new growing cell tip

Definition

Target type: cellularcomponent

A cell tip that was newly formed at the last cell division, and that has started to grow after the cell has activated bipolar cell growth (i.e. in which new end take-off, NETO, has taken place). New end take-off is when monopolar cells initiate bipolar growth. [GOC:expert_jd, GOC:mah, PMID:19431238]

The apical tip of a newly growing cell, often referred to as the "growing point," is a dynamic and intricate structure. It is characterized by a high concentration of specialized organelles and molecules, all working in concert to drive cell elongation and expansion.

**Key Cellular Components:**

- **Plasma membrane:** The outer boundary of the cell, it actively participates in the uptake of nutrients and the secretion of cell wall components, essential for growth. It is also responsible for maintaining the turgor pressure within the cell, pushing against the cell wall to enable elongation.

- **Cell Wall:** A rigid, yet flexible, structure that provides structural support and protection to the cell. It is continuously synthesized at the apical tip, with new wall material being deposited in a precise and regulated manner. This process involves a complex interplay of enzymes, proteins, and polysaccharides.

- **Microtubules:** These dynamic, protein-based filaments play a crucial role in shaping the cell and guiding the movement of organelles. In the apical tip, microtubules form a network that directs the deposition of cell wall material and the distribution of other essential components, contributing to the overall direction of growth.

- **Actin Filaments:** Another type of cytoskeletal filament, actin filaments are involved in the transport of vesicles and organelles, including those containing cell wall components. They also play a role in the formation of the tip growth zone, where new cell wall material is actively being deposited.

- **Golgi apparatus:** This organelle is responsible for processing and packaging proteins and other molecules, including those needed for cell wall formation. It receives materials from the endoplasmic reticulum and sends out vesicles that fuse with the plasma membrane, releasing their contents to the cell wall.

- **Endoplasmic reticulum (ER):** This network of interconnected membranes plays a crucial role in protein synthesis, modification, and transport. It also synthesizes lipids and other components needed for cell growth.

- **Vacuole:** This large, fluid-filled organelle occupies a significant portion of the cell's volume. It is involved in maintaining turgor pressure, storing nutrients and waste products, and playing a role in cell growth regulation.

- **Nucleus:** The control center of the cell, the nucleus contains the cell's DNA and directs the synthesis of proteins needed for cell growth.

- **Ribosomes:** These small, protein-synthesizing organelles are abundant in the apical tip, reflecting the high rate of protein synthesis needed for cell growth.

**Dynamic Processes:**

- **Tip Growth:** The apical tip is the site of active cell wall synthesis and extension, leading to the elongation of the cell. This process is highly regulated and involves a complex interplay of the cellular components mentioned above.

- **Polarity:** The apical tip is a highly polarized structure, with a distinct "leading edge" where growth occurs and a "trailing edge" where the cell wall is being deposited. This polarity is established and maintained by a complex network of signaling pathways and cellular components.

- **Signaling Pathways:** Numerous signaling pathways control the processes of cell growth and development at the apical tip. These pathways involve the interaction of hormones, proteins, and other molecules, ensuring the coordinated and regulated growth of the cell.'
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Proteins (1)

Compounds (31)