Ribosome, mRNA, tRNA

Distinguishing Characteristics: Ribosomes are typically composed of two subunits: a large subunit and a small subunit. Ribosomal subunits are synthesized by the nucleolus. These two subunits join together when the ribosome attaches to messenger RNA (mRNA) during protein synthesis. Ribosomes along with another RNA molecule, transfer RNA (tRNA), help to translate the protein-coding genes in mRNA into proteins. Location in the Cell: There are two places that ribosomes usually exist in the cell: suspended in the cytosol and bound to the endoplasmic reticulum. These ribosomes are called free ribosomes and bound ribosomes respectively. In both cases, the ribosomes usually form aggregates called polysomes or polyribosomes during protein synthesis. Free ribosomes usually make proteins that will function in the cytosol (fluid component of the cytoplasm), while bound ribosomes usually make proteins that are exported from the cell or included in the cell’s membranes. Interestingly enough, free ribosomes and bound ribosomes are interchangeable and the cell can change their numbers according to metabolic needs. Protein Assembly: Protein synthesis occurs by the processes of transcription and translation. In transcription, the genetic code contained within DNA is transcribed into an RNA version of the code known as messenger RNA (mRNA). In translation, a growing amino acid chain, also called a polypeptide chain, is produced. Ribosomal RNA helps to link amino acids together to produce the polypeptide chain. The polypeptide chain undergoes several modifications before becoming a fully functioning protein. Proteins are very important biological polymers in our cells as they are involved in virtually all cell functions. #genomics #Iherb #phenotype #GeneticExamQuestionsSolutions #GeneticsExamQuestionsSolutions #Genetics #Prokaryotes #genes #genomes #transcription #Chromosomes #Cancer #genome #GeneticTesting #gene #geneExpression #GeneStructure #DNA #alleles #chromosome #geneticCode #genotype #Eukaryotes #MolecularBiology #GeneticsLecture #RNA #rRNA #DNAMolecule #Genetics101 #Proteins