figure 17.0 ribosome. dna and protein dna codes for your traits so you are different from other...
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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–
H
H3N+ C C
O
O–
H
CH3
H3N+ C
H
C
O
O–
CH3 CH3
CH3
C C
O
O–
H
H3N+
CH
CH
3
CH
2
C
H
H3N+
CH
3
CH
3
CH
2
CH
C
H
H3N+
C
CH
3
CH
2
CH
2
CH3N+
H
C
O
O–
CH
2
CH3N+
H
C
O
O–
CH2
NH
H
C
O
O–
H3N+ C
CH2
H2
C
H2
NC
CH
2
H
C
Nonpolar
Glycine (Gly) Alanine (Ala) Valine (Val) Leucine (Leu) Isoleucine (Ile)
Methionine (Met) Phenylalanine (Phe)
C
O
O–
Tryptophan (Trp) Proline (Pro)
H3C
Figure 5.17
S
O
O–
O–
OH
CH2
C C
H
H3N+
O
O–
H3N+
OH CH3
CH
C C
HO–
O
SH
CH2
C
H
H3N+ C
O
O–
H3N+ C C
CH2
OH
H H H
H3N+
NH2
CH2
O
C
C C
O
O–
NH2 O
C
CH2
CH2
C CH3N+
O
O–
O
Polar
Electricallycharged
–O O
C
CH2
C CH3N+
H
O
O–
O– O
C
CH2
C CH3N+
H
O
O–
CH2
CH2
CH2
CH2
NH3+
CH2
C CH3N+
H
O
O–
NH2
C NH2+
CH2
CH2
CH2
C CH3N+
H
O
O–
CH2
NH+
NH
CH2
C CH3N+
H
O
O–
Serine (Ser) Threonine (Thr)Cysteine
(Cys)Tyrosine
(Tyr)Asparagine
(Asn)Glutamine
(Gln)
Acidic Basic
Aspartic acid (Asp)
Glutamic acid (Glu)
Lysine (Lys) Arginine (Arg) Histidine (His)
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
1
2
3
Synthesis of mRNA in the nucleus
Movement of mRNA into cytoplasm
via nuclear pore
Synthesisof protein
NUCLEUS
CYTOPLASM
DNA
mRNA
Ribosome
AminoacidsPolypeptide
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
RNApolymerase
Non-templatestrand of DNA
RNA nucleotides
3 end
C A E G C AA
U
T A G G T TA
AC
G
U
AT
CA
T C C A AT
T
GG
3
5
5
Newly madeRNA
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 17.12 Translation: the basic concept
The structure of tRNA
Amino Acids attach here
Matches with codon on mRNA
Figure 17.17 The initiation of translation
Figure 17.18 The elongation cycle of translation
Figure 17.19 The termination of translation
Figure 17.25 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 17.23 The molecular basis of sickle-cell disease: a point mutation
Normal
Figure 17.24 Categories and consequences of point mutations: Base-pair substitution
Figure 17.24 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 17.12 Translation: the basic concept
Figure 17.13b The structure of transfer RNA (tRNA)
Figure 17.15 The anatomy of a functioning ribosome
Figure 17.17 The initiation of translation
Figure 17.18 The elongation cycle of translation
Figure 17.19 The termination of translation
Figure 17.25 A summary of transcription and translation in a eukaryotic cell
Figure 17.23 The molecular basis of sickle-cell disease: a point mutation
Figure 17.24 Categories and consequences of point mutations: Base-pair substitution
Figure 17.24 Categories and consequences of point mutations: Base-pair insertion or deletion