where are peptide bonds formed? A) peroxisomes B) ribosomes C) lysosomes D) chromosomes E) membranes 75) The DNA in our chromosomes encodes what information for a protein? A) primary structure B) secondary structure C) tertiary structure D) quaternary structure E) none