Module 1- basics of metabolism Flashcards
metabolism definition
enzyme catalyzed chemical reactions that occur in a cell to obtain energy or synthesize biomolecules
catabolism
breakdown biomolecules to produce ATP
Anabolism
synthesis of biomolecules that require an input of energy
metabolism is the sum of..
anabolism & catabolism
intermediate definition
produced then consumed
phosphoryl-transfer potential definition
tendency of phosphorylated molecule to under go hydrolysis
what are the 4 functions of metabolism
1) obtain ATP
2) convert ingested molecules into larger molecules
3) convert small building blocks into larger molecules
4) synthesize & degrade biomolecules
what are amphibolic pathways
pathways that can function anabolically & catabolically
example of amphibolic pathway
citric acid cycle
3 types of metabolic pathways
linear, branched & circular
the 1st committed step (1st reaction) in a pathway is usually a…
point of regulation
phototrophs
use photosynthesis to convert sunlight into chemical form
chemotrophs
obtain energy in form of ATP via oxidation of carbon fuels
3 reasons why living organisms require a continual input of free energy
1) mechanical work
2) active transport
3) synthesis of biomolecules
T or F: enzymes speed up rate of reaction but do not change equilibrium constant & cannot make unfavourable reaction proceed
T
Spontaneous vs non-spontaneous reaction (G, exergonic/endergonic, energy input)
spontaneous -G is negative, exergonic, doesn’t require energy input
non-spontaneous- G is positive, endergonic, requires energy input
exergonic vs endergonic
exergonic- release energy
endergonic- consume energy
what 2 things does ΔG determine?
1) if a reaction will occur spontaneously or not
2) rate at which reaction proceeds
what is ΔG°’
standard free energy at pH 7
what is ΔG°’ equation?
ΔG°’ = -2.3RT log Keq
how are thermodynamically unfavourable processes possible?
coupling
if Keq <1 then G will be…
positive value
what type of high energy bonds do ATP have?
acid anhydride
T or F: equilibriate extracellular & biomolecules of the cell is not a function of metabolism
T
redox vs oxidation reactions
oxidation- loss of electrons (becomes more positive)
redox- gain of electrons (becomes more negative) - H is produced
3 active carrier types
1) electrons for fuel oxidation
2) electrons for biosynthesis
3) two-carbon fragments
T or F: ATP is an intermediate among biologically phosphorylated molecules
T
what drives ATP synthesis?
transmembrane proton-motive force
what occurs during hydrolysis reaction
cleaving of ATP which releases energy
3 ways metabolism is regulated
1) amount of enzyme
2) enzyme activity
3) availability of substrates
T or F: the oxidation of fuel molecules forms ATP from ADP + Pi
T
ATP hydrolysis reaction
ATP -> ADP + Pi
what is always the end point of oxidation
ATP
4 factors that affect product/reactant stability
1) electrostatic repulsion
2) resonance stabilization
3) increase in entropy
4) stabilization from hydration
is ATP hydrolysis exergonic or endogonic?
exergonic
functional roles of ATP, NAD & FAD in metabolic processes
ATP- energy currency
FAD- carrier that allows FADH2 to be produced for ATP synthesis
NAD- carrier that allows NADH to be produced for oxidative phosphorylation
how much ATP is consumed per day?
80kg
how much ATP is consumed per minute during exercise
500g
what are the 2 activated carriers for fuel oxidation?
NAD & FAD
NADH is used for generation of ( ) while NADPH is used for ( )
ATP, biosynthesis
NAD+ to NADH + H is a ( ) reaction
redox
