2a Protein Synthesis Review Lesson

RNA, Transcription, and

Translation

� Central Dogma: Information flows in one

direction:
◦ DNA 🡪 RNA 🡪 Proteins
◦ Replication: duplication of DNA
◦ Transcription: Converting DNA message into RNA
◦ Translation: Interprets RNA into a string of amino

acids

DNA, RNA and Proteins

DNA

to

RNA

to

Protein

Multiple Choice

Genetic info flows in one direction. Which best represents this flow?

• DNA-protein-RNA
• Protein-RNA-DNA
• RNA-protein-DNA
• DNA-RNA-protein

RNA:Ribonucleic Acid

� Single stranded

� Polymer made up of monomers
called nucleotides

� Nucleotides are composed of:

1)

Nitrogen-containing base
* Cytosine, Guanine, Adenine, and
Uracil

2) 5-Carbon Sugar: Ribose
3) Phosphate Group

RNA structure

RNA structure

� Messenger RNA (mRNA) :

◦ Carries genetic info. from the nucleus to the ribosome
◦ mRNA is needed because DNA is too large to leave the nucleus

� Transfer RNA (tRNA) :

◦ Transports amino acids to the ribosome

� Ribosomal RNA (rRNA) :

◦ Creates peptide links between amino acids to create a protein
◦ Associates with proteins to form ribosomes

3 Types of RNA

Multiple Choice

Carries the amino acid used to make a protein

• mRNA

• rRNA

• tRNA

Multiple Choice

Factory for making a protein

• mRNA

• rRNA

• tRNA

Multiple Choice

Which type of RNA takes the instructions from the nucleus to the cytoplasm?

• mRNA
• tRNA
• rRNA
• RNA polymerase

Multiple Choice

What type of RNA is shown in this image?

• rRNA

• mRNA

• tRNA

� Transcription: The process of making mRNA from a DNA sequence

� Steps involved:

1. The desired part of DNA
   is unzipped

2. The DNA code is read and enzymes bind complementary RNA nucleotides together,
   creating mRNA

3. mRNA is created and moves out of the nucleus

Transcription

Multiple Choice

Where is DNA made into RNA?

• Cytoplasm

• Nucleus

• Ribosome

• Cell Membrane

Multiple Choice

Is this a strand of DNA or RNA?

TACGGACTA

• DNA

• RNA

• Impossible to tell

Multiple Choice

In RNA, C pairs with G , and A pairs with

• U

• A

• C

• T

Multiple Choice

CGAUCGAUCAAG

• This is a segment of DNA.

• This is a segment of RNA.

• It is impossible to tell if this is DNA or RNA.

Multiple Choice

During transcription:

• a DNA template is used to make DNA

• a DNA template is used to make mRNA

• mRNA is used to make a polypeptide/amino acid chain

• proteins are made

Multiple Choice

How would the DNA sequence GCTATA be transcribed to mRNA?

• GCUAUA
• CGATAT
• CGAUAU
• GCUTUT

Translation

Translation: The process that converts a mRNA message into a protein.
○ mRNA meets up with the ribosome

○ the nucleotides are read 3 at a time (1 codon at a time)

○ tRNA that has the complementary anti-codon that matches up with the mRNA and drops off the correct amino acid

○ rRNA binds the amino acids dropped off by the tRNAs together to form a protein (strand of amino acids)

� Anticodon:a set of three nucleotides that is

complementary to a mRNA codon.

Translation

� Codon: a three-nucleotide sequence that codes for an amino acid.

� These build proteins!

Translation

� Stop Codons: Signals the end of the protein chain

� Start Codons: Signals the start of translation.

Translation

Multiple Choice

Where does translation occur?

• nucleus

• golgi

• endoplasmic reticulum

• cytoplasm at the ribosome

Multiple Choice

During translation:

• a DNA template is used to make DNA

• a DNA template is used to make mRNA

• mRNA is used to make an amino acid/polypeptide chain

• DNA is replicated

Multiple Choice

Amino acids are attached to the top of which type of RNA?

• tRNA (transfer RNA)

• mRNA (messenger RNA)

• rRNA (ribosomal RNA)

Multiple Choice

When using the genetic code, you look up sets of 3 bases on the mRNA which are called:

• anticodons

• codons

• base pairs

• amino acids

Multiple Choice

If the mRNA codon is AUG, what would the matching tRNA anticodon be?

• UAC

• AUG

• TAC

• GUA

Multiple Choice

If the mRNA codon is AUG, what amino acid would the tRNA bring?

• Met

• GLu

• Ala

• Phe

Multiple Choice

What is the correct amino acid sequence for the mRNA code AUGCCAGUAUGA

• Met-Pro-Ala-Val
• Met-Pro-Val
• Tyr-Gly-His
• Tyr-Gly-Arg-His

Multiple Choice

What amino acid is represented by the codon UUA?

• Phenylalanine
• Tyrosine
• Leucine
• Stop codon

Multiple Choice

TRANSLATE this RNA sequence: AUGCAAUGA

• Met-Glu-Stop

• Met-His-Stop

• Thr-Glu-Stop

• Thr-Pro-Stop

Multiple Select

Select the RNA sequence or sequences for Glutamine.

• CGU

• CAG

• CUA

• CAA

Multiple Choice

Find the amino acid that this segment of RNA codes for: GAC

• Arginine

• Asparagine

• Aspartic Acid

• Alanine

Multiple Choice

Find the amino acid that this segment of DNA codes for: GAC

• Leucine

• Serine

• Aspartic Acid

• Histine

Multiple Choice

Find the amino acid that this segment of RNA codes for: UUG

• Glycine

• Asparagine

• Lysine

• Leucine

Multiple Select

Select the RNA sequence or sequences for STOP.

• UCC

• UAA

• UGA

• UAG

Match

Match the following

• DNA

• TRANSCRIPTION

• TRANSLATION

Code trapped in nucleus

Making mRNA from DNA

Constructing a protein by reading mRNA

• Code trapped in nucleus

• Making mRNA from DNA

• Constructing a protein by reading mRNA

Multiple Choice

Use the chart attached.

Code the following sequence:

AUG ACC GAG UAG

What is the correct Amino Acid sequence?

• Met, Thr,Glu, STOP

• Met, Lys, Glu, STOP

• Met, Thr, Glu, Tyr

• Ile, Thr, Glu, STOP