Question

In: Biology

1. These enzymes first discovered in bacteria, can cut within a DNA strand at specific palindromic...

1. These enzymes first discovered in bacteria, can cut within a DNA strand at specific palindromic consensus sequences, producing multiple fragments with blunt or “sticky” ends

peptidyl transferases

phosphatases

exonucleases

aminoacyl-synthetases

2. After binding of mRNA, the next step in translation initiation is binding of formyl-methionine-tRNA

in the P site of the large ribosomal subunit

in the E site of the small ribosomal subunit

in the P site of the Small ribosomal subunit

In the A site of the large ribosomal subunit

in the A site of the small ribosomal subunit

in the P site of the larger ribosomal subunit

3. Eukaryotic pre-mRNA transcripts undergo extensive processing in the nucleus to produce mature mRNA for transport to ribosomes in the cytoplasm. Describe the 3 most important steps in this process.

Expert Solution

Answer:

1). exonucleases

Explanation:

Exonuclease first attacks on the phosphodiester bond which removes the nucleotides one by one from the polynucleotide chain. The ends which are overhanging from the strand refers to “Cohesive or sticky ends”

2). in the P site of the large ribosomal subunit

Explanation: The first amino acid is formyl-methionine is the first amino acid in protein synthesis in prokaryotes. The first amino acid occupies on the P site of large ribosomal unit.

3). Pre.mRNA undergoes modification before translation. These are considered as post-transcriptional modifications.

5’ Capping: The 5' capping reaction replaces the triphosphate group at the 5' end of the RNA chain with a special nucleotide that is referred to as the 5' cap. It is thought to help with mRNA recognition by the ribosome during translation.
Polyadenylation: A modification also takes place at the opposite end of the mRNA transcript. To the 3' end of the RNA chain 30-500 adenines are added in what is called a poly A tail.
Splicing: Removal of introns is called splicing.
Alternate splicing: Alternative pattern of RNA splicing is adapted for the synthesis of tissue-specific proteins.

gladiator answered 2 years ago

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