mitochondria Flashcards
what is the purpose of mitochondria?
they are the “power house of the cell”
they are energy converting organelles
what does non-mendelian mean?
single genes are inherited and theres no genetic cross over between the maternal and paternal genetics
how are genetics for mitochondria inherited?
from the egg/ maternal side and it is inherited with the cytoplasm
how much does mitochondrial DNA code for proteins in mitochondria?
~2.5% of mitochondrial protein is circular
name the process that proteins found in the cristae of mitochondria are involved in?
oxidative phosphorylation
what process do proteins found in the mitochondrial matrix catalyse?
TriCarboxylic Acid Cycle (TCA)
where does ATP synthesis occur?
it occurs via the mitochondrial ATP synthase on the inner mitochondrial membrane
explain the stages of glucose metabolism?
- it enters the blood stream and becomes glucose 6-phosphate
- then the glucose is trapped within the cell as phosphorylated molecules cant cross the membrane
- glucose 6-phosphate can then be converted to pyruvate
- glycolysis occurs
What is glycolysis?
what are the end products in glycolysis?
glycolysis is a series of 10 enzyme catalysed reactions that breakdown glucose molecules to eventually result in 2pyruvate molecules, 2 ATP molecules and 2 NADH/H+ molecules
what steps does pyruvate go through in the presence of oxygen?
- pyruvate diffuses across the outer mitochondrial membrane, then its carried by the transporter protein to the inner mitochondrial membrane
- pyruvate dehydrogenase then catalyses the conversion of pyruvate to acetyl-SCoA
what in created in the TCA (tricarboxylic acid) cycle AKA citric acid cycle?
NADH and FADH2
what are the products of tricarboxylic cycle used for?
NADH and FADH2 are used to power pumps (electron transport chain) that make a proton gradient like ATP synthase
what is chemiosmosis?
its the build up of H+ ions which flow back into mitochondria through ATP synthase to drive ATP production
what does the electron transport chain consist of?
- 4 large protein complexes (complex I,II,III,IV)
- 1 smaller protein (cytochrome c)
- lipid-soluble organic molecule (Coenzyme Q; ubiquinone)
what electrochemical gradient does ATP synthase utilize in the synthesis of ATP?
the H+ electrochemical gradient
what is the proton motive force?
it is when outside the mitochondria theres a high conc. of protons (positively charged) inside there is a low conc. (negatively charged)
the difference if the electrochemical gradient and that constitutes the proton motive force
what is the final electron acceptor in the electron transport chain?
oxygen
what happens if the last electron acceptor is unavailable?
- the electectron transport chain backs up, as there is nothing to pull electrons down the chain.
- NADH and FADH2 cant unload H
- ATP production ceases
- cells run out of energy
- eventually you die
name a mitochondrial poison and how they affect bodily processes?
Cyanide- prevents the transport of electrons from cytochrome C to oxygen so cells are no longer able to produce ATP aerobically
what are NADH and FADH2 provided by?
the TCA cycle
