L1(1)-Types of Chemical Bonds and Their Biological Roles

Question 1

What are the main types of chemical bonds?

Answer 1

1.Covalent bonds – atoms share electron pairs

2.Ionic bonds – one atom fully transfers electrons to another

3.Weak bonds – include hydrogen bonds and Van der Waals forces
Each type differs in strength and biological role.

Question 2

What are covalent and ionic bonds, and how do they differ?

Answer 2

Covalent bonds:
 - Electrons are shared between atoms
 -** Very strong**,
1. stabilize molecules,
2. store energy (e.g., C(carbon)–H(hydrogen) bonds)
 - Can be single/double/triple and polar or non-polar

Ionic bonds:
- Electrons are transferred → forms
* positive (cation) and
* negative (anion) ions
 - Strong,
1.  - form salts/crystals,
2.  but weaker in water and with distance

Question 3

What are weak chemical bonds?

Answer 3

1.Hydrogen bonds:
 1- Form between hydrogen and electronegative atoms (e.g., O(oxygen), N(nitrogen))
 2- Important for
* water cohesion,
* DNA structure, and
* protein folding

2.Van der Waals forces:
 1.- Temporary dipole interactions in nonpolar molecules(Brief electron shifts causing weak attractions between nonpolar molecules)
 2.- Very weak (1–4 kcal/mol) but:
1. essential for molecular shape,
2. membrane dynamics, and
3. state of matter

Question 4

What are the biological functions of each bond type?

Answer 4

Covalent bonds:
1. Build the stable backbone of organic molecules

Ionic bonds:
1. Help form salts,
2. maintain cellular ion balance

Weak bonds:
1. Crucial for protein folding,
2. DNA pairing,
3. membrane structure, and
4. molecular interaction