Question

• Describe the mechanisms that cells can use to make a nonspontaneous reaction spontaneous
• Describe metabolite activation and its role in metabolism

brief explanation on each, please. No pictures or anything needed, basic concept works! thanks so much!!

Answer 1

spontaneity of a chem energy to occur. The the - * Many chemical reactions are not spontaneous require reaction is determined by its Gibbs free energy val If It is Negative, the reaction will proceed spontaneously If It is positive, the reaction will not be spon Note that this is not equivalent to Kinetics, or speed the reaction Gibbs face thergy only delermines on Spontaneity of a given reaction. How quickly to proceeds is delesmined by other factors, such as presence of enzymes, the amount of heal that the systems has available, and the physical properties of the reacting- molanty I Spontaneous reactions ocuy without need of exta energy but they happen slowly. In ordes to catalyze non-Spon- taneous reactions, such as Synthesis of maere molecules enzymes and coupling are used by the cell. Almost- call reactions that take place in cel are catalyzed by - enzymes that decuases the activation energy of the reaction. This means that the enzyme opens up a moze favouable path way for the reaction, allowing it to Initiate more easily than before, and with less enora In addition an unfavourable reaction can coupled together

with a favourable one to make the overall reaction favourable. For example: Greeose+ Pi Gluose-6-phosphate has a positive AG and is therefore enfavourable but it can be coupted- with ATP ADP+ Pi (which has negative ser] to make the reaction favourable. The overall reaction they becomes ATP + Gluose - ADP + Gluuose 6 phosphate and has negative AG. Therlone ATP is considered the energy - currency of the cell. Howeves it shouled be noted that other energy carrying molecules such as GTC doesist and are used for certain processes. "Anabolic and catabolic prows are example of how the cell. couples reactions to create efficient energy exelange cycles. Basically catabolic reactions are those that convert chemical fuels to nolemtes that the call can e for energy, Such- as ATP and othes high energy compounds. Anabolic reactions I are those that require some amount of energy to occus Thes, the call can conveniently couple anabolic reactions with cotabdic ones the products of catabolic reaction can be used to drive anabolic reactions to completion. This allows the call to link different types of reactions together efficiently. It's almost a type of " cellular sergeting as the products of one reaction (Catabolic) can be re- used to help another reaction reach completion [ Anabolic