Back to notes
Explain how hydrogen bonds form and give an example from DNA.
Press to flip
Hydrogen bonds form when hydrogen is covalently bound to an electronegative atom such as oxygen or nitrogen, creating a dipole. An example is the hydrogen bonding between DNA base pairs: adenine-thymine (A-T) with 2 H-bonds and cytosine-guanine (C-G) with 3 H-bonds.
What are hydrophobic interactions and how do they influence protein structure?
Hydrophobic interactions occur between nonpolar molecules in aqueous environments that aggregate to minimize water interaction, influencing protein structure by promoting the folding of proteins to hide hydrophobic residues inside.
What is the relevance of electronegativity in hydrogen bonding?
Electronegativity is crucial for hydrogen bonding because it creates partial charges, which are necessary for the attraction between the hydrogen atom and the electronegative atom of another molecule.
What is the octet rule in chemistry?
The octet rule states that atoms prefer to have eight electrons in their valence shell for stability.
Why do van der Waals interactions play a crucial role in molecular biology?
Van der Waals interactions are crucial in molecular biology because they contribute to the overall shape and stability of biomolecules like proteins and DNA through weak, but numerous, interactions.
Define dipole-dipole interactions and where they are relevant in biology.
Dipole-dipole interactions occur between two polar molecules that have permanent dipoles. They are relevant in biology for molecular recognition and intermolecular interactions.
Provide an example of a dipole-induced dipole interaction in biological systems.
An example of a dipole-induced dipole interaction in biological systems is the interaction between a polar membrane lipid and adjacent nonpolar lipid molecules, where the polar lipid induces a dipole in the nonpolar lipid.
What atoms are highly electronegative and commonly involved in hydrogen bonding?
Oxygen (O), nitrogen (N), and fluorine (F) are highly electronegative atoms commonly involved in hydrogen bonding.
Why are weak interactions significant in biology despite their individual weakness?
Weak interactions are significant in biology because their cumulative effect can be very strong and essential for biological processes.
Compare the strengths of hydrogen bonds between A-T and C-G base pairs in DNA.
Hydrogen bonds between adenine-thymine (A-T) base pairs are weaker with 2 hydrogen bonds, while cytosine-guanine (C-G) base pairs are stronger with 3 hydrogen bonds.
What is the main characteristic of van der Waals radius?
The van der Waals radius is the effective distance at which two uncharged atoms can interact and attract each other.
How do hydrophobic interactions reduce surface area exposure to water?
Hydrophobic molecules aggregate to minimize their surface area exposed to water, thus reducing the energetically unfavorable arrangement and stabilizing the structure in aqueous environments.
Describe an ionic interaction and provide a biological example.
An ionic interaction is an electrostatic interaction between charged particles. A biological example is the interaction between the positive lysine and negative glutamate in amino acids.
What role do van der Waals interactions play in protein structure?
Van der Waals interactions contribute to protein folding and stability by fostering attractions between atoms within the Van der Waals radius.
What is the difference in behavior of ionic interactions in vacuum versus aqueous environments?
Ionic interactions are strongest in a vacuum and become weaker in aqueous environments due to the dielectric constant of water.
Previous
Next