Download RNA and Protein

DNA,RNA, and Protein
Synthesis
Chapter 12
What is a gene? Where is it
located in a cell?
What is a protein? Where are
they made in cells?
In cells, how do we get from a
gene to a protein?
The Central Dogma:
DNA > RNA > PROTEIN
What is RNA? Compare and
contrast to DNA:
RNA
Ribonucleic acid
Is single stranded
Has uracil
Has a ribose sugar
DNA
deoxyribonucleic acid
is double stranded
has thymine
has a deoxyribose
sugar
What are the 3 types of RNA?
What is the function of each?
mRNA – messenger RNA carries genetic
information from DNA in the nucleus to
direct protein synthesis in the cytoplasm.
tRNA – transfer RNA transports amino
acids to the ribosome
rRNA – ribosomal RNA associates with
proteins to form the ribosomes
Two Stages of Protein Synthesis:
I.
The first Stage is Transcription – the
process in which mRNA is synthesized
from template DNA.
Firefly - http://learn.genetics.utah.edu/content/begin/dna/
RNA Editing:
• Before the mRNA transcript (pre-mRNA)
can leave the nucleus, it must be edited.
The Genetic Code:
• The language of mRNA
TACAGCGTGATT = DNA Sequence
?
mRNA Sequence
?
amino acid sequence
THE GENETIC CODE:
II.
The Second Stage of Protein Synthesis
is Translation:
http://highered.mcgrawhill.com/sites/0072437316/student_view0/chapter15/animations.html#
Animations:
•
Transcription/Translation Animation http://www.pbs.org/wgbh/aso/tryit/dna/shockwave.html
•
Firefly - http://learn.genetics.utah.edu/content/begin/dna/
•
Transcribe and Translate Game http://www.pbs.org/wgbh/aso/tryit/dna/shockwave.html
•
McGraw-Hill Higher Ed Translation Animation – http://highered.mcgrawhill.com/sites/0072437316/student_view0/chapter15/animations.html#
Mutations:
• Are permanent changes in a cell’s DNA.
• Are mutations good or bad?
Mutations can be good!
- Lead to adaptations which are
important for survival
- And genetic diversity which makes you,
YOU!
Mutations can also be bad:
• Mutations can cause changes in a gene that
cause a protein to be nonfunctional.
• TYPES OF MUTATIONS:
1. Point Mutations are single base
substitutions (one base is exchanged for
another).
a. Missense Mutations (code for wrong aa)
b. Nonsense Mutations (cause termination)
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THE BIG RAT
2. Frameshift Mutations – result from the
insertion or deletion of bases which cause a
shift in the frame of the amino acid sequence.
Insertion – a gain of a nucleotide in the
DNA sequence.
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Deletion – the loss of a nucleotide in the
DNA sequence.
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Duplication:
THE BIG FAT CAT ATE THE WET RAT
THE BIG FAT CAT ATE THE WET RAT
THE BIG FAT CAT ATE THE WET RAT
THE BIG FAT CAT ATE THE WET RAT