TCA CYCLE AND ELECTRON TRANSPORT CHAIN - ENERGY PRODUCTION

Question 1

Where does TCA cycle occur?

Answer 1

matrix of mitochondria

Question 2

what is the process of TCA cycle?

Answer 2

Uses acetyl CoA (pyruvate from glycolysis is converted into acetyl CoA) - goes into the cycle

• Oxidation of acetyl CoA produces……
• produces NADH and FADH2
• Produces ATP
• Produces CO2 as a waste product

Question 3

what cellular metabolites does TCA cycle use to produce high energy molecules?

Answer 3

pyruvate, fatty acids

Question 4

what pathway best describes how high energy electron carriers that drive ATP synthesis are generated?

Answer 4

TCA cycle

Question 5

what do the electron carriers NADH and FADH2 do after tca cycle?

Answer 5

go into the electron transport chain to give up electrons and create more ATP

Question 6

what is oxidative phosphorylation in TCA?

Answer 6

process by which ATP is produces as electrons as transferred from NADH / FADH2 to oxygen. Occurs in mitochondria.

Question 7

what complex’s are used in electron transport chain?

Answer 7

NADH
Cytochrome b-C1
Cytochrome oxidase
ATP synthase

Question 8

what mobile carriers are used in electron transport chain?

Answer 8

cytochrome C

ubiquinone

Question 9

what are other key components of the electron transprort chain?

Answer 9

NADH (& electrons)
H+ ions
Oxygen
Water
ADP and Pi - inorganic phosphate (resulting in ATP)

Question 10

where does ATP synthesis (electron transport chain) take place?

Answer 10

inner mitochondrial membrane

Question 11

what ions are essential for the electron transport chain?

Answer 11

Fe and Cu

Question 12

what is the direct energy source that drives ATP synthesis in mitochondria?

Answer 12

Transmembrane proton gradient

Question 13

what is the electron transport chain?

Answer 13

the LAST step in respiration and produces the MOST ATP molecules

Question 14

what happens in electron transport chain?

Answer 14

NADH and FADH2 release the electrons in to the chain - then the electrons transfer their energy to proteins in the membrane, thus providing energy for the H+ ions to be pumped across the membrane.
This series of H+ pumping creates a proton gradient - the energy from this is used by ATP synthase to generate ATP from ADP and Pi.

Question 15

how many ATP molecules are produced from NADH, and FADH2?

Answer 15

NADH = 3 ATP 
FADH2 = 2 ATP

Question 16

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

Answer 16

oxygen - it combines with hydrogen to form water.

Question 17

what is oxygen (the last electron acceptor) isn’t present?

Answer 17

then hydrogen cannot pass through the electron transport chain so there’s a reduction of ATP molecules produced.

Question 18

what molecule in the electron transport chain also plays a role in apoptosis?

Answer 18

Cytochrome C

Question 19

what is the name of the high energy molecule used by cells?

Answer 19

ATP - adenosine triphosphate

Question 20

where does glycolysis take place and what does it produce?

Answer 20

cytoplasm - produces 2 pyruvate and 2 ATP

Question 21

in cellular respiration - how many ATP produced?

Answer 21

38

2 glycolysis, 2 TCA, 34 electron tc

Question 22

how many ATP molecules does TCA produce?

Answer 22

2

Question 23

what enzymes does the mitochondrial matrix contain?

Answer 23

contains enzymes that metabolise pyruvate and fatty acids to produce acetyl CoA
also has enzymes that oxidise acetyl CoA in the TCA cycle

Question 24

describe the inner mitochondrial membrane

Answer 24

specialised lipid bilayer that is impermeable to ions and is the site of electron transport chain / ATP synthesis

It is also convuluted - forms folds called Cristae that project into the matrix and increase the surface area which then produces more ATP

Question 25

give 5 roles of mitochondria

Answer 25

1. Uses cellular metabolites to generate ATP
2. regulates cytosolic Ca2+ conc
3. buffer redox potential of cells - NAD+/NADH
4. Detoxify ammonia in urea cycle
5. Produces heat
6. Apoptosis