Hydrogen bonding

Definition

Hydrogen bonding is a type of attractive interaction that occurs between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom. This interaction is crucial in stabilizing the structures of many biological molecules, such as proteins and nucleic acids, and plays a significant role in determining the physical properties of water.

5 Must Know Facts For Your Next Test

1. Hydrogen bonds are typically weaker than covalent bonds, but they are crucial for the structure and function of biomolecules.
2. The unique properties of water, such as its high boiling point and surface tension, are largely due to hydrogen bonding between water molecules.
3. In DNA, hydrogen bonds between complementary base pairs hold the double helix structure together, allowing for stable genetic information storage.
4. Proteins achieve their secondary and tertiary structures through hydrogen bonding between amino acid side chains and backbone atoms.
5. Hydrogen bonds can be influenced by changes in temperature and pH, which can lead to denaturation of proteins and other biomolecules.

Review Questions

• How do hydrogen bonds contribute to the structural stability of biomolecules like proteins and nucleic acids?
  • Hydrogen bonds play a critical role in maintaining the structural integrity of biomolecules such as proteins and nucleic acids. In proteins, hydrogen bonds stabilize the secondary structures like alpha helices and beta sheets, while in nucleic acids, they connect complementary base pairs in DNA. These interactions ensure that the biomolecules can maintain their functional shapes under physiological conditions.
• Discuss the impact of hydrogen bonding on the unique properties of water and its significance in biological systems.
  • Hydrogen bonding significantly affects the properties of water, including its high specific heat capacity, high boiling point, and surface tension. These properties make water an excellent solvent for biochemical reactions, allowing for efficient transport of nutrients and waste in living organisms. Additionally, the cohesive and adhesive properties of water due to hydrogen bonding are essential for processes such as transpiration in plants.
• Evaluate how alterations in hydrogen bonding could affect protein folding and function in living organisms.
  • Alterations in hydrogen bonding can greatly affect protein folding and function by disrupting the delicate balance required for maintaining tertiary and quaternary structures. Changes in temperature or pH can weaken or break these bonds, leading to misfolding or denaturation. Such alterations can have dire consequences for cellular function, as misfolded proteins may lose their biological activity or gain toxic properties that contribute to diseases like Alzheimer's.

Related terms

Covalent bond: A type of chemical bond where two atoms share electrons, leading to the formation of molecules.

Electronegativity:

The tendency of an atom to attract electrons towards itself in a chemical bond, affecting bond polarity.

Van der Waals forces: Weak attractions between molecules or parts of molecules that result from transient local partial charges.