Watch the animation and complete the card sort. The cell has reached the interphase of its cell cycle DNA is now in the form of identical sister chromatids The double helix untwists Hydrogen bonds start to break which ‘unzips’ the DNA The bases on each strand are now exposed Free nucleotides form hydrogen bonds with their complementary exposed base Covalent bonds form between the phosphate group on one nucleotide with the sugar on another nucleotide to seal the backbone This continues all the way down the DNA molecule until an exact replica of the original DNA molecule has been made

Transcription and Translation Compare the structure of RNA and DNA Outline DNA transcription in terms of the formation of an RNA strand complementary to the DNA strand by RNA polymerase. Describe the genetic code in terms of codons composed of triplets of bases.

Look at the pictures of DNA and RNA – how many differences/similarities can you notice?

Introducing RNA DNA RNA Very long strands, several million nucleotides Contains deoxyribose Contains bases C,G,A and T (not U) Consists of two polynucleotide strands of complementary base pairs held by H-bonds in the form of a double helix Relatively short strands, 100 to several thousand molecules Contains ribose Contains C,G, A and U (not T) Consists of single strands and in three functional forms messenger RNA (mRNA) transfer RNA (tRNA) ribosomal RNA (rRNA)

Transcription RNA polymerase causes DNA to unwind and hydrogen bonds are broken at the site of the gene being transcribed. In RNA synthesis Uracil pairs with Adenine. Once mRNA strand is formed, it leaves the nucleus through pores in the nuclear membrane and passes to ribosomes in the cytoplasm, where the information can be ‘read; and used in the synthesis of a proteins.

Match and sort these statements up with pictures on your hand out Part of the DNA double helix of one chromosome RNA polymerease catalyses the synthesis of mRNA C. DNA of a gene unwinds D. mRNA is transported to ribosomes in the cytoplasm. E. Strand of mRNA formed by pairing so that the mRNA is complementary to the coding strand of DNA

Outline of transcription ____________________ binds to a site on the DNA at the start of a gene called the ______________ region. RNA polymerase moves along the gene separating DNA into a single strand and pairing up ____ nucleotides with complementary bases on one strand of the DNA. RNA polymerase forms covalent bonds between the RNA nucleotides Transcription stops at the end of the gene when the terminator region is reached and the mRNA molecule is released.

Transcription A. Part of the DNA double helix of one chromosome C. DNA of a gene unwinds B. RNA polymerease catalyses the synthesis of mRNA E. Strand of mRNA formed by pairing so that the mRNA is complementary to the coding strand of DNA D. mRNA is transported to ribosomes in the cytoplasm.

If the mRNA strand has the following code: CGAAUAG On the dry wipe boards If the mRNA strand has the following code: CGAAUAG What was the original DNA template code? Draw the basic structure of a nucleotide Name the enzymes involved in DNA replication.

If the mRNA strand has the following code: C G A A U A G G G C C U A G On the dry wipe boards If the mRNA strand has the following code: C G A A U A G G G C C U A G G C T T A T C C C G G A T C What was the original DNA template code? Draw the basic structure of a nucleotide Illustrate the number of hydrogen bonds between A-T and C-G in DNA. Name the two enzymes involved in DNA replication.

Transcription Compare the structure of RNA and DNA Outline DNA transcription in terms of the formation of an RNA strand complementary to the DNA strand by RNA polymerase. Describe the genetic code in terms of codons composed of triplets of bases.

If this is the answer what is the question: Phosphate group Nitrogenous base Adenine Semi-conservative Complementary base pairing Protein Hydrogen bond

Transcription RNA polymerase causes DNA to unwind and hydrogen bonds are broken at the site of the gene being transcribed. In RNA synthesis Uracil pairs with Adenine. Once mRNA strand is formed, it leaves the nucleus through pores in the nuclear membrane and passes to ribosomes in the cytoplasm, where the information can be ‘read; and used in the synthesis of a proteins.

Match these statements up with the picture on the board. Part of the DNA double helix of one chromosome RNA polymerease catalyses the synthesis of mRNA C. DNA of a gene unwinds D. mRNA is transported to ribosomes in the cytoplasm. E. Strand of mRNA formed by pairing so that the mRNA is complementary to the coding strand of DNA

Transcription A. Part of the DNA double helix of one chromosome C. DNA of a gene unwinds B. RNA polymerease catalyses the synthesis of mRNA E. Strand of mRNA formed by pairing so that the mRNA is complementary to the coding strand of DNA D. mRNA is transported to ribosomes in the cytoplasm.

If the mRNA strand has the following code: CGAAUAG On the dry wipe boards If the mRNA strand has the following code: CGAAUAG What was the original DNA template code and the coding strand code? Draw the basic structure of a nucleotide Illustrate the number of hydrogen bonds between A-T and C-G in DNA. Name the two enzymes involved in DNA replication.

If the mRNA strand has the following code: C G A A U A G G G C C U A G On the dry wipe boards If the mRNA strand has the following code: C G A A U A G G G C C U A G G C T T A T C C C G G A T C What was the original DNA template code? Draw the basic structure of a nucleotide Illustrate the number of hydrogen bonds between A-T and C-G in DNA. Name the two enzymes involved in DNA replication.

If this is the answer what is the question: Phosphate group Nitrogenous base Adenine Semi-conservative Complementary base pairing Protein Hydrogen bond