MINISTRY OF DEFENCE

Image
  MINISTRY OF DEFENCE. Establishment Of National University In Islamabad Total position. 29 Domicile , All over Pakistan    Qualification  intermediate to bachelor positions . Project Engineer(Civil) account Officer  supervisor assistant office boy     How to apply.   Apply online through the link https://www.fgei-cg.gov.pk/nup-rec.php   Last date to apply  02 April 2023. No TA/DA Fo Interview 
Post a Comment

Action Of Enzyme (Mechanism Of Action of Enzyme)

Action Of Enzyme (Mechanism Of Action of Enzyme)


The specificity of enzyme is very important in the metabolism of living system its catalytic activity is restricted to a reaction or a group of related reaction.
For example: Urease is specific for urea substrate.
 Enzymes combined with their substrate and form Complex, called enzyme substrate Complex.
Enzymes have an active site with which a substrate molecule is attached.

The Action Of Enzyme depends upon the structure of enzyme.
 It has three dimensional structure.
It has an active site which is of a particular size and shape.
This active site is attached with Substrate.

 Two theories have been proposed about the action of enzyme.

 I) Key Lock Theory:
Key and lock theory of Enzyme

 This theory has proposed by Fischer in 1898, and it has improved by Paul filder and D.D woods.

According to this theory the enzyme is attached with specific substrate by its active site to form an association this association is like a lock and key Association.
 It helps in the catalytic action. Sometimes other molecules or substrate are connected with active site, but there is no Bond formation and no chemical reaction.


ii) Induced Fit Model Theory
 This theory is proposed by koshland in 1959. According to this theory when enzyme combines with the substrate, some changes occur in the substrate of enzyme, due to this change the enzyme performs catalytic activity in more effective manner.

Comments

Post a Comment

Popular posts from this blog

Neurotransmitters and receptors

Image
Neurotransmitters and receptors Did you know there are billions of neurons—and trillions of synapses—in your amazing brain? ^1 1 start superscript, 1, end superscript  (No wonder you can learn anything, including neurobiology!) Most of your synapses are  chemical synapses , meaning that information is carried by chemical messengers from one neuron to the next. In the article on synapses, we discussed how synaptic transmission works. Here, we’ll focus on  neurotransmitters , the chemical messengers released from neurons at synapses so that they can “talk” to neighboring cells. We’ll also look at the receptor proteins that let the target cell “hear” the message. Neurotransmitters: Conventional and unconventional There are many different kinds of neurotransmitters, and new ones are still being discovered! Over the years, the very idea of what makes something a neurotransmitter has changed and broadened. Because the definition has expanded, some recently discovered n
Read more

Excretion in Invertibrate,(Excretion in Planaria, Excretion in Earthworm,Excretion in Cockroach)

Image
Excretion in Invertibrate Excretion in Planaria Habitat : Planaria is a fresh water invertebrate.   Excretory product: planaria remove ammonia and it is ammonotlic. This excretion occurs by two methods, diffusion, specialized excretory system. Excretory organs: Planaria has simple tubular excretory system called protonephiridia. Protonephridia arranged in two longitudinal trunk one on each side of the body. Each track consists of a network of tubules without internal openings. These tubules divide into small branches which open in flame cells. Tubules open on the outside by small opening called nephridiophores. Structure of flame cell: Flame cells are club shaped hollow cells. Each flame cell contains nucleus, cytoplasm and internal cavity. Group of cilia is present in the cavity. Cilia perform a movement like a flame of candle. Flame cells also has many cytoplasmic elongations. Mechanism of excretion: Flame cells absorb wastes and push them into the cavit
Read more

Waste Products Of Animals

Image
Nitrogenous Wastes Of Animal: Waste Products Of Animals: The nitrogenous wastes are urea,ammonia and uric acid . These all wastes are not removed by the same animal. These wastes are produced and excreted by different animal which are living in different habitats. The type of nitrogenous waste and their excretion depend upon the habitat of an animal. 1.Ammonia (NH3): It is the excretory product of aquatic animals ,developes by the break down of amino acids,harmful to the living cells,excreted by diffusion and highly soluble in water. About 500 ml of water is needed to remove one gram of ammonia . Animals those excrete ammonia are called ammonotelic . Examples: Eartworm, protozians, sponges and fishes etc. 2.Urea {CO (NH2)2}: It is the excretory products of mostly land animals ,produced by the liver from ammonia,less toxic than ammonia and can be store in the body for short time. One gram of urea require 50 ml of water for excretion. Animals those remove urea are
Read more