ATP redox and electron carriers

metabolism

sum of all catabolic/anabolic reactions

catabolism

break compounds into smaller molecules to release energy

(energy stored within bonds is releasedwhen broken)

anabolism

creates larger compounds by using energy

metabolic pathways

• reactions follow a step-by-step sequences called metabolic pathways

• in each step of the pathway, enzymes are used to convert substrates to products

organisms do their work at the [__] level through a series of chemical reaction

organisms do their work at the molecular level through a series of chemical reaction

bond energy

• energy needed to break/form a bond in kJ

• molecular bonds are store energy that can be used by cells to do work if it’s released

• whenever a chemical bond form between 2 atoms, energy is RELEASED. to break that bond, energy is ABSORBED

amt of energy released when bonds form is the [__] amt required to break a bond

amt of energy released when bonds form is the same amt required to break a bond

the more energy stored in a bond, the more [__] it is and [__]

the more energy stored in a bond, the more stable it is and harder to break apart

thermodynamics

• describes how thermal energy changes in a system & surroundings

• energy released during chemical reactions is usually measured as thermal energy

1st law of thermodynamics

• total amt of energy in the universe is constant

• energy can’t be destroyed but only converted between forms

• eg. when running, chemical E → kinetic E

if heat/thermal energy isn’t doing work, then what does it do?

• heat increases randomness in the universe

• molecules are always moving randomly. Thermal energy causes molecules to move faster → more randomness

2nd law of thermodynamics

• during any change that occurs, the universe will move towards disorder/entropy

• heat from chem reaction increases entropy & reduces amt of energy that can be used to do work

how is life able to maintain order?

input energy to reduce randomness by using energy in our surroundings to keep us alive (eg photosynthesis, cleaning ur room)

gibbs free energy (G)

• a measure of how much energy is available to do useful work in a system

• helps determine whether or not reactions will occur spontaneously

gibbs free energy equation

ΔG = ΔH − (T)*(ΔS) ‍

enthalpy (H)

• energy stored in bonds in the form of heat

• ΔH = change in enthalpy of a reaction (products-reactants)

exothermic reaction

more E in reactants than products, thus E is released, ΔH = (-)

draw a graph of exothermic reaction

• x axis → reaction progress

• y axis → potential energy

• energy released

• etc

• exothermic

draw a graph of endothermic reaction

• x axis → reaction progress

• y axis → potential energy

• energy absorbed

• endothermic

endothermic reaction

less energy in reactants than in products, thus energy absorbed

ΔH = (+)

entropy (S)

randomness/disorder in a system

• ΔS = (+) → system becomes more disordered during the reaction

• ΔS = (-) → system becomes less disordered during the reaction

if reaction is [__], entropy [__]

if reaction is spontaneous, entropy increases

temperature (T)

• amount of kinetic E of molecules

• higher temps = faster molecule movement, thus entropy increases

exergonic reaction

• release free energy (ΔG = (-)) and increase entropy

• reactants have high potential E & are less stable

• products have less potential E and more stable

• reactions happen spontaneously with a small input of E to get things started

endergonic reaction

• uses free energy (ΔG = (+)), decrease entropy

• reactants have low Potential Energy & more stable

• products have more PE & less stable

• reactions need an input of free energy to occur aka not spontaneous

energy coupling in exer/endergonic reactions

endergonic reactions occur due to the free energy released during exergonic reactions (free energy in cells = ATP)