Figure 17.0 Ribosome

DNA and protein DNA codes for your traits So you are different from other people because your DNA is different DNA works by creating proteins So you are different from other people because your DNA makes different proteins

Protein Structure A protein is made up of hundreds or thousands of amino acids put together There are 20 different amino acids One protein is different from another because of the order of the amino acids

Amino Acids O O–O– H H3N+H3N+ C C O O–O– H CH 3 H3N+H3N+ C H C O O–O– C C O O–O– H H3N+H3N+ CH CH 3 CH 2 C H H3N+H3N+ CH 3 CH 2 CH C H H3N+H3N+ C CH 3 CH 2 C H3N+H3N+ H C O O–O– C H3N+H3N+ H C O O–O– NH H C O O–O– H3N+H3N+ C CH 2 H2CH2C H2NH2N C H C Nonpolar Glycine (Gly) Alanine (Ala) Valine (Val)Leucine (Leu)Isoleucine (Ile) Methionine (Met) Phenylalanine (Phe) C O O–O– Tryptophan (Trp) Proline (Pro) H3CH3C Figure 5.17 S O O–O–

Protein shape Placing amino acids in a certain sequence will cause a protein to have a different shape The shape of the protein affects its function

Shape and function If you change the shape of a protein it will not work in the same way You can change the shape of a protein by changing the order of the amino acids An example of this is with sickle cell anemia

Changing a protein’s shape affects its function Normal hemoglobin Sickle-cell hemoglobin

Overview of protein synthesis Synthesis of mRNA in the nucleus Movement of mRNA into cytoplasm via nuclear pore Synthesis of protein NUCLEUS CYTOPLASM DNA mRNA Ribosome Amino acids Polypeptide mRNA Figure 5.25

Figure 17.3 The triplet code

Figure 17.4 The dictionary of the genetic code

Paired Activity Create a polypeptide that is 8 amino acids long Choose any amino acids that you want, but must have a start and stop codon Begin by listing the 8 amino acids that you want Use arrow to show which bases you will need for mRNA Use arrows to show bases for DNA

Figure 17.5 A tobacco plant expressing a firefly gene

Elongation RNA polymerase Non-template strand of DNA RNA nucleotides 3 end C A E G C A A U T A G G T T A A C G U A T C A T CCA A T T G G Newly made RNA Direction of transcription (“downstream) Template strand of DNA

Figure 17.6 The stages of transcription: initiation, elongation, and termination (Layer 1)

Figure 17.6 The stages of transcription: initiation, elongation, and termination (Layer 2)

Figure 17.6 The stages of transcription: initiation, elongation, and termination (Layer 3)

Figure 17.6 The stages of transcription: initiation, elongation, and termination (Layer 4)

Figure 17.6 The stages of transcription: elongation

Figure Translation: the basic concept

The structure of tRNA Amino Acids attach here Matches with codon on mRNA

Figure The initiation of translation

Figure The elongation cycle of translation

Figure The termination of translation

Figure A summary of transcription and translation in a eukaryotic cell

Mutations Are changes in the DNA Can only be passed on to offspring if they occur in a sex cell Point mutation is a where only one or a few bases are affected

Figure The molecular basis of sickle-cell disease: a point mutation Normal

Figure Categories and consequences of point mutations: Base-pair substitution

Figure Categories and consequences of point mutations: Base-pair insertion or deletion

Mutations Are spontaneous and random Naturally happen Increase in mutations by things like radiation, smoking, etc…

Figure 17.6 The stages of transcription: initiation, elongation, and termination (Layer 1)

Figure 17.6 The stages of transcription: initiation, elongation, and termination (Layer 2)

Figure 17.6 The stages of transcription: initiation, elongation, and termination (Layer 3)

Figure 17.6 The stages of transcription: initiation, elongation, and termination (Layer 4)

Figure 17.6 The stages of transcription: elongation

Figure 17.8 RNA processing; addition of the 5 cap and poly(A) tail

Figure 17.9 RNA processing: RNA splicing

Figure Translation: the basic concept

Figure 17.13b The structure of transfer RNA (tRNA)

Figure The anatomy of a functioning ribosome

Figure The initiation of translation

Figure The elongation cycle of translation

Figure The termination of translation

Figure A summary of transcription and translation in a eukaryotic cell

Figure The molecular basis of sickle-cell disease: a point mutation

Figure Categories and consequences of point mutations: Base-pair substitution

Figure Categories and consequences of point mutations: Base-pair insertion or deletion