Why is there the largest variety of tRNAs involved in the synthesis of a peptide chain?

tRNA is a transducer RNA, which carries an anticodon, and the tRNA can recognize the codon on the mRNA through its own anticodon, and transport the amino acids corresponding to the codon to the polypeptide chain in ribosome synthesis. Each tRNA molecule theoretically carries only one codon, and to synthesize a single DNA, multiple different codons are required, so there are the most variety.

To translate a peptide chain, an mRNA template is required.

Ribosome. In the middle, the large subunit of the prokaryotic ribosomal contains one molecule of 5srRNA, one molecule of 23 sRNA, and the small subunit contains one molecule of 16srRNA. In eukaryotes, the large subunit has one molecule of 28 srRNA, one molecule, one molecule of 5 srRNA, and the small subunit contains one molecule of 18 srRNA, which is obviously numerous, and the number is very small.

But every three bases.

It will correspond to a tRNA, and in order to secrete a polypeptide with a specific function, it will definitely not encode such a few amino acids.

Therefore, there are the largest types of tRNA.

tRNA carries amino acids, and there are anticodons on it, and there are 20 kinds of amino acids corresponding to 61 codons in the organism, and there are 61 kinds of corresponding anticodons. When synthesizing peptide chains, mRNA only has one strand as a template, and every three adjacent bases constitute a codon, and when translating, the anticodon of the trna needs to be paired with it, so a few codons correspond to several anticodons, so the tRNA has the most types.

Because there is only one mRNA, and tRNA is an anticodon composed of three nucleotides corresponding to one codon (amino acid), there are more than 20 kinds of amino acids, and one amino acid corresponds to multiple anticodons, so there are many kinds of tRNA.

Now it is popular to say that one gene has a cistron, and the eukaryotic gene transcription product is a single cisstronic pin, that is, a gene encodes a polypeptide chain or RNA strand, and the originally transcribed RNA strand (unprocessed) is hnRNA heterogeneous RNA, so one gene is one hnrna

HNRNA can be processed post-transcriptionally and regulated by certain factors, such as alternative splicing, cis-splicing, trans-splicing, and various modifications. This results in the production of n kinds of mRNA and the expression of a variety of peptide chains.

The peptide chain can be processed after translation, such as methylation and other modifications, cleavage, etc., and the peptide chain is more diverse.

Let's start with the role of three RNAs.

mRNA is the template used for polypeptide chain synthesis ribosomes are connected in tandem on mRNA and then the corresponding amino acids are arranged to form polypeptide chains. Free ribosomes secrete internal proteins that attach to the endoplasmic reticulum.

tRNA is a tool to transport amino acids Every three bases on the mRNA is a codon, and there are also three bases on the tRNA that complement it called an anticodon tRNA carries a corresponding amino acid to arrange the amino acids according to the information of the mRNA.

RNA is the substance that makes up ribosomes.

Transcription of DNA is the unwinding of the double strands of DNA, and one of the strands is used as a template to transcribe an RNA under the corresponding enzyme and raw material

Replication is when the DNA is unwinded, and both strands make a new strand that is complementary to the original strand and form two DNA molecules.

Ribosomal RNA (RRNA) makes up about 80% of the total amount of RNA, and they bind to proteins to form the backbone of ribosomes. Ribosomes are the site of protein synthesis, so the virtual function of RNA is to participate in protein biosynthesis as an important component of ribosomes. RNA is the most abundant type of RNA in cells, and the molecular weight is relatively large, the metabolism is inactive, there are only a few species, there are mainly 5S rRNA, 16S rRNA and 23S rRNA in prokaryotes, and there are four main 5S rRNA, rRNA, 18S rRNA and 28S rRNA in eukaryotes.

Messenger RNA (messenger RNA, mRNA), which accounts for about 5% of the total amount of RNAmRNA is synthesized from DNA as a template, which is also a template for protein synthesis. It is a nucleic acid that carries one or several genetic information to the ribosome.

Since each peptide has a corresponding mRNA, intracellular mRNA is a very heterogeneous class of molecules. However, the amount of each mRNA is very low. This also explains why mRNA was discovered later than rRNA and tRNA.

Transfer RNAs (tRNA) account for about 15% of the total amount of RNAThe molecular weight of tRNA is around and above and consists of 70 90 nucleotides, so it is the smallest RNA molecule. Its main function is to accurately translate mRNA information into an adapter molecule in the amino acid sequence in the protein during protein biosynthesis, which has the function of transporting amino acids, and is named after this amino acid.

In addition, it also plays an important role in the initiation of protein biosynthesis, in DNA reverse transcription synthesis, and other metabolic regulation. There are many types of intracellular tRNA, and each amino acid has its corresponding tRNA or several

The tRNA has a clover structure. It consists of 3 rings, namely the D ring due to the high content of dihydrouridine (D), the anticipher ring (the middle of the ring is an anticodon) and the T C ring because the vast majority of tRNAs contain thymidylate (T), pseudouridine ( ) and cytidylate (C) in the order there, and four stems, namely D stem (the stem linked to the D ring), the anticodon stem (linked to the anti-cipher ring), the T C stem (linked to the T C ring) and the amino acid receiving stem are also called CCA stems, because all tRNA molecular ends contain cytidylate (C), cytidylate (C), Adenylic acid (A) sequence, CCA is indispensable for linking amino acids, and a variable arm composition located between the anticodon and the T C stem.

RNA (ribosomal RNA): The ribosomes of both prokaryotes and eukaryotes are made up of two subunits, large and small. RNA is single-stranded, and it contains unequal amounts of A and U, G and C, but has a wide range of double-stranded regions.

In the double-stranded region, the alkali genes are connected by hydrogen bonds, which appear as a missing hairpin helix.

mRNA: A class of single-stranded RNA with genetic information synthesized from DNA transcription, which acts as a template for protein synthesis and determines the order of peptide chains. Prokaryotic mRNA in general5'There is an untranslated region at the end, called the leading order, 3'There is an untranslated region at the end, and the middle is the coding region of the protein, which generally encodes several proteins.

Normally, mRNA (single-stranded) molecules fold back on their own to produce many double-stranded structures.

Same: all are composed of ribose, uracil, cytosine, guanine, adenine and phosphoric acid. ,4,

tRNA **Transport RNA): Most tRNA is composed of about 70-90 ribonucleotides and folded into a clover shape, which is used to transport amino acids during protein synthesis;

mRNA (messenger RNA): It is transcribed from DNA in the nucleus, which carries genetic information and acts as a template for protein synthesis to determine the amino acid order of peptide chains; mRNA is found in the cytoplasm of prokaryotes and eukaryotes and in certain organelles of eukaryotic cells, such as mitochondria and chloroplasts;

RNA (ribosomal RNA): is a component of ribosomes, it is the largest relative molecular mass of the three types of RNA, combined with proteins to form ribosomes, its function is to act as a scaffold for mRNA, so that mRNA molecules on it, to achieve protein synthesis.

RNA is the main component that makes up ribosomes.

tRNA transports amino acids to ribosomes.

The function of mRNA is to transcribe the genetic information on DNA accurately, in fact, these are also introduced in high school biology textbooks, I finished the college entrance examination this year, huhu, I hope you can get a good score.

Literally! tRNA is transporter RNA (clover-like, transporting amino acids) mRNA is messenger RNA (single-stranded, transcribed from DNA and carries genetic information) RRNA ribosomal RNA (clumpy, divided into two subunits, large and small, bind to mRNA and form proteins here).

I just graduated from high school this year, I wish you progress in your studies!

In most cases, one mRNA corresponds to one peptide chain, but there are a few exceptions:

1 One mRNA synthesizes multiple peptide chains, which are more common in viral mRNA, and such mRNA is called polycistron.

2 A single mRNA synthesizes a peptide chain, which is then cleaved to form several different proteins, and there are many examples of this in viruses.

3 Multiple mRNAs each synthesize a peptide chain, which aggregates together to form a protein composed of multiple subunits.

In your question, you mentioned that "multiple ribosomes can be bound continuously", it can be inferred that this is the mRNA of a prokaryotes, and generally prokaryotes use overlapping genes to translate proteins, usually an mRNA can encode 0-40 polypeptide chains, but not necessarily all of them are translated, and can generally be roughly deduced according to the SD sequence it contains. As for the half-life, it is generally 30 seconds to a few minutes, depending on the stability of the inverse repeat at the 3' end.

Very simple.

Only one peptide chain can be synthesized from one mRNA.

For proteins that contain multiple peptide chains, the peptide chain is synthesized and then cleaved to form a certain spatial structure.

Ribosomes are made up of only tRNA and no mRNA.

Ribosomes are made up of proteins and tRNA, while mRNA is messenger RNA, which is a template for the synthesis of proteins on ribosomes after being transcribed in the nucleus.

Yes, because only after the small subunit of the ribosome binds to the mRNA, the ribosome with the complete binding stroke of the large subunit will be the ribosome, and at the same time, the p-position A on the large and small subunit of the ribosome will bind to the tRNA for transcription.

Have those who say tRNA is only there ever considered how rRNA feels?

Ribosomes are made up of RNA and proteins, also known as nucleosomes.

In eukaryotes, mRNA is transcribed through the nuclear pore to the cytoplasm, and because the ribosome is a hollow structure, it can move on the mRNA, and the tRNA carries amino acids into the ribosome, and the protein is synthesized under the guidance of mRNA.

The main components of ribosomes are proteins and tRNA, and when it synthesizes proteins, it binds to mRNA.