The SN2 (Substitution Nucleophilic Bimolecular) reaction is a type of nucleophilic substitution reaction that involves the simultaneous interaction of two reactant molecules: a nucleophile and a substrate. The steps of an SN2 reaction are as follows: Nucleophile attack: In the first step of the reaction, the nucleophile approaches the substrate molecule and attacks the carbon atom that is attached to the leaving group (Cl). The nucleophile displaces the leaving group and forms a new bond with the carbon atom. Formation of a transition state: As the nucleophile attacks the substrate molecule, the leaving group starts to depart from the carbon atom, leading to the formation of a transition state with a pentacoordinate intermediate. This transition state is energetically unfavorable and has a high activation energy barrier, which means that the reaction rate is dependent on the concentration of both the nucleophile and the substrate. Formation of the product: In the final step of the r...

  How glucose levels are control in the cells?   Hexokines and Glucokinase are two enzymes that both convert glucose into glucose-6-phosphate. But the Km of Glucokinase is higher than the Hexokines. That means the affinity of Glucokinase is lower than that of Hexokines. Therefore, when  the concentration of glucose in the cell is low, Glucokinase Cannot convert converts glucose to glucose 6 phosphate. And since the Km of Hexokines is low, Hexokines can convert glucose into glucose 6 phosphate even if the concentration of glucose is low. On the other hand, the V max of Glucokinase is higher than Hexokines. As a result, when there is more glucose in the cell, Glucokinase can convert glucose into glucose 6 phosphate but Hexokines cannot. Thus, these two enzymes control the glucose level in the cells.

  How Glucose transport into the cell? Glucose cannot diffuse directly into cells, but enters by  one of two transport mechanisms: 1.    Na + -independent, facilitated diffusion transport sys tem 2.    Na + -monosaccharide cotransporter system.   Na + -independent, facilitated diffusion transport sys tem   This system is mediated by a family of 14 glucose  transporters in cell membranes.They are designated GLUT-1 to GLUT-14 (glucose  transporter isoforms 1–14). These transporters exist in the membrane in two  conformational states. Extracellular glucose binds to the transporter, which  then alters its conformation, transporting glucose across  the cell membrane. In facilitated diffusion, glucose movement follows a  concentration gradient, that is, from a high glucose concentration  to a lower one. For example, GLUT-1, GLUT-3, and GLUT-4 are primarily  involved in glucose uptake from the ...

  How blood glucose level is maintained normally in fasting state ? Ans: 1.    Reduction of Uptake of glucose by less vital tissues Due to low insulin level, glucose uptake by muscle and adipose tissue is reduced due to inhibition of glut-4-transporter 2.    Stimulation of glycogenolysis Glucagon through its receptors in liver cells activates phosphorylase enzyme through cyclic AMP. 3. Stimulation of gluconeogenesis Glucagon stimulates gluconeogenesis from amino acids through alanine- glucose cycle Lactate forms glucose in liver through Cori cycle - Lactate-glucose cycle. Epinephrine promotes glycogenolysis in muscle and on catabolism , lactate produced is carried to liver for gluconeogenesis     What is the   Difference Between Catabolism and Anabolism? Difference Between Catabolism and Anabolism Catabolism breaks down big complex molecules into smaller, easier to absorb molecules. Anaboli...