Topic 7 Flashcards
metabolism
metabolites and metabolic intermediates go through a series of enzyme catalyzed reaction
2 main goals of metabolism
obtain usable chemical energy and make specific molecules
Anabolic pathways
use energy to make molecules (e- used to make new bonds), usually reductive
Catabolic pathways
release energy when bonds are broken (e- removed and bonds break), usually oxidative
Amphibolic pathways
both catabolic and anabolic depending on conditionns
food to metabolic intermediates is
catabolic
metabolic intermediates to cellular constituents is
anabolic
macromolecules that are not a significant food source
nucleic acids (nucleotides)
macromolecules that are ok food sources
protein
macromolecules that are great food sources
polysaccharides and tricylgycerols
carbohydrates are stored as ____ in ____ cells
glycogen in liver (hepatocytes) and muscle (myocytes) cells
hepatocytes
maintain blood glucose
myocytes
greedy, keeps fat for itself
fatty acids stored as
adipocytes
most significant fuel molecule
adipocytes
free energy change depends on
concentration of substances
Biochemical standard state
pH 7, [S] and [P] at 1M, 25 C temp, pressure 1 atm, [H2O] 55M
A reaction will only proceed if
G is neg
G > 0
NOT PROCEED
G < 0
SPONTANEOUS
G «_space;0
IRREVERSIBLE
G ~ 0
REVERSIBLE, EQUILIBRIUM
if reversible reaction, what can change direction
changes in concentration
even for a pathway to proceed
G < 0
what kind of steps are regulated
irreversible
rate limiting step
irreversible, determines overal rate
product inhibition
enzyme inhibited by product of reaction
feedback inhibiton
enzyme inhibited by metabolite further down pathway
Feedback inhibition is usually
negative heteroallostery
feed forward activation
enzyme activated by metabolite upstream
reciprocal regulation
opposing pathways catalyze reverse (bad for net consumption of ATP), regulation occurs so both do not happen at the same time
high energy intermediates
compounds that contain usable chemical energy
3 major types of high energy molecules
electron carriers (NADH, FADH), nucleotide triphosphate, (ATP,GTP), thioesters
Catabolism
metabolites oxidized, cofactors reduced, NAD+ or FAD
Anabolism
metabolites reduced, cofactors oxidized, NAPDH
how can nucleotides be electron carriers
nitrogen base enables a reversibel reduction reaction
NAD+ and NADP are
co substrates
FAD is
prosthetic group
what must happen to FAD
Ubiquinone is reduced to ubiquinol which reoxidizes FADH back to FAD to be used
ATP is high energy cuz
phosphoanhydride bonds
approximately how much energy does hydrolysis of ATP molecule release
-32 kJ/mol
ADP vs ATP
decreased electrostatic repulsion, energetically favourable, resonance stabilization, solvation effects
which one is more electrostatic-ally favourable? ADP or phosphate alone
phosphate alone
thioesters
high energy, similar to esters but no e- delocalization
ATP
energy currency (phosphoanhydride bonds, catabolism (substrate level phosphorylation
ATP uses
coupling unfavourable reactions, muscle or flagella movement, primary active transport
how much energy does hydrolysis of phosphocreatine make
-43 kJ/mol
