3.1 Importance of ATP Flashcards
(17 cards)
Why is ATP so useful?
ItItss inert, soluble, easily transferable and releases energy efficiently.
What is the enzyme called that breaks the terminal bonds in ATP?
ATPase
Where does ATPase split the bond?
Splits between the last and middle phosphate group
How is ATP reformed?
By phosphorylation, the addition of a phosphate group to ADP by condensation reaction.
What are the components of ATP?
- 3 Phosphate groups
- Pentose sugar called Ribose
- Nitrogenous base called adenosine
Where does most ATP synthesis take place?
Internal membranes of mitochondria or chloroplasts.
What is chemiosmosis?
Chemiosmosis is the flow of protons down an electrochemical gradient, through ATP synthesise, this provides the necessary energy needed for the phosphorylation of ADP into ATP.
Direction of flow of protons in mitochondria
From the inner membrane space to the matrix
Direction of flow of protons in chloroplasts
From the thylakoid membrane into the stroma.
Components of the electron transport chain
Proton pumps and electron carriers.
Steps of the electron transport chain
- High energy electrons are received by the first electron acceptor from the oxidation of NADH.
- The electrons are then moved to the next proton pump by an electron carrier. This process drives electrochemical energy so that hydrogen ions can pass from the matrix against the gradient, through the proton pump into the inter membrane space.
- The electron carriers proceed to move the electrons from proton pump to pump, FAD also delivers hydrogen ions further along the chain creating a high concentration gradient of hydrogen ions in the inter membrane space.
- When received by the last proton pump the electrons are then accepted by oxygen which combines with hydrogen from the matrix to create water.
- Naturally the hydrogen ions want to diffuse from the high concentration in the inner membrane space to the low concentration in the matrix, they do this by facilitated diffusion through an ATP synthesise which generates energy for the phosphorylation of ADP into ATP.
What would happen if oxygen was not present in the ETC?
Oxygen would not be made available to receive the electrons and clear the proton pump meaning no further movement of the ETC. No more ATP produced.
What is an oxidation reaction?
When electrons are lost
What is a reduction reaction?
When electrons are gained.
Describe the role of ATP
ATP is synthesises when energy is made available and hydrolysed to release energy when needed.
Why has ATP been described as the universal energy currency?
As it’s used by all cells.
Describe the role of NAD in maintaining the proton gradient in mitochondria.
NAD provides the electrons needed for the ETC which drives the electrochemical energy needed to pump protons to maintain a gradient.
