Notes: DNA Replication and Transcription

Central Dogma of Molecular Biology  ______.  The transfer of information from DNA can be seen in 3 processes: 1. ______2. ______3. ______

DNA Replication

• If a cell reproduces, then the DNA reproduces so it must be copied ______in order for a new cell to function. • DNA replicates during the ______phase in Interphase of the Cell Cycle. • Step 1: • DNA ______unwinds the two strands of DNA and separates the strands like unzipping a zipper. • Notice the nitrogen bases are exposed. • Step 2: • The free bases floating around pair up with their ______bases. • A pairs with T • C pairs with G • Step 3: • The ______and ______parts bond together to form a complete new strand of DNA • DNA ______are the enzymes that bond the new nucleotides together. • There is one old strand of DNA and one new strand of DNA. This is called ______. • A section of DNA has a nucleotide sequence of • A-T-T-G-C-C What would be the sequence that form the complement? • ______• Practice • G-C-C-A-T-A ______• C-T-A-C-G-A ______• T-C-T-A-G-A ______• A-T-T-G-A-C ______

Transcription  All DNA is in the nucleus of a cell, however, the proteins are made ______the nucleus.  Something has to carry that information from the nucleus to the ribosome (where the proteins are assembled).  ______does this job. o It contains ribose sugar instead of deoxyribose.

Types of RNA • There are three types of RNA made in transcription: • ______RNA (mRNA) • ______RNA (tRNA) • ______RNA (rRNA) • mRNA Transcription • DNA is unwound and a complimentary strand of mRNA is made. • The same as replication EXCEPT: • Free RNA ______bind with the nitrogen bases on one strand of the unzipped DNA. • A pairs with ______(U) instead of T. There is no thymine in RNA!! • C still pairs with G. • mRNA is a ______strand. NOT a double strand. • Transcription copies the instructions in the DNA to make a strand of messenger RNA (mRNA). • The mRNA strand breaks away and the DNA zips back together. • mRNA carries the code to the ______. • Transcribe the DNA to mRNA G-C-A-T-T-A-C-G-A ______Codon • Every set of ______letters in the mRNA bases is called a ______. • Each codon represents either one ______or gives the “STOP” instruction. • There are 4 nucleotides- which allows for 64 possible combinations of codons. • There are 20 different ______s that codons can code for. • More than one codon can code for the same amino acid. mRNA Codon Chart