Introduction and types of respiration Questions in English

(C) Respiration is the metabolic process in living organisms,including plants,by which organic compounds (primarily glucose) are broken down to release energy in the form of $ATP$ (Adenosine Triphosphate).
Photosynthesis is an anabolic process that stores energy in the form of glucose.
Transpiration is the loss of water vapor from the aerial parts of plants.
Water absorption is the process of taking up water from the soil through the roots.
Therefore,the correct process for energy production is respiration.

(C) Respiration is a metabolic process in which living cells break down glucose to release energy in the form of $ATP$.
Unlike photosynthesis,which requires light and occurs only during the day,respiration is a continuous process that occurs in all living cells of a plant.
It takes place throughout the day and night to maintain cellular functions and growth.
Therefore,plants respire $24$ hours a day.

(A) The conversion of pyruvic acid to acetyl $CoA$ is known as the link reaction or oxidative decarboxylation.
In this process,pyruvic acid $(3C)$ undergoes oxidative decarboxylation to form acetyl $CoA$ $(2C)$.
During this reaction,one molecule of $NAD^+$ is reduced to $NADH + H^+$,and one molecule of $CO_2$ is released.
Since pyruvic acid loses electrons (via $NAD^+$ reduction) and hydrogen,it undergoes oxidation.

(C) Respiration is a fundamental metabolic process that occurs in all living cells of an organism,including plants.
It involves the breakdown of respiratory substrates (like glucose) to release energy in the form of $ATP$.
Unlike photosynthesis,which is restricted to green parts and occurs only in the presence of light,respiration is a continuous process that occurs $24$ hours a day in all living cells (roots,stems,leaves,etc.) to maintain cellular functions.

(C) The conversion of $1$ molecule of pyruvic acid into $1$ molecule of acetyl $CoA$ is known as the link reaction or oxidative decarboxylation of pyruvate.
During this process,$1$ molecule of $NAD^+$ is reduced to $1$ molecule of $NADH + H^+$.
This reaction does not directly produce any $ATP$ molecules.
Therefore,the net gain of $ATP$ during this specific step is $0$.

(A) Respiration is a catabolic process in which organic compounds, primarily glucose, are oxidized to release energy. The overall chemical equation for aerobic respiration is:
$C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy (ATP)}$.
As shown in the equation, the final products of aerobic respiration in plants are carbon dioxide $(CO_2)$, water $(H_2O)$, and energy in the form of $ATP$.

(A) The primary respiratory substrate used by living organisms for cellular respiration is $Glucose$.
Cellular respiration is the process of breaking down food materials within the cell to release energy,and $Glucose$ is the most preferred and readily available source of energy for this process.
Other substrates like fats and proteins are used only when $Glucose$ is unavailable.

(D) The conversion of $Pyruvic$ $acid$ $(3C)$ into $Acetyl-CoA$ $(2C)$ occurs in the mitochondrial matrix.
This process is catalyzed by the $Pyruvate$ $dehydrogenase$ complex.
During this reaction,one molecule of $CO_2$ is released (decarboxylation) and $NAD^+$ is reduced to $NADH + H^+$ (oxidation).
Therefore,this step is known as $Oxidative$ $decarboxylation$.

(C) Respiration and combustion are both oxidative processes,but they differ significantly in several ways:
$1$. Respiration is a controlled,multi-step enzymatic process occurring within cells,whereas combustion is a rapid,uncontrolled,non-enzymatic process.
$2$. In respiration,energy is released in a stepwise manner and stored as $ATP$,while in combustion,energy is released rapidly as heat and light.
$3$. Respiration requires specific enzymes to catalyze the reactions,which are absent in combustion.
$4$. Therefore,respiration differs from combustion due to the involvement of enzymes,the controlled release of energy,and the storage of energy as $ATP$.

(A) Respiration is a catabolic process in which organic molecules like glucose are broken down to release energy in the form of $ATP$.
Since energy is released during this process,it is considered an exothermic process.
Therefore,the correct option is $A$.

(A) Respiration is a catabolic process in which organic compounds,primarily glucose,are broken down to release energy in the form of $ATP$.
This energy is essential for various metabolic activities within the cell.
While respiration involves gas exchange,its fundamental biological purpose is the liberation of stored chemical energy from food molecules.

(A) Respiration is a catabolic process in which organic compounds, primarily glucose $(C_6H_{12}O_6)$, are oxidized in the presence of oxygen $(O_2)$ to release energy in the form of $ATP$.
The overall chemical equation for aerobic respiration is: $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy}$.
Therefore, glucose and oxygen are the essential raw materials required for the process of aerobic respiration.

(D) Respiration is a metabolic process that provides energy for cellular activities.
Meristematic tissues,such as $Cambium$ and $Primordia$,are actively dividing and growing,which requires a high rate of metabolic activity and thus a high rate of respiration.
In contrast,$Mature$ $plants$ and $mature$ $tissues$ have completed their growth and development phase,leading to a significantly lower metabolic demand and a slower rate of respiration.
Therefore,mature plants and mature tissues exhibit slow respiration.

(C) Respiration is a process in which complex organic molecules,such as glucose $(C_6H_{12}O_6)$,are broken down into simpler substances like carbon dioxide $(CO_2)$ and water $(H_2O)$ to release energy in the form of $ATP$.
Since this process involves the breakdown of complex molecules into simpler ones,it is classified as a catabolic process.
Anabolic processes involve the synthesis of complex molecules from simpler ones,whereas metabolic processes encompass both anabolic and catabolic reactions.

(B) Respiration is a metabolic process in which living organisms produce energy by breaking down glucose in the presence of oxygen. The general chemical equation for aerobic respiration is: $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy (ATP)}$. As shown in the equation, $CO_2$ (carbon dioxide) is released as a byproduct during this process.

(A) Respiration is a metabolic process that occurs in all living cells to release energy from organic compounds. Unlike photosynthesis,which requires light,respiration is independent of light and occurs continuously in all living cells,whether they are green or non-green,and in both light and dark conditions.

(B) Respiration is a complex biochemical process involving a series of metabolic reactions. Each step in these pathways,such as glycolysis,the Krebs cycle,and the electron transport chain,is catalyzed by specific enzymes. Enzymes are biological catalysts that lower the activation energy of reactions,thereby regulating the rate and sequence of the respiratory process. Therefore,the steps of respiration are controlled by enzymes.

(C) Respiration is a catabolic process where organic compounds,primarily glucose,are oxidized to release energy.
In germinating seeds,high metabolic activity occurs,leading to the breakdown of stored food.
This process is not $100\%$ efficient in converting chemical energy into $ATP$; a significant portion of the energy is released as heat.
This can be demonstrated experimentally using a thermos flask,where the temperature rises as the seeds respire.

(A) The term 'cytoplasmic' respiration is used when the respiratory substrate is $Carbohydrate$. In aerobic respiration,carbohydrates (like glucose) are broken down in the cytoplasm during glycolysis to form pyruvate,which then enters the mitochondria. When other substrates like proteins or lipids are used,they often require more complex processing or enter the respiratory pathway at different stages,and the term 'cytoplasmic' is specifically associated with the primary breakdown of carbohydrates in the cytoplasm.

(D) Cellular respiration is a metabolic process in which cells break down glucose to produce energy in the form of $ATP$.
While $CO_2$ is released as a byproduct during the process,the primary biological purpose and defining characteristic of cellular respiration is the release of energy stored in chemical bonds to perform cellular work.
Therefore,the process is fundamentally associated with the release of energy.

(C) Respiration is a cellular process that involves the oxidation of glucose to produce energy $(ATP)$ in the form of cellular respiration.
This process takes place in the mitochondria of all living cells of the body to sustain metabolic activities.
While the lungs are involved in the exchange of gases ($O_2$ and $CO_2$),the actual process of cellular respiration occurs within every living cell.

(A) During seed germination,the metabolic activity of the embryo increases significantly. The stored food (such as starch,proteins,or fats) is broken down through the process of respiration to provide energy for the growing seedling. Respiration is an exothermic process,meaning it releases energy in the form of heat. Therefore,heat is released during seed germination.

(B) In living organisms,glucose acts as a primary respiratory substrate. The energy required for various metabolic activities is derived from the breakdown of glucose through the process of cellular respiration. This process involves the controlled oxidation of glucose molecules,which releases energy stored in the chemical bonds,subsequently trapped in the form of $ATP$ (Adenosine Triphosphate). Therefore,the oxidation of glucose is essential for fulfilling the energy requirements of living organisms.

(D) The process of respiration involves the breakdown of respiratory substrates to release energy.
Among the given options, $Glucose$ $(C_6H_{12}O_6)$ is the most common and primary respiratory substrate used by cells to produce $ATP$ through glycolysis and subsequent aerobic or anaerobic respiration.
While other carbohydrates like starch or sucrose are eventually converted into glucose before entering the respiratory pathway, glucose remains the fundamental substrate.

(C) All living organisms require energy for their metabolic activities,growth,and repair. This energy is primarily derived from the oxidation of organic compounds,commonly referred to as food (such as glucose). Through the process of cellular respiration,the chemical energy stored in the bonds of food molecules is released and converted into $ATP$ (Adenosine Triphosphate),which serves as the energy currency of the cell.

(B) Respiration is a catabolic process in which complex organic molecules like glucose are broken down to release energy in the form of $ATP$.
Since energy is released during this process,it is classified as an exergonic process.
An endergonic process is one that requires the input of energy,which is the opposite of respiration.
Therefore,the correct answer is $B$.

(D) Respiration is the biochemical process in which the $C-C$ bonds of complex organic compounds (like glucose) are broken down through oxidation within the cells.
This process releases a significant amount of energy,which is stored in the form of $ATP$ (Adenosine Triphosphate).
Photosynthesis is an anabolic process that stores energy,while transpiration and root pressure are physiological processes related to water movement in plants.
Therefore,the correct process is Respiration.

(A) The link reaction,also known as the transition reaction or oxidative decarboxylation of pyruvate,acts as a bridge between glycolysis and the Krebs cycle.
In this process,the end product of glycolysis,pyruvate $(3C)$,undergoes oxidative decarboxylation to form Acetyl $CoA$ $(2C)$.
This reaction is catalyzed by the pyruvate dehydrogenase complex in the mitochondrial matrix.
Therefore,the correct reaction is Pyruvate $\rightarrow$ Acetyl $CoA$.

(D) Mature mammalian red blood cells $(RBCs)$ lack mitochondria and other organelles.
Since mitochondria are the sites of aerobic respiration (the Krebs cycle and electron transport chain),$RBCs$ cannot perform aerobic respiration to metabolize glucose into $CO_2$.
Instead,they rely entirely on anaerobic glycolysis to produce $ATP$ for their energy requirements.

(N/A) Respiratory substrates are the organic compounds that are oxidized during the process of cellular respiration to release energy in the form of $ATP$.
$1$. The most common respiratory substrate is $Glucose$ (a carbohydrate).
$2$. Other substances like fats, proteins, and organic acids can also act as respiratory substrates depending on the metabolic requirements of the cell.

(N/A) All living organisms require energy to perform essential biological activities. This energy is derived through the process of respiration.
$1$. Energy Requirement: Organisms need energy for daily life processes such as absorption,transport,movement,and reproduction. This energy is obtained from the food consumed.
$2$. Connection to Food: The process of respiration is fundamentally linked to the release of energy from food. Energy is obtained by the oxidation of macronutrients (food).
$3$. Autotrophs: Green plants and cyanobacteria synthesize their own food via photosynthesis,converting light energy into chemical energy stored in the bonds of carbohydrates like $glucose$,$sucrose$,and $starch$.
$4$. Cellular Limitation: In plants,only cells containing chloroplasts (usually in superficial layers) perform photosynthesis. Other cells,tissues,and organs depend on the energy stored in these carbohydrates.
$5$. Heterotrophs and Saprophytes: Animals (heterotrophs) obtain food directly or indirectly from plants,while saprophytes (like fungi) obtain nutrients from dead and decaying matter. Ultimately,all life relies on the energy stored through photosynthesis,which is released via respiration.

(N/A) Respiration is the process of breaking down $C-C$ bonds of complex organic compounds through oxidation within the cells, which leads to the release of a considerable amount of energy.
Respiratory substrates: The compounds that are oxidized during the process of respiration to yield energy are known as respiratory substrates.
Carbohydrates are the most common respiratory substrates. However, proteins, fats, and even organic acids can also be used as respiratory substrates in some plants under certain conditions.
During cellular oxidation, the energy contained in respiratory substrates is not released in a single step. Instead, it is released through a series of slow, enzyme-controlled, step-wise reactions.
This energy is trapped as chemical energy in the form of $ATP$ $(Adenosine Triphosphate)$. $ATP$ acts as the energy currency of the cell, providing energy for various metabolic processes.
Additionally, the carbon skeletons produced during respiration serve as precursors for the biosynthesis of other essential molecules within the cell.

(N/A) Each living cell in a plant is located quite close to the surface of the plant. This is true for leaves.
In stems,the 'living' cells are organized in thin layers inside and beneath the bark. They also have openings called lenticels.
The cells in the interior are dead and provide only mechanical support.
Thus,most cells of a plant have at least a part of their surface in contact with air. This is also facilitated by the loose packing of parenchyma cells in leaves,which provide an interconnected network of air spaces.
$C_{6}H_{12}O_{6} + 6O_{2} \rightarrow 6CO_{2} + 6H_{2}O + \text{Energy}$
The complete combustion of glucose,which produces $CO_{2}$ and $H_{2}O$ as end products,yields energy,most of which is given out as heat. If this energy is to be useful to the cell,it should be able to utilize it to synthesize other molecules that the cell requires.
The key is to oxidize glucose not in one step but in several small steps,enabling some steps to be just large enough such that the energy released can be coupled to $ATP$ synthesis.

(N/A) During the process of respiration,$O_2$ is utilized and $CO_2$,$H_2O$,and energy are released as products. The combustion reaction requires $O_2$.
However,some cells live in environments where $O_2$ may or may not be available.
The first cells on this planet lived in an atmosphere that lacked $O_2$.
Even among present-day living organisms,several are adapted to anaerobic conditions.
Some of these organisms are facultative anaerobes,while in others,the requirement for anaerobic conditions is obligate.
In any case,all living organisms retain the enzymatic machinery to partially oxidize glucose without the help of $O_2$. This breakdown of glucose into pyruvic acid is called glycolysis.

(A) Pyruvate is formed by the glycolytic catabolism of carbohydrates in the cytosol.
After entering the mitochondrial matrix,it undergoes oxidative decarboxylation through a complex set of reactions catalyzed by the enzyme complex pyruvic dehydrogenase.
Pyruvic dehydrogenase functions in the presence of cofactors like $NAD^{+}$ and Coenzyme $A$ $(CoA)$.
The reaction is: $\text{Pyruvic acid} + CoA + NAD^{+} \xrightarrow{Mg^{2+}, \text{Pyruvate dehydrogenase}} \text{Acetyl } CoA + CO_{2} + NADH + H^{+}$.
During this process,two molecules of $NADH$ are produced from the metabolism of two molecules of pyruvic acid (which were produced from one glucose molecule during glycolysis).
The resulting Acetyl $CoA$ then enters a cyclic pathway known as the tricarboxylic acid cycle,or Krebs' cycle.

(N/A)

Fermentation	Aerobic Respiration
$(1)$ Glucose is partially broken down into ethanol or lactic acid.	$(1)$ Glucose is completely oxidized into $CO_{2}$ and $H_{2}O$.
$(2)$ Only $2$ net molecules of $ATP$ are produced per glucose molecule.	$(2)$ $A$ large amount of $ATP$ molecules are produced.
$(3)$ Oxidation of $NADH$ to $NAD^{+}$ is a slow process.	$(3)$ Oxidation of $NADH$ to $NAD^{+}$ occurs rapidly.
$(4)$ It is a relatively simple process.	$(4)$ It is a complex process involving multiple pathways like the Krebs cycle and $ETC$.
$(5)$ Occurs primarily in microorganisms like yeast and some bacteria.	$(5)$ Occurs in most higher organisms.

(N/A)

Aerobic Respiration	Anaerobic Respiration
$(1)$ $O_{2}$ is utilized in this process.	$(1)$ $O_{2}$ is not utilized in this process.
$(2)$ Complete oxidation of respiratory substrates occurs.	$(2)$ Incomplete oxidation of respiratory substrates occurs.
$(3)$ Includes three phases: Glycolysis,Krebs' cycle,and Oxidative phosphorylation.	$(3)$ Process occurs primarily through Glycolysis followed by fermentation.
$(4)$ More energy is released (net $38$ $ATP$ per glucose molecule).	$(4)$ Less energy is produced (net $2$ $ATP$ per glucose molecule).
$(5)$ End products are $CO_{2}$ and $H_{2}O$.	$(5)$ End products are Ethanol + $CO_{2}$ or Lactic acid.

(N/A) $(1)$ The respiratory substrate,such as glucose,undergoes glycolysis in the cytoplasm (protoplasm) to produce pyruvic acid. This pyruvic acid then enters the mitochondria,where the Krebs cycle and oxidative phosphorylation take place. In these organelles,the respiratory substrate is completely oxidized,and energy is released in the form of $ATP$.
$(2)$ Unlike animals,plants do not possess specialized respiratory organs for gas exchange. Instead,they utilize stomata,lenticels,and general surface areas. Each part of the plant manages its own gas exchange requirements independently. Furthermore,the internal transport of gases between different plant parts is minimal,and the overall metabolic demand for gas exchange is lower in plants compared to animals. Consequently,the rate of respiration in plants is relatively slow.

(N/A) $\Rightarrow$ Plants require water for essential metabolic processes such as photosynthesis,transpiration,and respiration. However,excessive watering leads to plant death.
$\Rightarrow$ When the soil is waterlogged,the water fills the spaces between soil particles,displacing the air (oxygen) that is normally present.
$\Rightarrow$ Consequently,the roots are deprived of oxygen,which is necessary for aerobic respiration. Without oxygen,root cells cannot function and eventually die.
$\Rightarrow$ Once the root cells die,the plant loses its ability to absorb water and essential mineral nutrients from the soil,leading to the gradual death of the entire plant.

(N/A) Step-wise oxidative breakdown: Respiration is a phase-wise or step-wise oxidation of organic substances,which includes three main phases:
$(i)$ Glycolysis
$(ii)$ Krebs' cycle
$(iii)$ Electron transport system $(ETS)$.
Glucose undergoes a series of enzyme-catalyzed reactions,and at the end,it forms $H_2O$,$ATP$,and $CO_2$.
$(b)$ Organic substances: These are carbon-containing compounds found in living systems,typically in ring or long-chain forms,bonded with hydrogen,oxygen,and nitrogen atoms. Examples include glucose,fatty acids,and amino acids.
These substances are oxidized to release energy. The respiration of glucose and fatty acids is called floating respiration,while the respiration of amino acids is called protoplasmic respiration.

(N/A) The process of aerobic respiration is distributed into multiple steps: Glycolysis,$TCA$ cycle,$ETS$,and oxidative phosphorylation.
$1$. Energy conservation: If all energy were released in a single step,most of it would be lost as heat,making it unavailable for cellular work.
$2$. $ATP$ synthesis: Step-wise release allows the cell to capture energy in the form of $ATP$ molecules at various stages.
$3$. Enzymatic control: Each step is catalyzed by specific enzymes,allowing the cell to regulate the rate of respiration based on its energy requirements.
$4$. Efficiency: This sequential release ensures that the process is highly efficient and prevents the cell from being damaged by a sudden,massive release of heat energy.

(D) Cellular respiration involves the utilization of oxygen by organisms to indirectly break down nutrient molecules like glucose.
This process releases energy,which is used for performing various metabolic activities.
Additionally,carbon dioxide is produced and released as a byproduct during this process.

(B) The process described is cellular respiration.
Cellular respiration occurs continuously throughout the day and night in all living cells.
During this process,glucose is oxidized to produce $ATP$ (energy),$CO_2$ (carbon dioxide),and water $(H_2O)$.
Unlike photosynthesis,cellular respiration is not a light-dependent process.

(A) The process described involves the release of $ATP, CO_2,$ and water, which are characteristic products of cellular respiration.
Since it occurs throughout the day and is not light-dependent, it refers to aerobic respiration.
Respiration is a catabolic process because it involves the breakdown of complex organic molecules like glucose into simpler substances to release energy.
The chemical equation for this process is: $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy (ATP)}$.

(A) The process described is cellular respiration,which occurs throughout the day in all living cells. During aerobic respiration,glucose $(C_6H_{12}O_6)$ and oxygen $(O_2)$ are consumed as raw materials to produce $ATP$,$CO_2$,and water $(H_2O)$. This process is independent of light. Therefore,the raw materials are glucose and $O_2$.

(B) Water transport occurs through xylem vessels and tracheids,which are dead at maturity and lack protoplasm to provide an unobstructed path for water movement.
Food transport occurs through phloem sieve tube elements,which remain living and contain protoplasm at maturity to actively transport nutrients.

(D) Respiration is the process of breaking down respiratory substrates like glucose to release energy. In a starving plant,the availability of respiratory substrates is very low,which limits the rate of respiration. When glucose is provided,it acts as a readily available substrate,thereby increasing the rate of respiration.

(A) Respiration is defined as the process of breaking down the $C-C$ bonds of various organic molecules through oxidation to release energy for cellular use.

(A) Respiratory substrates are organic compounds (like glucose,fats,or proteins) that are broken down in the cell to release energy.
During the process of cellular respiration,these substrates undergo oxidation in the presence of oxygen (or through anaerobic pathways) to release energy in the form of $ATP$.
Therefore,the correct answer is that they are oxidised.

(A) In cellular respiration, glucose undergoes complete oxidation in the presence of oxygen to produce carbon dioxide, water, and energy. The balanced chemical equation for this process is:
$C_{6}H_{12}O_{6} + 6O_{2} \rightarrow 6CO_{2} + 6H_{2}O + \text{Energy}$