Bio Final Review PDF
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These notes cover key concepts in biology, including energy, enzymes, and thermodynamics. The material outlines concepts about energy and its forms, along with the role of enzymes and their function in lowering activation energies. It also introduces thermodynamics and types of reactions in the body. The notes summarize, in short, core concepts useful for biological studies and future bio classes.
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# Energy & Enzymes ## Energy - the capacity to do work - **Kinetic Energy**: energy of motion - **Potential Energy**: stored energy - kcal = 1000 calories - 1 calorie = heat required to raise temperature 1 degree Celsius of water - 1 Joule = 0.239 calories ## Activation Energy - energy ne...
# Energy & Enzymes ## Energy - the capacity to do work - **Kinetic Energy**: energy of motion - **Potential Energy**: stored energy - kcal = 1000 calories - 1 calorie = heat required to raise temperature 1 degree Celsius of water - 1 Joule = 0.239 calories ## Activation Energy - energy needed to initiate a chemical reaction - **Catalyst**: enzymes and proteins that lower activation energy ## Enzymes - lower activation energy - bringing two substrates together - stressing bonds in the substrate - **Substrate**: reactants - Substrates bind to the active site of the enzyme (**enzyme-substrate complex**) ## Factors that Influence Enzyme Function - **Temperature**: increase to an optimum temperature (increase in enzyme activity). Temperatures above optimum lead to denaturation. - **pH**: changes H+ concentration, shifting the balance between positively and negatively charged amino acids. ## Inhibitors/Activators - **Competitive**: compete for the active site. - **Non-competitive**: bind to an alternative (allosteric) site and change the shape of the enzyme. - **Allosteric Activator**: bind to the allosteric site and increase activity. - **Cofactors**: metal ions that participate at the active site. (Non-protein organic molecule = coenzyme) - **Feedback Inhibition**: end product binds to the allosteric site on the enzyme of the first reaction, inhibiting it. ## Free Energy - energy available to do work - **Gibbs Free Energy**: G - **ΔG = H - TΔS** - ΔG: free energy - H: enthalpy - T: temperature in Kelvin - ΔS: entropy - **Positive ΔG**: requires energy input, endergonic reaction - **Negative ΔG**: releases energy, exergonic reaction ## REDOX - potential energy in a chemical bond can be used to make new bonds - **Oxidation**: lose electrons - **Reduction**: gain electrons ## Thermodynamics - study of energy changes - **First Law**: energy cannot be created nor destroyed, it can only change form. - **Second Law**: we are constantly moving towards disorder (entropy). (More order = unstable). ## ATP - Tri-phosphate - Highly unstable - Highly negatively charged. Repel each other, creating high potential energy. - Hydrolyses to break the bond - 7.3 kcal/mol is released. - Used by the cells to drive reactions. ## Example: Thermostat - The thermostat is a simple example of feedback inhibition. When the temperature rises, the heat turns off. If the temperature falls, the heat turns on.
