The Central Dogma• States: Genetic

information flows in one direction from DNA to RNA to proteins. • Includes 3 processes:

• RNA is the link between DNA and proteins.

– Replication– Transcription– Translation

replication

transcription

translation

• Single nucleotide strand

• Sugar: Ribose• 4 Bases:

–A: Adenine–G: Guanine–C: Cytosine–U: Uracil

• U replaces T• Three Types of RNA

• AKA: mRNA• Function: Copies a section of the DNA code and moves to

a ribosome• Link between DNA and proteins• Allows ribosome to create a protein• Location: Starts in nucleus… moves to ribosome

• AKA: tRNA• Function: Transfers amino acids from the cytoplasm to

the ribosome• Ribosome will link amino acids together to form a protein• Location: Cytoplasm

Transfer RNAAmino acidProline

Amino acidSerine

• AKA: rRNA• Function:

components of ribosomes

• Location: Cytoplasm

Transcription• Defined: Process of making mRNA from a

sequence of DNA• Step 1: RNA Polymerase separates the DNA

nucelotides • Step 2: Free floating RNA nucleotides match

with the DNA

Reminder: U replaces T• Step 3: mRNA breaks free in separate pieces• Step 4: mRNA processing takes place

– Unused portions (introns) are removed and the used portions (exons) bond together

• Step 5: Final mRNA strand travels to ribosome• Step 6: DNA recombines to be used again

U|

G|C|A|A|G|U|C|A|U|U|C|

G|

Transcription Animation

Transcription Video

DNA vs. RNA• # of strands: Two (Double)• Sugar: Deoxyribose• Bases: A T C G• Location: Nucleus

• # of strands: One (Single)• Sugar: Ribose• Bases: A U C G• Location: Nucleus & Cytoplasm

Replication vs. Transcription• Enzymes: DNA Helicase and DNA

Polymerase• Base pairing rules:

• A=T, G=C• Copies: DNA

• Only one copy of DNA is made

• Location: Nucleus

• Enzymes: RNA Polymerase

• Base pairing rules:• A=U, G=C

• Copies: a gene• Many copies and types of

RNA are made• Location: Nucleus

DNA & RNA Comparison

Review• Name three different ways that DNA and RNA

differ.• Which RNA:

– is found inside the nucleus?– transports amino acids to the ribosome?– exits the nucleus to the ribosome?– copies the DNA code?– makes up the structure of ribosomes?

• Perform transcription by using the following piece of DNA. Introns are underlined. Write the final strand of mRNA created.T A C C G T A C A A T G G G A T C