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CHAPTER 8 - Coggle Diagram

- - - - The initial energy needed to break the bonds of the reactants is called the activation energy
        
        Heat in the form of thermal energy absorbed from the surroundings often supplies activation energy
      - The active site is the region on the enzyme, often a pocket or groove, that binds to the substrate
        
        Cofactors are nonprotein helpers that bind to the enzyme permanently, or reversibly with the substrate
- - - - PREVENTS A CELL FROM WASTING CHEM RESOURCES BY SYNTHESIZING MORE PRODUCT THAN IS NEEDED
  - - - Switching genes on and off
      - Regulating the activity of enzymes after they are produced.
- - - - The Structure and Hydrolysis of ATP
        
        ATP Structure: ATP consists of a ribose sugar, adenine (a nitrogenous base), and a chain of three phosphate groups.
        
        Role in RNA: ATP is one of the nucleoside triphosphates used to make RNA.
        
        Hydrolysis Reaction: ATP reacts with water to form ADP, inorganic phosphate and releases energy
        
        Phosphate Bonds: The term "high-energy phosphate bonds" is misleading; the energy release comes from the transition to a state of lower free energy.
        
        Instability of ATP: The mutual repulsion of the negatively charged phosphate groups contributes to the instability and high energy release of ATP.
        
        Energy Release: The hydrolysis of ATP releases 7.3 kcal/ mole under standard conditions, but about 13 kcal/ mole under cellular conditions
      - CELLULAR WORK (MECH, TRANS, CHEM) IS POWERED BY ATP HYDROLYSIS
        
        In the cell, energy from the exergonic hydrolysis of ATP is used to drive endergonic reactions
        
        Overall, the coupled reactions are exergonic
        
        Phosphorylation, transfer of a phosphate group from ATP to another molecule, is typically used to power endergonic reactions
        
        The recipient molecule, a phosphorylated intermediate, is more reactive (less stable, with more free energy) that the original molecule
- - - - Catabolic and anabolic pathways are the “downhill” and “uphill” avenues of the metabolic landscape.
        
        Energy released from downhill reactions of catabolic pathways can be stored and then used to drive uphill reactions of anabolic pathways.
    - - Some metabolic pathways release energy by breaking down complex molecules to simpler compounds
        
        These degradative processes are called catabolic pathways, or breakdown pathways.
        
        One major catabolic pathway is cellular respiration, which breaks down glucose and other organic fuels in the presence of oxygen to carbon dioxide and water.
      - ANABOLIC PATHWAYS: consume energy to build complicated molecules from simpler ones; they are sometimes called biosynthetic pathways
        
        Examples of anabolism are synthesis of an amino acid from simpler molecules and synthesis of a protein from amino acids.
  - - - SECOND LAW OF THERMODYNAMICS: EVERY ENERGY TRANSFER OR TRANSFORMATION INCREASES THE ENTROPY (DISORDER) OF THE UNIVERSE
        
        BIOENERGETICS: THE STUDY OF HOW ENERGY FLOWS THROUGH LIVING ORGANISMS
        
        KINETIC ENERGY IS ASSOCIATED W/ MOTION: FOR EXAMPLE, WATER GUSHING THROUGH A DAM TURNS TURBINES
        
        THERMAL ENERGY IS THE KINETIC ENERGY ASSOCIATED W/ RANDOM MOVEMENT OF ATOMS OR MOLECULES; THERMAL ENERGY IN TRANSFER FROM ONE OBJECT TO ANOTHER IS CALLED HEAT
        
        Potential energy is energy that matter possesses because of its location or structure; For example, water behind a dam possesses energy because of its altitude above sea level
        
        CHEMICAL ENERGY IS THE POT ENERGY AVAILABLE FOR RELEASE IN A CHEM REACTION-- COMPLEX MOLECULES LIKE GLUCOSE ARE HIGH IN CHEM ENERGY
        
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      - Entropy is a measure of molecular disorder, or randomness
        
        Every energy transfer or transformation increases the entropy of the universe
- - - - ENDERGONIC REACTION: ENERGY INWARD/ ABSORBS FREE ENERGY FROM THE SURROUNDINGS
        
        IN ENERDERGONIC REACTIONS, the products store more free energy than the reactants, because G is POSITIVE, endergonic reactions are nonspontaneous
        
        ENDERGONIC REQUIRES ENERGY; NONSPONTANEOUS/ EXERGONIC RELEASES ENERGY; SPONTANEOUS
      - EXERGONIC REACTIONS : products store less free energy than reactants: because G is negative , these reactions occur spontaneously, energetically favorable
  - - - A process is spontaneous and can perform work only when it is moving toward equilibrium
        
        THE CHEMICAL REACTIONS OF METABOLISM ARE REVERSIBLE, BUT NEVER REACH EQUILIBRIUM IN A LIVING CELL
        
        THIS IS ONE OF THE DEFINING FEAUTURES OF LIFE-- CELLS ALLOW MATERIALS T FLOW IN AND OUT WHICH PREVENTS METABOLIC EQUILIBRIUM, ENABLING CELLS TO CONTINUE DOING WORK