What is a Sense Strand?
A sense strand, or coding strand, is the DNA strand within double-stranded DNA that carries the translatable code in the 5’ to 3’ direction. Its complementary strand is called antisense strand, which does not carry the translatable code and serves as template during transcription. The sense strand of DNA has the same sequence as the mRNA that contains the codon sequences to build proteins, except that thymine, instead of uracil, takes its place in the sense strand of DNA.
The sense strand is the strand of DNA that has the same sequence as the mRNA, which takes the antisense strand as its template during transcription, and eventually undergoes (typically, not always) translation into a protein. The antisense strand is thus responsible for the RNA that is later translated to protein, while the sense strand possesses a nearly identical makeup to that of the mRNA. Note that for each segment of double stranded DNA, there will possibly be two sets of sense and antisense, depending on which direction one reads (since sense and antisense is relative to perspective). It is ultimately the gene product, or mRNA, that dictates which strand of one segment of dsDNA we call sense or antisense. But keep in mind that sometimes, such as in prokaryotes, overlapping genes on opposite strands means the sense for one mRNA can be the antisense for another mRNA.
What You Need To Know About Sense Strand
- Sense strand is directed in the 3’ to 5’ direction.
- Sense strand is not transcribed into mRNA.
- Sense strand contains the same nucleotide sequence as the mRNA, except thymine.
- Sense strand contains codons.
- No hydrogen bonds are formed between the sense strand and synthesizing mRNA.
- Sense strand contains the complementary nucleotide sequence as the tRNA.
What is a Antisense Strand?
Antisense is the non-coding DNA strand of a gene. A cell uses antisense DNA strand as a template for producing messenger RNA (mRNA) that directs the synthesis of a protein. Antisense can also refer to a method for silencing genes. To silence a target gene, a second gene is introduced that produces an mRNA complementary to that produced from the target gene. These two mRNAs can interact to form a double-stranded structure that cannot be used to direct protein synthesis.
Antisense is a term that’s used to describe one of the two strands of DNA, or actually in some cases also RNA. If you imagine that there’s a directional way that you read information from what’s called the five prime, or the front end, to the three prime, or the back end, that’s unidirectional. You can’t read DNA or RNA in both directions, and so there’s a sense strand for DNA, and then there’s a second strand of DNA which is called the antisense strand. The sense strand has the information that would be readable on the RNA, and that’s called the coding side. The antisense is the non-coding strand, but ironically, when you’re making RNA, the proteins that are involved in making RNA read the antisense strand in order to create a sense strand for the mRNA. There’s a second aspect of antisense, which is a fairly new discovery, called antisense RNA. These are RNAs that read in the opposite direction of the coding strand, and they actually bind to the coding strand of mRNAs and either target them for destruction or prevent them from being expressed. It’s sort of a new way of gene regulation that’s recently been developed.
What You Need To Know About Antisense Strand
- Antisense strand is directed in the 5’ to 3’ direction.
- Antisense strand is transcribed into mRNA.
- Antisense strand is the template strand for the RNA synthesis. Therefore, it contains the complementary nucleotide sequence to mRNA.
- Antisense strand contains anti-codons.
- Nucleotides in the antisense strand are temporarily hydrogen bonded with the complementary nucleotides in the synthesizing mRNA.
- Antisense strand contains the same nucleotide sequence as the tRNA.
Difference Between Sense And Antisense Strand In Tabular Form
|BASIS OF COMPARISON||SENSE STRAND||ANTISENSE STRAND|
|Description||Sense strand is directed in the 3’ to 5’ direction.||Antisense strand is directed in the 5’ to 3’ direction.|
|Transcription||Sense strand is not transcribed into mRNA.||Antisense strand is transcribed into mRNA.|
|Nucleotide Sequence||Sense strand contains the same nucleotide sequence as the mRNA, except thymine.||Antisense strand is the template strand for the RNA synthesis. Therefore, it contains the complementary nucleotide sequence to mRNA.|
|Codons||Sense strand contains codons.||Antisense strand contains anti-codons.|
|Hydrogen Bonds||No hydrogen bonds are formed between the sense strand and synthesizing mRNA.||Nucleotides in the antisense strand are temporarily hydrogen bonded with the complementary nucleotides in the synthesizing mRNA.|
|Complementary Nucleotide||Sense strand contains the complementary nucleotide sequence as the tRNA.||Antisense strand contains the same nucleotide sequence as the tRNA.|