2 phases 2 phases : 1.transcription 2.translation dna rna protein
Post on 11-Jan-2016
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How your cell makes proteins
2 phases:
1. Transcription
2. Translation
DNA RNA Protein
Before making proteins, Your cell must first make RNA
How does RNA (ribonucleic acid) differ from DNA (deoxyribonucleic acid)?
RNA differs from DNA
1. RNA has a sugar riboseDNA has a sugar deoxyribose
2. RNA contains uracil (U)DNA has thymine (T)
3. RNA molecule is single-strandedDNA is double-stranded
DNA Transcription DNA can “unzip”
itself and RNA nucleotides match up to the DNA strand
This process is started and controlled by an enzyme called RNA polymerase.
Both DNA & RNA are formed from NUCLEOTIDES and are called NUCLEIC acids.
Question:
What would be the complementary RNA strand for the following DNA sequence?
DNA 5’-GCGTATG-3’
Types of RNA
Three types of RNA:
A. messenger RNA (mRNA)
B. transfer RNA (tRNA)
C. ribosome RNA (rRNA)
Remember: all produced in the nucleus
mRNA
Carries instructions from DNA to the ribosome.
Tells the ribosome what kind of protein to make
(1961) Watson & Crick proposed…
…DNA controlled cell function by serving as a template for PROTEIN structure.
3 Nucleotides = a triplet or CODON(which code for a specific AMINO ACID)
AMINO ACIDS are the building blocks of proteins.
DNA Translation
The cell uses information from “messenger” RNA to produce proteins
A. Messenger RNA (mRNA)
methionine glycine serine isoleucine glycine alanine stopcodon
protein
A U G G G C U C C A U C G G C G C A U A AmRNA
startcodon
Primary structure of a protein
aa1 aa2 aa3 aa4 aa5 aa6
peptide bonds
codon 2 codon 3 codon 4 codon 5 codon 6 codon 7codon 1
rRNA
Part of the structure of a ribosome Helps in protein production
tRNA
A go-getter Gets the right parts to make the right protein according to mRNA instructions
B. Transfer RNA (tRNA)
amino acidattachment site
U A C
anticodon
methionineamino acid
End Product
The end products of protein synthesis is a primary structure of a protein.
A sequence of amino acid bonded together by peptide bonds.
aa1
aa2aa3
aa4aa5
aa200
aa199
Transcription/Translation Quiz1. Why is transcription necessary?2. Describe transcription.3. Why is translation necessary?4. Describe translation.5. What are the main differences
between DNA and RNA.6. Using the chart identify the
amino acids coded for by these codons:UGGCAGUGC
1. Why is transcription necessary?Transcription makes messenger RNA (MRNA) to carry the code for proteins out of the nucleus to the ribosomes in the cytoplasm.
2. Describe transcription.RNA polymerase binds to DNA, separates the strands, then uses one strand as a template to assemble MRNA.
3. Why is translation necessary?Translation assures that the right amino acids are joined together by peptides to form the correct protein.
4. Describe translation.The cell uses information from MRNA to produce proteins.
5. What are the main differences between DNA and RNA.DNA has deoxyribose, RNA has ribose; DNA has 2 strands, RNA has one strand; DNA has thymine, RNA has uracil.
6. Using the codon chart, identify the amino acids coded for by these codons: UGGCAGUGCtryptophan-glutamine-cysteine
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