Cellular Respiration - Aerobic and Anaerobic

Pyruvate oxidation, the Krebs cycle, and the electron transport chain occur in the mitochondria to produce ATP, CO2, and water.

The process of glycolysis yields 2 net ATPs and 2 NADH molecules. NADH is converted into ATP in mitochondrial electron transport chain if oxygen is present. In anaerobic respiration, there is no oxygen available so NADH does not lead to the formation of ATP molecules. Without oxygen, NADH builds up and the cell can run out of NAD. Without NAD glycolysis stops. To regenerate NAD, cells with anaerobic respiration carry out the process of fermentation in which NADH gets converted into NAD to restart glycolysis. 

In plants, the stoma is a tiny opening found on the under-surface of leaves. These pores provide the passage for the entry of the air and the exchange of gases. They are also useful during transpiration for the escape of water vapour into the atmosphere.

So the correct option is 'Stomata'

Plants perform photosynthesis to obtain the light energy from direct sunlight and convert it into chemical energy. This process utilizes carbon dioxide, water and sunlight to produce carbohydrates and oxygen. It acts as a counterbalance to respiration by utilizing the carbon dioxide generated by all breathing organisms and giving out the oxygen back to the atmosphere. 

So the correct option is ' Carbon Dioxide, Oxygen'

• The growth of Obligate aerobes will be slow in comparison to the other bacteria.
  
• These group of bacteria require oxygen to grow as they cannot respire anaerobically.
• Its growth depends on aerobic respiration and use oxygen as a terminal electron acceptor.
  
• The correct answer is OPTION A.

The HMP pathway or pentose phosphate pathway that produces 5 carbon compound and NADPH in the form of energy. Additionally, these pathways can operate in the anabolic direction to transform glycolytic intermediates into other compounds. So, HMP pathway is a  direct oxidation pathway performed without glycolysis cycle. HMP shunt produces some glycolytic intermediated like glyceraldehyde-3-phosphate and fructose-6-phosphate that can directly involve in the glycolysis pathway or EMP. Thus, the correct answer is option A.

Hydrolysis of complex organic compounds (like in anaerobic digestion) typically occurs under anaerobic conditions, where oxygen is absent.

Respiration is the process in which the food substrate is broken down to produce energy-rich molecules. In the aerobic respiration, the respiration is carried out in the presence of oxygen and carbon dioxide with water are released as products. This is an essential process in all the living organisms for the production of ATP. 

Aerobic respiration is the breakdown of glucose in the presence of oxygen and anaerobic respiration is the breakdown of energy in absence of oxygen.

Aerobic respiration is a type of respiration in which the breakdown of organic compounds takes place with the presence of oxygen and release a large amount of energy in the form of ATP.

Aerobic respiration is the complete oxidation of sugars in presence of oxygen.

Aerobic respiration requires oxygen and it takes place in mitochondria and produces carbon dioxide, water and 686 kilo calories of energy.

Anaerobic respiration occurs in the absence of oxygen and is less efficient than aerobic respiration. Unlike aerobic respiration, the end products here are ethyl alcohol as in alcoholic fermentation and lactic acid as in animal cells. So the answer is 'Ethyl alcohol and lactic acid'.

Oxygen from air is the chief requirement for aerobic respiration to take place in the cells. However, in absence of air or oxygen, many organisms are capable to respire using anaerobic respiration. Life without air is considered anaerobic.

Anaerobic respiration takes place in the the cytoplasm of the cell, at a distance from mitochondria. After the glycolysis, pyruvate is further oxidised anaerobically producing energy which is much less than that produced aerobically.

Glycolysis takes place in the anaerobic condition in the cytosol of cytoplasm in all cells, Krebs cycle takes place in the aerobic condition in the mitochondrial matrix of eukaryotic cells.

Acetyl CoA is synthesized during oxidative decarboxylation of pyruvic acid and the reaction takes place in the mitochondrial matrix in which two molecules of NADH are produced and it enters the citric acid cycle.

The pentose phosphate pathway (PPP) or HMP shunt is a biochemical pathway parallel to glycolysis that generates NADPH (reduced energy) and pentoses. PPP was described by Warburg and Dickens. 

An anaerobic respiration a type of respiration in which an organism generates usable energy without the involvement of oxygen. So, in brief, it is respiration without oxygen. It was first reported by Kostychev.

A.Oxidation – Release of electrons and protons or reaction with oxygen

B.Reduction – Acceptance of electrons and protons or release of oxygen.

C. Hydrolysis – Breaking of molecules in presence of water.

D.Synthesis – Process of formation of biomolecules.

So, the correct option is ‘oxidation’.

Fermentation is an anaerobic energy-releasing process where an organic substrate is oxidized without an external inorganic electron acceptor. In contrast, aerobic and anaerobic respiration use an electron transport chain.

The complete aerobic oxidation of one mole of glucose releases approximately 686 kcal of energy under standard biological conditions. This is a standard biochemical constant taught in cellular respiration.

In cellular respiration: NADH and FADH2 are converted to ATP through an electron transport chain with oxygen as the 'terminal electron acceptor'. Oxygen is the final electron acceptor. This is the only reason oxygen is required for living systems.

Substrate level phosphorylation provides quicker, less efficient, source of ATP, independent of external electron acceptors.This is only present in human erythrocytes which have no mitochondria and in oxygen depleted muscle. 

Glucose breakdown into pyruvic acid in the absence of oxygen and in the absence of oxygen pyruvic acid is converted into lactic acid even yeast in converted to ethyl alcohol in no-oxygen.

Yeast possesses good fermentation potential in the absence of oxygen. Saccharomyces grow anaerobically (without oxygen) same as it grows in aerobically (with oxygen).

The first statement is the correct one which say the organism grow with no oxygen is called as anaerobes.

Maximum number of ATP is generated per glucose molecule oxidation by aerobic respiration.

Aerobic respiration occurs in the presence of oxygen. Glycolysis, Krebs' cycle and ETS are all stepwise processes of aerobic respiration. While glycolysis occurs in the cytoplasm, Krebs' cycle and ETS both take place in the mitochondria of the cell. 

A unicellular organism like yeast can carry out both aerobic as well as anaerobic respiration depending on the environmental conditions. Anaerobic respiration is usually alcoholic fermentation and the end products are ethanol and carbon dioxide. Aerobic respiration produces CO$ _2$ and H$ _2$O as end products.

In anaerobic respiration (fermentation) in yeast, 1 molecule of glucose yields 2 ATP molecules. To produce 38 ATP molecules, one needs 38 / 2 = 19 glucose molecules.

Anaerobic respiration is a type of respiration where energy is produced in the absence of oxygen. It occurs in plant cells and some microorganisms (such as yeast) and produces ethanol and carbon dioxide in the presence of little or no oxygen. For example, the roots of plants in waterlogged soils and bacteria in puncture wounds.

Anaerobic respiration is a process of formation of energy in the absence of oxygen. Fermentation is a form of anaerobic respiration and called as intramolecular respiration. Intramolecular respiration is characteristic of certain tissues (the meristem, the fleshy parts of fruits, tubers). Chemically, the intramolecular respiration of green plants is closely related to alcoholic fermentation. 

Anaerobic respiration in plants typically results in ethanol and carbon dioxide (alcoholic fermentation). Lactic acid fermentation is characteristic of animals and some bacteria.