Biochemistry Chapter 8 Flashcards

Exergonic reactions release free energy during the reaction, meaning the products have less free energy than the reactants. Think of a ball rolling downhill: it releases energy as it moves.

Enthalpy is the total heat content of a system. Think of it as the energy stored in the chemical bonds within a system.

ATP is the energy currency of the cell, coupling energy-releasing (exergonic) reactions to energy-requiring (endergonic) reactions. Think of ATP as a battery charging other processes in the cell.

ATP is structurally very similar to an RNA nucleotide, both sharing a phosphate group, ribose sugar, and a nitrogenous base. Most importantly, both have a ribose sugar component, which distinguishes them from DNA.

Catabolic pathways break down complex molecules into simpler ones, releasing energy in the process, primarily in the form of ATP. Imagine breaking down a large meal into smaller, usable nutrients.

ATP and the precursor of the A nucleotide in RNA have the same structure. They both consist of adenine, ribose sugar, and three phosphate groups.

Enzymes speed up reactions by lowering the activation energy, which is the initial energy needed to start a reaction. Think of an enzyme as a key that unlocks the reaction potential.

Activation energy is the minimum amount of energy required for reactants to overcome a thermodynamic barrier and proceed with a reaction. It's like a hill that reactants need to climb to reach the product side.

Starch at room temperature does not readily decompose into simple sugars because the activation energy barrier is too high, preventing the reaction from progressing at a significant rate. Think of the reaction as stuck on a plateau.

Enzymes are biological catalysts that accelerate the rate of a reaction by lowering the activation energy barrier, allowing reactions to proceed faster. Imagine an enzyme as a bridge lowering the hill reactants need to climb.