Quiz 1

Question 1 (2 points) Saved Listen The example of water freezing into ice is an example of _______________. Question 1 options: no change in the entropy of the system. an increase in entropy of the system. a decrease in entropy of the system. a decrease in the entropy of the surroundings. Question 2 (2 points) Saved Listen The study of biochemistry attempts to explain_________________. Question 2 options: biological processes at the molecular and cellular level. physical processes at the macromolecular level. the nature of life. chemical processes at the atomic level. Question 3 (2 points) Saved Listen A hydrogen bond can best be described as a ________________. Question 3 options: weak noncovalent interaction. strong ionic interaction. weak covalent interaction. strong covalent interaction. Question 4 (2 points) Saved Listen

Choose the ONE true statement referring to the following coupled reactions: Rxn1 A↔B D G°' = -2 kJ/mol Rxn2 B↔C D G°' = +7 kJ/mol Rxn3 C↔D D G°' = -8 kJ/mol Net Rxn A↔D D G°' = -3 kJ/mol Select 1 correct answer(s) Question 4 options: The net reaction of A→D is unfavorable because the  D G°' value is less than 0. Rxn1 is a favorable reaction and will proceed in cells even if cellular concentrations of reactants and products change. For Rxn2, if the  D G°' value changes to +9 kJ/mol, the rate of the overall reaction A↔D will decrease. Rxn2 (B↔C) is unfavorable in the forward direction on its own, but if coupled to Rxn3 (C↔D), the overall conversion of B to D will occur. Question 5 (2 points) Saved Listen An example of experimental biochemistry is trying an experiment and _________________. Question 5 options: successfully proving your hypothesis after the first attempt. quitting after it fails to prove your hypothesis. continuing to try with no changes to protocol. optimizing experimental design.

The Biosphere 2 project, in Tucson, Arizona, was an experiment involving a large sealed terrarium with humans and photosynthetic plants living in balance. Why did the project have to be interrupted after only a few months? Question 4 options: Levels of CO 2  rose to dangerous levels. The humans ran out of food. The plants stopped producing oxygen. The rate of photosynthesis was too high. Question 5 (2 points) Saved Listen If the equilibrium constant (K eq ) is greater than 1, which direction will the reaction proceed? Question 5 options: neither direction Not enough information is given to determine the direction of reaction. spontaneously to products spontaneously to reactants

Question 1 (2 points) Saved Listen Which of the following best defines the first law of thermodynamics? Question 1 options: All spontaneous processes in the universe tend toward dispersal of energy. Entropy is a measure of disorder. There is no entropy at zero Kelvin. Total amount of energy in the universe is a constant. Question 2 (2 points) Saved Listen What is the overall balanced reaction for the light reactions of photosynthesis? Question 2 options: 3 CO 2  + 6 NADPH + 9 ATP + 6 H 2 O   Glyceraldehyde-3-phosphate + 6 NADP +  + 9 ADP + 9 P i 2 H 2 O + 8 photons + 2 NADP +  + 3 ADP + 3 P i    O 2  + 2 NADPH + 3 ATP O 2  + 2 NADPH + 3 ATP   2 H 2 O + 2 NADP +  + 3 ADP + 3 P i O 2  + 8 photons + NADP +  + 3 ATP   2 H 2 O + NADP +  + 3 ADP + 3 P i Question 3 (2 points) Saved Listen Binding of glucose to hexokinase causes a conformational change in the enzyme. This is an example of the __________ model of enzyme catalysis. Question 3 options: lock and key induced fit substrate induced glove and hand