Aerobic respiration

Question 1

function of mitochondria

Answer 1

synthesis of ATP during the last stages of respiration called oxidative phosphorylation

Question 2

main structures in mitochondria

Answer 2

-outer membrane
-inner membrane
-intermembrane space
-matrix

Question 3

diff between outer and inner membrane

Answer 3

-outer, smooth, permeable to small molecules
-inner, folded (cristae), less permeable, site of electron transport chain used in oxidative phosphorylation, location of ATP synthase enzymes

Question 4

intermembrane space

Answer 4

low pH due to high conc of protons, conc gradient between intermembrane space and inner membrane = essential for ATP sythesis

Question 5

matrix

Answer 5

aqueous solution within inner membrane
-contains enzymes ribosomes and DNA

Question 6

role of cristae

Answer 6

-provides large SA in order for membrane to contain as many electron transport chains as possible
-more active cells have tightly packed cristae and larger mitochondria

Question 7

define aerobic respiration and list the 4 stages

Answer 7

-the process of breaking down a respiratory substrate to produce ATP using oxygen
- glycolysis, link reaction, krebs, oxidative phosphorylation

Question 8

glycolysis description + location

Answer 8

-phosphorylation and splitting of glucose (cell cytoplasm)

Question 9

link reaction description + location

Answer 9

-decarboxylation and dehydrogenation of pyruvate
(Mitochondrial matrix)

Question 10

krebs cycle + location

Answer 10

cyclical pathway with enzyme -controlled reactions (mitochondrial matrix)

Question 11

oxidative phosphorylation +location

Answer 11

-production of ATP through oxidation of hydrogen atoms (inner membrane of mitochondria)

Question 12

glycolysis full steps

Answer 12

glucose + 2 ATP- hexosebisphosphate- 2 x triose phosphate- + 2x phosphate - 2x triosebisphosphate. Per triosebisphosphate, 2x ATP, 1x reduced NAD, (1 pyruvate)
ATP produced from ADP + Pi
-enzyme dehydrogenase to produce NADH

Question 13

net production of ATP, pyruvate and NADH in glycolysis

Answer 13

-2 of each

Question 14

after gylcolysis, how does pyruvate move across the membrane

Answer 14

-via active transport with a transport protein

Question 15

what is decarboxylation and dehydrogenation

Answer 15

-decarb, removing a carbon
-dehydr, removing a hydrogen

Question 16

steps in link reaction

Answer 16

-pyruvate is oxidised by enzymes to produce acetate (2C) and CO2 which requires the reduction of NAD-NADH
-acetyl CoA produced

Question 17

steps of krebs

Answer 17

-4 carbon oxaloacetate accepts 2C acetyl to form 6C Citrate (CoA released in reaction)
-citrate then converted back to oxaloacetate after several redox reactions
-redox reactions are, decarboxylation of citrate (releasing 2 CO2), oxidation of 3NAD, 1 FAD, and substrate level phosphorylation of ADP + Pi to ATP

Question 18

net production from krebs for one glucose

Answer 18

• 6x NADH, 2X FADH, 2X ATP, 4X CO2

Question 19

role and composition of coenzyme A

Answer 19

-consists of a nucleoside (ribose and adenine) and a vitamin
-binds to acetate to form acetyl CoA

Question 20

Role of FAD and NAD coenzymes

Answer 20

They transfer the hydrogen atoms (hydrogen ions and electrons) from the different stages of respiration to the electron transport chain on the inner mitochondrial membrane, the site where hydrogens are removed from the coenzymes

Question 21

outline of oxidative phosphorylation

Answer 21

-H+ ions donated by NADH and FADH2 from krebs, and split into electrons or H+
-high energy electrons enter ETC and transfer energy as they move through
-energy used to transfer protons from matrix to intermembrane space which creates a conc gradient
-protons return to matrix via facilitated diffusion through ATP synthase which provides energy for ATP synthesis
-oxygen acts as the final electron acceptor + combines with H+ and electrons to form water