Chemiosmosis Flashcards
What is involved in the synthesis of ATP?
A flow of protons through the enzyme ATP synthase, chemiosmosis and the electrochemical gradient..
What is chemiosmosis
Synthesis of ATP takes place by the means of a slow of protons across these membranes down a concentration gradient through ATP synthase located in the stalked particles.
Where is ATP produced?
On the internal membranes of mitochondria and chloroplast.
Explain the synthesis of ATP in mitochondria?
The protons flow across the inner membrane against a concentration gradient via proton pumps found in the inner membrane which use energy from high energy electrons. Protons accumulate in the inter-membrane space and they diffuse down the concentration gradient into the matrix through stalked particles (ATP synthase). Energy released is used to combine ADP + Pi —> ATP
Explain the synthesis of ATP in chloroplast?
Proton pumps in the thylakoids membrane use energy from high energy electrons to pump protons across the membrane against a concentration gradient. Protons accumulate in the thylakoid membrane and diffuse down a concentration gradient back into the stroma through stalked particles (ATP synthase). Energy released is used to combine ADP + Pi —> ATP
Where does ATP synthesis occur in respiration?
The inner membranes of the mitochondria.
Where does ATP synthesis occur in photosynthesis?
The thylakoids membranes of the chloroplast
Why are the inner membrane and thylakoids membranes classed as sealed membranes?
As they only allow protons through
What are the differences between the mitochondria and chloroplast in chemiosmosis?
High energy electrons are derived from the reduced enzymes FAD and NAD in respiration.
High energy electrons are produced when photons of light energy excite chlorophyll molecules in photosynthesis.
What are the similarities between the mitochondria and chloroplast in chemiosmosis?
Both produce a proton gradient across the membrane for ATP synthesis.
Protons diffuse down the proton gradient through ATP synthase.
ATP is produced.
Energy is associated with excited electrons.
How is the electron transport chain formed and how is a proton concentration maintained?
It is formed from an alternate arrangement of pumps and electron carriers. To maintain the proton concentration in the inter-membrane/thylakoid space protons are needed which are fuelled by energy from electrons.
What does disrupted proton gradient cause?
Death
What is apoptosis?
It is programmed cell death which prevents proton gradient across cell membranes from forming
What is DNP?
It is a mitochondrial poison which allows electron transport but not ATP synthesis.
The energy for proton pumps and the ETC is derived from what type reactions?
Oxidation reactions
