Lecture 18: Principles Of metabolism Flashcards
Anabolism does what?
Use the energy harvested from catabolism to drive the synthesis of many molecules that form the cell.
Use the energy harvested from catabolism to drive the synthesis of many molecules that form the cell, is what?
Anabolism.
What is oxidation?
When the energy from organic molecules is extracted.
When the energy from organic molecules is extracted, is what?
Oxidation.
What is aerobic respiration?
When cells allow carbon and hydrogen atoms to combine to make H20 and CO2 to obtain energy.
When cells allow carbon and hydrogen atoms to combine to make H20 and CO2 to obtain energy.
Aerobic respiration.
What is the most energetically stable form of carbon and hydrogen?
CO2 and H20
Describe the relationship between oxidation and reduction.
They occur simultaneously. If one molecule gains an electron, another one loses an electron.
When a molecule picks up an electron, what does it also do?
It also picks up a proton, since protons are freely available in water.
What are the important carrier molecules?
NADH, NADPH, ATP.
Catabolic pathways do what?
They break down food molecules into smaller molecules.
How is ATP synthesized? Is this favorable or unfavorable?
When a terminal phosphate is added to ADP, this is energetically unfavorable.
They break down food molecules into smaller molecules, is what?
Catabolism.
What are the two opposing streams of reactions that take place in cells?
Catabolic pathways and anabolic pathways.
When the phosphoryl group of ATP is transferred between molecules to release the energy contained in the high energy bonds of ATP, is what?
Phosphoryl-transfer reaction.
If C-H bonds increases, this is reduction or oxidation?
Reduction.
What do activated carrier molecules do?
They store and transfer energy.
For metabolism, what stores and transfers energy?
Activated carrier molecules.
True or false: ATP is the only carrier molecule that contains high energy phosphoryl bonds.
False. Other molecules, like phosphoenolpyrivate and creative phosphate also have high energy phosphoryl bonds.
What is absolutely needed for cell metabolism, and why?
Enzymes are absolutely needed, because they catalyze the rates of reactions within the cell.
Why is ATP an energy rich molecule?
It has two high-energy phosphoanhydride bonds.
How is ATP hydrolyzed? Is this energetically favorable or unfavorable?
ATP is hydrolyzed when the terminal phosphoanhydride bond is hydrolyzed to make ADP and P/inorganic phosphate.
How are unfavorable metabolic reactions driven?
By coupling them with the hydrolysis of ATP.
Is the NAD+ to NADH ratio kept high or low, and why?
The ratio is kept high, so there’s a lot of NAD+ to be an oxidizing agent in catabolic pathways.
What keys points about how energy is stored by activated carrier molecules?
- they are stored in one or more energy-rich covalent bonds
- they are stored in an easily exchangeable form, either as a transferable chemical group or electrons at a high energy level.
If C-H bonds decreases, this is reduction or oxidation?
Oxidation.
NADH, NADPH, ATP, are examples of what?
Carrier molecules.
In addition to the hydrolysis of ATP, what other mechanism drives transfer of energy within cells?
Phosphoryl transfer reactions.
What is a phosphorylating transfer reaction?
When the phosphoryl group of ATP is transferred between molecules to release the energy contained in the high energy bonds of ATP.
How are unfavorable condensation reactions forced to occur?
By phosphoryl transfers.
Is the ratio of NADP+ to NADPH kept high or low, and why?
The ratio is kept low, so that there is a lot NADPH to act as a reducing agent in anabolic pathways.
How does the extra phosphate differentiate NADH from NADPH?
The extra phosphate group is far from the region involved in electron transfer so there’s no effect on the electron-transfer properties, but it does affect how it is recognized differently by enzymes than NADH.
NADH is used for what? NADPH is used for what?
NADH is used as an intermediate in catabolic pathways to generate ATP, NADPH is used to catalyze anabolic reactions.
What is phosphoryl transfer potential?
The energy stored in a phosphoryl bond.
