Samacheer Kalvi 11th Bio Botany Guide Chapter 14 Respiration

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Bio Botany Guide Pdf Chapter 14 Respiration Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Bio Botany Solutions Chapter 14 Respiration

11th Bio Botany Guide Respiration Text Book Back Questions and Answers

Part-I.

Question 1.
The number of ATP molecules forme by complete oxidation of one molecule of pyruvic acid is
a) 12
b) 13
c) 14
d) 15
Answer:
d) 15

Question 2.
During oxidation of two molecules of cytosolic NADH + H+, number of ATP molecules produced in plants are
a) 3
b) 4
c) 6
d) 8
Answer:
b) 4

Question 3.
The compound which links glycolysis and Krebs cycle is
a) succinic acid
b) pyruvic acid
c) acetyl COA
d) citric acid
Answer:
c) acetyl COA

Question 4.
Assertion (A): Oxidative phosphorylation takes place during the electron transport chain in mitochondria.
Reason (R): Succinyl Co A is phosphorylated into succinic acid by substrate phosphorylation.
a) A and R is correct. R is correct explanation of A
b) A and R is correct but R is not the correct explanation of A,
c) A is correct but R is wrong
d) A and R is wrong
Answer:
c) A is correct but R is wrong

Question 5.
Which of the following reaction is not involved in krebs cycle.
a) Shifiting of phosphate from 3C to 2C
b) Splitting of Fructose 1,6 bisphophate into two molecules 3C compounds.
c) Dephosphorylation from the substrates.
d) All of these
Answer:
d) All of these

Question 6.
What are enzymes involved in phosphorylation and dephosphorylation reactions in EMP pathway?
i) Enzymes involved in phosphorylation are
a) Hexokinase and phospnofructio kinase.
(ii) Enzymes involved in dephosphorylation are
a) Phosphoglycerate Kinase
b) Pyruvate Kinase

Question 7.
Respiratory quotient is zero in succulent plants. Why?
Answer:
Respiratory quotient is zero in succulent plants like Opuntia, Bryophyllum carbohydrate are partially oxidised to organic to acid, particularly malic acid without corresponding release of CO2 but O2 is consumed hence the RQ value will be zero
2 C6H12O6 + 3O2 → 3C4H605 + 3H2O+ Energy Glucose Malic acid
R.Q. of glucose in succulents \(\frac{=\text { Zero molecule of } \mathrm{CO}_{2}}{3 \text { molecules of } \mathrm{O}_{2}}\)
= O (zero)

Question 8.
Explain the reactions taking place in mitochondrial inner membrane.
Answer:
Electron and hydrogen (proton) transport takes place across four multiprotein complexes (I-IV). They are.
Complex-I (NADH dehydrogenase).
It contains a flavoprotein (FMN) and associated with non-heme iron Sulphur protein (Fe-S). This complex is responsible for passing electrons and protons from mitochondrial NADFI (Internal) to Ubiquinone (UQ)
NADH+H+UQ ⇌ NAD+UQH2

In plants, an additional NADH dehydrogenase (External) complex is present on the outer surface of inner membrane of mitochondria which can oxidise cytosolic NADH + H+.
Ubiquinone (UQ) or Coenzyme Quinone (CoQ) is a small, lipid soluble electron, proton carrier located within the inner membrane of mitochondria).

Complex-II (succinic dehydrogenase) It contains FAD flavoprotein is associated with non-heme iron Sulphur (Fe-S) protein. This complex receives electrons and protons from succinate in Kerbs cycle and is converted into fumarate and passes to ubiquinone.
Succinate + UQ Fumaraic LQH2

Complex-III (Cytochrome bcj complex) This complex oxidises reduced ubiquinone (ubiquinol) and transfers the electrons through Cytochrome bc1 Complex (Iron Sulphur centci bcl complex) to cytochrome c.
Samacheer Kalvi 11th Bio Botany Guide Chapter 14 Respiration 1

Complex IV (Cytochrome c oxidase) Complex IV is the terminal oxidase and brings about the reduction of 1/2 O2 to H2O. TWO protons are needed to form a molecule of H2O (terminal oxidation).
Samacheer Kalvi 11th Bio Botany Guide Chapter 14 Respiration 2

Question 9.
What is the name of alternate way to glucose breakdown? Explain the process in involved in it?
Answer:

  • Pentose phosphate pathway is the alternate pathway for breakdown of glucose.
  • Pentose phosphate pathway was described by warburg, Dickens and Lipmami (1938).
  • It is also known as Hexose mono phosphate shunt (HMP shunt) or Direct oxidative phase and non – oxidative phase.
  • The oxidative phase convert six molecules of six carbon Glucose 6 phosphate to 6 molecules of five carbon sugar Ribulose – 5 Phosphate with loss of 6CO2 and generation of 12 NADPH + H+
  • Non oxidative pathway convert Ribulose – 5 – phosphate molecules to various intermediates such as
    Ribose – 5 – phosphate (5C)
    Xylulose – 5 – phosphate (5C)
    Glyceraldehyde – 3 – phosphate (3C)
    Sedoheptulose – 7 – phosphate (7C) and
    Erythrose – 4 – phosphate (4C)
  • Finally five molecules of glucose 6 – phosphate is regenerated
    6 x Glucose – 6 – phosphate + 12NADP+ + 6H2O

    5 x glucose – 6 – phosphate + 6CO2 + Pi + 12 NADPH + 2H+
    The net result of complete oxidation of one glucose – 6 – phosphate yield 6CO2 and 12 NADPH + H+. The oxidative pentose phosphate pathway is controlled by glucose – 6 – phosphate dehydrogenase enzyme which is inhibited by high ratio of NADPH to NADP+.

Question 10.
How will you calculate net products of one sucrose molecule upon complete oxidation during aerobic respiration as per recent view?
Answer:
Sucrose is dissacharide it will convert into glucose and fructose. In glycolysis both will give glyceraldehyde – 3 phosphate that undergo further process of respiration to yield 36 ATPS. So Net products of one sucrose molecule during aerobic respiration will yield 72 ATP.

Part-II.

11th Bio Botany Guide Respiration Additional Important Questions and Answers

I. Choose The Correct Answer

Question 1.
Pepys (1966) coined the term ………………..
a) Glycolysis
b) Respiration
c) ATP
d) GTP
Answer:
b) Respiration

Question 2.
Black man divided respiration into floating respiration and protoplasmic respiation based on respiratory ………..
a) Quotient
b) respiratory reaction
c) respiratory pathway
d) substrate
Answer:
d) substrate

Question 3.
The amount of heat energy liberated during respiration is ……………….. KJ
a) 686
b) 2868
c) 8268
d) 8628
Answer:
b) 2868

Question 4.
The type of respiration which is rare and liberates toxic ammonia
a) Protoplasmic respiration
b) floating respiration
c) Aerobic respiration
d) Anaerobic respiration
Answer:
a) Protoplasmic respiration

Question 5.
It is an nuclear tide consist of a base adenine a pentose sugar – ribose and three phosphate groups called
a) FAD
b) NAD
c) FADH2
d) ATP
Answer:
d) ATP

Question 6.
To convert Kcal to KJ multiply by 4.18(100 Kcal=418 KJ) calculate the amount KJ energy for 7.3 Kcal
a) 30.6 KJ
b) 32.06 KJ
c) 29.03 KJ
d) 5.01 KJ
Answer:
a) 30.6 KJ

Question 7.
The Reaction which is important in cellular respiration is
a) Respiration
b) Redox reaction
c) Oxidation
d) Reduction
Answer:
b) Redox reaction

Question 8.
Food materials like carbohydrate, fat and proteins are completely oxidised into CO2, H2O and energy in ………………. respiration
a) anaerobic
b) aerobic
c) Bacterial respiration
d) Facultative
Answer:
b) aerobic

Question 9.
Which is the common stage for both aerobic and anaerobic respiration
a) preparatory phase
b) pay off phase
c) Electron transport system
d) Glycolysis
Answer:
d) Glycolysis

Question 10.
Which process is occur in yeast and some bacteria and 2 ATP molecules are produced during this process.
a) Anaerobic respiration
b) aerobic respiration
c) mixed fermentation
d) CAC cycle
Answer:
a) Anaerobic respiration

Question 11.
Two ATP molecules are consumed during this phase of Glycolysis
a) endergonic phase
b) Oxidative phase
c) Pay off phase
d) triose phase
Answer:
a) endergonic phase

Question 12.
Net product in Glycolysis are
a) 4ATP and 2NADH + H+
b) 2 ATP and 2NADH + H+
c) 6ATP
d) 24 ATP ,
Answer:
b) 2ATP and 2NADH + H+

Question 13.
Sir Hans Adolf Kreb was awarded Nobel prize in physiology in 1953 for the discovery of
a) Kreb cycle (or) TCA cycle
b) Glycolysis
c) ETC
d) Calvin Cycle
Answer:
a) Kreb cycle (or) TCA cycle

Question 14.
Which is the raw material for the formation of chlorophylls, cytochrome, phytochrome and pyrrole substance
a) acetyl COA
b) Pyruvic acid
c) Malic acid
d) Succinyl COA
Answer:
d) Succinyl COA

Question 15.
Which is act as metabolic sink and central role in intermediary metabolism
a) Calvin cycle
b) Glycolysic
c) Kreb cycle
d) Pebntose pathway
Answer:
c) Kreb cycle

Question 16.
Which cycle is considered as amphibolic pathway.
a) Calvin cycle
b) Glycolysic
c) ETS chain
d) Kreb cycle
Answer:
d) Kreb cycle

Question 17.
Which is final common pathway for oxidation of fuel molecule like amino acid, fatty acid and Carbohydrate.
a) Calvin cycle
b) ETS system
c) Kreb cycle
d) Glycolysis
Answer:
c) Kreb cycle

Question 18.
The complex system responsible for passing electrons and protons from mitochondria to ubiquinone is ………………..
a) Complex I
b) Complex II
c) Complex III
d) Complex IV
Answer:
a) Complex I

Question 19.
Which is small lipid soluble, electron proton carrier located within the inner membrane of mitochondria?
a) Cytochrome
b) Ubiquinone
c) Phytochrome
d) Mitochondria
Answer:
b) Ubiquinone

Question 20.
Which are the high energy phosphate groups in ATP
a) adenine
b) Pentose sugar
c) Last two phosphate group
d) First two phosphate group
Answer:
c) Last two phosphate group

Question 21.
Common steps of aerobic and anaerobic respiration takes place in
a) Entirely in Cytoplasm
b) Partialy in Cytoplasm
c) Mitochondrial Matrix
d) Paitialy in mitochondria
Answer:
a) Entirely in Cytoplasm

Question 22.
How many ATP molecules are produced when a molecule of glucose undergo fermentation?
a) TwoATPs
b) Six ATPs
c) Eight ATPs
d) one ATP
Answer:
a) Two ATPs

Question 23.
Identify from the following one which is not act as respiratory substrate
a) Carbohydrate
b) Protein
c) Glucose
d) Minerals
Answer:
d) Minerals

Question 24.
Enzymatic reaction for partial oxidation of glucose in the absence of oxygen is present in
a) Some Bacteria
b) Yeast fungus
c) A and B
d) Bryophytes
Answer:
c) A and B

Question 25.
Pyruvic acid produced by glucolysis are further undergoing the reaction like
a) Alcoholic fermentation
b) Lactic acid fermentation
c) Aerobic Respiration
d) Pentose phosphate pathway
Options:
a) A, B, and C
b) C and D
c) A and B
d) B C and D
Answer:
a) A, B, and C

Question 26.
Match the Column I with the enzyme responsible for its production in column II
Answer:

Column I Column II
A. Citric acid 1. Hexose Kinase
B. Glucose 6-Phosphate 2. Lactate dehydrogenase
C. Lacticacid 3. Pyruvatc dehydrogenase
D. Acetvl CO.A 4. Citric acid Synthetase

Samacheer Kalvi 11th Bio Botany Guide Chapter 14 Respiration 3

Answer:
a) A-4,B -1,C-2,D-3.

Question 27.
Which one is wrongly matched

Column I Column II
A. NADH +H+ Three ATP
B. Glycolysis Twenty four ATP
C. FAD Two ATP
D. Cytoplasmic NADH+H+ Two ATP

Answer:
B. Glycolysis – Twenty four ATP

2 Mark Questions

II.

Question 1.
What is ATP? Why it is called universal energy currency of the cell?
Answer:

  • ATP is a nucleotide consisting of a base adenine a pentose sugar – ribose and three phosphate groups.
  • On hydrolysis, it release energy from three phosphate group and hence it is called universal energy currency of the cell.

Question 2.
Name some High energy compounds present in a cell
Answer:

  • ATP → Adenosine Tri Phosphate
  • GTP → Guanosine Tri Phosphate
  • UTP → Uridine Tri Phosphate

Question 3.
What is Redox reaction? Is it important?
Answer:

  • The reaction in which NAD+ and FAD gain (reducation) (or) lose (oxidation) electrons are called redox reaction.
  • Yes it is important in cellular respiation.

Question 4.
What is Anaerobic respiration? What are its steps?
Answer:

  • In the absence of molecular oxygen glucose is incompletely degraded into either ethyl alcohol (or) Lactic acid.
  • It includes two steps (i) Glycolysis (ii) Fermentation

Question 5.
What is Glycolysis? (or) EMP Pathway?
Answer:

  • Glycolysis is conversion of glucose into pyruvic acid in cytoplasm of cell.
  • The enzymes which are required for glycolysis are present in the cytoplasm.
  • The Net gain of glycolysis is 2 ATP and 2 NADH2
  • [These reactions of glycolysis were worked out in yeast cells by three scientist Gustav Embden (German) otto Meyerhoff (German) and J Pamar (Polish) So it is called as EMP pathway]

Question 6.
What is Link reaction?
Answer:
In aerobic respiration, Conversion of Pyruvic acid into acetyl coenzyme – A in the mitochondrial matrix with two molecules of NADH + H+ and 2 CO2. This is called Link reaction (or) transition reaction.

Question 7.
What is Kreb cycle (or) Citric acid cycle (or) TCA cycle?
Answer:

  • Kreb cycle is conversion of acetyl coenzyme A into CO2 and water in the mitrochondrial matrix.
  • It is named after its discoverer, German Bio Chemist Sir Hans Adolf Kreb (193 7).

Question 8.
Why Kreb cycle is called as citric acid cycle (or) Tri Carboxylic acid Cycle?
Answer:

  • TCA cycle starts with condensation of acetyl COA with oxaloacetate in the presence of water to yield Citri acid (or) Citrate.
  • So it is also known as citric acid cycle (or) Tri carboxylic acid cycle.

Question 9.
What is Substrate level phosphorylation?
Answer:
A molecule of ATP synthesis from substrate without entering the electron transport chain is called substrate level phosphorylation.

Question 10.
Which cycle is amphibolic pathway? Why? kreb cycle is called ainphib Jic pathway.
Answer:

  • Kreb cycle is primarily a catabolic pathway Later it is an anabolic pathway too.
  • Hence it is called amphibolic pathway.

Question 11.
What is climacetric? Give example.
Answer:
Abnormal rise in respiratory rate of ripening in fruits is called climacteric, ex. apple, banana mango, papaya. Pear.

Question 12.
How many ATP molecules are produced in aerobic respiration present in plants?
Answer:
In aerobic respiration net gain of 36 ATP molecules produced in complete oxidation of glucose.

Question 13.
How many ATP molecules are produced in aerobic prokaryotes? Why?
Answer:
In the case of Aerobic prokaryotes due to lack of mitochondria each molecule of glucose produce 38 ATP molecules.

Question 14.
Who was awarded Nobel Prize for coupling of oxidation and phosphorylation in mitrochondria?
Answer:
Peter mitchel, a British Bio chemist received Nobel Prize for chemistry in 1978.

Question 15.
Write the significance of RQ.
Answer:

  • RQ value indicates which type of respiration occurs in living cells, either aerobic (or) anaerobic
  • It also helps to know which type of respiratory substrate is involved.

Question 16.
Define mixed acid fermentation.
Answer:

  • Formation of Lactic acid, ethanol, formic acid and gases like CO2 and H2 from pyruvic acid.
  • eg. Enterobacteriaceae.

Question 17.
Characteristics of Anaerobic Respiration.
Answer:

  • Anaerobic respiation is less efficient than the aerobic respiration.
  • Limited number of ATP molecules is generated per glucose molecule.
  • Formation of CO2 and it is used for carbon fixation in photosynthesis.

Question 18.
Why microorganisms respire an anaerobically?
Answer:

  • Bacteria are prokaryotes and they are devoid of membrane bound organelle mitrochondria.
  • So they are respire anaerobically.

Question 19.
Does anaerobic respiration take place in higher plants?
Answer:”

  • Normaly higher plants do not show an aerobic respiration.
  • If the roots of a plant get water logged they use a different form of respiration called anaerobic respiration.

Question 20.
Complete the following Picture.
Samacheer Kalvi 11th Bio Botany Guide Chapter 14 Respiration 4
Answer:
A. Compensation point
B. Rate of Respiration

Question 21.
Write the missing A and B
Samacheer Kalvi 11th Bio Botany Guide Chapter 14 Respiration 5
Answer:
A. Ribose
B. Adenine

3 Mark Questions

III.

Question 1.
“Over all process of respiration corresponds to a reversal of photosynthesis” – State whether it is true.
Answer:

  • Yes. The overall process of respiration corresponds to a reversal of photosynthesis.
  • Overall equation of Respiration is
    C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy (686 KCal (or) 2868KJ)

Question 2.
What is Respiration?
Answer:

  • Breaking of C-C bonds of complex organic compounds through oxidation within the cells.
  • The energy released during respiration is stored in the form of ATP and heat is liberated.
  • It occurs in all the living cells of organisms.

Question 3.
What is Compensation Point?
Answer:

  • The point at which CO2 released in respiration is exactly compensated by CO2 fixed in photosynthesis.
  • At this moment the amount of O2 released from photosynthesis is equal to the amount of oxygen utilized in respiration.

Question 4.
Differentiate floating respiation and protoplasmic respiration.
Answer:

Floating respiration Protoplasmic respiration
Carbohydrate (or) fat (or) organic acid serves as respiratory substrate Where as protein as a respiratory substrate.
It is a common mode of respiration and does not produce any toxic product. It is rare and liberates toxic ammonia.

Question 5.
Define Aerobic respiration.
Answer:

  • Respiration occuring in the presence of oxygen is called aerobic respiration.
  • It is very complex process during which food materials like Carbohydrates, fats and proteins are completely oxidised into CO2, H2O and energy.
  • It consist of four major Steps.

Question 6.
Define ETS (or) Electron transport chain (or) What is the importance of ETS and oxidative Phos-phorylation in respiration.
Answer:

  • Electron transport chain and oxidative phosphorylation remove hydrogen atoms from the products of glycolysis, link reaction and Krebcycle.
  • It releases water molecule with energy in the form of ATP molecule in mitrochondrial inner membrane.

Question 7.
What is gluconeogenesis?
Answer:
The synthesis of glucose from certain non – Carbohydrate Carbon Subtrates cuch as proteins and lipids are called gluconeo genesis.

Question 8.
Write the differnces between ubiquinone and Cytochrome C.
Answer:

Ubiquinone Cytochrome C
It is a small, lipid soluble electron, proton carrier located within the inner membrane of mitochondria. It is a small protein attached to the outer surface of inner membrane of mitochondria
It is associated with ETS – complex I It is associated with ETS – complex IIII

Question 9.
What is respiratory Quotient?
Answer:
The ratio of volume of Carbon dioxide given out and volume of Oxygen taken in during respiration is called R.Q.
\(\mathrm{RQ}=\frac{\text { VolumeofCOliberated }}{\text { VolumeofOconsumed }}\)
RQ value depends upon respiratory substrates.

Question 10.
RQ will be less than one in Red colour Parts Present in Plants? Why?
Answer:

  • Red colour parts present in plants is due to the presence of anthocyanin
  • Synthesis of anthocyanin require more O2 than CO2 evolved.
  • So RQ will be less than one.

Question 11.
What is alcoholic fermentation?
Answer:

  • The cells of roots in water logged soil respire by alcoholic fermentaion because of lack of oxygen by converting pyruvic acid into ethyl alcohol and CO2.
  • Eg Yeast (Saccharomyces)

Question 12.
Define Lactic acid fermentation.
Answer:

  • Formation of Lactic acid from pyruvic acid is Lactic acid fermentation.
  • Eg. Bacillus bacteria, fungi, muscles of vertebrates.

Samacheer Kalvi 11th Bio Botany Guide Chapter 14 Respiration 6

Question 13.
What is Pentose phosphate pathway?
Answer:

  • It is an alternate pathway for break down of glucose.
  • It takes place in cytoplasm of mature plant cells.
  • In this pathway glucose 6 phosphate molecule is converted to Ribulose 5 phosphate with CO2 and NADPH + H+.

Question 14.
How alcoholic beverages like beer and wine is made?
Answer:

  • The conversion of pyruvate to ethanol takes place in melted barley and grapes through fermentation.
  • Yeast Carryout this process under anaerobic conditions and this conversion increases ethanol concentration.
  • If the concentration increases It’s toxic effect kills yeast cells and the left out is called beer and wine respectively.

5 Mark Questions

IV.

Question 1.
Abulate the differences between aerobic and anaerobic respiration.
Answer:

Aerobic respiration Anaerobic respiration
1. It occurs in all living cells of higher organisms. It occurs yeast and some bacteria.
2. It requires oxygen for breaking the respiratory substrate Oxygen is not required for breaking the respiratory substrate.
3. The end products are CO2 and H2O The end products are alcohol and CO2 (or) lactic acid
4. Oxidation of one molecule of glucose produces 36 ATP molecules Only 2 ATP molecules are produced.
5. It consists of four stages – glycolysis, link reaction, TCA cycle and electron transport chain. It consists of two stages – glycolysis and fermentation.
6. It occurs in cytoplasm and mitochondria It occurs only in cytoplasm

Question 2.
Draw the flow chart diagram For Glycolysis (or) EMP pathway.
Answer:
Samacheer Kalvi 11th Bio Botany Guide Chapter 14 Respiration 7
Samacheer Kalvi 11th Bio Botany Guide Chapter 14 Respiration 8

Question 3.
Explain the Pay – off phase of EMP Pathway of Glycolysis (or) Explain the oxidative phase of Glycolysis (or) Triose phase of Glycolysis.
Answer:

  • Two molecules of glyceraldehyde 3 – phosphate oxidatively phosphorylated into two molecules of 1-3
    bisphospho glycerate.
  • During this reaction 2 NAD+ is reduced to 2NADH+ H+ by glyceraldehyde 3-phosphate dehydrogenase.
  • Further reactions are carried out by different enzymes at the end two molecules of pyruvate are produced.
  • In this phase 4 ATPS are produced (at step 7 and step 10)
  • Through Direct transfer of phosphate from substrate molecule to ADP and is converted into ATP is called substrate Phosphotylation. (or) Direct Phosphorylation (or) transphosphorylation.
  • During the reaction (at step 9)2 phospo glycerate dehydrated into phosphoenol pyurvate, a water molecule is removed by the enzyme enolase.
  • As a result enol group is formed within the molecule. This process is called Enolation.

Energy Budge of pay off phase:

  • In the pay off phase totally 4 ATP and 2NADH + H+ molecules are produced.
  • Since 2 ATP molecules are already consumed in the preparatory phase the net products in glycolysis are 2ATP and 2NADH + H+

Question 4.
Explain the preparatory phase of Glycolysis (or) EMP pathway (or) Describe the energonic phase phase of Glycolysis (or) EMP pathway. Describe the hexose phase of Glycolysis (or) EMP pathway.
Answer:
Glycolysis is a linear servies of reactions in which 6- carbon glucose split into two molecules of 3 carbon pyruvic acid.
Preparatory phase:

  • Glucose enters the glucolysis which is the end product of photosynthesis.
  • Glucose is phosphorylated into glucose 6 phosphate by the enzyme hexokinase and subsequent reactions are carried out by different enzymes.
  • At the end of this phase fructose 1,6 – bisphote is cleaved into glyceraldehyed 3- phosphate and dihydroxy acetone phosphate by the enzyme aldolase.
  • These two are Isomers.
  • Dihydroxy acetone phosphate is isomerised into glyceralde hyde 3- phosphate by the enzyme triose phosphate isomerase.
  • Now two molecules ofglyceraldehyde 3 phosphate enter into pay off phase.

During preparatory phase two ATP molecules are àonsumed.
Samacheer Kalvi 11th Bio Botany Guide Chapter 14 Respiration 9
Samacheer Kalvi 11th Bio Botany Guide Chapter 14 Respiration 10

Question 5.
Explain pyruvate oxidation (or) Link reaction of Glycolysis.
Answer:
Two molecules ofpyruvatc formed by glycolysis in the cytosol enters into mitochondnal rnatrxi.
In aerobic respiration this pyruvate with co enzyme A is oxidatively decarboxylated into acetyl CoA by pyruvate dehydrogenase complex. .
It produces two molecules of NADH + H+ and 2CO2
It is also called transition reaction (or) Link reaction.
Samacheer Kalvi 11th Bio Botany Guide Chapter 14 Respiration 11
Pyruvate de hydrogenase complex consist of three distinct enzymes.
1. Pyruvate dehydrogenase
2. Dihydroiipoyil transacetylase
3. Dihydrolipoyil dehydrogenase and 5 coenzymes TPP (thymine pyro phosphate)
NAD+
FAD
COA and lipoate.

Question 6.
Draw the flow chart diagram for Kreb cycle (or) Citric acid cycle.
Answer:
Samacheer Kalvi 11th Bio Botany Guide Chapter 14 Respiration 12

Question 7.
Explain Kreb cycle (or) Citric acid cycle (or) TCA cycle.
Answer:

  • Two molecules of acetyl CoA formed from link reaction now enter into Kreb Cycle.
  • It is named after its discoverer German Bio chemist Sir Hans Adolf Kreb (1937).
  • It is takes place in mitrochondrial matrix and Inner membrane of mitochondria.
  • The enzymes needed for TCA cycle are found in mitochondiral matrix except succinate dehydrogenase which is found in mitochondiral inner membrane.
  • First step starts with condensation of acetyl CoA with oxaloacetate in the presence of water to yield citric acid (or) citrate.
  • It is followed by the action of different enzymes in cyclic manner.
    During the conversion of succinyl CoA to succinate by the enzyme succinyl CoA synthetase a molecule of ATP Synthesis from Substrate without entering the electron transport chain is called substrate level phosphorylation.
  • Krcb Cycle is repeated twice for every glucose molecule.
  • Where two molecules of pyruvic acid produces six molecules of CO2, eight molecules of NADH+H+ two
    molecules of FADH2 and two molecules of ATP.

Question 8.
Significance of Kreb Cycle.
Answer:

  • TCA cycle is to provide energy in the form of ATP for metabolism in plants.
  • It provides carbon skeleton or raw material for various anabolic process.
  • many intermediates of TCA cycle are further metabolised to produce amino acids, proteins and nucleic acids.
  • Succinyl CoA is raw material for formation of chlorophyll, cytochrome, phytochrome and other pyrroles
    substances.
  • Ex – ketoglutarate and oxaloacetate undergo reductive amination and produce amino acids.
  • it acts as metabolic sink which plays a central role in intermediary metabolism.

Question 9.
Write four Electron transport chain in hibitors.
Answer:

  • 2,4 DNP (Dinitrophenol) – It prevents synthesis of ATP from ADP, as it directs electrons from CoQ to O2
  • Cyanide – It prevents flow of electrons from Cytochrome a3 to O2
  • Rotenone – It prevents flow of electrons from NADH + H+ / FADH2 to Co Q
  • Oligomycin – It inhibits oxidative phosphorylation

Question 10.
Tabulate Net Products of ATP gained during aerobic respiration per glucose molecule.
Answer:
Samacheer Kalvi 11th Bio Botany Guide Chapter 14 Respiration 13

Question 11.
Experiment to demonstrate the production of CO2 in aerobic respiration.
Answer:

  • Take small quantity of any seed (groundnut or bean seeds) and allow them to germinate by imbibing them.
  • While they are germinating place them in a conical flask.
  • A small glass tube containing 4 ml of freshly prepared Potassium hydroxide (KOH) solution is hing into the conical flask with the help of a thread and tightly close the one holed cork.
  • Take a bent glass tube, the shorted end of which is inserted into the conical flask through the hole in the cork.
  • The longer end is dipped in a beaker containing water.
  • Observe the position of initial water level in bent glass tube.
  • This experimental setup is kept for two hours.
  • After two hours, the level of water rises in the glass tube. It is because the CO2 evolved during aerobic
    respiration by germinating seeds will be absorbed by KOH solution and the level of water will rise in the glass tube.

CO2 + 2KOH → K2CO3 + H2O
Samacheer Kalvi 11th Bio Botany Guide Chapter 14 Respiration 14

Question 12.
Compare Alcoholic fermentation.
Answer:

Alcoholic fermentation Lactic acid fermentation
1. it produces alcohol and releases CO2 from pyruvic acid It produces lactic acid and does not release CO2 from pynivic acid
2. It takes place in two steps. It takes place in single steps.
3. It involves two enzymes, pyruvate decarboxylase with Mg++ and alcohol dehydrogenase It uses one enzyme, lactate dehydrogenase with Zn++
4. It forms acetaldehyde as intermediate compound Does not form any intermediate compound.
5. It commonly occurs in yeast. Occurs in bacteria, sorne fungi and vertebrate muscles.

Question 13.
Write the Industrial uses of alcoholic fermentation.
Answer:

  • In bakeries, it is used for preparing bread, cakes, biscuits.
  • In beverate industries for preparing wine and alcoholic drinks.
  • In producing vinegar and in tanning, curing of leather.
  • Ethanol is used to make gasohol (a fuel that is used for cars in Brazil).

Question 14.
Tabulate the companision betweeen glycolysis and fermentation.
Answer:

Glycolysis Fermentation
1. Glucose is converted into pyruvic acid Stars from pyruvic acid and is converted into alcohol or lactic acid.
2. It takes place in the presence or absence of oxygen. it takes place in the absence of oxygen.
3. Net gain is 2ATP. No net gain of ATP molecules.
4. 2NADH + H+ molecules are produced. 2NADH+ H+molecules are utilised
5. It commonly occurs in yeast. Occurs in bacteria, some fungi and vertebrate muscles.

Question 15.
Explain about demonstration of alcoholic fermentation.
Answer:

  • Take a Kuhne’s fermentation tube which consists of an upright glass tube
    with side bulb
  • Pour 10% sugar solution mixed with baker’s yeast into the fermentation tube the side tube is filled plug the mouth with lid.
    After some time, the glucose solution will be fermented. The solution will give out an alcoholic smell.
  • Level of solution in glass column will fall due to the accumulation of CO2 gas.
  • It is due to the presence of zymase enzyme  yeast which converts the glucose solution into alcohol and CO2
  • Now introduce a pellet of KOH into the tube, the KOH will absorb CO2 and the level of solution will rise in upright tube.

This experiment proves during fermentation CO2 gas is evolved.
Samacheer Kalvi 11th Bio Botany Guide Chapter 14 Respiration 15

Question 16.
Write the Factors (Internal and External) which affect the process of respiration.
Answer:
External Factors:

  • Optimum temperature for respiration is 30°C. At low temperatures and very high temperatures rate, of respiration decreases.
  • When sufficient amount of O2 is available the rate of aerobic respiration will be optimum and anaerobic respiration  is completely stopped. This is called Extinction point.
  • High concentratin of CO2 reduces the rate of respiration.
  • A plant or tissue transferred from water to salt solution wi li increase the rate of respiration. It is called silt respiration.
  • Light is an indirect factor affecting the rate of respiration.
  • Wounding of plant organs stimulates the rate of respiration in that region.

Internal Factors:

  • Concentration of respiratory substrate is proportional to the rate ofrespiration
  • The amount of protoplasm and its state of activity influence the rate of respiration.

Question 17.
Write about the alternate pathway for glucose break down (or) Write about pentose phosphate pathway. (or) Phosphogluconate pathway (or) War burg – Dickens Lipmann pathway (or)Hexose Monophosphate pathway (or) HMP Shunt pathway.
Answer:
Pentose phosphate pathway was described by Warburg, Dickens and Lipmann (1938). Hence, it is also
called Warburg – Dickens Lipmann pathway.

  • It takes place in cytoplasm of mattre plant cells. It is can alternate way for break4own of glucose.
  • It consists of two phases, oxidative phase and non oxidative phase.
  • The oxidative events concert six molecules of six carbon Glucose 6 phosphate to 6 molecules of five carbon sugar Ribulose -5 phosphate with loss of 12 NADPH + H+ (not NADH).
  • The remaining reactions known as non oxidative pathway, covert Rihulose 5phosphate molecules to various intermediates such as Ribose – 5 – phosphate (5C), Xylulose – 5 – phosphate (5C), Glyceraldehyde – 7 – Phosphate (7C), and Eiythrose -4- phosphate (4C).
  • Finally, five molecules of glucose -6- phosphate is regenerated. The overall reaction is:
    6 x Glucose – 6 – Phosphate + 12NADP+ + 6H2O

    5 x Glucose-6- Phosphate + 6CO2 + Pi + 12NADPH + 12H+
  • The net result of complete oxidation of one glucose-6-phosphate yield 6CO2 and12NADPH+H+

Question 18.
Draw the cycle for pentsoe phosphate pathway (or) Draw the flow chart for HMP Shunt.
Answer:
Samacheer Kalvi 11th Bio Botany Guide Chapter 14 Respiration 16

Question 19.
Write about Significance of Pentose Phosphate pathway.
Answer:

  • HMP shunt is associated with the generation of two important products. NADPH and pentsoe sugars, which play a vital role in anaholic reactions .
  • Coenzyme NADPH generated is used lbr reductive bisynthesìs and counter damaging the effects of oxygen
    free radicals.
  • Ribose – 5 – phosphate and its derivatives are used in the synthesis of DNA, RNA, ATP, NAD, FAD and
    Coenzynie A. .
  • Erythrose is used for synthesis fanthocyanin Jignin and other aromatic compounds.

 

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