Translation and Transcription

• What is transcription?

  When DNA is copied into mRNA
• What is translation?

  mRNA joins with ribosome that codes for the synthesis of a protein
• What is mRNA?

  Messenger RNA. Caries genetic code from DNA to ribosomes. Single polynucleotide strand consisting of pentose sugar, phosphate and base. 3 bases make a codon.
• What is tRNA?

  Transfer RNA. Anticodon is complementary to codon on mRNA. It carries amino acids to ribosomes. Single polynucleotide folded into a clover shape. Has an amino acid binding site.
• What are the differences between mRNA and tRNA?

  mRNA has no hydrogen bonds, tRNA has hydrogen bonds. mRNA is a linear straight chain, tRNA is a folded clover leaf shape, mRNA is longer, tRNA is shorter, mRNA has codons, tRNS has anticodons.
• Describe the process of transcription

  Hydrogen bonds between DNA bases break by DNA helicase. DNA strand acts as template strand. Free nucleotides align on template strand by complementary base pairing. Uracil pairs with adenine. RNA Polyermase joins nucleotides and makes phosphodiester bonds. Hydrogen bonds reform naturally. Pre-mRNA is spliced to remove introns. mRNA leaves the nucleus through nuclear pores.
• Describe the process of translation

  mRNA attaches to ribosome. tRNA anticodons bind to mRNA codons. tRNA brings specific amino acid. Amino acids join by peptide bonds with the use of ATP. tRNA released after amino acid joins to polypetide. Ribosome moves along mRNA to next tRNA.
• What is the role of ATP in translation?

  Provides energy for the bond between tRNA and the amino acid
• During translation when does the polypeptide end?

  When there is a stop signal.
• During transcription when does RNA polymerase stop?

  When there is a stop code.
• What reaction occurs when the amino acids and bound together in translation?

  Condensation reaction.
• Why does the ribosome move along the mRNA after translation?

  To get to the next two parts mRNA as only 2 amino acids can bind at once.
• What breaks hydrogen bonds in Transcription?

  RNA Polymerase
• What is the template strand known as in transcription?

  Antisense strand.