What happens in E coli that signals the termination of transcription?

In this process, rapid translation of the leader sequence in an mRNA favors a RNA secondary structure that terminates transcription prematurely by a Rho-independent mechanism. coli require the action of Rho protein, an ATPase that dislodges the 3′ end of a growing RNA chain from the active site of RNA polymerase.

Who broke the DNA code?

Marshall Nirenberg

Why does DNA replication go from 5 to 3?

DNA replication goes in the 5′ to 3′ direction because DNA polymerase acts on the 3′-OH of the existing strand for adding free nucleotides.

What amino acid does this codon code for?

Reading the genetic code Methionine is specified by the codon AUG, which is also known as the start codon. Consequently, methionine is the first amino acid to dock in the ribosome during the synthesis of proteins.

What are three ways in which eukaryotic cells can control gene expression?

Eukaryotic gene expression can be regulated at many stages

Chromatin accessibility. The structure of chromatin (DNA and its organizing proteins) can be regulated.
Transcription. Transcription is a key regulatory point for many genes.
RNA processing.

What can happen if the reading frame is altered?

The ways of breaking nucleotide strands into codons. If the reading frame was altered, then an entirely different set of nucleotides would be synthesized.

How do you know which end is 3 and 5?

Each DNA strand has two ends. The 5′ end of the DNA is the one with the terminal phosphate group on the 5′ carbon of the deoxyribose; the 3′ end is the one with a terminal hydroxyl (OH) group on the deoxyribose of the 3′ carbon of the deoxyribose. 4.

What happens during the termination step of DNA transcription?

Termination is the ending of transcription, and occurs when RNA polymerase crosses a stop (termination) sequence in the gene. The mRNA strand is complete, and it detaches from DNA.

What does 3 prime and 5 Prime mean?

Each end of DNA molecule has a number. One end is referred to as 5′ (five prime) and the other end is referred to as 3′ (three prime). The 5′ and 3′ designations refer to the number of carbon atom in a deoxyribose sugar molecule to which a phosphate group bonds.

What are two ways in which eukaryotic cells regulate gene expression quizlet?

Like prokaryotes, eukaryotes can control gene expression at the levels of transcription, translation, and post-translation.

What is the most common form of gene expression regulation in both bacteria and eukaryotes?

Transcriptional control is the primary means of regulating gene expression in eukaryotes, as it is in bacteria. In eukaryotic genomes, cis-acting control elements that regulate transcription from a promoter often are located many kilobases away from the start site.

How does DNA convert to RNA?

In the first step, the information in DNA is transferred to a messenger RNA (mRNA) molecule by way of a process called transcription. The pre-mRNA is processed to form a mature mRNA molecule that can be translated to build the protein molecule (polypeptide) encoded by the original gene.

What are the 3 reading frames?

There are three possible reading frames in any sequence, depending on the starting point. If the first frame starts at position 1, the second frame starts at position 2, and the third frame starts at position 3.

What controls gene expression?

Gene expression is primarily controlled at the level of transcription, largely as a result of binding of proteins to specific sites on DNA. Regulation of protein production is largely achieved by modulating access of RNA polymerase to the structural gene being transcribed.

What signals the termination of transcription?

Transcription begins when RNA polymerase binds to a promoter sequence near the beginning of a gene (directly or through helper proteins). Transcription ends in a process called termination. Termination depends on sequences in the RNA, which signal that the transcript is finished.

How did Nirenberg figure out which amino acids went with which codes?

C) How did Nirenberg “figure out” which amino acids went with which codes? Nirenberg synthesized mRNA with identical letters to determine the codons for four amino acids. He placed these in a mixture of ribosomes and all amino acids.

What factors increase gene expression?

The expression of genes in an organism can be influenced by the environment, including the external world in which the organism is located or develops, as well as the organism’s internal world, which includes such factors as its hormones and metabolism.

What are three factors that affect gene expression?

Various factors, including genetic makeup, exposure to harmful substances, other environmental influences, and age, can affect expressivity. Both penetrance and expressivity can vary: People with the gene may or may not have the trait and, in people with the trait, how the trait is expressed can vary.

What are two ways in which eukaryotic cells regulate gene expression?

Eukaryotic gene expression is regulated during transcription and RNA processing, which take place in the nucleus, and during protein translation, which takes place in the cytoplasm. Further regulation may occur through post-translational modifications of proteins.