Respiration in Plants Test - 4

• Holozoic modes of nutrition is a method of nutrition that involves the ingestion of liquid or solid organic material, digestion, absorption and assimilation of it to utilize it.
  Example: Amoeba. 
• Saprophytes are the animals which feed on dead and decaying animals.
  Example: Moulds, Mushroom etc. 
• Parasitic mode of nutrition is that in which organism feeds on a living organism (host).
  Example: Leach, Flatworm,Plain worms etc. 
• Autotroph is an organism that manufactures its own food from inorganic substances, such as carbon dioxide and ammonia. Most autotrophs, such as green plants, certain algae, and photosynthetic bacteria, use light for energy.

The energy stored to synthesize a larger number of ATP molecules.

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

During anaerobic respiration, incomplete oxidation of glucose takes place but during aerobic respiration complete oxidation of glucose occurs in which less energy is produced.

The two molecules of pyruvic acid (produced from one glucose molecule during glycolysis). The acetyl CoA then enters a cyclic pathway, tricarboxylic acid cycle, more commonly called as Krebs’ cycle. Thus, acetyl-CoA interconnecting between two cyclic pathways.

Plants unlike animals have no special systems for breathing or gaseous exchange. Stomata and lenticels allow gaseous exchange by diffusion.

In this process, glucose undergoes partial oxidation to form two molecules of pyruvic acid.

Aerobic respiration is the process that leads to a complete oxidation of organic substances in the presence of oxygen, and releases carbon dioxide, water and a large amount of energy present in the substrate. This type of respiration is most common in higher organisms.

Aerobic Respiration:

Fermentation is a kind of anaerobic respiration in absence of oxygen to produce ethanol and carbon dioxide gas. Dough kept overnight in warm place becomes soft and spongy due to carbon dioxide gas released during fermentation.

When proteins are respiratory substrates the ratio would be about 0.9.

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

In animal cells, like muscles during exercise, when oxygen is inadequate for cellular respiration pyruvic acid is reduced to lactic acid by lactate dehydrogenase. The reducing agent is NADH+ and H+ which is reoxidised to NAD+ in both the processes.

Citrate is first isomerised to isocitrate and then followed by decarboxylation, leading to the formation of α-ketoglutaric acid.

Anaerobic respiration in man occurs in muscle cells during sudden activity in cells to form lactic acid. In yeast anaerobic respiration occurs in absence of oxygen to form ethanol.

During breakdown and synthesis of protein too, respiratory intermediates form the link. Breaking down processes within the living organism is catabolism, and synthesis is anabolism. Because the respiratory pathway (Kreb’s cycle) is involved in both anabolism and catabolism, it would hence be better to consider the respiratory pathway.

• Oxysomes refer to small round structures present within the folds of the cristae of the inner mitochondrial membrane. It is also known as F₀-F₁ particles.
• F₀ and F₁ particles are found in the inner mitochondrial region and are attached to the cristae and help in ATP production and oxidation.

Reduction in consumption of respiratory substrate when the mode of respiration is changed from aerobic to anaerobic is called pasture effect. It is studied in the case of Saccharomyces.

Acetyl CoA is the connecting link between glycolysis and Kreb's cycle. The end product of glycolysis is pyruvate. It is converted to Acetyl CoA which enters the krebs cycle by combining with oxaloacetic acid (OAA) to form a 6 - C compound citric acid.

Acetyl CoA (2-carbon compound) combines with oxaloacetate (4-carbon compound) in the presence of condensing enzyme citrate synthase to form a tricarboxylic 6-carbon compound called citric acid. It is the first product of kerbs' cycle. CoA is liberated.

The ratio of the volume of carbon dioxide evolved to the volume of oxygen consumed in respiration is called the respiratory quotient(RQ) or respiratory ratio

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

Formation of pyruvate is not a prerparatory phase or energy spending phase of Glycolysis. In this phase one ATP molecule is released.

Fermentation is the process of anaerobic respiration in which incomplete oxidation leads to formation of ethanol in absence of oxygen. Fermentation occurs in yeast.

There is a sequential, orderly pathway functioning, with one substrate forming the next and with glycolysis, TCA cycle and ETS pathway following one after another.

The value of R.Q. depends upon the nature of the respiratory substrate (the organic food matter oxidised in respiration) and its oxidation.