Respiration 5.2

Question 1

What are the 4 processes of respiration?

Answer 1

-Glycolysis
-Link Reaction
-Krebs Cycle
-Oxidative phosphorylation

Question 2

Name the structures of a mitochondria

Answer 2

-Inner Membrane
-Outer Membrane
-Crista
-Matrix

Question 3

Where does Glycolysis take place?

Answer 3

In the cytoplasm

Question 4

What are the steps of glycolysis?

Answer 4

-Glucose is phosphorylated (6C) into glucose phosphate (6C)
-Using Phosphates from 2 ATP molecules
-The glucose phosphate splits into two molecules of two triose phosphate (3C)
-Each triose phosphate is oxidised to pyruvate (3c) (2 pyruvate formed)
-2 hydrogen released which reduce 2NAD to 2NADH
-For each triose phosphate two ATP molecules are made to make 4 ATP total BY SUBSTRATE LEVEL PHOSPHORYLATION

Question 5

What is a coenzyme?

Answer 5

Used to pick something up from somewhere and move it somewhere else eg NAD
NOT an enzyme

Question 6

What is the difference between NAD and NADP?

Answer 6

-NAD used in respiration NADP used in photosynthesis (p for photosynthesis)

Question 7

Where does the link reaction take place?

Answer 7

The matrix of the mitochondria

Question 8

What is the steps in the link reaction?

Answer 8

-2x Pyruvate (3C) enters the mitochondrial matrix by active transport
-2x Pyruvate (3C) is oxidised to 2x acetate (2C) releasing a 2H which reduces 2x NAD to produce 2x NADH
-2x CO2 (1C) is also produced
-Acetate (2C) combines with coenzyme to produce acetyl coenzyme A (2C)

Question 9

What are the products of the glycolysis?

Answer 9

X2 NADH
X2 ATP
X2 Pyruvate

Question 10

What are the products of the Link Reaction?

Answer 10

X2 Acetyl COA
X2 NADH
X2 CO2

Question 11

How much ATP is made and used in Glycolysis? How much is made in total?

Answer 11

-2 ATP used to convert glucose into glucose phosphate by the addition of Pi
-4ATP made by substrate level phosphorylation (converting 2 triose phosphate into 2 pyruvate)
2 ATP TOTAL

Question 12

Where does the Krebs cycle take place?

Answer 12

The Matrix of the mitochondria

Question 13

What are the steps in the Krebs cycle?

Answer 13

-Acetyl coenzyme A reacts with a 4C molecules releasing coA to make a 6C molecule
-The 6C molecule is oxidised into a 5C releasing a CO2 and reducing NAD into NADH
-The 5C molecule is oxidised into a 4C molecule releasing a CO2 and converting 2x NAD into 2x NADH, FAD is converted into FADH
-A molecule of ATP is made by substate level phosphorylation
-The cycle repeats twice for each glucose molecule

Question 14

What are the net products in the Krebs Cycle?

Answer 14

X6 NADH
X2 ATP
X4 CO2
X2 FADH

Question 15

Where does oxidative phosphorylation take place?

Answer 15

the inner membrane of the mitochondria

Question 16

What is the steps in oxidative phosphorylation

Answer 16

-NADH and FADH are oxidised, donating a hydrogen and the hydrogen dissociates into a proton and electron
-The electrons pass down the electron transfer chain in a series of redox reactons
-Electrons loose energy which is used to pump Hydrogen ions through the inner membrane into the intermembrane space forming a proton gradient
-Some energy is also lost as heat
-Hydrogen ions diffuse back through the inner membrane via ATP synthase (called chemiomosis)
-This releases energy to form ATP from ADP+Pi
-34 molecules of ATP are formed
-The electrons and hydrogen ions combine with oxygen to form water
-Oxygen is the terminal electron acceptor

Question 17

What are the net products of Oxidative Phosphorylation

Answer 17

X34 ATP

Question 18

How many molecules of ATP are made in Aerobic respiration in total?

Answer 18

X38 molecules ATP per 1 molecule of glucose

Question 19

What is Chemiosmosis?

Answer 19

The movement of ions across a selectively permeable membrane down their electrochemical gradient

Question 20

What is the role of oxygen in aerobic respiration?

Answer 20

Combine with hydrogen ions and electrons to form water
Acts as the terminal electron acceptor
(Is dangerous to have reactive ions hanging around)

Question 21

What part of Respiration is similar to Photosynthesis

Answer 21

Oxidative phosphorylation is similar to the light dependent reaction

Question 22

When is water formed in aerobic respiration?

Answer 22

In oxidative phosphorylation
-Electrons and hydrogen ions combine with oxygen to form water

Question 23

Where is carbon dioxide formed in aerobic respiration?

Answer 23

-Released in the krebs cycle when oxidising 6C compound into 5C compound and 5C compound into 4C compound
-Released in the Link Reaction when pyruvate is oxidised to acetate

Question 24

How does anaerobic respiration occur?

Answer 24

-No oxygen for terminal electron acceptor
-Glycolysis occurs producing 2x ATP, 2x NADH AND 2x pyruvate
-For glycolysis to continue NAD must be regenerated
-NADH reduces pyruvate to form NAD and:
->lactic acid in animals
->Ethanol and carbon dioxide in plants
-2 molecules of ATP made per glucose

Question 25

How many molecules of ATP are formed per molecule of glucose in anaerobic respiration compared to aerobic respiration?

Answer 25

Aerobic x38 ATP
Anaerobic x2 ATP

Question 26

What waste products are formed in anaerobic respiration in plants and animals?

Answer 26

Plants- Carbon dioxide, ethanol
Animals- Lactic acid

Question 27

When is CO2 produced in Anaerobic respiration in Plants and fungi?

Answer 27

-When pyruvate is reduced

Question 28

Which stages of respiration does anaerobic respiration use?

Answer 28

Glycolysis

Question 29

Describe how lipids are used as respiratory substrates?

Answer 29

-Lipids are hydrolysed into fatty acids and glycerol
-The glycerol is phosphorylated and converted into triose phosphate which enters glycolysis
-The fatty acids are broken down into 2C fragments which are converted into Acetyl coA which enters the krebs cycle

Question 30

Describe how proteins are used as respiratory substrates?

Answer 30

-The proteins are hydrolysed into amino acids
-The amine group is removed from the amino acid by deamination
-3C compounds are converted into pyruvate in glycolysis
-4C and 5C compounds are converted into the Krebs cycle intermediates