mitochondria

Question 1

what is the purpose of mitochondria?

Answer 1

they are the “power house of the cell”

they are energy converting organelles

Question 2

what does non-mendelian mean?

Answer 2

single genes are inherited and theres no genetic cross over between the maternal and paternal genetics

Question 3

how are genetics for mitochondria inherited?

Answer 3

from the egg/ maternal side and it is inherited with the cytoplasm

Question 4

how much does mitochondrial DNA code for proteins in mitochondria?

Answer 4

~2.5% of mitochondrial protein is circular

Question 5

name the process that proteins found in the cristae of mitochondria are involved in?

Answer 5

oxidative phosphorylation

Question 6

what process do proteins found in the mitochondrial matrix catalyse?

Answer 6

TriCarboxylic Acid Cycle (TCA)

Question 7

where does ATP synthesis occur?

Answer 7

it occurs via the mitochondrial ATP synthase on the inner mitochondrial membrane

Question 8

explain the stages of glucose metabolism?

Answer 8

• 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

Question 9

What is glycolysis?

what are the end products in glycolysis?

Answer 9

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

Question 10

what steps does pyruvate go through in the presence of oxygen?

Answer 10

• 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

Question 11

what in created in the TCA (tricarboxylic acid) cycle AKA citric acid cycle?

Answer 11

NADH and FADH2

Question 12

what are the products of tricarboxylic cycle used for?

Answer 12

NADH and FADH2 are used to power pumps (electron transport chain) that make a proton gradient like ATP synthase

Question 13

what is chemiosmosis?

Answer 13

its the build up of H+ ions which flow back into mitochondria through ATP synthase to drive ATP production

Question 14

what does the electron transport chain consist of?

Answer 14

• 4 large protein complexes (complex I,II,III,IV)
• 1 smaller protein (cytochrome c)
• lipid-soluble organic molecule (Coenzyme Q; ubiquinone)

Question 15

what electrochemical gradient does ATP synthase utilize in the synthesis of ATP?

Answer 15

the H+ electrochemical gradient

Question 16

what is the proton motive force?

Answer 16

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

Question 17

what is the final electron acceptor in the electron transport chain?

Answer 17

oxygen

Question 18

what happens if the last electron acceptor is unavailable?

Answer 18

• 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

Question 19

name a mitochondrial poison and how they affect bodily processes?

Answer 19

Cyanide- prevents the transport of electrons from cytochrome C to oxygen so cells are no longer able to produce ATP aerobically

Question 20

what are NADH and FADH2 provided by?

Answer 20

the TCA cycle