mitochondria - lecture 11 Flashcards
Structure of a mitochondria
- matrix
- cristae
- Inner membrane
- outer membrane
Structure of the chloroplast
- Stroma
- Thylakoid
- Granum
- Inter membrane space
- Inner membrane
- outer membrane
What is the primary function of the mitochondria and chloroplasts?
ATP synthesis
What is an anabolic reaction?
responsible for growth and repair processes
What is a catabolic reaction?
release energy needed to drive anabolic reactions
Why is ATP the most common energy intermediate?
efficient linking or coupling of energy yielding to energy requiring processes
Where is ATP synthase found?
the mitochondrial inner membrane, the chloroplast thylakoid membrane and the inner membrane of eubacteria
How is the large F - type ATPase made up?
F0 which is integral in the membrane and F1 which is peripheral
How is ATP synthesised by the Fo and F1 subunits?
As protons pass through the F0 prortion from one side of the membrane to the other a stalk rotates. This causes conformational changes in F1 that facilitate the production of ATP.
What is the name of the protein that. rotates to drive the synthesis of ATP?
The gamme subunit
What does the proton gradient do between the inter membrane space and the matrix?
Made up of two components. 1: Difference in voltage across the membrane (the membrane potential) + 2: the difference in proton concentration (remember pH is a measure of proton concentration).
How many molecules of ATP can be produced per second?
100
How many protons are needed to synthesise 1 molecule of ATP?
3
How is the proton gradient across the mitochondrial membrane generated ?
High energy electrons are passed along an electron transport chain
These electron transfers release large amounts of energy which is used to pump H+ across the membrane creating an electrochemical proton gradien
Where do the electrons come from in the electron transport chain?
The NADH
Where is the NADH generated?
citric acid cycle
What is NADH short for?
Nicotinamide adenine dinucleotide
What is the name of the first electron carrier?
Ubiquinone
What is the role of Ubiquinone?
carries electrons from the NADH dehydrogenase to the cytochrome b - c1 complex
What is the name of the second electron carrier?
Cytochrome C
What is the role of the cytochrome c electron carrier?
carries electrons from the cytochrome b-c1 complex to the cytochrome oxidase complex
What is oxidative phosphorylation?
The linkage of electron transport, proton pumping and ATP synthesis
How do electrons move along the electron transport chain?
By a series of oxidation, reduction reactions
As one reactant is oxidised (loses electrons) another is reduced (gains electrons)
What is in the matrix?
Enzymes of citric acid cycle,
mitochondrial DNA etc
What is the inner membrane?
Electron transfer
proteins, ATP synthase, transport
proteins.
What is the outer membrane?
Has large pores,
lipid synthesis, and conversion of
lipid substrates into forms that can
be metabolised in the matrix
What is the inter membrane space?
Several
enzymes that use ATP passing out of
the matrixto phosphorylate other
nucleotides
