1. I will understand the general pathway of transcription and translation
Biology
MT 5: Protein Synthesis
Bullet 1 and 2:
I will understand the general pathway of transcription and translation
Biology
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2. 12-3 RNA and Protein Synthesis
“making a protein”
Step 1. Transcription
Step 2. Translation
DNA to mRNA
mRNA to protein
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Types of RNA
What are the three main types of RNA?
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Types of RNA
Types of RNA
There are three main types of RNA:
messenger RNA (mRNA)
ribosomal RNA (rRNA)
transfer RNA (tRNA)
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Types of RNA
The three main types of RNA are messenger RNA, ribosomal RNA, and transfer RNA.
Messenger RNA (mRNA) carries copies of DNA with instructions to make proteins.
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Types of RNA
Amino acid
The three main types of RNA are messenger RNA, ribosomal RNA, and transfer RNA.
Transfer RNA
During protein construction, transfer RNA (tRNA) transfers each amino acid to the ribosome.
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Types of RNA
Ribosome
Ribosomal RNA
The three main types of RNA are messenger RNA, ribosomal RNA, and transfer RNA. Ribosomal RNA is combined with proteins to form ribosomes.
Ribosomes are made up of proteins and ribosomal RNA (rRNA).
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8. 12-3 RNA and Protein Synthesis
“making a protein”
Step 1. Transcription
Step 2. Translation
DNA to mRNA
mRNA to protein
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Transcription
What is transcription?
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Transcription
Transcription
- One strand of DNA being copied into one piece of mRNA
- Occurs in the nucleus
- DNA  mRNA
During translation, or protein synthesis, the cell uses information from messenger RNA to produce proteins. The cell uses all three main forms of RNA during this process.
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11. Steps to Transcription
4. RNA polymerase makes pre- mRNA by joining RNA base pair to DNA
1. Part of DNA unwinds in nucleus
2. RNA polymerase binds to promoter (T-A-T-A) (“start”) region on DNA strand
3. RNA polymerase unzips DNA strand
5. RNA polymerase reaches “stop” region and pre- mRNA released from DNA
6. Pre-mRNA removes introns (unwanted mRNA) to make mature mRNA
7. mRNA exits the nucleus into cytoplasm
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Transcription
RNA
RNA polymerase
DNA
During transcription, RNA polymerase uses one strand of DNA as a template to assemble nucleotides into a strand of RNA.
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Translation
What is translation?
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Translation
Messenger RNA is transcribed in the nucleus, and then enters the cytoplasm where it attaches to a ribosome.
Nucleus
During translation, or protein synthesis, the cell uses information from messenger RNA to produce proteins. The cell uses all three main forms of RNA during this process.
mRNA
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15. Translation 1. Ribosome attaches to mRNA at AUG codon
2. Ribosome “decodes” codon and brings in loaded tRNA
3. Ribosome moves and decodes next codon and brings in loaded tRNA
4. 1st tRNA unloads amino acid to the 2nd tRNA
5. 1st tRNA then unbinds from mRNA
6. Results in a chain of amino acids
(protein!)
7. Cycle continues until stop codon reached
During transcription, RNA polymerase uses one strand of DNA as a template to assemble nucleotides into a strand of RNA.
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Translation
The ribosome binds new tRNA molecules and amino acids as it moves along the mRNA.
Lysine
Phenylalanine
tRNA
Methionine
Ribosome
During translation, or protein synthesis, the cell uses information from messenger RNA to produce proteins. The cell uses all three main forms of RNA during this process.
mRNA
Start codon
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Translation
Protein Synthesis
Lysine
tRNA
During translation, or protein synthesis, the cell uses information from messenger RNA to produce proteins. The cell uses all three main forms of RNA during this process.
mRNA
Translation direction
Ribosome
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18. Amino acids within a polypeptide
Genes and Proteins
Codon
Codon
Codon
IN A NUTSHELL:
The sequence of bases in DNA is used as a template for mRNA.
The codons of mRNA specify the sequence of amino acids in a protein.
Single strand of DNA
Codon
Codon
Codon
mRNA
This diagram illustrates how information for specifying the traits of an organism is carried in DNA. The sequence of bases in DNA is used as a template for mRNA. The codons of mRNA specify the sequence of amino acids in a protein, and proteins play a key role in producing an organism’s traits.
Alanine
Arginine
Leucine
Amino acids within a polypeptide
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The Genetic Code
Q: How do I find the amino acids that link together to form a protein?
A codon is a group of three nucleotides on messenger RNA that specify a particular amino acid.
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The Genetic Code
A codon consists of three consecutive nucleotides on mRNA that specify a particular amino acid.
A codon is a group of three nucleotides on messenger RNA that specify a particular amino acid.
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The Genetic Code
The genetic code shows the amino acid to which each of the 64 possible codons corresponds. To decode a codon, start at the middle of the circle and move outward.
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