1. What are the functions of DNA?
Protein Synthesis
What are the functions of DNA?

2. Central Dogma of Biology
DNA  RNA  Protein
Proteins then have the ability to directly/indirectly influence every aspect of a cell
Transcription: The process by which the information in a segment of DNA (a gene) is transferred to RNA
Translation: The process by which RNA’s message is converted into protein

3. RNA Stands for ribonucleic acid Another type of nucleic acid
Usually single-stranded
Contains the bases: Adenine (A), Guanine (G), Cytosine (C), and Uracil (U)
U is complementary with A

4. NUCLEIC ACIDS are built from subunits called ____________________
NUCLEOTIDES
SUGAR in RNA is
________________
ribose

5. 3 KINDS OF RNA HELP WITH INFO TRANSFER FOR PROTEIN SYNTHESIS
RIBOSOMAL
_________________RNA (rRNA)
Combines with proteins to form ribosomes
_________________RNA (tRNA)
Matches m-RNA codon to add correct
amino acids during protein synthesis
_________________RNA (mRNA)
carries code from DNA to ribosomes
TRANSFER
MESSENGER

6. Enzyme called _____________________
Adenine (DNA and RNA)
Cystosine (DNA and RNA)
Guanine(DNA and RNA)
Thymine (DNA only)
Uracil (RNA only)
RNA polymerase
DNA
RNA
Enzyme called _____________________
separates strands, then uses one strand
as a template to assemble an RNA copy.
RNA POLYMERASE

7. Transcription
Three Steps:
Initiation
Elongation
Termination

8. Initiation
RNA Polymerase binds to places with specific DNA sequences called _______________.
PROMOTERS tell the enzyme where to start.
PROMOTERS

9. Elongation
RNA polymerase then moves along the gene sequence and adds the complementary _________ nucleotides.
RNA

10. Termination
RNA polymerase eventually reaches a _____ signal at the end of the gene, and transcription is then complete. The DNA molecule then comes back together.
stop

12. RNA’s require EDITING before use
The DNA of eukaryotic genes contain sequences of nucleotides, called __________, that are not involved in coding for proteins.
The DNA sequences that code for proteins are called __________.
introns
exons

13. RNA’s require EDITING before use
A _____________________ is added to the 5' end of the pre-mRNA while elongation is still in progress
A _______________ is added to the 3' end of the pre-mRNA once elongation is complete.
Both protect the mRNA from degradation.
7-methylguanosine cap
poly (A) tail

14. RNA Editing The __________ are cut out of the RNA
The __________ are spliced together to form the mRNA.
introns
exons

15. RNA Editing

16. The Big Picture “Blueprints” of master plan
TRANSCRIPTION (DNA→ RNA)
& PROCESSING takes place in nucleus
TRANSLATION (RNA→ proteins)
takes place on ribosomes in cytoplasm
“Blueprints” of master plan
are carried to building site

17. Translation

18. Why are Proteins Important?
Proteins directly and indirectly affect every function of a cell
Some common, important types of proteins:
Enzymes (facilitate chemical reactions)
Membrane proteins (help regulate what passes in/out of the cell membrane)
Regulatory proteins (regulate key processes in the cell)

19. The Genetic Code
In transcription, the ‘message’ within a gene was transcribed from the ‘language’ of DNA to the ‘language’ of RNA
In translation, the message will be translated from the ‘language’ of RNA (nucleotides) to the ‘language’ of proteins (amino acids)
The instructions for making a protein are stored in three-nucleotide sequences on the mRNA called codons

20. The Genetic Code
Each codon in an mRNA strand corresponds to an amino acid, a start, or a stop signal
The following charts are used to decipher the mRNA codons into their corresponding amino acids

21. AUG 64 possible codons 20 amino acids
Section 12-3
64 possible codons
20 amino acids
Some amino acids have more than one
codon.
START= _______
3 codons for _____
AUG
STOP

22. Codon Charts

23. Interpreting Codon Charts
Which amino acid corresponds to the codon “UCA”?
Which amino acid corresponds to the codon “GUA”?

24. Interpreting Codon Charts
Which amino acid corresponds to the codon “CCA”?
Which amino acid corresponds to the codon “AUC”?

25. EACH tRNA
carries only
one kind of
_____________
amino acid
ANTICODON
___________
on tRNA
matches up with
________
on mRNA
CODON

26. Translation
Three Steps:
Initiation
Elongation
Termination

27. Initiation start The ribosome assembles around the target mRNA.
The first tRNA is attached at the ______ codon.
start

28. Elongation
The tRNA transfers an amino acid to the tRNA corresponding to the next codon
The ribosome then moves (translocates) to the next mRNA codon to continue the process, creating an amino acid chain.

29. Termination The ribosome disassembles.
When a stop codon is reached, the ribosome releases the polypeptide.
The ribosome disassembles.

31. What kind mutations do you think are most detrimental?

32. What are Mutations? ____________ are changes in the genetic material.
Mutations can happen when cells make _________ in copying their own DNA or be caused by _______________ or
___________ in the environment.
________________ is more prone to making mistakes than _________________.
Mutations
mistakes
radiation
chemicals
RNA polymerase
DNA polymerase

33. KINDS OF MUTATIONS
Mutations that produce changes in a single gene = ____________________.
Mutations that produce changes in whole chromosomes = _______________________.
GENE MUTATIONS
CHROMOSOMAL MUTATIONS

34. GENE MUTATIONS Mutations involving ________________
____________ = __________________ because they occur at a single point in the DNA sequence.
TYPES OF POINT MUTATIONS:
Substitutions
Deletions
Insertions
one or a few
nucleotides
Point mutation

35. SUBSTITUTION A T T C G A G C T A T T C T A G C T
Changes one base for another
A T T C G A G C T
A T T C T A G C T
How many amino acids are changed?

36. SUBSTITUTION Three Types:
Silent: change in the genetic sequence that does not change the protein sequence
Missense: change in DNA sequence that changes the codon to a different amino acid
Nonsense: change in the genetic code that results in the coding for a stop codon rather than an amino acid

37. SICKLE CELL ANEMIA CAUSE: (autosomal recessive)
A changed to T (glu to val)
gene on chromosome #11
that codes for part of
hemoglobin protein
(carries oxygen in blood)

38. DELETION A T T C G A G C T A T T C A G C T
Piece of DNA code is lost
A T T C G A G C T
A T T C A G C T
How many amino acids are changed?

39. INSERTION A T T C G A G C T A T T C G C A G C T
Extra piece of DNA is added
A T T C G A G C T
A T T C G C A G C T
How many amino acids are changed?

40. GENE MUTATIONS
Substitutions usually affect no more than a single ____________, but deletions and insertions can have a more dramatic effect.
Amino acid

41. FRAME SHIFT MUTATIONS Change multiple bases in code
thefatcatatetherat
INSERTION
thefatcataatetherat
DELETION
the fat cat ate the rat
the fat cat aat eth era t
the fat ata tet her at

42. FRAME SHIFTS
Frame shift mutations change every ___________ in the ___________ that follows the shift.
Frame shifts can alter a protein so much it is unable to _____________.
amino acid
protein
function

43. Location of the shift is important!
AT BEGINNING
the fat cat ate the rat
AT END
the fac ata tet her at
the fat cat ate thr at
MUTATIONS AT _____________OF GENE DAMAGE __________ OF THE CODE!
BEGINNING
MORE

44. CHROMOSOMAL MUTATIONS
Mutations involving changes in the _____________ or ______________
of whole chromosomes
TYPES OF CHROMOSOMAL MUTATIONS:
Deletions
Duplications
Inversions
Translocations
number
structure

45. DELETION Piece of chromosome is lost
________________________________________

46. Duchenne Muscular Dystrophy
CAUSE:
(X linked recessive)
DELETION in gene that codes for a muscle protein

47. DUPLICATION Piece of DNA is copied too many times
_________________________________________________

48. HUNTINGTON’S Degenerative brain disorder Symptoms appear age 30-40
Lose ability to walk, think, talk, reason
Cause = ADDITION of extra CAG repeats

49. INVERSION
Segment flips and reads backwards

50. TRANSLOCATION
Segment breaks off and joins a different non-homologous chromosome

51. MUTATIONS
Most mutations are ____________ meaning they have little or no effect on gene ____________.
Mutations that cause ________________ are usually ____________
Harmful mutations are associated with many
________________ and can cause
_________.
neutral
function
defective proteins
HARMFUL
genetic disorders
cancer

52. MUTATIONS Mutations are also a source of _________________ and can be
_____________.
genetic variability
beneficial
Can help an organism
_____________________.
Provide _________
in population
for ________________
to act upon.
survive and reproduce
variation
natural selection

53. POLYPLOIDY
Condition in which an organism has extra sets of chromosomes
= _______________
__________ in humans, but beneficial
in some ___________.
Triploid (___) or tetraploid (___) plants are often ________________
than diploid plants.
POLYPLOIDY
LETHAL
plants 3N 4N
larger and stronger