bch 3025 module 1 Questions With Correct Answers

A dynamic steady state results when A. a molecule stops being degraded. B. an organism is at equilibrium with its surroundings. C. there is no net energy transfer. D. the rate of intake or synthesis of a molecule equals the rate of its disappearance - Choice D is correct. A dynamic steady state results when the rate of synthesis or intake of a molecule equals the rate of its breakdown, consumption, or conversion into some other product. For example, a dynamic steady state in the blood maintains constant levels of hemoglobin and glucose. all cells have these things in common (3 things) - 1. are bounded by a plasma membrane a cytosol containing metabolites, coenzymes, inorganic ions, and enzymes; have a set of genes contained within a nucleoid (bacteria and archaea) or nucleus (eukaryotes). An open system is one A. that exchanges neither matter nor energy with its surroundings. B. that exchanges energy but not matter with its surroundings. C. that exchanges both matter and energy with its surroundings. D. that exchanges matter but not energy with its surroundings. - Choice C is correct.If a system exchanges energy and matter with its surroundings, it is called an open system. A living organism, for example, is an open system because it exchanges matter and energy with its surroundings. Both prokaryotic and eukaryotic cells possess which of the following? - Choice D is correct. Prokaryotic and eukaryotic cells both have a plasma membrane that encloses the cytoplasm Exergonic and endergonic reactions differ in that A. exergonic reactions have a positive free energy change (ΔG is positive) and endergonic reactions have a negative free energy change (ΔG is negative). B. exergonic reactions require an input of energy and endergonic reactions release free energy. C. exergonic reactions produce products with less free energy than the reactants; endergonic reactions produce products with more free energy than the reactants. D. exergonic reactions consume more free energy than is released and endergonic reactions release more free energy than is consumed. - Choice C is correct. Exergonic reactions produce products with less free energy than the reactants; endergonic reactions produce products with more free energy than the reactants. Because the products of an exergonic reaction have less free energy than the reactants, the reaction releases free energy that is available to do work How can thermodynamically unfavorable reactions, such as the synthesis of DNA and protein polymers, occur in cells? A. Cells couple thermodynamically unfavorable reactions to reactions that result in a positive change in enthalpy. B. Cells couple thermodynamically unfavorable reactions to the hydrolysis of ATP. C. Cells couple thermodynamically unfavorable reactions to reactions that have a positive free energy. D. Cells couple thermodynamically unfavorable reactions to reactions that result in a decrease in entropy. - Choice B is correct