Understanding Cytoplasm and Its Key Components

Cytoplasm:

The cell space between the nuclear envelope and plasma membrane. Comprising cytosol, cytoskeleton, and organelles.

Cytosol:

The internal environment of the cytoplasm (75-85% water). It performs the synthesis of ribosomes and protids (enzymes, small molecules, or proteins). It forms filaments of the cytoskeleton. Due to the presence of many enzymes, there are numerous metabolic reactions.

Cytoskeleton:

In eukaryotes, it forms a network of protein filaments. Features:

• Maintaining the shape of the cell and the possibility of changing it.
• The possibility of moving the cell.
• Contraction of muscle.
• Transport and organization of organelles.

Microfilaments:

Actin filaments are the main components of the cytoskeleton. Usually, they partner with other microfilaments (myosin contractile structures).

• Responsible for cytoplasmic streaming.
• Formation of the contractile ring in cytokinesis.

Intermediate Filaments:

Microtubules consist of filamentous proteins (neurofilaments in neurotic axons, tonofilaments in epithelial cells).

Microtubules:

Filaments consisting of tubulin protein. They can form stable structures (centrioles and derivatives such as cilia and flagella) and structures of limited duration (achromatic fibers) in the cytoskeleton.

• Separation of chromosomes during cell division.

Organelle: Ribosomes

Cell structures without globular membrane proteins, consisting of several types of rRNA. They comprise two subunits (60S and 40S). Their function is protein biosynthesis.

Endoplasmic Reticulum:

A membranous system consisting of a series of internal sac-like spaces called lumen.

Rough Endoplasmic Reticulum (RER):

Contains ribosomes. It synthesizes proteins, introduces ribonucleic acids, and participates in glucosylation and transport to organelles.

Smooth Endoplasmic Reticulum (SER):

Does not synthesize membrane lipids. It participates in detoxification processes, muscle contraction, and the release of calcium, as well as glycogen synthesis and glycogenolysis.

Golgi Apparatus:

A membranous cell system consisting of dictyosomes (sac-like structures) that transport, mature, accumulate, and transport proteins. It is involved in the glucosylation of lipids and proteins and the synthesis of proteoglycans.