Saturday, July 25, 2020

The Wobble Hypothesis

The Wobble Hypothesis

There are more than one codon for one amino acid. This is called degeneracy of genetic code.

To explain the possible cause of degeneracy of codons, in 1966, Francis Crick proposed “the Wobble hypothesis”.

According to this hypothesis, only the first two bases of the codon have a precise pairing with the bases of the anticodon of tRNA, while the pairing between the third bases of codon and anticodon may Wobble (wobble means to sway or move unsteadily).

The phenomenon permits a single tRNA to recognize more than one codon. Therefore, although there are 61 codons for amino acids, the number of tRNA is far less (around 40) which is due to wobbling.

The Wobble Hypothesis

The wobble hypothesis states that the base at 5′ end of the anticodon is not spatially confined as the other two bases allowing it to form hydrogen bonds with any of several bases located at the 3′ end of a codon. This leads to the following conclusions:

The first two bases of the codon make normal (canonical) H-bond pairs with the 2nd and 3rd bases of the anticodon.

At the remaining position, less stringent rules apply and non-canonical pairing may occur. The wobble hypothesis thus proposes a more flexible set of base-pairing rules at the third position of the codon.

The relaxed base-pairing requirement, or “wobble,” allows the anticodon of a single form of tRNA to pair with more than one triplet in mRNA.

The rules: first base U can recognize A or G, first base G can recognize U or C, and first base I can recognize U, C or A.

Crick’s hypothesis hence predicts that the initial two ribonucleotides of triplet codes are often more critical than the third member in attracting the correct tRNA.

Wobble base pairs

A wobble base pair is a pairing between two nucleotides in RNA molecules that does not follow Watson-Crick base pair rules.

The four main wobble base pairs are guanine-uracil (G-U), hypoxanthine-uracil (I-U), hypoxanthine-adenine (I-A), and hypoxanthine-cytosine (I-C).

In order to maintain consistency of nucleic acid nomenclature, “I” is used for hypoxanthine because hypoxanthine is the nucleobase of inosine.

Inosine displays the true qualities of wobble, in that if that is the first nucleotide in the anticodon then any of three bases in the original codon can be matched with the tRNA.

Significance of the Wobble Hypothesis

Our bodies have a limited amount of tRNAs and wobble allows for broad specificity.

Wobble base pairs have been shown to facilitate many biological functions, most clearly proven in the bacterium Escherichia coli.

The thermodynamic stability of a wobble base pair is comparable to that of a Watson-Crick base pair.

Wobble base pairs are fundamental in RNA secondary structure and are critical for the proper translation of the genetic code.

Wobbling allows faster dissociation of tRNA from mRNA and also protein synthesis.

The existence of wobble minimizes the damage that can be caused by a misreading of the code; for example, if the Leu codon CUU were misread CUC or CUA or CUG during transcription of mRNA, the codon would still be translated as Leu during protein synthesis.




Goose flesh is a Pimply State of the Skin, Produced by Cold or Fright

Goose flesh is a Pimply State of the Skin, Produced by Cold or Fright

Goose flesh is the reaction of the skin to cold or fear. The blood vessels contract and the small muscle attached to the base of each hair follicle also contracts, causing the hairs to stand up: this gives the skin an appearance of plucked goose skin. That stimulus causes a nerve discharge from the sympathetic nervous system. The nerve discharge causes contraction of little muscles called the arrector pilorum (the hair erector muscles). Contraction of these muscles elevates the hair follicles above the rest of the skin. And it is these tiny elevations we perceive as goose bumps. Gooseflesh is also referred to as "goose bumps."


Friday, July 24, 2020

Decible (dB)

Decibel (dBA) is an International Scale of Sound Levels.

Decibel (symbol dB) is unit of measure used originally to compare sound intensities. Nearly all audible sounds lie between 0 and about 140 dB, where 0 dB is the 'threshold of hearing. A whisper has a sound intensity of 20 dB and 140 dB (a jet aircraft taking off nearby) is the threshold of pain. An increase of 10 dB means that the noise perceived by a listener has roughly doubled in loudness. A car passing at 70 dB sounds twice as loud as one passing at 60 dB. The dB measurement is widely used throughout the world for determining approximate human reaction to noise.

Thursday, July 23, 2020

People who have Dimples, Tend to have Children with Dimples

People who have Dimples, Tend to have Children with Dimples
A dimple is the word given to natural indentation on the face. Dimples often occur on both the cheeks. They are most commonly visible when someone smiles. Dimples are due to a genetic trait following an autosomal dominant pattern of inheritance. Transfer of dimples from parents to children occurs due to just one gene. Dimples are highly heritable, meaning that people who have dimples tend to have children with dimples. The truth is that dimples are actually genetic defects that are revealed by shortened facial muscles. Dimples are caused by a fault in the subcutaneous connective tissue that develops in the course of the embryonic development.

Achondroplasia is Inherited Condition of Abnormal Cartilage Development

Achondroplasia is Inherited Condition of Abnormal Cartilage Development
Achondroplasia is a disorder, inherited as a dominant characteristic, in which the bones of the arms and legs fail to grow to normal size due to a defect in both cartilage and bone. It results in a type of dwarfism characterized by short limbs, a normal-sized head and body, and normal intelligence. Achondroplasia is the commonest form of human dwarfism. The condition is controlled by an autosomal dominant gene and thus affected children born to normal parents must result from a mutation in one or other parent. The majority of achondroplastics die in early childhood but those surviving are fertile.


Ability to set Goals

The ability to set Goals and make plans for there accomplishment is the master Skill of success.
Developing this skill will do more to ensure your success than anything else you could ever do.
Goals are the fuel in the furnace of achievement. A person without goals is like a ship without a rudder, drifting aimlessly and always in danger of ending up on the rocks. A person with goals is like a ship with a rudder, guided by a captain with a map, a compass, and a destination, sailing straight and true toward a port of his own choosing.

You are where you are and what you are because you have decided to be there. Your thoughts, your actions and your behaviour have gotten you to your present position in life, and they could have brought you to no other place, rightly considered.

If your goal is to get through the day and then get home and watch tv, you will achieve it. If your goal is to be fit and healthy and to live a long life, then you will achieve that too. And if your goal is to be financially independent or even wealthy, if that is truly your goal, then there is nothing that can stop you from reaching it, sooner or later.

Your only limitation is your desire, How badly do you want it.

Wednesday, July 22, 2020

Hemophilia

Hemophilia is Inherited Blood Disorder Resulting Severe Bleeding
Haemophilia is a rare human blood disorder in which blood clots very slowly, resulting often in severe bleeding internally and externally. The condition is due to a lack of fibrin in the blood and is controlled by two closely linked genes on the X-chromosome that are responsible for the production of different clotting factors. Haemophilia A individuals lack antihaemophilic factor, while haemophilia B individuals lack plasma thromboplastin. Males carrying the mutant alleles will be affected, although heterozygous females have normal blood. The patient may experience prolonged bleeding following any injury or wound. Haemophilia may be treated by transfusions of plasma (which contains the missing factor).

Visual Acuity

Visual Acuity Commonly Refers to the Clarity of Vision.
Visual acuity describes how well you see detail with your central vision. This is usually measured using a special chart with rows of letters that start with one big one at the top and get smaller row by row - called a Snellen scale. There are many tests of visual acuity. One of the more common is the Snellen test type. This is made up of many letters of different size. By conventions the chart is placed 6 metres away from the patient. Each eye is assessed with two numbers, such as having 6/6 vision. The first number is the distance the chart is viewed from. The second is the distance at which the person being tested can see a letter clearly. If they are only able to see the top letter they have 6/60 vision. ‘Normal’ vision is 6/6.

Thursday, July 16, 2020

Biofilm

Biofilm is a Collection of Micro-Organisms and their Products.
Biofilm is a collection of microbial cells covered by and embedded in a matrix of extracellular  microbial products, such as mucilage or slime, at an interface. Biofilms are found, for example, on the surface of stones in rivers and ponds, in water pipelines, as dental plaques on teeth and on surgical implants. Biofilm formation can have serious implications in industrial, environmental, medical and public health situations. Biofilms form in the micro-environment (rhizosphere) surrounding plant roots, where they assist the plant in absorbing nutrients from the soil.


Thursday, July 9, 2020

Following is Revised Syllabus fot NTA NEET As well as Boards 2021 & 2022 aspirants.

Following is Revised Syllabus fot NTA NEET As well as Boards 2021 & 2022 aspirants.
There have been SIGNIFICANT REDUCTIONS which you can go through.

Revised Syllabus For Biology

https://documentcloud.adobe.com/link/review?uri=urn:aaid:scds:US:34309892-d3c1-4ee7-8d80-4b0361ef7fd7

Revised Syllabus For Chemistry

https://documentcloud.adobe.com/link/review?uri=urn:aaid:scds:US:b4a38b7a-4fe6-453c-93d2-b81e0d8c176c

Revised Syllabus For Physics

https://documentcloud.adobe.com/link/review?uri=urn:aaid:scds:US:9b889e8d-3a84-4326-9440-7676f158d9ad

Revised Syllabus For Mathematics 

https://documentcloud.adobe.com/link/review?uri=urn:aaid:scds:US:fed963e1-12ee-4c28-8e4c-cd92ede829ed

Revised Syllabus for Science  (IXand X)

https://documentcloud.adobe.com/link/review?uri=urn:aaid:scds:US:dc9a9b72-8fff-46ca-9d38-3b1b75e19297

Revised Syllabus for Mathematics  (IXand X)


https://documentcloud.adobe.com/link/review?uri=urn:aaid:scds:US:cfa58567-5907-40e2-b08a-4225667f6153









Most Important Topics for NEET 2022 Physics, Chemistry, and Biology

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