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Serving Quality Education
Translation It is the process of protein synthesis by reading the mRNA codons. It occurs in cytoplasm. Ribosomes are the sites for protein synthesis in a cell. Process of Translation Charging of tRNA: Binding of specific amino acid to the tRNA…
Transcription Transcription is the process where genetic information from a strand of DNA is copied to form the RNA. The RNA is formed as a complementary strand to the DNA strand. Here during the addition of bases in RNA, adenine…
Enzyme Machinery and Process of DNA Replication The most important enzyme involved in DNA replication is the DNA polymerase. DNA replication is an energy dependent process. Replication begins on the specific site on the DNA, known as the origin of replication (ori).…
DNA Replication DNA replication is a process where two identical copies of DNA are produced from a single DNA molecule. It involves the separation of the two strands of a DNA helix to form two new DNA molecules. Out of…
Hershey-Chase Experiment Alfred Hershey and Martha Chase (1952) gave proof that DNA is the genetic material. In the experiment, bacteriophages (viruses that infect bacteria) were used. They grew some bacteriophages on a medium that contained radioactive phosphorus and some others on a sulphur-containing radioactive medium. The bacteriophages grown…
Griffith’s experiment Rough strain of Streptococcus was injected into the mouse. The mouse lived. Smooth strain of Streptococcus was injected into the mouse. The mouse died. When heat-killed smooth strain of Streptococcus was injected into the mouse, the mouse lived. In the last set of experiments,…
Molecular Basis Of Inheritance – A good summary makes the whole chapter easy. 1 DNA, RNA and Search for Genetic Material The DNA DNA (Deoxyribonucleic acid) is a double-stranded, helical molecule. Its structure was cracked by Watson and Crick based on the X-ray crystallography results provided…
Molecular Basis Of Inheritance – All formulas of the chapter at one glance. 1 Formula for Calculating the Length of DNA Total length of double helix DNA = Total number of base pairs x distance between two consecutive base pairs Example:…
Lac operon
Mechanism of protein synthesis
Reverse transcription 1. Reverse transcription is the synthesis of DNA from an RNA template. 2. A class of RNA viruses, called retroviruses, are characterized by the presence of an RNA-dependent DNA polymerase (reverse transcriptase). 3. For example, the virus that causes AIDS, is…
Wobble hypothesis 1. Wobble hypothesis explains the phenomena of multiple codons coding for the code for a single amino acid. 2. According to this theory the base in the first position of the anticodon on tRNA is an abnormal base which…
Characteristics of genetic code 1. Triplet code2. Start signal3. Stop signal4. Universal code5. Nonambiguous codons6. Related codons7. Commaless8. Polarity9. Degeneracy of code
Enzymes required for DNA replication 1. DNA Polymerase – Elongates a new DNA strand at a replication fork. Adds nucleotides one by one to the new and growing DNA strand. 2. DNA ligase – Joins sugar-phosphates of Okazaki fragments. Okazaki fragments…
Clover -leaf model of t-RNA 1. The structure of RNA was explained by cloverleaf in the cloverleaf model.2. It helps in providing the anticodon to the m-RNA template.3. They have several loops like aminoacyl binding loop, anticodon loop and ribosomal binding loop…
Nucleosome model 1. Woodcock stated that chromatin appears as a chromatin beads.2. These beads like structure were referred to as nucleosome.3. This nucleosome is composed of DNA and histone proteins.4. The central core is made up core histones H2A, H2B, H3,…
Molecular Basis Of Inheritance – A quick revision tool for the grip on the chapter. 1 Nucleosome model 1. Woodcock stated that chromatin appears as a chromatin beads.2. These beads like structure were referred to as nucleosome.3. This nucleosome is composed…
Molecular Basis Of Inheritance 1 2
Down’s and Patau’s Syndrome Chromosomal abnormalities are responsible for miscarriages and stillbirths. Down’s syndrome and Patau’s syndrome are trisomy disorders, where the individuals have three copies of a chromosome rather than the normal two. Patau’s syndrome (Trisomy of 13th chromosome), is…
Klinefelter’s And Turner’s SyndromeKlinefelter’s syndrome(KS) (47XXY or XXY) and Turner’s syndrome(TS) (45X or X0) are common cases of sex chromosome aneuploidy (SCA). In humans, with an approximate occurrence of KS is 1 in 600 males and TS is 1 in 2,000 female livebirths. Let us understand the…