Cellular organization

Living things are highly organized and structured, following a hierarchy that can be examined on a scale from small to large. The atom is the smallest and most fundamental unit of matter.Atoms form molecules Many molecules that are biologically important are macromolecules,   An example of a macromolecule is deoxyribonucleic acid (DNA), which contains the instructions for the structure and functioning of all living organisms.

Macromolecules can form aggregates within a cell that are surrounded by membranes; these are called organelles. Organelles are small structures that exist within cells. Examples of these include: mitochondria and chloroplasts, which carry out indispensable functions. Mitochondria produce energy to power the cell while chloroplasts enable green plants to utilize the energy in sunlight to make sugars. All living things are made of cells, and the cell itself is the smallest fundamental unit of structure and function in living organisms.

cells combine to make tissues, which are groups of similar cells carrying out similar or related functions. Organs are collections of tissues grouped together performing a common function.

Life exhibits a wide variety of levels of organization. For one, the cell is considered as the smallest living functional unit of entity and is always been known as the basic unit of life. Despite their minute size, cells are still organized in a precise manner.

cellular organization is the components that make up the cell and how they are arranged inside it. Each component, called an organelle, performs a specific function that is vital for the cell. In this article, we will explore the basic functional components of the cell and cell shape and its size. Let’s take a closer look.

1)Nucleus:

the nucleus (plural: nuclei) is known to be the control center of the cell. It houses the cell’s genome (genetic material) and it is where the processes such as DNA replication, transcription, and the processing of RNA take place.

The presence of a nucleus is the principal characteristic that distinguishes eukaryotes from prokaryotes. The latter only have a so-called nucleoid wherein the genetic material is embedded.

In addition to that, the nucleus of eukaryotic organism is surrounded by a nuclear membrane that functions to separate the nucleus from the rest of the organelles in the cytosol.

2)Cell Membrane: 

the cell membrane is composed of a phospholipid bilayer 

the phospholipid bilayer is composed of two layers of phospholipids, with one layer having hydrophilic heads

The proteins found in the bilipid layer performs selective transport of molecules and recognition and of cells.

3)Cytoplasm:

 the cytoplasm is the fluid that fills the cell up and is surrounded by the cell membrane. The cytoplasm is mainly composed of salts and proteins dissolved in water.

4)Cell Wall:

The outer covering of cells (plants, fungi, algae, bacteria, and archaea) located next to the cell membranes is called the cell wall.

While the cell membrane is made up of phospholipids, the cell wall is made up of a sturdier compounds – polysaccharides, usually cellulose (in plants) and peptidoglycan (in bacteria).

5)Mitochondria: 

Known as the powerhouse of the cell, the mitochondrion (plural: mitochondria) is the double-membraned organelle where the process of cellular respiration takes place. During the cellular respiration, a usable form of energy is produced from precursor molecules like sugars and other carbohydrates

6)Chloroplasts:

Specific to plant cells and algae, chloroplasts are double-membraned organelles that can convert light energy, carbon dioxide (CO2), and water (H2O) to carbohydrates in a process called photosynthesis.

7)Rough Endoplasmic Reticulum:

 The rough endoplasmic reticulum (ER) is the extensive and highly convoluted organelle that is involved in the production, folding, and regulation of proteins.

Basically, the rough ER is called as such because of the ribosomes that are attached to it.

8)smooth endoplasmic reticulum:

 The more tubular type of the endoplasmic reticulum, the smooth ER forms an interconnecting network in the endoplasmic reticulum and the Golgi body.

Contrary to the rough ER, the smooth ER is called as such because it is associated with slippery fat molecules and there are no attached ribosomes to it.

9)Ribosomes:

 Ribosome are the sites where protein synthesis occurs. These proteins are important as they serve a variety of purposes like catalyze biochemical reactions, act as structural support, and building blocks of some membranes.

Found in both prokaryotes and eukaryotes.

10)Golgi body:

named after the scientist camillio golgi the Golgi body (also known as Golgi Apparatus or Golgi Complex) is the organelle where the final modification and packaging of molecules like proteins occur. These molecules when packages, are either sent outside of the cell or stored in vesicles.

The Golgi body is also responsible for the production of lysosomes.

11)vesicles:

vesicles are membrane-sac that function for storage and transport of molecules within and outside of the cells. Usually, molecules are transported outside the cell through exocytosis and imported from the cell through phagocytosis and endocytosis.

Vesicles are formed when a portion of the cell membrane is pinched off.

12)Vacuoles:

Vacuoles are membrane-bound organelles that store food, nutrients, and even non-nourishing chemicals. Aside from that, vesicles can also be temporary storage for waste products.

In plant cells, vacuoles contribute to the rigidity of the overall structure by storing water in order to create hydro-static pressure.

13)Lysosomes:

Lysosomes are the membrane-bound organelles that are considered to be the “digestive system” of the cell as they contain a wide array of enzymes that can break down and degrade complex biological molecules (i.e. carbohydrates, proteins, lipids, and nucleic acids).

Aside from digesting foreign materials and molecules, lysosomes can function to degrade the component of the cell itself.

Sometimes, lysosomes are considered to be specialized vacuoles whose main function is digestion.

14. Centrioles:

CentriolesCentrioles are minute cylindrical organelles found only in animal cells and some plant cells.

 Basically, they consist of set of micro-tubules arranged in specific patterns. See the differences between centrosome and centriole here.

Centrioles play an important role in the development of spindle fibers during cell division.