IBDP Chemistry Question Analysis Topic: Chemistry - Short Questions
Exam Questions:
1) What type of bonding helps in stabilizing the α−helix structure of proteins?
2) Of physisorption or chemisroption, which has a higher enthalpy of adsorption?
Answer:
For IBDP Chemistry, you should know:
1) Alpha helices are stabilized by hydrogen bonding. The alpha-helix (α-helix), which is a right-hand-coiled or spiral conformation (helix), is a frequent motif in the secondary structure of proteins. Every backbone N-H group gives a hydrogen bond to the backbone C = O group of the amino acid.
2) While physisorption is an exothermic process, it has low enthalpy values due to its weak van der Waals forces (20-40 kJ mol-1). It is basically a reversible process as well due to its low activation energy.
Chemisorption is exothermic too, however as it involves formation of chemical bonds, the enthalpy values are higher (80-240 kJ mol-1). Hence, it has a higher enthalpy of adsorption.
Work hard for your IBDP Chemistry examination!
End of analysis. Great!