What is the task of the messenger RNA in the formation of proteins?
Messenger RNA (mRNA, messenger RNA): carries the genetic information from the cell nucleus to the ribosomes, the place in the cell where proteins are made. Ribosomal RNA (rRNA): is involved in the structural formation of the ribosomes.
What happens after translation?
d) End of translation and finished amino acid chain The whole process is repeated until the ribosome reaches a stop codon (UAA, UAG and UGA). These do not have to be at the end of the mRNA. When translation is complete, the ribosome, protein and tRNA detach from the mRNA and the ribosome breaks down into its individual parts.
What happens to the mRNA after transcription?
In eukaryotes, the pre-mRNA produced by transcription must be converted to mRNA (processing), which then leaves the cell nucleus. Only then can the translation take place. During processing, the introns that do not contain any information for the synthesis of a protein are removed (splicing).
What happens if mRNA is not degraded?
Translation and Degradation This process usually produces a single protein molecule. The ribosome then separates from the mRNA and a (different) ribosome can attach if it is not broken down beforehand. As a rule, several ribosomes attach themselves to an mRNA and synthesize the protein encoded in it.
Why is RNA degraded?
Certain classes of mRNAs, on the other hand, are deliberately degraded by the cell, either because they have a defect and are detected by quality control or because the transcripts contain a regulatory sequence which, via mRNA degrada- tion, controls the expression of the corresponding one gene dampens.
Why does it make sense that mRNA is short-lived?
A short-lived mRNA is therefore an advantage for proteins that have to be “switched off” quickly when needed, i.e. that must no longer be present. The stability of the mRNA can be regulated by attachments that protect the RNA from degradation. Completely processed mRNAs are discharged from the nucleus.
Why is gene regulation needed?
Regulatory factors can have an impact on each of these steps and control the process. In prokaryotes, gene regulation largely serves to adapt to a changing environment, such as a reduced supply of oxygen or a changing supply of nutrients.
What is the function of mRNA?
The mRNA (English messenger RNA = Messenger RNA) is an RNA, which is made from the DNA. It contains the blueprint for the proteins that are produced during protein biosynthesis.
Why do genes need to be regulated?
In order to use the genetic information in living cells, genes have to be activated. Gene activation begins with a copying process, transcription, in which a copy of the gene is created in the form of RNA.
What are regulated genes?
These genes are also called constitutive genes. Genes that code for enzymes are also called structural genes. However, the majority of genes are subject to regulation. Regulated genes are inactive most of the time and are only activated when the corresponding protein they represent is needed.
Where does gene regulation take place?
In the case of prokaryotes, such as the bacterium Escherichia coli, the so-called operon model is used for gene regulation. At the level of the DNA, certain gene sections lie one after the other in an operon: Promoter: binding site within the operon for the RNA polymerase.
Why is DNA more stable than RNA?
This difference makes RNA less stable than DNA, since it allows hydrolysis by bases: the OH group at the 2′-position of the sugar is stripped of its proton by a negatively charged hydroxide ion of a base, and the oxygen then left behind undergoes a ring bond with the phosphorus, making the…
What is the difference between DNA and RNA?
DNA / RNA difference: In DNA (deoxyribonucleic acid or in German deoxyribonucleic acid) we have deoxyribose as the sugar, in RNA (ribonucleic acid or in German ribonucleic acid) the sugar is ribose. Both DNA and RNA have the bases adenine, cytosine and guanine.
Why is DNA the carrier of genetic information and not RNA?
If foreign DNA is taken up by cells, this can lead to an altered phenotype. This is called a transformation. Through transformation experiments with bacteria, AVERY and co-workers were able to show that DNA and not RNA or proteins are the carriers of genetic information in bacteria.
Why is thymine in DNA and not uracil?
Thymine replaces uracil in DNA. Uracil can be formed relatively easily from cytosine by deamination and hydrolysis, which then alters (mutates) the base sequence and potentially alters the information genetically encoded in the nucleotide sequence.
Why does DNA have to be double stranded?
The DNA is a double strand and is present as a so-called double helix. Due to the base pairing, the organic bases in the two partner strands are not identical, but complementary – they complement each other! The naming of the DNA strands is also based on the nomenclature of the carbon atoms of deoxyribose.
Is the DNA loaded?
Chemical and physical properties of the DNA double helix. DNA is a negatively charged molecule at neutral pH, with the negative charges sitting on the phosphates in the backbone of the strands.
What is the backbone of DNA?
The sugar-phosphate backbone consists of the sugar deoxyribose and a phosphate residue. Sugar and phosphate are linked by an ester bond.
What is meant by the term antiparallelism of DNA?
In relation to nucleic acids, antiparallelism is usually the result of complementary base pairings between different strands or different sections of a single strand. It can occur in both DNA and RNA strands as well as in two strands of DNA/DNA, DNA/RNA or RNA/RNA.
What is stored in DNA?
The bases always appear in the double helix as adenine-thymine or guanine-cytosine pairs. The order of the bases is like a code that stores information that influences the structure of the organism and its biochemistry on certain sections of DNA. These sections of DNA are called genes.
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