Introduction To the Enzymes. Part#1
by Unknown
February 22, 2017
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Today, Let you know about enzymes the keys to speedy reactions of our body. Enzymes are basic proteins which help in our proper routine functioning. Without enzymes I think, we might not digest a single bread in several days.
Credit Amoeba Sisters via youtube
This topic is quite big and can't be covered In just one blog that's why I am dividing it into two parts.
The key points of first part are following
The key points of first part are following
What are enzymes?
Structure of enzymes
Where enzymes are located
Important properties of enzymes.
Mechanism of enzyme function.
Structure of enzymes
Where enzymes are located
Important properties of enzymes.
Mechanism of enzyme function.
Other points which I will be discussing in second part of the blog are
Classification of enzymes.
Factors affecting enzyme action.
Some popular enzymes
Inhibitors of enzymes.
So let's start playing with scientific terms.
Enzyme.
Enzyme is a protein created by an organism that increases the rate at which chemical reactions occur.definition by yourdictionary.
Enzymes are the most important group of proteins which are biologically active. They increase the efficiency of a biological reaction and are specific in action. They are catalysts of biological reactions.
The structure of enzymes.
Enzymes consist of hundreds is amino acids joined together to and coiled upon themselves to form a globular structure. The catalytic activity is restricted to a small portion of the structure known as the active site. The substrate is attached to the active site of an enzyme and is converted to the products.
Some enzymes consist solely of proteins. Other enzymes have a non-protein part which is known as co- factor, which is necessary for proper functioning of the enzyme.
Cofactor acts as a bridge between the enzyme and the substrate. It also provides energy to carry the reaction sometimes. Some enzymes use metal ions as cofactors such as Mg+2, Fe+2, Cu+2, Zn+2 etc. The detachable cofactor is known as activator if it is an inorganic ion.
If protein part is permanently bonded with covalent bonds then it is called Prosthetic group and if it is closely attached to enzyme than it is coenzyme. Mostly vitamins are found in coenzymes.
An enzyme without its coenzyme or prosthetic group is called apoenzyme. While enzyme with its coenzyme or apoenzyme attached is called holoenzyme.
Photo Credit essays.biochemistry.org via image
Where enzymes are found or produced.
Many enzymes are dissolved in the cytoplasm. But other enzymes are bound to places where they are used. They are produced by cells near the place where they are needed.
For example, enzymes required for photosynthesis are found in the chloroplast while enzyme used in cellular respiration are present in mitochondria.
For example, enzymes required for photosynthesis are found in the chloroplast while enzyme used in cellular respiration are present in mitochondria.
Most enzymes do not float about in cytoplasmic soap but are attached to membranes inside the cell in specific order. Examples are Mitochondria and Chloroplast.
Properties of Enzymes.
Enzymes are biological catalysts they possess following important functional and structural properties.
Structurally all enzymes are basically globular protein.
They increase the rate of biological reaction and themselves are not used up. So, they can be used again and again.
They just speed up the reaction and do not affect the nature of product formed at the end of the reaction.
Even the very small amount of enzyme can speed up the biological reaction.
Enzymes are known for their specificity in their action, a single enzyme only catalyzes a single reaction or group of similar related reactions.
Photo Credit slideshare. via slide
Enzymes are very sensitive to the environment in which they are working.even a small change in PH, temperature or substrate concentrate can disturb proper functioning of enzymes.
As discussed above some enzymes need cofactor for proper functioning.
Enzymes increase the rate of biological reaction by lowering the activation energy of a reaction.
Enzymes increase the rate of biological reaction by lowering the activation energy of a reaction.
Some enzymes are very dangerous in active form. That's why they are produced inactive form and are activated only at their action place.
For example, pepsin is an inactive form of pepsinogen, that is activated only in digestive track where it helps on digestion if proteins.
Mechanism of enzyme action (Catalysis).
Every enzyme by virtue of its specificity recognizes and react with special chemical substrate transforming it into the products. The enzyme is then released undisturbed and can be used again and again.
An enzyme and its substrate react with each other through a definite charge bearing site of the enzyme that is called active site. The active site is formed with specific amino acids present here.
Photo Credit slideplayer via slide
The active site of the enzyme is made up of two regions, the binding site, and catalytic site. The binding site helps the enzyme in recognizing and then binding of proper substrate to produce enzyme substrate complex. This action activates the catalytic site. And activated catalytic site catalyzes the transformation of the substrate into products.Thus the enzyme after catalysis detaches itself from product and can be used again and again.
Photo Credit slideplayer.com via slide
Models of Enzyme Action.
Two model are proposed for explaining the mechanism of enzyme activity.
Lock and key Model
Emil Fischer in 1890 proposed a lock and key model to explain the enzyme and substrate reaction. According to him as one specific key can open only one lock, in the same way, one specific enzyme can catalyze only one specific substrate into products. So, the active site is a ridged structure and there is no modification or flexibility in the active site before or after the enzyme activity.
Photo Credit answers.com via slide
But later studies did not support this lock and key model a new modl named induce fit model was proposed.
Induced Fit Model
Koshland in 1959 proposed modified firm of luck and key model. He argued that when a substrate binds to an enzyme it induces changes in the structure of an enzyme. So, these changes enable the enzyme to perform its activity more efficiently than lock and key model.
Photo Credit slideplayer.com via enzyme slide
This is what I decided to discuss in the first part of this blog. I will continue this topic in next blog.
The topics covered in next blog are effects of different conditions on enzyme activity, classification of enzymes, some examples if popular enzymes and inhibitors of enzymes.
So, you can check out next blog here
The topics covered in next blog are effects of different conditions on enzyme activity, classification of enzymes, some examples if popular enzymes and inhibitors of enzymes.
So, you can check out next blog here
Thanks, stay blessed and keep smiling.
post published origanally here
post published origanally here
Introduction To the Enzymes. Part#1
Reviewed by Unknown
on
February 22, 2017
Rating: 5
Reviewed by Unknown
on
February 22, 2017
Rating: 5
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