Each nuclear pore is formed from an elaborate structure termed the nuclear pore complex (NPC), which is one of the largest discrete protein assemblages in the cell.

TLS Online TPP Program

#Id: 7759

#Unit 1. Molecules and their Interaction Relevant to Biology

Some elements exist naturally as molecules. For example, hydrogen and oxygen exist as two-atom molecules.

TLS Online TPP Program

#Id: 7760

#Unit 1. Molecules and their Interaction Relevant to Biology

Sulfur normally exists as an eight-atom molecule, S8, while phosphorus exists as a four-atom molecule, P4

TLS Online TPP Program

#Id: 7761

#Unit 1. Molecules and their Interaction Relevant to Biology

A covalent bond is a chemical bond that occurs when two or more atoms share electrons. The sharing of electrons helps complete the outer shell, or valence shell, of both atoms. The sharing of electrons creates a stable balance of attractive and repulsive forces between atoms.

TLS Online TPP Program

#Id: 7762

#Unit 1. Molecules and their Interaction Relevant to Biology

In a covalent bond, electrons are shared between atoms. In an ionic bond, electrons are transferred between atoms.

TLS Online TPP Program

#Id: 7763

#Unit 1. Molecules and their Interaction Relevant to Biology

Breaking a bond always require energy to be added to the molecule. Correspondingly, making a bond always releases energy.

TLS Online TPP Program

#Id: 7766

#Unit 1. Molecules and their Interaction Relevant to Biology

Atoms are indivisible particles that can't be created or destroyed in a chemical reaction