14 respiration in plant · respiration in plant kad tutorial opc. pvt. ltd. kota • contact :...

Respiration is a Amphibolic & exergonic cellular process. Respiration is an enzymatic process, which is also known as internal respiration / tissue

respiration/dark respiration / cellular respiration / mitochondrial Respiration. An important feature of respiration is liberation of metabolic energy as ATP.

Respiratory substrate :(Carbohydrates Fats Protein others)

When respiratory substrates are carbohydrates like glycogen, starch, sucrose, hexose orfats, then respiration is known as floating respiration.

When protein is oxidised in respiration, then respiration is Known as protoplasmicrespiration protoplasmic components or cellular proteins may oxidised at the time of starvation& disease.

Exceptionally oxidation of proteins in legume seeds is called floating respiration.

Types of respiration :(A) Aerobic respiration :- The complete oxidation of food with the use of oxygen and when

entire carbon released, as CO2 is called as aerobic respiration.

C6H12O6 + 6O2 + 6H2O Enzyme

cyto mito

. &6CO2 + 12H2O + 686 Kcal E (38/36 ATP)

(B) Anaerobic respiration :- This is an incomplete oxidation. When food is oxidized into alcohol or organic acids without use of oxygen.

During it most of the energy is lost in form of heat. It occurs in cytoplasm and only 2ATP areproduced.

C6H12O6 Enzymes

cytoplasm 2C2H5OH + 2CO2+ 21 KCal

(2ATP)

Anaerobic respiraton was first reported by Kostytchev. Anaerobic respiration may takes place in bacteria, some lower parasitic animals (Ascaris,

Taenia) plants, R.BCs. & muscles of human body. When oxygen is not available, then food isincompletely oxidised in to some organic compounds like ethanol, acetic acid, lactic acid.

RESPIRATION IN PLANT14

69KAD Tutorial OPC. Pvt. Ltd. Kota • Contact : 9875255506

Respiration In Plant


In muscle cells & some bacteria, the energy is produced by breaking of glucose into lacticacid inside the cells.

The amount of energy released in anaerobic respiration is much less than aerobic respiration. Fermentation is performed by only some fungi & some bacteria (only by microbes) and is

an extracellular process. No ATP is produced. If occure inside the cell then 2ATP forms.

C6H12O6 Yeast

Bact

. 2C2H5OH + 2CO2 + Heat

In energy generating processes either inorganic or organic compounds function as electronacceptors. The terms aerobic respiration, anaerobic respiration and fermentation are oftenused on energy generating processes.

In aerobic respiration the final electron acceptor is free O2. In anaerobic respiration the final electron acceptors is organic compound or inorganic

compounds (nitrates) other than free O2

In fermentation, the final electron acceptor is organic intermediates of the process, no externalsubstance.

Both anaerobic respiration and fermentation are incomplete oxidations. Inhibitory effect on respiration high conc. of oxygen is called Pasteur effect.

Steps of Respiration :-(1) Glycolysis – Occurs in cytosol/cytoplasm(2) Formation of Acetyl COA – (Link Reaction) Perimitochondrial space (outer chamber)(3) TCA cycle or Kreb's cycle – Matrix of mitochondria & cytosol in bacteria(4) ETS – Occurs in cristae or inner memberane of mitochondria and Oxidative phosphorylation

–Occrus in Oxysome head (F1 particle)

(1) Glycolysis – EMP – (Embden, Meyerhof, Parnas) pathway. The glycolysis is common phase for aerobic & anaerobic respirations both. Glycolysis involves a series of ten biochemical reactions in cytoplasm. In glycolysis, neither consumption of oxygen nor liberation of CO2 take place. In glycolysis, 1 glucose, produces 2mol. of pyruvic acids (3C) 2NADH2 & 2ATP are generated in glycolysis, which are equal to 8 ATP. Substrate level phosphorylation forms 4 ATP :- [When the substrate releases energy for

phosphorylation of ADP OR formation of ATP, without ETS then called as substrate levelphosphorylation]

Glycolysis is also known as oxidative anabolism or catabolic resynthesis, because itlinks with anabolism of fats and amino acids. An intermediate PGAL is used for the synthesisof glycerol later forms fats or lipid. PGA is used for synthesis of Serine, Glycine, Cystine.Alanine forms from pyruvate.



1, 3, 10 are irrev. reactis in EMP pathway.

Biochemical reactions of Glycolysis

Glucose Hexo Kinase

Mg++

ATP ADP

Glucose - 6P

2. Glucose-6P Isomerase Fructose - 6P

3. Fructose-6P Phosphofructokinase

Mg++

ATP ADP

Fructose -1,6-BiP

4. Fructose-1,6-BiP Aldolase

PGAL

DHAP

Isomerase

5. 2 PGAL Non enzymatic + 2 ip 1,3 Bi PGAL(2mol.)

(Phosphoglyceraldehyde)3 c

Starting of energy conserving phase :6. 2,1,3 BiPGAL dehydrogenase

2NAD 2NADH 2

1,3 Bi PGA (2mol.)( Iodoacetate inhibits this reaction)

7. 2,1,3 BiPGA Transphosphorylase

2ADP + ip 2ATP

(kinase) 3 – PGA (2mol.)

8. 2,3–PGA Phosphoglyceromutase 2-PGA

9. 2, 2–PGA Enolase

Mg++ 2, 2–PEP

10. 2-PEP Pyruvate kinase

2ADP + ip 2ATPK , mg+ + +

2, Pyruvic Acid(3C)

Phosphofructokinase is an allosteric enzyme. The phosphorylation of fructose 6 phosphateis the most important regulation point of glycolysis.

Phosphofructokinase has multiple allosteric modulator. It's activity is inhibited by ATP(–ve modulator) and stimulated by ADP & AMP (+ve modulator). Most of the biochemicalreactions catalysed by allosteric enzymes are irreversible type and these are control point ofglycolysis.

(2) Formation of Acetyl-Co-A :- (Link/Gateway reaction) When respiration is aerobic, then pyruvic acid is oxidised to form 2C compound – Acetyl

Co-A. It occurs in presence of O2 and CO2 is released first time during it. Acetyl Co-A is a connecting link between glycolysis & Krebs-cycle. Decarboxylation

and dehydrogenation (Oxidative decarboxylation) take place during formation of acetylCo-A.



Acetyl Co-A is formed in perimitochondrial space by enzyme pyruvate dehydrogenasecomplex. (Mg++, LA (Lipoic Acid), TPP(Thiamine pyrophosphate), NAD, CoA)

2Pyruvic Acid + 2Co–A 2Acetyl Co-A + 2CO2

Acetyl Co-A is also common intermediate between fat & carbohydrate metabolism.

(3) Kreb cycle / TCA (Tricarboxylic acid) Cycle / Citric acid cycle :- This cycle was discovered by H.A. Kreb. (Nobel prize) TCA cycle occurs in mitochondrial matrix or power house of cell. Kreb cycle begins by formation of citric acid [TCA(Tri carboxylic acid)] & O.A.A. is the

acceptor molecule of Acetyl CoA in Kreb's cycle. A number of Krebs cycle intermediates are used in synthetic (anabolic) pathways, thus TCA

cycle is also called amphibolic pathway or anaplerotic pathway. Succinyl CO–A is important for synthesis of porphyrin ring compounds like Chlorophylls,

Phytochromes, Cytochromes, Haemoglobin etc. -ketoglutaric acid (5c) involves in Amino Acid formation (Nitrogen-metabolism) Oxidation occurs at 4 sites in Kreb cycle. 3NADH2, 1FADH2 & 1GTP (ATP) produced by each turn of TCA cycle.(=12 ATP) All the enzymes of TCA cycle, except marker enzyme Succinic dehydrogenase (on inner

mitochondrial membrane) present in matrix.

Bio Chemical reactions in Krebs Cycle

1. Acetyl Co–A + OAA CitrateSynthase

Citric Acid + Co–A

(2C) (4C) (TCA)

2. Citric AcidAconitase

Fe

Cis Aconitic Acid Isocitrate

(6C)

3. Isocitrate + NAD+ IsocitricDehydrogenase

Oxalosuccinic Acid + NADH2

(6C)

4. Oxalosuccinic Acid MnDecarboxylase

Ketoglutarate + Co2

(6C) (5C)

5. Ketoglutaric AcidDehydrogenase comp.

NAD NADH 2

TPP, LA, Mg CoA++ ,

Succinyl Co A + Co2

(5C) (4C)(This reaction similar to link reaction)



6. Succinyl Co A Thiokinase

GDP + ip GTP

Succinic Acid + Co A(4C) (4C)

[Energy of thioester bond is released, which used in formation of GTP]

(GTP + ADPNucleoside

diphosphokinase GDP + ATP)

The GTP formed in reaction 6, reacts with ADP to form ATP and GDP, as GTP and ATPhave approximatly same energy.

7. Succinic Acid Succinic dehydrogenase

FAD FADH 2

Fumaric Acid(4C) (4C)

8. Fumaric Acid Fumarase Malic Acid(4C) (4C)

9. Malatedehydrogenase

NAD FADH 2

OAA (Acceptor of Acetyl CoA)(4C) (4C)

– Ketoglutaric acid + NH4+ + NAD (P)H

Glutamate

dehydrogenase Glutamate + H2O + NADP+

This is known as reductive amination . The first formed amino acid (in plants) is glutamic acid, which forms other types of amino

acids by the process of transamination.Ex. Glutamic acid + Pyruvic acid –Ketoglutarate + alanine.

(4) ETS & Oxidative phosphorylation : (Terminal oxidation of NADH2 & FADH2) ETS (Respiratory chain) consists of four components

(i) FP (FMN), (ii) Fe–S Protein, (iii) Co-Q (UQ) & (iv) Cytochromes. Cytochromes are cyto.-b, cyto. – C1 & cyto. – C, cyto-a & cyto a3. Now components of ETS are categorise as follows :

Name of complexes Components of ETS InhibitorsComplex-I FMN-NADH2 dehydrogenase Rotenone & amytalComplex-II CoQ/UQ-FADH2 dehydrogenase/Succinate dehydrogenaseComplex-III Cytochrome b-Cyto c1 antimycinComplex-IV Cyto. a and Cyto. a3 cyanide, COComplex-V ATP synthetase/ATPase

UQ and Cyto. c are mobile e– carriers in mitochondrial ETS. (PQ and PC is mobile in z-scheme)

Cytochrome a3 is last cytochrome in respiratory chain or electron transport chain (ETC).



O2 is last e– acceptor in oxidative phosphorylation & due to this metabolic water is formed.DNP (Dinitrophenol) and oligomycin both are called uncouplers.

Enzyme Cytochrome oxidase is responsible for oxidation of cyto. a3 & reduction of O2. Enzyme Cytochrome oxidase has cyto. a & a3 as its components. (Cu present in cyto a

and cyto. a3) Cytosolic or extra mitochondrial or glycolytic 2NADH2 comes at ETS by two type of

shuttles (Only in eukaryotes) :(i) Glycerol phosphate shuttle :- In brain/muscle cells.

GLYCEROL-PHOSPHATE SHUTTLE SYSTEM

Cytoplasm OM PMS IM Matrix

NADH2 FADH2

NADFAD

DHAPDHAPGlycerol PO4 Glycerol PO4

ETS

2NADH2 2FADH2 = 4ATP 1 Glucose = 36 ATP

(ii)Malate aspartate shuttle :-MALATE - ASPARTATE SHUTTLE SYSTEM

Cytoplasm OM PMS IM Matrix

NADH2 NADH2

NADNAD

OAAOAAMALATE MALATE

ASPARTICACID

ASPARTICACID

ETS

2NADH2 = 6ATP 1 Glucose = 38 ATP In prokaryotes, shuttle mechanism is absent. They always get 38 ATP from aerobic

respiration of 1 glucose mol. Cyanide inhibits the activity of cytochrome oxidase & inhibits the oxidation of cyto-a3. In mitochondria, of some plants alternative oxidase system is present, in which ETS

continues even in presence of cyanides. This type of respiration is known as cyanideresistance respiration or Alternate electron pathway. Ex. Spinacea, Pisum.



FMN

FMNH2

NADH2

FADH2

O2

NAD

FAD

Fe-S

CoQ

Cyt b

Fe-S

Cyt C1

Cyt C

Cyt a

Cyt a3

2H+

2H+

2H+

2H+

2H+

2H+

+++++

ADP+Pi

ATP

IMMPMS MATRIX

H O2

12

ETSOxidative phosphorylationChemiosmotic theory / Coupling theory :-

During ETC of respiration CoQ & FMN can releases H+ ions in perimitochondrial space andleads to differenctial H+ ion concetration across inner mitochondrial membrane. Thisdifferential H+ ion concentration across inner mitochondrial membrane leads to creation ofproton gradiant (PH gradient) and Electrical potential (diffrence of charge). Both arecollectively known as Proton motive force (PMF).

PMF donot allow stay of H+ ions in Perimitochondrial space (PMS) so they return towardsthe matrix through F0 particales selectively.

The passage of 3H+ ions activate ATP synthase and gives rise to 1ATP from ADP & Pi. Some physiologist beleive that passage of 2H+ ions through F0 particle or coupling factor or

proton channel leads to synthesis of 1 ATP.

2

2

10NADH 30 ATP

1Glucose 2FADH 4 ATP34ATP

? ?? ??? ?

?? ?? ?? ?? ?



Bioenergetics of respiration – (1 mol. of glucose)(1) EMP-Pathway

(i) ATP formed at substrate level phosphorylation 4.ATP(ii) ATP produced via ETS (2NADH2) 6 ATP(iii) ATP consumed in glycolysis 2 ATP

10 ATP – 2 ATP = 8 ATP

Gross – Expenditure = Net or Total gainDirect Gain = 2 ATP

(2) Link reaction or Gateway reaction –

2NADH2 = 6 ATP (via ETS)

(3) Kreb's Cycle –(i) ATP produced at substrate level phosphorylation = 2 GTP/2ATP

(ii) ATP produced via ETS

6NADH2 18 ATP2FADH2 4 ATP

24 ATP

Total 38 ATP

1 Sucrose = 80 ATP 1 Fructose 1,6–Bisphosphate = 40 ATP 1 Pyurvic acid = 15 ATP 1 Acetyl Co-A or 1 TCA cycle = 12

ATP Pentose phosphate pathway (PPP) /

HMP (Hexose mono phosphate) Shunt/ Warburg-Dickens pathways

PPP is also called as Warburg - Dickenspathway/HMP shunt/Phosphogluconolactone pathway/Carbohydrate degradation withoutmitochondria/Cytosolic oxidativedecarboxylation/Horecker -RackerPathway

Glycolysis & TCA cycle is the main route of carbohydrate oxidation, but Warburg & Dickens(1935) discovered an alternative route of carbohydrate break down, existing in plants, someanimal tissues (Mammary glands, adipose, liver & microbes).



HMP/PPP occurs when(i) NADPH2 requirement of cell increases during biosynthetic processes.(ii) When EMP pathway blocked by iodoacetate, fluorides, arsenates.(iii) When mitochondria is busy in other pathways.

Most of the intermediates are similar to Calvin cycle, but PPP is amphibolic and oxidativeprocess.

One ATP is utilised in phosphorylation of glucose, so net gain equals to 35 ATP. (12 NADPH2)

Significance of HMP shunt :-(1) An intermediate erythrose-P (4C) of this pathway is precursor of shikimic acid, which

goes to synthesis of aromatic compounds and amino acids.(2) This cycle provides pentose sugars Ribose-p for synthesis of nucleotides, nucleosides, ATP

and GTP.(3) A five carbon intermediate Ribulose-5-phosphate may used as CO2 acceptor in green

cells.(4) This pathway produces reducing power NADPH2 for the various biosynthetic pathways,

other than photosynthesis like fats synthesis, starch synthesis, hormone synthesis andchlorophyll synthesis.

(5) Intermediates like PGAL and fructose-6-phosphate of this pathway may link with glycolyticreactions.

-Oxidation of Fatty acids :- -oxidation takes place mainly in perimitochondrial space but also in glyoxisome,

peroxisome, cytosol. Liberation of 2C segments from the fatty acid mol. in the form of acetyl Co-A is known as

-oxidation. These acetyl-CoA provides ATP after oxidation in kreb cycle. Acetyl CoA is oxidised in TCA cycle to CO2 & H2O with the production of 12 ATP

molecules.

16C palmitic acidNADH2 FADH 2 Acetyl Co-A

Enzymes

( = 5 ATP) (2C) oxidised in Krebs cycle

5 ATP × 7 times = 35 ATP12 ATP × 8 Acetyl CoA = 96 ATP

131 ATP(1 stearic acid = 146 ATP) – 2 ATP consumed

1 palmitic acid = 129 ATP



Fats Carbohydrates Proteins

Amino acidsSimple sugars e.g. Glucose

Fatty acids and glycerol

Glucose 6-phosphate

Fructose 1.6 bisphosphate

Dihydroxy Acetone Phosphate Glyceraldehyde 3-phosphate

Pyruvic acid

Acetyl CoA

H O2

Co2

Krebscycle

Interrelationship among metabolic pathways showing respirationmediated breakdown of different organic molecules to CO2 and H2O

Glyoxylate Cycle

Discovered by Kornberg & Krebs,during germination of fatty seeds. This cycle converts fats into sugars so it is an example of gluconeogenesis in plants. Glyoxylate cycle occurs in glyoxisome, cytosol, & mitochondria.

Fermentation :- Cruick Shank & Pasteur (1898). Fermentation is much similar to anaerobic respiration, but this is an extracellular process &

substrate is present outside the cell. Energy released as heat, no ATP generated. Buchner discovered the enzyme zymase complex, which is responsible for alcoholic

fermentation.

Types of Fermentation :-(i) When the one type of product formed in fermentation then it is called homofermentation.(ii) When the products of fermentation process are more than one type, then process is

heterofermentation.(1) Alcoholic fermentation :-

This is the oldest & the best known type of fermentation performed by yeast & somebacteria.



C6H12O6 Zymase Bact

yeast

( .) 2C2H5OH + 2CO2 + Energy..

Alcoholic fermentation(2) Lactic acid fermentation :-

It occurs during curd formation.

Lactose Hexose / C6H12O6 Lactate de

Lactobacillus

hydrogenase 2C3H6O3

L. Acid

(3) Acetic acid fermentation :-This is aerobic fermentationC2H5OH + O2 Acetobacter sp. CH3COOH + H2O

Acetic acid

(4) Butyric acid fermentation :-In rancid butter, butyric acid fermentation takes place. Also in jute fiber.C6H12O6 C butyricum. C4H8O2 + 2CO2+ 2H2

Other eg. are curring of tea, tanning of leather, retting of fibers, processing of Tobacco

Respiratory quotient (R.Q.) The ratio of the volume of CO2 released to the volume of O2 taken in respiration is called R.Q.

2

2

vol. of CO liberatedR.Q.

vol. of O consumed

Value of R.Q. depends upon the type of respiratory substrate used & measured byGanong's respirometer.

(1) Carbohydrates :- R.Q. = 1C6H12O6 + 6O2 + 6H2O 6CO2 + 12 H2O + E

(2) Fat / Oil R.Q. = 0.70 or R.Q. < 12C51 H98O6 + 145O2 102 CO2 + 98 H2O +EFatty seeds germination-castor, R.Q. < 1

At the time of formation of fatty seeds, (maturing fatty seed) R.Q. is more than 1 becausemore CO2 is released than O2 consumed.

(3) Organic acids :- (In succulent xerophytes at day time)Malic acid :- R.Q. = 1.33C4H6O5+ 3O2 4CO2 + 3H2O + EnergyOxalic acid R.Q. = 4Citric acid R.Q. = 1.3



(4) Incomplete oxidation of carbohydrates :-In CAM plants during night :- R.Q. = 02C6H12O6+ 3O2 3C4H6O5 + 3H2O + Energy

(5) Protein :- R.Q. = 0.8 or 0.9 or < 1

(6) Anaerobic respiration :- RQ = Anaerobic respiration 2

2

2CO0O

(Infinite)

Factors Effecting Cell Respiration :-(1) Temperature :- Optimum temp. for respiration is between 20-35°C. Maximum temp. is

around 45°C. At low temp respiration is low due to inactivation of enzymes (Freeze preserve the food)

while at very high temp. decrease, as enzyme denatured. Q10 = 2 to 3 for respiration. Production of potato crop is high on the hill areas due to low temp. throughout year.

CPRI (Central potato Research Institute is situated at Kufri-Shimla (H.P.)

(2) Oxygen :- The inhibition of anaerobic respiration by O2 concentration is called as Pasteur'seffect.

The minimum amount of oxygen, at which aerobic respiration takes place & anaerobicrespiration become extinct is called as extinction point.

Oxygen concn at which both aerobic & anaerobic respiration take place simultaneously iscalled as transition point.

(3) CO2 :- If CO2 concentration increases, then rate of respiration decreases in plants, (becausestomata get closed).

(4) Salts :- If a plant is transferrered from water to salt solution, it's respiration increases, this isknown as salt respiration. Because absorption of ions requires metabolic energy.

(5) Hormones :- IAA, GA & cytokinin increase the respiration rate. The rapid increase in rate of respiration during ripening of fruits and senescence of leaves

and plant organs is called as "Climacteric respiration". This rate is decrease after sometime.It is due to production of ethylene hormone.

(6) Light :- Rate of respiration increases with increase in light intensity.Light controls the stomatal opening & influence on temp. and also produce respiratorysubstrates.

(7) Injury, disease & wounds :- The respiration increases due to injury wounding & infection.

(8) Inhibitors : CN, azides, DNP (Dinitrophenol), CO, rotenone, antimycin, amytal. etc inhibitthe respiration.

(9) Age : Rate of respiration is more in young cells. Rate of respiration at meristem apex ishigh.

(10) Water : Seeds are slow respiring part of plants, because dry seeds are deficient of H2O.



IMPORTANT POINTS OF RESPIRATION & ENZYMESNAD = Nicotinamide Adenine DinucleotideDPN = Diphospho Pyridine NucleotideNADP = Nicotinamide Adenine Dinucleotide PhosphateTPN = Triphospho Pyridine NucleotideFAD = Flavin Adenine DinucleotideFMN = Flavin Mono NucleotideCo-A = Adenosine Triphospho Panto Thenylthio Ethanol Acetyl Amine

ATP discovered by Lohman, while importance of ATP in metabolism by Lipman. 1 gram of fat equals to 9.8 K.Cal.

Proteins = 4.8 K. CalCarbohydrate = 4.4 K. Cal (Old 3.8 K. Cal)(Fat is energy rich respiratory substrate)

Almost all enzymatic reactions are reversible type. Cytochromes are Iron - porphyrin protein discoverd by MacMunn (Termed by Keilin) Entener - Doudoroff pathway, Occurs only in bacteria (Pseudomonas and Azotobacter

for Carbohydrate - oxidation. (Bact. respiration)1 ATP = 7.6 K.Cal. (now 1 ATP = 8.9 K. Cal.)

Imp. Coenzymes are :-Co - I (NAD) / DPN.......................... NiacinCo - II (NADP) / TPN .......................NiacinFAD ....................................................... RiboflavinFMN....................................................... RiboflavinTPP ....................................................... ThiamineCO - Q .................................................. UbiquinoneCO-R ..................................................... BiotineCO - A ................................................... Pantothenic Acid

Important Co-factor :-Fe++ = Cytochrome oxidase, catalase, peroxidase, aconitaseCu++ = Cytochrome oxidase, tyrosinaseZn++ = Carbonic anhydrase, alcohol dehydrogenaseMg++ = Hexokinase, glucokinase, pyruvate kinase, pepcase, Rubisco.K+ = Pyruvate kinase



Mn++ = arginase, ribonucleotide reductase, decarboxylase.Mo= Nitrogenase complex, Nitrate reductase.Se = Glutathione peroxidase

When respiratory substrate is fats or proteins, then level of Hg rises in Ganong's respirometer,because more O2 absorbed than CO2 released.

In bacteria site of ETS is mesosome.

Respiration efficiency :-

1 glucose = 686 Kcal. 38 ATP × 7.6 Kcal. = 288 Kcal

100686

= 42%

Thus efficiency of aerobic respiration is 42% +. For the complete oxidation of one glucose if, in option 38 or 36 ATP are not given, then the

answer goes to 32 or 30 ATP.

Significance of respiration :-1. The energy released during respiration is used for the various metabolic processes.2. Various chemical substances are formed in this process which are important for cellular

componants.3. CO2 released in this process maintains a balance in the atmosphere.4. Complex insoluble food materials are converted into simple soluble molecules by this

process.5. It converts the stored (static)energy into more useful (kinetic) form.



1. Which one is both structural & functional (catalytic) protein :(1) Hexokinase (2) Myosine (3) Ribozyme (4) Acetyl Co-A

2. The following is required both by the process of respiration and photosynthesis(1) Carbohydrates (2) Sunlight (3) Chlorophyll (4) Cytochromes

3. Which one of the following is not true for iso enzymes ?(1) iso enzymes are quartenary proteins (2) all forms synthesized by different genes'(3) increase activation energy of substrate. (4) All the above

4. Number of every cytochrome molecule require for transfer of 2e— in ETS :(1) 2 (2) 4 (3) 1 (4) 10

5. Kreb's cycle takes place in(1) Vesicles of E.R. (2) Mitochondrial matrix(3) Dictyosomes (4) Lysosomes

6. Most of the energy of the carbohydrates is released by oxidation when(1) Pyruvic acid is converted into CO2 and H2O(2) Pyruvic acid is converted into acetyl Co-A(3) Sugar is converted into pyruvic acid(4) Glucose is converted into alcohol and CO2

7. The universal hydrogen acceptor is(1) NAD (2) ATP (3) Co-A (4) FMN

8. Iron-porphyrin protein complex occurs in –(1) phytochrome (2) cytochrome (3) chlorophyll (4) both (1) and (3)

9. In the process of Respiration in plants 180 gm of Glucose plus 192 gm of oxygenproduce –(1) 132 gm of CO2, 54 gm of H2O & 483 Cal .E.(2) 264 gm of CO2,216 gm of H2O, & 686 K.Cal E.(3) 200 gm of C2H5OH, 72 gm of H2O & 21 K. Cal E.(4) None

10. Respiratory enzymes are localised in(1) Ribosomes (2) Chloroplast (3) Mitochondria (4) none of the above

11. Glycolysis involves the conversion of(1) Protein into glucose (2) Glucose into fructose(3) Starch into glucose (4) Glucose into pyruvic acid

EXERCISE



12. The end product of glycolysis is(1) Glycolate & ethanol (2) Glyoxylic acid & CO2

(3) Glucose or hexose units (4) Pyruvate13. The common phase between aerobic & anaerobic respiration is

(1) TCA cycle (2) Kreb's cycle (3) Glycolysis (4) Photo respiration14. Which of the following scientist discovered the conventional path of anaerobic glycolysis

(1) Embeden, Myerhof and Parnas (2) Emerson, Hoffman and Peterson(3) Embeden, Morrison and Pitcher (4) Warburg, Dickens and Horecker

15. What is active glucose(1) FAD glucose (2) NAD glucose (3) Glucose-6-P (4) Glycerophosphate

16. The enzyme which converts glucose to glucose-6-phosphate -(1) Phosphorylase (2) Gluco-phosphorylase(3) Hexokinase (4) Phospho glucomutase

17. Glycolysis give rise to(1) 8ATP, 2NADH2, 2 Pyruvate (2) 2ATP, 2CoA, 2NADH2

(3) 2ATP, 2NADH2 ,2 Pyruvate (4) 2ATP, 2 acetate, 2NADPH2

18. The inhibitory effect of the presence of O2 on anaerobic respiration is termed :(1) Warburg effect (2) Pasteur effect (3) Emerson's effect (4) Oxygen effect

19. During glycolysis the mineral needed as an enzyme activator is(1) Mn++ (2) Fe++ (3) Ca++ (4) Mg++

20. Anaerobic respiration was reported for the first time by(1) Pasteur (2) Kosty chev (3) Klein (4) Pfeffer

21. Which of the following is not an enzyme ?(1) Oxidase (2) Pepsin (3) Auxin (4) Trypsin

22. Enzyme capable of changing their shape are called(1) Apoenzyme (2) Coenzyme(3) Allosteric enzyme (4) Co-factor

23. What is the chemical nature of the majority of prosthetic groups?(1) Lipoidal (2) Organic (3) Metallic (4) Alkaloidal

24. Which of the following coenzyme is a derivative of pantothenic acid ? (vit - B complex)(1) NAD (2) NADP (3) FAD (4) Co-A

25. Which of the following is not consumed in a biochemical process ?(1) Hormone (2) Enzyme (3) vitamin (4) Nucleotide

26. The chief enzyme found in yeast cell is ?(1) Invertase (2) Maltase (3) Zymase (4) Amylase

27. Which of the enzyme joins the broken strands of DNA ?(1) Nuclease (2) Kinase (3) Ligase (4) Endonuclease



28. Inhibition of succinic dehydrogenase by malonate is an example of(1) Competitive inhibition (2) Non competitive inhibition(3) Allosteric inhibition (4) Enzyme repression

29. At a temperature below the freezing point an enzyme is(1) Unaffected (2) Inactivated(3) Slightly inactivated (4) Killed

30. At boiling temperature an enzyme is(1) Denatured (2) Unaffected (3) Inactivated (4) Killed

31. Which enzyme break downs the fructose-1, 6-Diphosphate ?(1) Hexokinase (2) Phosphatase (3) Aldolase (4) None

32. How many ATP equivalent energy will be produced by HMP shunt ?(1) 40 ATP (2) 38 ATP (3) 35 ATP (4) 8 ATP

33. Link between glycolysis & TCA cycle is –(1) Pyruvic acid (2) Acetyl Co-A (3) Citric acid (4) None

34. Acceptor of acetyl Co-A in Kreb's-cycle is(1) Malic acid (2) Fumaric acid(3) – ketoglutaric acid (4) Oxalo acetic acid

35. Enzyme alternate oxidase is inhibited by :(1) NADP(2) SHAM (Salicyl hydroxamic acid)(3) m - CLAM (m-chloro-benzhydroxamic acid)(4) 2 & 3

36. When 2-pyruvic acids forms two lactic acid by anaerobic respiration then ?(1) One ATP is lost (2) 3 ATP is lost (3) 6 ATP is lost (4) None

37. During oxidative phosphorylation following provides energy for the ATP formation –(1) Co-A (2) NADPH(3) Efflux of proton to PMS (4) Pyruvic acid

38. Anaerobic respiration takes place in :(1) Ribosome (2) Nucleus (3) Cytoplasm (4) Vacuole

39. What is the energy coin of a cell ?(1) DNA (2) RNA (3) ATP (4) Minerals

40. Allosteric enzymes have allosteric sites for –(1) Inhibition only (2) Activation only(3) Reduction in activation energy (4) Both activation and inhibition

41. Conversion of pyruvic acid into ethyl alcohol is facilitated by the enzymes(1) Carboxylase (2) Dehydrogenase(3) Decarboxylase and dehydrogenase (4) Phosphatase



42. During anaerobic respiration in yeast(1) Water and CO2 are end products(2) CO2, C2 H5 OH and energy are end products(3) H2 S, C6 H12 O6 and energy are the end products(4) H2 O, CO2 and energy are the only end products

43. Fermentation is represented by the equation\(1) C6H12O6 + 6O2 6CO2 + 6H2O + 673 k cal(2) C6H12O6 2C2H5OH + 2CO2 + 18 k cal

(3) 22612622 66126 OOHOHCOHCOlChlorophyl

Light

(4) 6CO2 + 6H2O C6 H12O6 + 6O244. Anaerobic respiration takes place in the

(1) Mitochondria (2) Cytoplasm (3) Lysosomes (4) ER45. Anaerobic synthesis found in bacteria is

(1) Endergonic (2) Exergonic(3) Isothermal (4) None of the above

46. End product of anaerobic respiration is(1) Glucose (2) Pyruvic acid(3) Ethyl alcohol and CO2 (4) None of the above

47. In anaerobic respiration in plants(1) Oxygen is taken in (2) Oxygen is given out(3) Carbon dioxide is given out (4) Carbon dioxide is taken in

48. Anaerobic respiration was first of all reported by(1) Maguenne (2) Kostychev (3) Klein (4) Pfeffer

49. What is the total gain of energy during anaerobic respiration(1) One molecule of ATP (2) Two molecules of ATP(3) Four molecules of ATP (4) Eight molecules of ATP

50. In fermentation, yeast secrets one of the following enzyme(1) Invertase (2) Zymase (3) Dehydrogenase (4) Anolase

ANSWER KEY

Q.No. 1 2 3 4 5 6 7 8 9 10Ans. 2 4 3 1 2 1 1 2 2 3Q.No. 11 12 13 14 15 16 17 18 19 20Ans. 4 4 3 1 3 3 3 2 4 2Q.No. 21 22 23 24 25 26 27 28 29 30Ans. 3 3 2 4 2 3 3 1 2 1Q.No. 31 32 33 34 35 36 37 38 39 40Ans. 3 3 2 4 4 3 3 3 3 4Q.No. 41 42 43 44 45 46 47 48 49 50Ans. 3 2 2 2 1 3 3 2 2 2

14 respiration in plant · respiration in plant kad tutorial opc. pvt. ltd. kota • contact :...

Documents