**Plasma Membrane vs Plasma Lemma**

Plasma membrane and plasma lemma are two terms that are often used interchangeably, but they actually refer to different structures. Let's explore the differences between these two terms in detail.

**Plasma Membrane:**
The plasma membrane is a fundamental component of all living cells, including plant and animal cells. It is a selectively permeable barrier that separates the cell's internal environment from its external surroundings. The plasma membrane is composed of a phospholipid bilayer, which consists of two layers of phospholipids. The hydrophilic (water-loving) heads of the phospholipids face outward, while the hydrophobic (water-fearing) tails face inward, creating a barrier to the movement of substances in and out of the cell.

**Plasma Lemma:**
On the other hand, the term "plasma lemma" is specific to plant cells. It refers to the plasma membrane of a specialized plant cell called a sieve-tube element. Sieve-tube elements are elongated cells that form a part of the phloem tissue, which is responsible for the transport of nutrients, such as sugars, throughout the plant.

**Differences:**

1. **Composition:**
- The plasma membrane found in all cells is composed of a phospholipid bilayer, whereas the plasma lemma is also composed of a phospholipid bilayer but with additional specialized proteins and structures specific to sieve-tube elements.

2. **Functions:**
- The plasma membrane serves as a protective barrier for the cell, controlling the entry and exit of substances and maintaining the cell's internal environment. It is involved in processes such as cell signaling, transport of molecules, and cell adhesion.
- The plasma lemma, specifically in sieve-tube elements, is responsible for the transport of sugars and other organic molecules throughout the plant. It forms a part of the phloem tissue, which is essential for the distribution of nutrients produced in the leaves to other parts of the plant.

3. **Location:**
- The plasma membrane is present in all living cells, including both plant and animal cells. It encloses the entire cell, separating its internal contents from the external environment.
- The plasma lemma, on the other hand, is specific to sieve-tube elements in plant cells. These cells are part of the phloem tissue, which is found in the vascular system of plants.

In conclusion, while both plasma membrane and plasma lemma are important structures in cells, they have distinct differences. The plasma membrane is a universal component of all cells, whereas the plasma lemma specifically refers to the plasma membrane of sieve-tube elements in plant cells.

Yes they are same...The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates the interior of all cells from the outside environment (the extracellular space) which protects the cell from its environment.