Question

Would you expect the transfer RNA molecules and the messenger RNA molecules to be the same in the cells of a horse as in similar human cells? Give reasons for your answer in each case.

Short answer

In conclusion, tRNA molecules in horse and human cells are likely to be similar but not identical, due to their conserved structure and function across all organisms that use the same genetic code for protein synthesis. However, mRNA molecules can be expected to have more differences than similarities, as they carry genetic information that varies between species, resulting in distinct proteins and traits for each organism.

Step-by-step solution

Background: tRNA and mRNA

Transfer RNA (tRNA) and messenger RNA (mRNA) molecules are types of RNA involved in the process of protein synthesis. Both molecules have distinct roles and structures. mRNA carries the genetic information from DNA in the nucleus to ribosomes in the cytoplasm, where proteins are synthesized. The sequence of nucleotides in mRNA is translated into a sequence of amino acids to form proteins. tRNA molecules are adapter molecules that transfer specific amino acids to the growing polypeptide chain during protein synthesis. Each tRNA molecule has a specific anticodon that is complementary to the codon sequence on the mRNA, allowing it to recognize the correct amino acid to add to the polypeptide chain.

tRNA molecules in horse and human cells

tRNA molecules in horse and human cells could be expected to be similar, but not necessarily identical, due to their conserved structure and function. Since both organisms use the same genetic code, similar tRNA molecules would be required to transfer the respective amino acids during protein synthesis. However, there might be some variations in the nucleotide sequences of the tRNA molecules, as these could vary between species, but the overall structure and function would be conserved.

mRNA molecules in horse and human cells

The mRNA molecules in horse and human cells would be expected to have more differences than similarities. This is because the mRNA molecules carry the genetic information for the synthesis of various proteins, which can be distinct between species. Although some proteins in different species may share similarities in their structure, and the corresponding mRNA sequences would also show some similarities, there would be significant differences due to variations in the organisms' genomes. These differences govern the unique traits present in each species.

Conclusion

In conclusion, tRNA molecules in horse and human cells will likely be similar due to their conserved structure and function throughout all organisms. However, the mRNA molecules can be expected to have more differences than similarities, as they carry the genetic information that varies between species. This variation in mRNA sequences accounts for the differences in proteins produced by the different organisms, which contributes to their distinct traits and characteristics.

Key concepts

tRNA Molecule Function

Transfer RNA (tRNA) is essential in the synthesis of proteins within a cell. Its primary function is to transport specific amino acids to the ribosome, the cellular 'factory' where proteins are assembled. Each tRNA molecule is specialized to recognize and carry only one type of amino acid. It does this with the help of a three-nucleotide sequence known as an anticodon.

At the ribosome, tRNA molecules match their anticodon with the appropriate codon on the messenger RNA (mRNA) strand. This process ensures that the amino acids are added in the correct order as dictated by the mRNA template, which is a direct translation of the cell’s genetic information.

mRNA Molecule Differences

Messenger RNA (mRNA) molecules differ fundamentally from tRNA in structure and role. Unlike tRNA, mRNA carries the genetic blueprint from the DNA in the nucleus to the ribosomes in the cytoplasm. The sequence coded within mRNA dictates the specific order in which amino acids must be linked to produce a protein.

Differences in mRNA between species like humans and horses reflect their unique genetic makeups. These differences are at the heart of why these species have distinct physical and biological traits. The genetic information embedded in the nucleotide sequence of mRNA guides the synthesis of proteins that determine species-specific characteristics.

Protein Synthesis in Eukaryotes

In eukaryotes, such as humans and horses, protein synthesis is a complex but meticulously organized process that occurs in the cytoplasm. This process, known as translation, involves numerous cellular components, including mRNA, tRNA, ribosomes, and various enzymes.

Protein synthesis begins with transcription in the nucleus where DNA is converted into mRNA. The mRNA then travels to the ribosome, where tRNA molecules assist in translating the nucleotide sequence into a chain of amino acids, creating a polypeptide chain that will eventually fold into a functional protein. This multistep process is highly conserved in eukaryotes, showcasing the shared mechanisms underlying life processes across diverse organisms.

Genetic Code Conservation

The genetic code is remarkably conserved across all known forms of life, from simple bacteria to complex multicellular organisms like humans and horses. This code is the set of rules by which information encoded within genetic material is translated into proteins by living cells. The universality of the genetic code implies that the same codon (three-nucleotide sequence) specifies the same amino acid in almost all organisms.

This conservation is further evidenced by the functionality of tRNA molecules. Despite small variations, tRNA in both horses and humans adheres to the universal genetic code, ensuring that proteins can be synthesized in a standardized and predictable manner. The conservation of the genetic code is one of biology's fundamental principles, illustrating the interconnectedness of life.