LO: SWBAT explain how protein shape is determined and differentiate between the different types of mutations.

DN: h/0 protein synthesis

HW: Read pp 307-308# 1-5

HW: page 306 #1-51. Types of RNA: mRNA, tRNA2. Transcription: mRNA makes a copy of DNA in the

nucleus3. Translation: tRNA reads mRNA codons (3 bases) and

brings the correct amino acid to the ribosome4. Sugar: DNA= deoxribose, RNA= ribose Bases: DNA has T and RNA has U DNA: double stranded, RNA: single stranded5. UGG CAG UGC Try Glu Cys

HormoneAll are proteins with a specific shape that determines their function.

What do enzymes, antibodies, hormones, hemoglobin and membrane proteins have

in common?

AntibodiesHemoglobin

Enzymes

What determines a protein’s Shape?

A protein’s shape is determined by its sequence of amino acids.

What happens after translation of the genetic code?

Proteins do not remain as single strands of amino acids, rather the amino acids chain gets folded into a specific shape. This shape is determined by the ORDER of the amino acids in the chain.

Protein Shape:1) The DNA base sequence (order) determines the sequence of amino acids.

2) The sequence (order) of amino acids in a protein determine its shape.

3) The shape of a protein determines its activity.

Transcription & Translation:The processes of transcription and translation, lead to the final shape of a protein. Therefore it is the genetic code: DNA base sequence that ultimately determine a protein’s sequence of amino acids.

A – T U

C – G G Tryptophan

C – G G

Mutations

Mutations (changes in the genetic code) that can lead to changes in the amino acid

sequence and ultimately to the overall shape of the protein. Why?

What causes mutations errors in DNA replication?

• Chemicals

• UV Radiation

• X-Ray radiation

Mutated Proteins

It changes the amino acids sequence which determines protein shape

How does a mutated protein affect a cell?

•The mutated protein may have a different shape and disrupt its normal activity.

Types of Mutation

• Substitution

• Deletion

• Insertion

• Inversion

Original DNA Strand

Copy the Normal DNA Strand:

DNA CCT CAA GAT GCG

RNA

AA Sequence

GGA GUU CUA CGC

Gly – Val – Leu - Arg

Substitution• Substitution – One nitrogenous base is substituted for another.

DNA CCC CAA GAT GCG

RNA GGG GUU CUA CGC

Amino Gly - Val - Leu - Arg

acid

DNA CCT CAA GAT GCG

Deletion

• One nitrogenous base is deleted (removed).

DNA CTC AAG ATG CGmRNA GAG UUC UAC GCAmino Glu - Ala - Tyr- acid

DNA CCT CAA GAT GCG

Insertion (Addition)• Insertion – Extra nitrogenous bases are

added to the genetic code.

DNA CCT CTA AGA TGC G

mRNA GGA GAU UCU ACG C

Amino Gly - Asp - Ser - Thr -

acid

DNA CCT CAA GAT GCG

Inversion• Inversion – The genetic code is

inverted or reversed.

DNA CCT CAA TAG GCGmRNA GGA GUU AUC CGCAmino Gly - Val – Iso - Argacid

DNA CCT CAA GAT GCG

Sickle Cell Anemia

Point mutation

A change in ONE nitrogenous base, the overall number of bases stays the same

(Substitution or Inversion)

Frame shift mutation

A change in the number of overall nitrogenous bases in the genetic code

(Addition or Deletion)

What type of mutation is it?