RNA and Protein Synthesis Nancy DowJill Hansen

Tammy Stundon

October 20, 2012

Gulf Coast State College Panhandle Area Educational Consortium

5230 West Highway 98 753 West Boulevard

Panama City, Florida 32401 Chipley, Florida 32428

850-769-1551 877-873-7232

www.gulfcoast.edu

Biology Partnership

(A Teacher Quality Grant)

Pre-testPre-testQ and A boardQ and A board

What is RNA How do we use RNA?

What are the different forms of RNA?How do we produce an actual human

from just a series of letters??

Florida Next Generation Sunshine State Standards

SC.912.L.16.3 Describe the basic process of DNA replication and how it relates to the transmission and conservation of the genetic information.

Also Assesses

SC.912.L.16.4 Explain how mutations in the DNA sequence may

or may not result in phenotypic change. Explain how mutations in gametes may result in phenotypic changes in offspring.

SC.912.L.16.5 Explain the basic processes of transcription and

translation, and how they result in the expression of genes.

SC.912.L.16.9 Explain how and why the genetic code is universal

and is common to almost all organisms

Benchmark Clarifications• Students will describe the process of DNA replication and/or its role

in the transmission and conservation of genetic information.• Students will describe gene and chromosomal mutations in the DNA• sequence.• Students will explain how gene and chromosomal mutations may or

may not result in a phenotypic change.• Students will explain the basic processes of transcription and/or

translation, and their roles in the expression of genes.• Students will explain that the basic components of DNA are universal

in organisms.• Students will explain how similarities in the genetic codes of

organisms are due to common ancestry and the process of inheritance.

Florida Next Generation Sunshine State Standards

Content Limits• Items requiring the analysis of base pairs for gene

mutations are limited to changes in a single gene.• Items may refer to but will not assess the cell cycle,

mitosis, and/or meiosis.• Items will not require memorization of specific conditions

resulting from chromosomal mutations.• Items may refer to the process of meiosis in the context of

mutations but will not assess meiosis in isolation.• Items addressing transcription or translation will not

require specific knowledge of initiation, elongation, or termination

Florida Next Generation Sunshine State Standards

Blame it on the DNA

Structure of DNAStructure of DNA DNA is made of

subunits called nucleotides

DNA nucleotides are composed of a phosphate, deoxyribose sugar, and a nitrogen-containing base

The 4 bases in DNA are: adenine (A), thymine (T), guanine (G), and cytosine (C)

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Remember Replication?

Hold up, Hold up, wait a minute….wait a minute….

• DNA is only found in the nucleus

• Who we are, how we look, and the mechanisms that make our body function are all determined by proteins

• Proteins are only made in the ribosome..

Why do we need Why do we need bothboth DNA and DNA and RNA?RNA?

• DNA holds all the genetic information

• DNA damage = mutation

• Safer in the nucleus

• RNA acts as messenger

Why do we need Why do we need bothboth DNA and DNA and RNA?RNA?

Central Dogma holds that genetic information is expressed in a specific order. This order is as follows

Central Dogma Video

DNA vs RNA

Sugar

Bases

Strand

DNA vs RNADNA vs RNA

Types of RNATypes of RNA

RNA Foldable

Types of Types of RNARNA

11

11

22

22

33

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. Three Types of RNAThree Types of RNA

1. Messenger RNA (mRNA) copies DNA’s code & carries the genetic information to the ribosomes

2. Ribosomal RNA (rRNA), along with protein, makes up the ribosomes

3. Transfer RNA (tRNA) transfers amino acids to the ribosomes where proteins are synthesized

Protein Synthesis: Step 1

Transcription –the making of messenger RNA (mRNA) from DNA in the nucleus

DNA unwinds and mRNA is made complementary to the

DNAA=UG=C

3 nitrogen bases in mRNA is called a codon

Where to start?

1. DNA unzips along hydrogen bonds2. Free RNA nucleotides pair with the

complementary DNA bases (C-G and U-A) along the exposed DNA strand forming an RNA transcript

3. RNA transcript released from the DNA

4. DNA closes again

Protein Synthesis: Step 1Protein Synthesis: Step 1

The transfer of information in the nucleus from a DNA molecule to

an RNA molecule

Protein Synthesis: Step 1Protein Synthesis: Step 1

• Only 1 DNA strand serves as template

• Starts at promoter DNA (TATA)• Ends at terminator (AAAAA)• When complete, preRNA

molecule is released

• A specialized nucleotide is added to the beginning of each mRNA molecule which forms a cap. It helps the mRNA strand bind to a ribosome and prevents the strand from being broken down too fast.

• The end of the mRNA molecule gets a string of AAAA nucleotides (poly A tail) that helps the mRNA molecule exit the nucleus.

• The extra footage takes the form of nucleotide segments that are not included in the final protein.

Protein Synthesis: Step 1 ½ Protein Synthesis: Step 1 ½

Not all the RNA codes for something!!

• Contains unwanted bases• The ‘junk’ sequences (called

introns) are removed from the message and the remaining sequences (exons) are linked together to produce a sequence of codons that will translate into a polypeptide.

• This process occurs before the message leaves the nucleus.

Cleaning Up the MessageCleaning Up the Message

Protein Synthesis: Step 1 ½ Protein Synthesis: Step 1 ½

Final processing of the mRNA includes removal of Final processing of the mRNA includes removal of intronsintrons, leaving the , leaving the exonsexons to direct protein synthesis to direct protein synthesis

There’s Junk in

My DNA!

Need a Potty Break

Need a Potty Break??

See you in 15

See you in 15

Let’s Catch Up Let’s Catch Up

DNA Codes for RNA,

Which Codes for Protein

• Each 3 nucleotide sequence in an mRNA strand is called a codon.

• Each codon codes for a 1 amino acid.

• The codon sequence codes for an amino acid using specific rules. These specific codon/amino acid pairings is called the Genetic Code.

The Language of Proteins The Language of Proteins

• There are 64 (43) possible codes, but only 20 amino acids.

• More than 1 triplet may code for the same amino acid. This is fine as long as no triplet can code for more than one a.acid.

• Note that several codons can also act as start (AUG) or stop (UAA) signals.

The Language of Proteins The Language of Proteins

The Genetic Code

Toss the Ball Review

Codon Music

Time to Practice!

MutationsMutations

• Mutation: change in DNA

• If a base is substituted or deleted, the triplet(s) are different

• This sometimes leads to difference in the protein

Putting it All Together Putting it All Together

1) rRNA (ribosomal RNA) attaches to mRNA and starts reading the codons

2) tRNA (transfer RNA) – carries amino acids and attaches them to the growing protein chain

3) When protein production is complete, the ribosome releases the protein chain

Putting it All Together Putting it All Together

Structure• Two subunits, each composed of ribosomal RNA (rRNA) and protein

Function• Bring tRNA bearing an amino acid close enough to mRNA to interact

– Permit alignment of anticodon and codon

Putting it All Together Putting it All Together

DNA Codes for RNA, DNA Codes for RNA, Which Codes for ProteinWhich Codes for Protein

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TranscriptionTranscription

TranslationTranslation

Scavenger hunt

UAG

Follow UpFollow Up

Q/A board Q/A board

Post TestPost Test

Try It - SimulationsTry It - Simulations

Awesome Scarf

Genome Quilts

Cool StuffCool Stuff

From Gamer to Scientist

Some Other GoodiesSome Other Goodies

• Trippy Protein Synthesis Dance• http://www.youtube.com/watch?v=gqvYOr78THo (Blame it on the

DNA)• http://www.youtube.com/watch?v=_Q2Ba2cFAew&feature=related

(Central dogma)• http://www.youtube.com/watch?v=bpMhgAGybe4 • http://www.youtube.com/watch?v=ZPlnDzkBrpc (mario translation)• http://www.youtube.com/watch?v=5ldkJxCzXak (sing along)?• http://www.youtube.com/watch?v=tQv5Ho8zsKI codon bell ringer

• http://www.youtube.com/watch?v=tVrkBJz9q0g Born to be wildtype (bad singing)

• Trippy Protein Synthesis Dance• Tik Tok (Protein Synthesis)• Translation Mario Style• The Cell Will Survive (Sing Along)• Genetic Music• DNA Song• DNA, Hotpockets, and the Longest Word Ever