bioenergetics sucka Flashcards
bioenergetics
describes the transfer and utilization of energy in biological systems (mitochondria)
Energy
- the ability to do work
- energy is neither created nor lost, just converted into different forms
free energy change
- delta G
- provide a measure of the energetic feasibility of a chemical reaction
- allows us to predict whether a reaction will take place or not
metabolism
- all of the chemical reactions that take place inside the organism
- when pathways intersect to form integrated network of chemical reactions
gibbsFree energy change
- measure of the energy transfers between chemical reactions.
- enthalpy and entropy
- deltaG=deltaH-TdeltaS
- depends on concentration of reactants and product
Enthalpy
- delta H
- a measure of the change in heat content of the reactants and prodcts
Entropy
- deltaS
- a measure of the change in randomness or disorder of the reactants and products
Exergoinc
- deltaG is negative
- can happen spontaneously
- energy is released
Endergonic
- deltaG is positive
- cannot happen spontaneously
- energy must be added
when deltaG=0
- the reactant and product reach equilibrium
- reaction will continue, but deltaG wont change
Standard free energy
the free energy change under standard conditions
- when A and B are equal, standard free energy=gibbs free
- not possible in body system
Metabolic pathway
- organized reactions in multistep sequences
- the product of one reaction serves as the substrate of the subsequent reaction
free energy change of a metabolic pathway
- when overall deltaG is negative, the pathway can proceed even if some individual steps are positive
- the actual rate of the pathway depends on the activity of the enzymes that catalyze each step.
Favorable reactions
-happen spontaneously all the time
Unfavorable reactions
-never can happen in a living organism
Coupling of favorable/unfavorable reactions
- coupled reactions with overall negative deltaG allow the unfavorable reaction to proceed.
- the favorable and unfavorable reactions must share a common intermediate to couple
- ATP–>ADP+PI is favorable
- Glucose+PI—>glucose-6-P is unfavorable
- they work together lets gooooooooo
What makes up adenosine/Guanosine?
Adenosine- ribose+adenine
guanine-ribose+guanidine
What makes up AMP
adenosine+alpha bond of phosphomonoester
What makes up ADP
Adenosine+alpha bond of phosphomonoester+beta bond of phosphoaldehyde
Catabolism
- releases the energy stored in the complex during their break down to simple end products.
- exergonic reactions
- stored in NADH or used to synthesize ATP
- carbohydrates—>CO2
Anabolism
- consumes energy to synthesize complex molecules from simple precursors
- endergonic reactions
- fatty acids–>lipids
- divergent process in which few common precursors form a wide variety of complex products.
Metabolic maps
- provides a big picture so you can see how individual pathways work in conjunction with each other
- shuttling of metabolic intermediates
- visualize what happens when one enzyme is blocked by disease or drug(detours)
purposes of catabolic pathways
- capture energy in the form of ATP or reduced compounds(NADH,NADPH) from the degradation of energy rich-fuel molecules
- Allows dietary molecules stored in cells to be converted into building blocks to be used for the synthesis of complex molecules(intermediates of catabolic make energy for anabolic)
Steps of a catabolic pathway
- Hydrolysis of complex molecules(to component building blocks)
- Conversion of building blocks to simple intermediates(acetylCoA) with some capture of energy
- Oxidation of acetly CoA(TCA cycle is common final step to produce NADH and FADH2)
regulation of metabolism
- -all pathways must be coordinated so end products meet the needs to the cell
- cells do not function in isolation, but interact as tissues and organs
- system with regulators signals that inform the cells for the metabolic state of the body
- want to maintain a steady state.
