Cell Structure

  What is cell? 

It is important to note that the cell's are not only the building blocks of the body but are the functional unit of life too. The basic unit of life. A cell is the smallest self-functioning unit found in all the living organisms. Cells may exist as independent unit of life or may form colonies or tissue as in the higher plants and animals. Each cell is enclosed by an outer membrane or cell wall called as the cell membrane. 

Cell structure:-

The animal cell is made up of several structure organelles enclosed in the plasma membrane, that enable it to function properly, eliciting mechanism that benefit the host (animal). The working together of all cells gives an animal it's ability to move, to reproduce, to respond to stimuli, to digest and absorb food, etc. Generally, the combined effort by all animal cells is what enables the normal functioning of the body. 

Eukaryotes are organisms consisting of one or more eukaryotic cells, such cells contains membrane bound nuclei, as well as organelles. Animals, plants, fungi and various other groups collectively referred to as protista are all eukaryotes, varying from single-celled organisms to truly multicellular forms, in which different cells are specialized different tasks and in general do not survive when isolated.

Functions:

• Structure and Support. You know a house is made of bricks. ...
• Growth. In complex organisms such as humans, the tissues grow by simple multiplication of cells. ...
• Transport. ...
• Energy Production. ...
• Metabolism. ...
• Reproduction.
• Cell Structure
  • cell walls.
  • mitochondria.
  • chloroplasts.
  • cell membrane.
  • vacuole.
  • nucleus.
  • ribosomes.
  • plasmids.

Plasma membrane:-

It is a thin semipermeable protein-membrane layer that surrounds an animal cell. 

°Functions :

To enclose and protect the cell content.To also regulate the molecules that pass into and out of the cells, through the plasma membrane. Therefore it controls homeostasis. The protein are actively involved in transporting material across the membrane.

°Nucleus:- 

The nucleus is called the control center of the cell. 

°Functions:-

• control of the genetical information of the cell and thus the heredity characteristics of an organism,
• control of the protein and enzyme synthesis.
• control of cell division and cell growth.
• storage of DNA, RNA and ribosome.
• regulation of the transcription of the mRNA to protein.
• production of ribosomes.

°Cytoplasm:-

This is a gel-like material that contains all the cell organelles, enclosed within the cell membrane. These organelles include, mitochondria, ribosomes, endoplasmic reticulum, golgi apparatus, lysosomes intermediate filaments,microfilaments microtubules, vesicles. 

°Mitochondria:-

Mitochondria are surrounded by a double-membrane system, consisting of inner and outer mitochondrial membranes separated by an intermembrane space. 

 

°Functions :

• It plays an important role in energy production through oxidative phosphorylation.
• It is involved in the detoxification process in hepatocytes.
• It helps in regulating the metabolic activities of the cell.
• It promotes the cell growth and multiplication of cells.

°Ribosomes:-

A ribosome is an intercellular structure made of both RNA and protein, and it is the site of protein synthesis in the cell. 

°Functions:-

Responsible for protein synthesis.

Serve as the site of mRNA translation.

It assembles amino acid to form proteins.

The DNA produces mRNA by the process of DNA transcription.

°Endoplasmic Reticulum (ER):-

The endoplasmic reticulum (ER) is a large, dynamic structure that serves many roles in the cell including calcium storage, protein synthesis and lipid metabolism. 

°Functions:-

ER (Endoplasmic reticulum) is responsible for transport. ...

It plays an important role in the synthesis of lipids, glycogen, and proteins. ...

They provide a wide area for cellular reactions.

It acts as an Intracellular supporting framework that also maintains the form of the cell. 

 1) ROUGH ENDOPLASMIC RETICULUM:-

This is an extensive organelle composed of greatly convoluted but flattish sealed sacs, which are contiguous with the nuclear membrane. It is called 'rough' endoplasmic reticulum because it is studded on its outer surface (the surface in contact with the cytosol) with ribosomes.

°Functions:-

The rough ER purpose is to produce proteins that will become part of the endomembrane system, the plasma membrane or to be secreted. 

 

 2)Smooth endoplasmic reticulum (SER):-

 Smooth endoplasmic reticulum (SER), meshwork of fine dislike tubular membrane vesicles, part of a continuous membrane organelle within the cytoplasm of eukaryotic cells. 

°Functions:-

Smooth ER is responsible for the synthesis of essential lipids such as phospholipids and cholesterol. Smooth ER is also responsible for the production and secretion of steroid hormones. It is also responsible for the metabolism of carbohydrates. The smooth ER store and releases calcium ions.

°Golgi Apparatus:-

A Golgi body, also known as a Golgi apparatus, is a cell organelle that helps process and package proteins and lipid molecules, especially proteins destined to be exported from the cell.

°Functions:-

 

The three primary functions of the Golgi apparatus are the transport, sorting and modification of both protein and lipid, and the protein composition of the organelle reflects these functions.