Mr Dewhurst- respiration

Question 1

what is the equation for aerobic respiration

Answer 1

(6)O2 + C6H12O6= (6)CO2 + (6) H20 + 2870 kj (energy)

Question 2

what are some examples of what respiration is needed for

Answer 2

metabolic reactions (energy)
anabolic reactions (synthesis of large molecules)
active transport
mechanical work
maintain body temp

Question 3

what is ATP and how does it work (ADP/AMP)

Answer 3

ATP- adenosine triphosphate
ADP- adenosine diphosphate
AMP- adenosine monophosphate
remove phosphate group- ADP releases 30.5 KJmol-1 of energy
universal- used by all organisms which proves it has evolved from the start of life

Question 4

what is phosphorylation

Answer 4

an inorganic phosphate is added to a molecule like ATP during respiration.

Question 5

where does glycolysis occur and what is it needed for

Answer 5

occurs in the cytoplasm in both anaerobic and aerobic respiration as glucose is to large to fit through mitochondria so is broken down into pyruvate

Question 6

1st stage of glycolysis

Answer 6

ATP phosphorylates glucose (donates phosphate) and another ATP is added so another phosphate is added (Hexose bisphosphate)

Question 7

2nd stage of glycolysis

Answer 7

this splits into 2, 3 carbon molecules called triose phosphate
NADH has been reduced as gained a hydrogen
makes 2 ATP ( with ADP left from start and one attached from cytoplasm) each but 2 used at the start

Question 8

3rd stage of glycolysis

Answer 8

make a pyruvate which is transformed glucose to fit into mitochondria

Question 9

what happens in the link reaction

Answer 9

1-pyruvate molecules pumped into mitochondria’s matrix via specific pyruvate H+ symport
2-pyravate reacts with coenzyme A to produce acetyl COA
3- pyruvate is decarbonated (coz is released) and NAD+ is reduced to become NADH

Question 10

what is the 1st step in Krebs cycle

Answer 10

1-acetyl is brought to cycle as acetyl COA, this combines with oxaloacetate to form citrate which is a 6-carbon sugar and the COA is then recycled to bring another acetyl to the cycle.

Question 11

what is the 2nd step in the Krebs cycle

Answer 11

citrate is dehydrogenated as hydrogen leaves to reduce the NADH to produce NADH+H and is decarbonated as co2 is released, as a carbon is lost this produces a 5-carbon molecule

Question 12

what is the 3rd step in the Krebs cycle

Answer 12

this is repeated so NAD is reduced to produce NADH +H which is from the environment and releases one co2 this then produced a 4 carbon compound

Question 13

what is the 4th step in the Krebs cycle

Answer 13

the 4 carbon compound generates molecule of ATP by substrate- level phosphorylation

Question 14

what is the 5th step in Krebs cycle

Answer 14

4 carbon-compound is dehydronated to reduced the FAD to produce FADH2 which produces a different 4 carbon molecule

Question 15

what is the 6th step in the Krebs cycle

Answer 15

4 carbon molecule is dehydrogenated and NAD is reduced to make NADH

Question 16

what is the 7th step of Krebs cycle

Answer 16

the last 4c compound is converted to oxaloacetate

Question 17

how are each compound converted

Answer 17

enzymes

Question 18

how many ATP, NADH, FADH2, CO2 are produced in glycolysis for one glucose molecule

Answer 18

ATP- 2
NADH- 2
FADH2-0
CO2-0

Question 19

how many ATP, NADH, FADH2, CO2 are produced in the link reaction for one glucose molecule

Answer 19

ATP-0
NADH-2
FADH2- 0
CO2- 4

Question 20

how many ATP, NADH, FADH2, CO2 are produced in the Krebs cycle for one glucose molecule

Answer 20

ATP-2
NADH-6
FADH2-2
CO2- 4

Question 21

Explain the electron transport chain

Answer 21

NAD is delivered where it is oxidised where it releases an e- and H, this electron is transferred to reduce the protein
Electrons being passed on creates energy to actively pump in H+ ions into the inter membrane
This creates high conc. of H+ causing electrochemical gradient
H+ go down conc gradient through atp synthesise which generates energy to bind adp to pi creating atp
This is then ready for oxidase phosphorylation
Electrons bind in inter membrane to form water

Question 22

what is chemiosmosis

Answer 22

concentration of hydrogen ions that generates energy through ATP synthase

Question 23

explain what is meant by leaky mitochondria

Answer 23

some ATP is lost, meaning it can’t pump pyruvate into mitochondria so no ATP can be made from cycles

Question 24

what is meant by anaerobic respiration

Answer 24

no oxygen so reduced NAD cannot be recycled so Krebs and glycolysis cannot occur as not enough ATP

Question 25

explain the lactate fermentation pathway

Answer 25

2 reduced NAD from glycolysis, the pyruvate accept the 2 hydrogen atoms catalysed by enzyme lactase dehydrogenase, meaning pyruvate is reduced and converted to two molecules of lactate. The reduced NAD are deoxidised to recycle them back to glycolysis

Question 26

explain the ethanol fermentation pathway

Answer 26

the two pyruvate are decarbonated, x2 reduced NAD are deoxidised giving their oxygen to the ethanal to create ethanol