Replication, Transcription, Translation 2.6 and 4.4
DNA Replication Transcription RNA Translation Protein DNA to Protein DNA Replication Transcription RNA Translation Protein
DNA to Protein DNA and RNA are nucleic acids The monomers of nucleic acids are nucleotides Each nucleotide has a nitrogen base Adenine, thymine, cytosine, and guanine in DNA Adenine, uracil, cytosine, and guanine in RNA The sequence of bases is unique for each person, which leads to different proteins being produced, which gives each person unique characteristics.
Replication The message encoded within the sequence of bases in DNA must be copied so that it can be passed to the next generation of cells Occurs in the nucleus The DNA strands are separated and free nucleotides are added to both strands following the complementary base pair rules by an enzyme called DNA polymerase. Results in two DNA molecules that are identical to each other and to the original DNA molecule
Replication
Transcription Part of the message encoded within the sequence of bases in DNA must be transcribed into a sequence of bases in RNA before translation can occur mRNA, tRNA, and rRNA all must be transcribed Occurs in the nucleus An enzyme called RNA polymerase separates a section of the DNA molecule and adds complementary base pairs to one strand of the DNA molecule forming an RNA strand. The new RNA single strand peels off and the DNA double strand goes back together as RNA polymerase moves down the DNA molecule. Remember RNA contains uracil instead of thymine. So if the DNA strand contains an adenine, then uracil will be added to the RNA strand.
Transcription Modifications of mRNA Poly-A tail added G-cap added Introns = noncoding region are cut out Exons = coding region are spliced together
Transcription
Translation The base sequence in DNA determines the base sequence in RNA (transcription), and the RNA sequence determines the amino acid sequence which makes up the protein (translation). During translation the RNA bases are “read” in groups of 3. 3 bases are called codons and each combination of 3 bases codes for a specific amino acid. Some amino acids are coded for by several different codons, but a specific codon always codes for the same amino acid. Genetic Code p92
Translation Types of RNA mRNA (messenger RNA)- messenger, contains the codons that are translated into an amino acid sequence by the ribosomes tRNA (transfer RNA)- interpreter, contains an anticodon which is complementary to the codon in mRNA. Also carries the corresponding amino acid which is added to the polypeptide chain (protein) rRNA (ribosomal RNA)- coordinator, makes up the ribosomes along with proteins. Ribosomes can be free-floating in the nucleus or embedded in the RER. They coordinate the process of translation.
Translation http://www.youtube.com/watch?v=5bLEDd-PSTQ