Biomolecules Test 1

Amount of usable energy which is available for doing work when the temperature and pressure are uniform throughout the system is called gibbs free energy.

△G is a change in gibbs free energy.

Anabolic pathways require an input of energy to synthesize complex molecules from simpler ones.
Example: Synthesis of large proteins from amino acid building blocks, and the synthesis of new DNA strands from nucleic acid building blocks.

These biosynthetic processes are critical to the life of the cell, take place constantly, and demand energy provided by ATP and other high-energy molecules like NADH (nicotinamide adenine dinucleotide) and NADPH.

Living organisms are not in equilibrium because the system at equilibrium cannot perform work. As living organisms work continuously, they cannot afford to reach equilibrium. 

The living organisms exist in a steady-state characterized by the concentration of each of the biomolecules. These biomolecules are in metabolic flux.

On complete combustion of one glucose molecule into carbon dioxide and water, the great amount of energy is released i.e. about 686 kilocalories. On the metabolism of the glucose molecule, it can take place by the process of respiration in which energy is released in the form of ATP.

Respiration can takes place by two mechanisms:
(I) Aerobic respiration: This is the process in which the metabolism takes place in the presence of oxygen.
(II) Anaerobic respiration: This process takes place in the absence of oxygen.
The ATP production rate changes with the type of respiration. In aerobic respiration the net ATP produced is 38. One ATP yields approximately 10 kilocalories of energy. Thus, the energy liberated during the metabolism of one mole of glucose is 380 kilocalories.

The correct option is D i.e. 380.

Additional information: The respiration mainly involves 3 processes that are:
- Glycolysis: In this process the glucose (6C) molecule gets converted into the two molecules of pyruvate (3C). The pyruvate formed is converted into Acetyl coA in presence of ions and pyruvate dehydrogenase enzyme.
- Kreb’s cycle: It is also known as Tricarboxylic acid cycle (TCA) or citric acid cycle. In this process Acetyl coA is entered into the TCA cycle which is the cyclic process. It is responsible for the production of ATP in large amounts. It takes place in a mitochondrial matrix.
- Electron transport system: In this system, the NADH and FADH formed in the krebs cycle are utilized and produce 3 molecules of ATP and 2 molecules of ATP respectively.
 

All chemical reactions, including exothermic reactions, need activation energy to get started.
Activation energy is needed so reactants can move together, overcome forces of repulsion, and start breaking bonds.

The rate of oxygen consumption is commonly used to infer metabolic energy use in heterotrophic organisms because these organisms use oxygen in respiration to release energy via the Krebs cycle. 

Allosteric control refers to a type of enzyme regulation involving the binding of a non-substrate molecule, known as the allosteric effector, at locations on the enzyme other than the active site.

All the biomolecules are constantly being changed into some other biomolecules and also made from some other biomolecules. The turnover of biomolecules takes place continuously. All these reactions are together called metabolism.

Calories are needed to provide energy so, the body functions properly. The number of calories in a food depends on the amount of energy the food provides.

The number of calories a person needs depends on age, height, weight, gender and activity level. People who consume more calories than they bum off in normal daily activity or during exercise are more likely to be overweight.
Fat (1 gram) = 9 calories
Protein (1 gram) = 4 calories
Carbohydrates (1 gram) = 4 calories
Tri-glycerol is an ester derived from glycerol and three fatty acids. It is the main constituent of vegetable oil and animal fats.

Therefore, the approximate ratio of the energy content in kcal/g of carbohydrate: protein : tri-glycerol is 1 : 1 : 2.

Catabolic pathways involve the degradation of complex molecules into simpler ones, releasing the chemical energy stored in the bonds of those molecules. Conversion of glucose to lactic acid glucose molecule is catabolic pathway.