Chapter 12: Respiration in Plants

Question 1

All the energy required for life processes is obtained by oxidation of some macromolecules that we call ____________

Answer 1

Food

Question 2

Only green plants and _______________ can prepare their own food; by the process of Photosynthesis they trap light energy and convert it into chemical energy that is stored in the bonds of carbohydrates like glucose, sucrose and starch

Answer 2

Cyanobacteria

Question 3

Even in green plants all other organs, tissues and cells that are non-green, need food for ______________

Answer 3

oxidation

Question 4

Animals are _______________, i.e., they obtain food from plants directly(herbivores) or indirectly (Carnivores)

Answer 4

Heterotrophic

Question 5

Fungi are ________________ , dependent on dead and decaying matter

Answer 5

Saprophytes

Question 6

Photosynthesis takes place within the _________________(in the eukaryotes), whereas the breakdown of complex molecules to yield energy takes place in the cytoplasm and in the ________________ (also only in eukaryotes)

Answer 6

Chloroplasts

Mitochondria

Question 7

The breaking of the C-C bonds of complex compounds through oxidation within the cells, leading to release of considerable amount of energy is called ___________________

Answer 7

Respiration

Question 8

The compounds that are oxidised during this process are known as _________________

Answer 8

Respiratory substrates

Question 9

Usually ______________ are oxidised to release energy, but proteins, fats and even organic acids can be used as respiratory substances in some plants, under certain conditions

Answer 9

Carbohydrates

Question 10

Energy released by oxidation in respiration is cannot be used directly but is used to synthesise _______________

Answer 10

ATP

Question 11

ATP acts as the ___________ currency of the cell.

Answer 11

Energy currency

Question 12

In stems, the living cells are organised in thin layers inside and beneath the bark. They also have openings called __________

Answer 12

Lenticels

Question 13

The complete combustion of glucose, which produces CO₂ and H₂O as end products, yields energy most of which is given out as heat the equation is

C₆H₁₂O₆ + ___ O₂ ——-> _____ CO₂ + 6H₂O + energy

Answer 13

C₆H₁₂O₆ + 6O₂ ——-> 6CO₂ + 6H₂O + energy

Question 14

During respiration , the combustion reaction requires ___________

Answer 14

oxygen

Question 15

All living organisms retain the enzymatic machinery to partially oxidise glucose without the help of oxygen. this breakdown of glucose to Pyruvic acid is called ______________

Answer 15

Glycolysis

Question 16

The scheme of glycolysis was given by Gustav Embden, Otto Meyerhof and J. Parnas, and is ofen referred to as the ___________ pathway

Answer 16

EMP pathway (glycolysis)

Question 17

In anaerobic organisms, ____________ is the only process in respiration

Answer 17

Glycolysis

Question 18

Glycolysis occurs in the __________ of the cell and is present in all living organisms

Answer 18

Cytoplasm

Question 19

In glycolysis(EMP) process, glucose undergoes partial oxidation to form two molecules of ________________, In plants, this glucose is derived from sucrose, which is the end product of photosynthesis

Answer 19

pyruvic acid (pyruvate)

Question 20

In plants __________ is converted into glucose and fructose by the enzyme, invertase and these two monosaccharides readily enter the glycolytic pathway

Answer 20

Sucrose

Question 21

Glucose and fructose are phosphorylated to give rise to glucose-6-phosphate by the activity of the enzyme ________________

Answer 21

Hexokinase

Question 22

The phosphorylated form of glucose then Isomerises to produce ___________________

Answer 22

Fructose-6-phosphate

Question 23

In glycolysis, a chain of Ten(10) reactions, under the control of different enzymes, takes place to produce ____________ from glucose

Answer 23

Pyruvate (pyruvic acid)

Question 24

ATP is utilised at two steps: first in the conversion of glucose into ________________ and second in the conversion of fructose-6-phosphate to __________________

Answer 24

Glucose-6-phosphate

fructose1,6-bisphosphate

Question 25

The **Fructose1,6-bisphosphate** is split into **dihydroxyacetone phosphate** and _____________________

Answer 25

**3-phosphoglyceraldehyde** (PGAL)

Question 26

There is one step where **NADH + H⁺** is formed from **NAD⁺** ; this is when **3-phosphoglyceraldehyde** (**PGAL**) is converted to __________________

Answer 26

**1,3-bisphosphoglycerate** (1, 3-bisphosphoglyceric acid) (**BPGA**)

Question 27

The conversion of **BPGA** to **3-phosphoglyceric acid (PGA)**, is also an energy yielding process; this energy is trapped by the formation of __________

Answer 27

**ATP**

Question 28

Another **ATP** is synthesised in glycolysis during the conversion of **PEP (phosphoenolpyruvate)** to _____________

Answer 28

**Pyruvic acid** (pyruvate)

Question 29

_____________ is then the key product of **glycolysis**

Answer 29

**Pyruvic acid** (pyruvate)

Question 30

There are three major ways in which different cells handle **Pyruvic acid** produced by **glycolysis** these are 1.______________ 2.______________ 3.______________

Answer 30

1. **lactic acid fermentation** 2. **alcoholic fermentation** 3. **aerobic respiration**

Question 31

_________________ takes place under **anaerobic conditions** in many **prokaryotes** and **unicellular eukaryotes**.

Answer 31

**Fermentation**

Question 32

For complete oxidation of glucose to **CO₂** and **H₂O** , organisms adopt __________cycle which is also called as **aerobic respiration**. This requires **O₂** supply

Answer 32

**Krebs' cycle**

Question 33

In fermentation by **yeast**, the incomplete oxidation of **glucose**is achieved under **anaerobic conditions** by sets of reactions where pyruvic acid is converted to ________ and _________

Answer 33

**CO₂** **Ethanol** Note:- The enzymes, **pyruvic acid decarboxylase** and **alcohol dehydrogenase** catalyse these reactions.

Question 34

Some bacteria produce **lactic Acid** from _______________

Answer 34

**pyruvic acid**

Question 35

In animal cells also, Like **muscles** during exercise, when **oxygen** is inadequate for cellular respiration **pyruvic acid** is reduced to **lactic acid** by enzyme _________________

Answer 35

**lactate dehydrogenase**

Question 36

In both **lactic acid** and **alcohol** fermentation not much energy is released; less than __________ percent of the energy in glucose is released and not all of it is trapped as high energy bonds **ATP**

Answer 36

**7 %**

Question 37

**Yeasts** poison themselves to death when the concentration of **alcohol** reaches about __________ percent

Answer 37

**13 %**

Question 38

______________ respiration is the process that leads to a **complete oxidation** of organic substances in the presence of **oxygen** and release **CO₂**

Answer 38

**Aerobic respiration** Note:- takes place within the mitochondria

Question 39

**Aerobic respiration** take place within the **mitochondria**, the final product of **glycolysis**,____________ is transported from the **cytoplasm** into the **mitochondria**

Answer 39

**Pyruvate**

Question 40

The complete oxidation of **Pyruvate** by the stepwise removal of all the _____________ atoms, leaving **three** molecules of **CO₂**

Answer 40

**Hydrogen**

Question 41

The complete oxidation of **Pyruvate** in aerobic respiration takes place in the matrix of __________________

Answer 41

**Mitochondria**

Question 42

The passing of electron or **Electron transport system**(ETS) is located on the ____________ membrane of the **Mitochondria**

Answer 42

**Inner membrane**

Question 43

**Pyruvate**(pyruvic acid), after it enters mitochondrial matrix undergoes oxidative decarboxylation catalysed by **pyruvic dehydrogenase** require the participation of several **coenzymes**, including **NAD⁺ and _______________

Answer 43

**Coenzyme A**

Question 44

________ molecules of **NADH** are produced from the metabolism of **two** molecules of **pyruvic acid**(produced from one glucose molecule during glycolysis)

Answer 44

**Two**

Question 45

The **acetyl CoA** enters a cyclic pathway, **tricarboxylic acid cycle**, more commonly called as __________ cycle

Answer 45

**Krebs' cycle** note: Scientist name **Hans Krebs**

Question 46

The **TCA** cycle starts with the condensation of **acetyl group** with **oxaloacetic acid (OAA)** and water to yield __________

Answer 46

**citric acid** (Citrate)

Question 47

Citrate is isomerised to isocitrate and after two successive steps of decarboxylation, leading to the formation of **α-ketoglutaric acid** and then _______________

Answer 47

**succinyl-CoA**

Question 48

During the conversion of of **succinyl-CoA** to **succinic acid** a molecule of ____________ is synthesised.

Answer 48

**GTP**(guanosine triphosphate)

Question 49

**GDP**(guanosine diphosphate) is converted to **GTP**(guanosine triphosphate) with the simultaneous synthesis of _________ from **ADP**

Answer 49

**ATP**

Question 50

There are **three** points in the **TCA**(Tricarboxylic Acid Cycle) or **Krebs' cycle** where **NAD⁺** is reduced to **NADH + H⁺** and __________ point where **FAD⁺** is reduced to **FADH₂**

Answer 50

**One**

Question 51

In **TCA** cycle glucose has been broken down to release **CO₂** and _________ molecules of **NADH + H⁺**; **two** of **FADH₂** have been sysnthesised besides just two molecules of **ATP** in **TCA** cycle

Answer 51

**8 (eight)** **Pyruvic acid +4NAD⁺ +FAD⁺+2H₂O+ADP+Pi→3CO₂+4NADH+4H⁺+ATP+FADH₂** note:- its per **Pyruvate** calculation , for every glucose there was **two** pyruvate from glycolysis ​

Question 52

The metabolic pathway through which the electron passes from one carrier to another, is called the ________________ and it is present in the **inner mitochondrial membrane**

Answer 52

***Electron transport system (ETS)*** or **oxidative phosphorylation** note: This is the system where **oxygen** is used in **respiration**

Question 53

Electrons from **NADH** produced in the mitochondrial matrix during **citric acid cycle** are oxidised by an ______________ (**complex I**)

Answer 53

**NADH** dehydrogenase (complex I)

Question 54

After **Complex I**( NADH dehydrogenase) electrons are then transferred to _________________

Answer 54

**Ubiquinone** Note:- in picture **Ubiquinone** is marked as **Q**

Question 55

**Ubiquinone** also receives reducing equivalents via **FADH₂** which is also known as **Complex II** or _________________

Answer 55

**Succinate dehydrogenase** (complex II)

Question 56

The reduced ***ubiquinone*** (**ubiquinol**) is then oxidised with the transfer of electrons to **cytochrome c** via **Cytochrome bc₁** (also known as) ___________________

Answer 56

**Complex III**

Question 57

**Cytochrome c** is a small protein attached to the ***outer surface*** of the ___________ membrane and acts as a mobile carrier for transfer of electrons between **complex III** and **IV**

Answer 57

***inner membrane***

Question 58

**complex IV** refers to **cytochrome c oxidase** complex containing ___________ and _________ **Copper** centres.

Answer 58

**Cytochromes a and a₃** **Two (2)**

Question 59

When the **electrons** pass from one carrier to another via **complex I** to **IV** in the **ETS**, they are coupled to **ATP Synthase** (**Complex V**) for the production of **ATP** from ______ and ___________

Answer 59

**ADP** **Inorganic phosphate**(P_i)

Question 60

Oxidation of one molecule of **NADH** gives rise to _______ molecules of **ATP** while that of one molecule of **FADH₂** produces _______ molecules of **ATP**

Answer 60

**Three (3)** **Two (2)**

Question 61

The presence of **oxygen** is vital, since it drives the whole process by removing ___________ from the system

Answer 61

**hydrogen**

Question 62

**Oxygen** acts as the final ____________ acceptor.

Answer 62

**Hydrogen**

Question 63

The energy released during the **electron transport system** (ETS) is utilised in synthesising **ATP** with the help of ____________ (**complex V**). This complex consists of two major components, **F₁** and **F₀**.

Answer 63

**ATP synthase** Note:- **F₀** lie within inner mitochondrial membrane and **F₁** lies in mitochondrial matrix

Question 64

In **ATP synthase** the __________ headpiece is a peripheral membrane protein complex and contains the site for synthesis of **ATP** from **ADP**

Answer 64

**F₁**

Question 65

For each **ATP** produced ___ **H**⁺ passes through **F₀** from the intermembrane space to the matrix down the electrochemical proton gredient.

Answer 65

**4** (four)

Question 66

There can be a net gain of _______ **ATP** molecules during **aerobic respiration** of one molecule of **Glucose**

Answer 66

**38**

Question 67

Fermentation accounts for only a **partial breakdown** of **glucose** whereas in **aerobic respiration** it is completely degraded to ________ and __________

Answer 67

**CO₂** **H₂O**

Question 68

In fermentation there is a net gain of only ________ molecules of **ATP** for each molecule of glucose degraded to **pyruvic acid**.

Answer 68

**Two**

Question 69

All **carbohydrates** are usually first converted into _________ before they are used for **Respiration**

Answer 69

**Glucose**

Question 70

Other substrate can also be respired, as **Fat** would need to be broken down into __________ and ____________ first

Answer 70

**Glycerol** **Fatty acids**

Question 71

If **Fatty acids** from **fats** were to be respired they would first be degraded to ___________ and enter the pathway.

Answer 71

**acetyl CoA**

Question 72

**Glycerol** from **fat** would enter the pathway after being converted to ______________

Answer 72

**PGAL**

Question 73

The respiratory pathway is involved in both **anabolism** and **catabolism**, it would hence be better to consider the respiratory pathway as an _____________ rather than as a catabolic one.

Answer 73

**Amphibolic Pathway**

Question 74

The **ratio** of the volume of **CO₂** evolved to the volume of **O₂** consumed in respiration is called the _____________________ or **respiratory ratio**

Answer 74

**respiratory quotient** (**RQ**)

Question 75

When carbohydrates are used as substrate and are completely oxidised, the **RQ** (respiratory quotient) will be __________, because equal amounts of CO₂ and O₂ are evolved and consumed.

Answer 75

**1** (One)

Question 76

When fats are used in respiration, the **RQ** is _______. Calculations for a fatty acid , **tripalmitin** if used as substrate is

Answer 76

**less than 1**

Question 77

When **proteins** are respiratory substrates the **RQ** ratio would by about ____________

Answer 77

**0.9**