intro

مدونتي راح تتخصص بالmolecular biology  و biotechnology science  :-

و هو علم يتخصص بال DNA و دراسة علم الوراثه و يندرج ضمنه علم البايوتكنولوجي و هو  علم يهتم بدراسة الصفات الوراثيه و كيف يمكن معالجة المنتجات لتصبح افضل من حيث الهيئه و الطعم و القيمة الغذائيه سواء بالنباتات او الحيوانات و هو علم مهم من الجانب الطبي ايضا بصناعة الادويه و اللقاحات لمحاربة الامراض و تحديد الامراض الجينيه  .

و سوف تكون مدونتي باللغه الانقليزيه 

lets start with molecular biology :)

first we will begin with the basics :)

The cell

With in the cell nucleus is the observable genetic material known as the chromosomes. In body cells chromosomes are found in pairs (Half from the female parent and half from the male parent.) In reproductive cells/gametes, they occur in a single set called haploid and represented by n but in body cells they occur in a double set called diploid and represented by 2n.

: we have two different kind of cells

 prokaryotic cells

eukaryotic cells

eukaryotic cell

prokaryotic cells 

  

:Chromosomes

These are threadlike structures found in the nucleus of the cell and they contain the genetic material responsible for inheritance. They form the physical basis for inheritance since their structure can be observed under a high power microscope.

Each chromosome is made up of two longitudinal strands called the chromatids.

Each chromatid has a double helical DNA molecule. The two chromatids are held together by a structure called the centromere. During cell division, the spindle fibres are attached to the centromeres

DNA

Is the chemical compound responsible for inheritance of characters.

DNA is one of the nucleic acids and the other is RNA

What do RNA and DNA stand for? 

RNA : Ribonucleic acid

DNA : Deoxyribonucleic acid

The chemical DNA was first discovered in 1869, but its role in genetic inheritance was not demonstrated until 1943. In 1953 James Watson and Francis Crick determined that the structure of DNA is a double-helix polymer, a spiral consisting of two DNA strands wound around each other. Each strand is composed of a long chain of monomer nucleotides. The nucleotide of DNA consists of a deoxyribose sugar molecule to which is attached a phosphate group and one of four nitrogenous bases: two purines (adenine and guanine) and two pyrimidines (cytosine and thymine). The nucleotides are joined together by covalent bonds between the phosphate of one nucleotide and the sugar of the next, forming a phosphate-sugar backbone from which the nitrogenous bases protrude. One strand is held to another by hydrogen bonds between the bases; the sequencing of this bonding is specific—i.e., adenine bonds only with thymine, and cytosine only with guanine.

https://www.britannica.com/science/DNA

Francis Crick

James Watson

 Both are similar in composition but different in structure. 
different in the uracil and thymine _

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-> this process we call the central dogma <-

The central dogma of molecular biology describes the flow of genetic information in cells from DNA to messenger RNA (mRNA) to protein. It states that genes specify the sequence of mRNA molecules, which in turn specify the sequence of proteins.

DNA replication

It’s the ability of DNA to produce a copy of its self.

DNA replication occurs in three stages and its catalyzed by a series of enzymes.

i)      Twisted strands un wind giving two strands. The strands are still joined.

ii)   Weak bonds between the nitrogen bases will be broken down to give two separate strands.

iii  One strand will induce the formation of another strand which is complimentary to it and the same thing will    happen to the other strand and this process happens from the 5 prime to the 3 prime

After replicating, two new DNA molecules similar to the original DNA molecule are formed.

 to be continued :)