Answer:
a. transcription unit -------------------> The section of the DNA strand to be copied into messenger RNA
b. RNA polymerase -------------------> The enzyme that copies the DNA code into messenger RNA
c. termination signal -------------------> The DNA code that stops the transcription process
d. uracil -------------------> The base that replace thymine in RNA molecules
e. promotor -------------------> The area upstream from the DNA code to be copied
f. introns -------------------> The "junk" material that is removed in RNA splicing
g. exons -------------------> The parts of the messenger RNA that will be spliced together to form the code to make the protein
Step-by-step explanation:
Transcription unit:
Transcription unit is a short sequence of DNA that is transcribed into RNA. The transcription unit contains the promoter and the coding region for one or more genes. The coding region can be any length, but it must contain enough information to code for a protein. Transcription units are often called genes because they encode proteins; however, they do not necessarily encode all of the same proteins in an organism. For example, some bacteria have only one gene encoding a protein involved in nitrogen metabolism while humans have many different genes encoding similar proteins involved in this process.
RNA polymerase:
The enzyme that copies the DNA code into messenger RNA is called an RNA polymerase. The process begins with an initiation step, in which a specific sequence on the template DNA binds to a specific site on the core protein (called RPA). Once bound, the initiator tRNA molecule forms a ternary complex with RPA and ribosomal subunits. This ternary complex then moves along by sliding along microtubules until it reaches its active site where it can bind to mRNA molecules and initiate their synthesis.
Termination signal:
The termination signal is a short sequence of nucleotides that signals to stop transcription and start translation. It is found at the end of most genes, but not all. It acts as an inhibitor of DNA replication and transcription. The term "terminal" means the end, or final stage, of something. Termination signals are used in many different organisms to control the growth and development of cells during embryonic development, including plants and animals. They are also used by bacteria to regulate gene expression (the process by which genes make proteins). In eukaryotes (organisms with complex multicellular structures), they can be found on chromosomes or at specific sites called promoters where they act as molecular switches
Uracil:
The base that replaces thymine in RNA molecules is uracil. The chemical formula of uracil is C(5H)-U-N(1). The chemical name for uracil is 5-methyluracil. The base that replaces thymine in RNA molecules is uracil. Uracil is a derivative of uric acid, which is a breakdown product of purines, the building blocks of DNA and RNA. The enzyme that synthesizes uracil from its precursor adenosine triphosphate (ATP) uses energy from glucose to reduce adenosine diphosphate (ADP) to ADP-ribose, an intermediate in the synthesis of nucleotides. This reaction takes place on ribosomes, small organelles within cells that are responsible for protein synthesis.
Promoter:
In other words, we want to copy a piece of DNA that is located upstream from where it is being copied. The area upstream from the DNA code to be copied is a region of DNA that includes the nucleotides (A, T, C and G) that are used in the replication process. This is also called the 'promoter' or 'core promoter'. The core promoter has been defined as follows: "The sequence of nucleotides immediately 5' of ATG [the start codon] which initiates transcription."
Introns:
The "junk" material that is removed in RNA splicing is called introns. Introns are short sequences of DNA found within the genes of eukaryotic organisms. The function of introns has been a source of much speculation and controversy, but their removal from messenger RNAs (mRNAs) seems to be essential for the proper functioning of cells. In fact, it has been suggested that the removal of introns may be one reason why many viruses have evolved to encode their own mRNA molecules with the same information as host mRNAs.
Exons:
Exon is the part of the messenger RNA that will be spliced together to form the code to make the protein. exon, intron and promoter are all parts of mRNA. The exon codes for a specific amino acid in a protein. Mutation or deletion of an exon can cause disease or produce abnormal proteins (e.g., cystic fibrosis).