DNA

Replication to Transcription to Translation

DNA Replication

• Replication : DNA in the chromosomes is copied in the nucleus.

• DNA molecule is unzipped.

• Free nucleotides pair up

DNA Replication

• Each original strand of DNA acts as a pattern or template for the new strand.

• DNA is unzipped and new strand is formed

• A pairs with T• C pairs with G

DNA Replication

DNA Replication

• The DNA strands run in one direction. 5’-3’ (Think of it as left to right.)

• The complimenting strand will run in the opposite direction 3’-5’

DNA Replication

• DNA copies in one direction.

• 5’ to the 3’

DNA Replication

• Complete the strand of DNA that compliments this DNA

5’ 3’• C A G T A T G C

• G T C A T A C G3’ 5’

Transcription• Genes made of DNA contain the information to make proteins.

• DNA in the nucleus gives the instructions to RNA

• RNA takes the information to the cytoplasm

RNA• Single strand nucleic acid

• Sugar is ribose• Nitrogenous

bases are • Adenine• Cytosine• Guanine• Uracil (different

from DNA)

• Transcription: RNA is made from a DNA strand

• DNA is the template

• Free nucleotides pair with DNA

• This RNA is mRNA• C = G• A = U

Transcription

Transcription

• Complete the strand of RNA that compliments this DNA

• G C A T A T G C

• C G U A U A C G

Translation

• Translation : the process of changing the information in mRNA into a protein

Translation

• The messenger RNA (mRNA) takes the instructions out of the nucleus to the cytoplasm

• It will bind to a ribosome to make the protein

Translation

• Once the mRNA is attached to the ribosome the code is read

• The code is read 3 letters at a time

• Codon: a group of 3 nitrogenous bases

Translation

• Each codon represents one amino acid ( the building blocks of protein)

Translation

• Name the amino acid coded for in the following codons

• AAG• GCG• UAG• AUG

Translation

• Once the mRNA is attached to the ribosome, tRNA begins to deliver amino acids

• The tRNA pairs its anticodon to the codon of the mRNA

Translation

Translation

• Which anticodon will pair with the codon?(they are opposite of the codon)

• CGA UAC AAG CGC ACG

• GCU AUG UUC GCG UGC

Translation• The ribosome

attaches the tRNA anticodon to the mRNA codon.

• The amino acids attach with peptide bonds

• Once the amino acid is attached the tRNA is released.

Translation

• The ribosome will begin to assemble the amino acids at the “start” codon AUG

• It will end when it reads a “stop” codon

• Name a “stop” codon.

Translation

• Once the completed amino acid chain is released, the amino acids twist and curl into complex 3-D shapes forming the protein

Central Dogma

• The pathway of information in a cell flows from

DNA mRNA Protein Trait

This is true in all living things !