Energy Flow and Enzymes

Exam 1

First law of thermodynamics

energy can’t be created or destroyed it can only be changed from one form to another

Radient energy

light energy, energy or electomagnetic radiation

Mechanical energy

energy that moves mass

Chemical energy

energy released from chemical bonds, ex: enthalpy

Electrochemical energy

energy released from movement of separated electric charges and/or movement of substances down their concentration gradient

Heat energy

energy of molecules from their random thermal motion

Open system

energy grom environment enters organisms and exits as waste products and heat, entropy in organisms is kept low

Closed system

no input of energy, organisms can’t do work, leading to increasing entropy and eventually equilibrium (death)

OIL RIG

Oxidation Is Loss, Reduction Is Gain

Enthalpy (H)

energy of chemical bonds, includes non-covalent

Energy of molecular disorder

Entropy (S) X Temperature (T)

Spontaneous process

when total potential energy of the initial state is higher than the final state

Gibbs free energy (delta G)

energy available that can do work, change in enthalpy minus temperature times change in entropy, if negative: spontaneous process (exergonic and no energy input required), if positive: non-spontaneous process (endergonic and energy input is required)

Catalyst

a susbstance that speeds up a chemical reaction without being used up or changed by it, lower the energy of activation

Enzymes

proteins that act as biological catalysts, lower the energy of activation, can be denatured in high temps (like when reaction has been sped up)

Active site

specific location where enzymes specificity for substrates is determined by the 3D-structure and chemical properties of the amino acid side chains located there

Metabolic pathways

the product of one enzymatic reaction becomes the reactant of the second reaction and so one, enzymes often function in this way

Exergonic

energy released, no energy input required

Endergonic

energy absorbed, energy input required