BIOC192 Lecture 27 - Overview of Metabolism: Bioenergetics Flashcards
what is the first law of thermodynamics?
energy can not be created or destroyed
what is the major energy intermediate of the cell?
ATP
what does Gibbs energy tell us?
tells us about the energy stored in the chemical bonds of the products and substrates
is ATP hydrolysis energetically favourable?
yes, ATP hydrolysis is energetically favourable –> spontaneous
- delta G = -30kJ/mol
- releases energy
is ATP synthesis energetically favourable?
no, ATP synthesis is energetically unfavourable –> non-spontaneous
- delta G = 30kJ/mol
- requires energy
how do enzymes perform unfavourable reactions?
enzymes couple reactions with a spontaneous reaction with a non-spontaneous reaction to make the overall reaction spontaneous (-)
what are the 2 types of key reactions for energy conversions?
1) phosphorylation of ADP to ATP
2) redox reactions
what is function of stepwise oxidation of sugar?
energy is captured for ATP production
what are the coenzymes that need to be reduced in the pathway for processing food molecules for ATP synthesis?
coenzymes of NAD and FAD that interact with various enzymes to accept and donate reducing equivalents
what do biological redo reactions involve the transfer of?
involves the transfer of a hydrogen atom and an electron
H= H+ + e-
what Is hydrogen in terms of redox?
a reducing equivalent
what are dehydrogenases?
enzymes that catalyse biological redo reactions
what are 3 features of coenzymes?
1) low concentration in the cell
2) act as carriers
3) exist in 2 forms
what is NAD derived from?
niacin (vitamin B3)
what does NAD undergo in terms of reduction?
NAD undergoes a 2 electron reduction (accepts 2 reducing equivalents)
