Bioenergetics Flashcards
What is the difference between NADPH and NADH?
The ratio of NAD+ to NADH inside the cell is high, while the ratio of NADP+ to NADPH is kept low. The role of NADPH is mostly anabolic reactions, where NADPH is needed as a reducing agent, the role of NADH is mostly in catabolic reactions, where NAD+ is needed as a oxidizing agent
why is gibbs free energy important?
it tells you if a reaction is going to be favorable or not
How do cells maintain their free energy?
by nutrients and sunlight
If we have a reaction that needs input of energy into the system for it to proceed, what type of reaction do we have?
a reaction that favors its substrate
what type of conditions doe delta G exist under?
cellular conditions
can delta G naut be positive in a spontaneous reaction?
yes, delta G naut does sign does not tell you if the reaction will be spontaneous or nonspontaneous delta G does
In biochemical pathways, a reaction was processed and the delta G was calculated and was a small number, what type of reaction occurred in the reaction?
readily reversible reaction also know as near equilibrium
A chemist noticed that the delta G was near equilibrium, which type of reaction is this?
reversible
a chemist noticed that the delta G was far from equilibrium with a negative sign, what type of reaction is this?
irreversible
which equilibrium is usually the regulatory step?
far from equilibrium
which equilibrium controls the flux of the reaction?
far from equilibrium
if delta G is large an positive what needs to happen for this reaction to proceed?
it is nonspontaneous, and it must be pushed by coupling with hydrolysis of ATP
What does ATP normally exist as?
magnesium 2
what cells require continous free energy?
osmotic, electrical, mechanical, and biosynthetic
Why does ATP have electrostatic repulsion?
there are 4 negative charges in close proximity
after a meal, glycolysis is initiated, and to allow the glucose to enter the cell glucokinase is required. in using ATP to add a phosphate group, how was ATP harnessed ?
by a phosphoryl group transfer
what is the purpose of ATP in biosynthetic reactions?
it typically pushes the reaction
what type of bond does acetyl CoA have?
thioester bond, which allows storage of energy
what is acetyl CoA synthetase ?
a transient high-energy AMP-bound intermediate is formed (on an enzyme)
when acetylCoA is formed what type of acetyl CoA is formed what type of transfer is this classified as?
nucleotidyl group transfer
what is phosphagens?
a high E phosphoamide compound
after eating a big meal, and sitting down to watch TV, what does happens to the elevated amount of glucose /ATP in the body??
it is stored as creatin kinase
after eating a big meal and you decide to exercise, what will happen and your ATP levels are decreased and you needed more ATP how will it be made?
By creatin kinase
What are the 3 energy rich thioester bonds?
Acetyl-CoA, Succinyl-CoA, Acyl CoA
when CoA-SH is complexed with something what is the complex called?
Acetyl-CoA
why must the net sum of delta G of a reaction need to be negative?
because cells like favorable reactions
when you couple glucose(14) and ATP (-30.5) and the delta G naut is equated to -16.5, what does this number mean?
since it is negative- it means that energy is being released
when coupling glucose with ATP, the glucose reaction is switched and the reaction reads glucose+pi—> glucose-6-p +H2O and delta G naut is 14kJ/mol, what will happen to the delta G naut?
it will become negative because now energy is being released instead of absorbed
can 2 reactions coupled through a common intermediate?
yes
what enzyme helps cellular energy homeostasis?
adenylate knase
the phosphotransferase kinase, adenylate kinase helps maintain cellular energy homeostasis by?
by recycling AMP back into the ATP/ADP cycle
GDP + ATP —> GTP +ADP , for nucleoside triphosphates,What enzyme is used in this process tohelp cells get rephosphorylate by ATP?
nucleoside diphosphosphokinase
what is nucleoside diphosphosphokinase?
exchanges of phosphate groups between different nucleoside diphosphates
