Question

What is activation energy? What effect does on enzyme have on the required activation energy? Give the function of each of the following: (a) coenzyme (b) allosteric site Explain the roles of the following in aerobic respiration: (a) NAD+ (b) oxygen List the end products of glycolysis

Answer 1

1. Answer:

• In a chemical reaction the minimum amount of energy required to form products
• Though catalyst/enzymes are having vacant d-orbitals, so it;s easier to make new and break old bonds of a product and reactants respectively.
• Though in enzyme-linked reactions, lock, and key mechanism works, so it becomes easy for the enzyme to facilitate the reaction in a proper orientation.
• the enzymes form an intermediate product called as ES complex(enzyme substrate complex), during this condition the enzymes lowers the activation energy than the initial.
• of course, without intermediate product, there is no way to form the product.

2. Answer:

(a) Coenzyme: There is a specific location on an enzyme which binds to substrates and converts them into products. That location is called as the active site, is where the coenzymes bind.

There are some ways in which coenzymes help in enzyme function, that includes changing their shape to activate, or aiding in chemical reactions by acting as carriers of energy or molecular groups.

(b) allosteric sites:

the site on which an enzyme molecule binds with a non-substrate molecule is called allosteric site. that induces a conformational change which results in an alteration of the affinity of the enzyme for its substrate.

these not only speed up the reactions in metabolic pathways but also control the rates of pathways. In order to bind with the signaling molecules to specific regulatory sites, allosteric enzymes are involved, they also regulate the reaction rate. This binding induces conformational changes which result in alterations in catalytic activity.

3. Answer

(a) NAD become NADH because it becomes electron carriers. This happens during the breakdown of Acetyl CoA in the Krebs Cycle inside the second membrane of the mitochondria. The electrons are supplied to the Electron Transport Chain on the internal membrane by NADH; due to this transfer of the electron's energy allows the proteins crossing the membrane to pump hydrogen ions into the space between the two membranes and creates a gradient for chemiosmosis.

(b) Oxygen

due to the presence of Oxygen, the energy released from the breakdown of glucose gives more energy. In this process, oxygen combines with glucose (oxidation of glucose is taken lace) to form Carbon dioxide and water and ATP.

As the electrons go down the chain, their energy is caught which controls a H+ pump to pump the H+ ions out of the internal mitochondrial matrix and into the intermembrane matrix (recollect the mitochondria have 2 membranes-inward and external and that between the 2 membranes is the intermembrane matrix). The pumping out of H+ causes a concentration gradient (a distinction in concentration over the internal membrane) which tempts the H+ ions to stream once more into the inward matrix through a unique structure that catches the energy from this action and uses it to frame ATP. The H+ ions in addition to the electrons they beforehand surrendered now join with oxygen to frame water. The part of oxygen is to be utilized as a part of this last stride. It is important to frame water while creating a great deal of ATP by this component. Without oxygen, the cell can just experience glycolysis and make little measures of ATP and lactic acid.

Hope this may help you the role of oxygen

4.Answer

At the end of glycolysis, each molecule of glucose gives rise to

2 molecules of pyruvate,

2 molecules of NADH,

a net of 2 molecules of ATP.

Energy in the form of ATP (adenosine tri-phosphate).