7 Globular Protein Functions: That You Should Know

This article would discuss different facts associated with globular protein along with various globular protein functions in a detailed manner. 

Globular proteins are the most common types of proteins which are spherical and water-soluble. The globular protein functions are diverse but the primary function is to act like the enzymes to catalyse organic reactions within the body. 

  • Globular protein as Enzymes  
  • Globular protein as Hormones
  • Globular protein as Transporters
  • Globular protein as Regulators
  • Globular protein as Structural
  • Globular protein as Integral membrane proteins
  • Globular protein as Trans-membrane proteins

Globular protein functions in cell membrane 

Globular proteins are made up of primary, secondary, tertiary and even quaternary structures where the secondary structures are established in straight chains joined with peptide bonds. These are soluble in water, bases and acids and are spherical in shape. 

There are diverse functions of globular proteins like metabolism, synthesis, catalysis and storage within cells. Based on the types, the globular proteins functions would be as follows: 

Enzymes 

The globular protein enzymes help in catalysing various organic reactions within the organisms under defined mild conditions and maintaining high specificity. This role is fulfilled by various esterares. 

One example of globular protein enzyme would be Hexokinase which helps in phosphorylation of hexose, which is a six-carbon compound to hexose phosphate. 

Hormones

The globular protein hormones work as a messenger where messages are transmitted in regulating various biological processes within the body. 

Examples of globular protein hormones would be Insulin which helps in regulating the concentration of glucose in the blood and is produced by the beta cells of the islets of langerhans within the pancreas.  

Transporters 

The transporter globular proteins help in the effective movement of ions, various molecules, be it macromolecules or small molecules through the cell membrane. These proteins are effective in assisting the movement of substances and help in processes like diffusion and active transport. 

The example of a transporter globular protein would be haemoglobin which transports oxygen from lungs to various parts of the body to supply it to all the other organs. 

globular protein functions
An example of globular protein: Haemoglobin from Wikipedia

Regulatory 

The globular proteins engage in the regulatory roles like generegulations or metabolic regulations where the living organisms engage in regulating the body processes in accordance with the environment. 

For example, homeostasis where the body temperature and body fluids are managed in accordance with the surroundings. 

Structural 

This type of globular proteins help in providing shape to the cells and facilitating the movement of various structures like muscles, cartilage, bones and hair. 

The major structural proteins, named as actin and tubulin are globular proteins. Actin forms the microfilaments and Tubulin polymerases into microtubules to support eukaryotic cytoskeleton. 

Globular protein function in fluid mosaic model

The globular proteins play an important role in the fluid mosaic model, which are listed below: 

Integral membrane proteins

The globular proteins function as the integral membrane proteins in the fluid mosaic model which are accumulated within the phospholipid bilayer and have two sticking out ends. These globular integral proteins help in the transportation of larger molecules across the membranes. 

Trans-membrane proteins

There are also trans-membrane globular proteins which help in establishing hydrophilic ion channels within the membranes. They are important in maintaining the cellular ionic balance along with the electrical properties of the membrane.  

Fibrous protein vs globular protein

There are two broad types of proteins, fibrous proteins and globular proteins. The Fibrous proteins are long with narrow strands while globular proteins are round and compact. A comparison between the two proteins are as follows: 

Properties Fibrous proteins Globular proteins
Shape long with narrow strandsround and compact
Role various structural roles like providing shape to the cells to maintain a structure.various functional roles like metabolism, synthesis, catalysis and storage within cells.
Solubility Insoluble in water Soluble in water 
Amino acid sequence Repetitive Irregular 
Stability Higher stability and lower sensitivity level under high temperature of higher changes in pHLower stability and higher sensitivity level under high temperature of higher changes in pH
Examples Collagen and KeratinInsulin, actin, haemoglobin 

Are globular proteins enzymes?

There are various types of globular proteins, and one such type is the enzymes composed of globular proteins which participate in catalysing various organic reactions within the organisms under defined mild conditions and maintaining high specificity. 

One example of globular protein enzyme would be Hexokinase which helps in phosphorylation of hexose, which is a six-carbon compound to hexose phosphate. 

Is globular protein fibrous?

Globular proteins are not fibrous. Globular proteins and fibrous proteins are two different types of proteins differentiated based on the structure and the functional role. 

The Globular proteins are round and more compact with various functional roles like metabolism, synthesis, catalysis and storage within cells. The Fibrous proteins are long with narrow strands which provide shape to the cells to maintain a structure. 

Conclusion 

In conclusion, it can be identified that there are a series of globular protein functions that are important for the various eukaryotic processes like metabolism, synthesis, catalysis and storage within cells.  

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