Gene to Protein Unit TestReview

Test Date: Tuesday, 2/24/15

Codon Chart

• If given a DNA sequence of TACAAACGTAATCGA, what would the mRNA, tRNA sequences look like?

• Which sequence of codons will determine the amino acid order/sequence?

Codon Chart

• If given a DNA sequence of TAC AAA CGT AAT CGA, what would the

mRNA, tRNA sequences look like?• mRNA: AUG UUU GCA UUA GCU• tRNA: UAC AAA CGU AAU CGA• Which sequence of codons will determine the

amino acid order/sequence?• mRNA

Making Proteins

• A specific locus of a chromosome will hold the key to making certain proteins. What is this area called?

Making Proteins

• A specific locus of a chromosome will hold the key to making certain proteins. What is this area called?

• GENE

Mutations

TACAAACGTAATCGA

• What would this DNA sequence look like if there was a point mutation (where C is misread as G) at the 1st C?

• What would this DNA sequence look like if there

was a insertion (frameshift mutation) at the 1st C?

• What would this DNA sequence look like if there was a deletion (frameshift mutation)at the 1st C?

MutationsTACAAACGTAATCGA

• What would this DNA sequence look like if there was a point mutation (where C is misread as G) at the 1st C?

TAG AAA CGT AAT CGA (code for wrong amino acid)• What would this DNA sequence look like if there was a

insertion (frameshift mutation) at the 1st C? TAC GAA ACG TAA TCG A (extra base – everything shifts right when you add a base)• What would this DNA sequence look like if there was a

deletion (frameshift mutation)at the 1st C? TAA AAC GTA ATC GA (missing base – everything shifts leftwhen you delete a base)

Mutations

• Of the mutations previously mentioned…which is possibly the most catastrophic to the genome?

• More specifically, where along the strand (DNA or RNA) would this mutation be most devastating/destructive?

Mutations

• Of the mutations previously mentioned…which is possibly the most catastrophic to the genome?

• FRAMESHIFT (insertion or deletion)• More specifically, where along the strand (DNA

or RNA) would this mutation be most devastating/destructive?

• The closer to the beginning of the strand (everything thereafter will shift)

Mutations

• A simple base change/insertion/deletion could shift the entire reading frame of a DNA or RNA sequence. This could result in what?

Mutations

• A simple base change/insertion/deletion could shift the entire reading frame of a DNA or RNA sequence. This could result in what?

• Incorrect amino acid being coded (thus, incorrect protein being synthesized)

• No change at all (some codons code for the same amino acid)

mRNA & tRNA

• How do the codon and anticodon of mRNA and tRNA communicate?

• Where? • Why?

mRNA & tRNA

• How do the codon and anticodon of mRNA and tRNA communicate? – Codon of mRNA and Anticodon of tRNA form

complimentary base pairs• Where? – RIBOSOME

• Why?– mRNA brings the correct code (from the DNA in the

nucleus) while the tRNA brings the corresponding Amino Acid based on the mRNA codon to put them in the correct order to build the protein.

RNA

• mRNA: – carries the code (from nucleus to ribosome) in the form of a “triplet”

base ______– Transcribed by RNA Polymerase ___

• tRNA:– Gets the Amino Acid that corresponds with it’s anticodon by the

enzyme _________________________– Brings the amino acid to the ribosome to pair it’s ________ with the

mRNA’s codon– Transcribed by RNA Polymerase ___

• rRNA:– Transtribed by RNA Polymerase ___– Helps build the __________

RNA

• mRNA: – carries the code (from nucleus to ribosome) in the form of a “triplet”

base CODON– Transcribed by RNA Polymerase II

• tRNA:– Gets the Amino Acid that corresponds with it’s anticodon by the

enzyme Aminoacyl tRNA Synthetase– Brings the amino acid to the ribosome to pair it’s ANTICODON with the

mRNA’s codon– Transcribed by RNA Polymerase III

• rRNA:– Transtribed by RNA Polymerase I– Helps build the RIBOSOME

DNA Replication

• What enzymes aid in the process of DNA Replication?

DNA Replication

• What enzymes aid in the process of DNA Replication?– Topoisomerase – unwinds DNA– Helicase – unzips DNA (break H bonds)– Primase – builds PRIMER (which signals start and

brings in free Nucleotides)– DNA Polymerase – Covalent bonds between

phosphates & sugars along NEW backbone– Ligase – ensures all nucleotides are bonded and

correct

DNA Replication

• The segments of DNA that are being added to the newly synthesized COPY of DNA one nucleotide at a time form the _____ strand.

• The segments of DNA that are being added to the newly synthesized COPY of DNA in “chunks” at a time form the _____ strand; these chunks are called ______________.

DNA Replication

• The segments of DNA that are being added to the newly synthesized COPY of DNA one nucleotide at a time form the LEADING strand.

• The segments of DNA that are being added to the newly synthesized COPY of DNA in “chunks” at a time form the LAGGING strand; these chunks are called OKAZAKI FRAGMENTS.

New DNA: Leading vs. Lagging

• The _____strand that’s forming in DNA replication builds from __’ - __’ (reading the template strand from __’ - __’) from the outside toward the replication fork.

• The _____strand that’s forming in DNA replication builds from __’ - __’ (reading the template strand from __’ - __’) from the replication fork outward.

New DNA: Leading vs. Lagging

• The Leading strand that’s forming in DNA replication builds from 5’ - 3’ (reading the template strand from __’ - __’) from the outside toward the replication fork.

• The Lagging strand that’s forming in DNA replication builds from 5’ - 3’ (reading the template strand from 3’ - 5’) from the replication fork outward.

TRANSCRIPTION

• What enzymes are involved in Transcription?

• What are the 3 important regions &/or proteins that signal the process of Transcription?

TRANSCRIPTION

• What enzymes are involved in Transcription?• RNA Polymerase

• What are the 3 important regions &/or proteins that signal the process of Transcription?– Promoter Region: “Starting line”– Transcription Factor: “Gun” – “signal to start”– Terminator: “Finish line”

RNA Splicing

• What molecule runs along the Primary mRNA before it leaves the nucleus to remove all the “JUNK”?

• In this process, what parts of the mRNA is considered “junk” and what parts are kept to code as the mature mRNA? (what do we call it)

RNA Splicing

• What molecule runs along the Primary mRNA before it leaves the nucleus to remove all the “JUNK”?

• SLICEOSOMES• In this process, what parts of the mRNA is

considered “junk” and what parts are kept to code as the mature mRNA? (what do we call it)

• INTRONS are removed (“junk”)• EXONS are kept and put together to create the

mature mRNA for coding Amino Acids

Mature mRNA

• Once the mRNA has only what it needs (exons) it will leave the nucleus and travel through the cytoplasm toward the ribosome for Protein Synthesis.

• What is needed on this mRNA to protect it from the dangers w/in the cytoplasm?

Mature mRNA

• Once the mRNA has only what it needs (exons) it will leave the nucleus and travel through the cytoplasm toward the ribosome for Protein Synthesis.

• What is needed on this mRNA to protect it from the dangers w/in the cytoplasm?– 5’ GTP Cap– Poly-A Tail (@ 3’ end)

Complimentary Base Pairing

• In DNA replication, what pairs with what?

• In Transcription, what pairs with what?

Complimentary Base Pairing

• In DNA replication, what pairs with what?A – TG – C

• In Transcription, what pairs with what?DNA – RNA A – U

T – AG – CC – G

• Purines (Double Ringed) and Pyrimidines (Single Ringed) form complimentary base pairs.

From Gene to Protein

• Identify the function of each:– DNA Replication– Transcription– Translation

From Gene to Protein

• Identify the function of each:– DNA Replication• Copy genetic code for cell/body growth, cell replication,

tissue repair, fetal growth/development, etc.

– Transcription• mRNA takes DNA “genetic code” from the Nucleus (to

be able to make the protein in the Ribosome)

– Translation• Coding for the correct Amino Acids in the correct order

to make the correct Protein (based on the mRNA sequence)

Gene Expression

• Certain PROTEINS are allowed to be expressed in certain cells (turned on or off, more or less significant) by a process known as…

Gene Expression

• Certain PROTEINS are allowed to be expressed in certain cells (turned on or off, more or less significant) by a process known as…

GENE REGULATION