Please enable JavaScript.
Coggle requires JavaScript to display documents.
Chapter 6: Metabolism - Coggle Diagram
Chapter 6: Metabolism
Energy is the capacity to cause change. It exists in various forms and is fundamental to all metabolic processes.
Potential energy is stored in a gravitational field, electrical field, or compressed spring
Kinetic energy is energy in motion, movement of objects. Thermal energy is associated with the random movement of atoms or molecules
Thermodynamics: 1. Energy cannot be created nor destroyed, only transferred and transformed. 2. Spontaneous changes that do not require outside energy increase entropy (disorder) in the universe
-
A spontaneous reaction occurs in a given set of conditions without intervention or energy input. Increases entropy of the universe
Examples of spontaneous reactions: gravitational motion, diffusion, chemical reaction. The system becomes more stable and releases energy
Free energy is a thermodynamic concept that encompasses kinetic and potential energy used to determine the feasibility of a chemical reaction and indicates if a reaction occurs spontaneously (it does if delta g is negative)
-
Active site mechanisms
Can lower activation energy barrier by orienting substrates correctly, straining substrate bonds, providing a good microenvironment, covalently bonding to the substrate
Enzymes turn off and on based on needs.
Off inhibitors. Reversible or irreversible (must make new enzyme) Reversible enzymes may have competitive inhibition and noncompetitive inhibition and feedback inhibition
-
Metabolic pathways have many steps. Each step is a separate chemical reaction and each is catalyzed by a specific enzyme
-
-
Reactions in metabolism
Exergonic reaction: proceeds with a net release of free energy (negative delta G) and is spontaneous
-
ATP powers cellular work by coupling exergonic and endergonic reactions. A cell does 3 main kinds of work: mechanical, chemical, and transport. Energy released from exergonic reactions is usually coupled by ATP to endergonic reactions
Adenosine triphosphate drives endergonic reactions by phosphorylation (transferring a phosphate to other molecules). Energy is released when the terminal bond is broken
Metabolism of the living cell requires thousands of biochemical reactions and all require energy transformations
Metabolism is the totality of an organism's chemical reaction, it transforms matter and energy