1. 12-3 RNA and Protein Synthesis
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2. 12–3 RNA and Protein Synthesis
Genes are coded DNA instructions that control the production of proteins.
Genetic messages can be ______________ by copying part of the nucleotide sequence from DNA into RNA.
RNA contains coded information for making_________________________.
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The Structure of RNA
The Structure of RNA
RNA consists of a long chain of ______________.
Each nucleotide is made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base.
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The Structure of RNA
There are three main differences between RNA and DNA:
The sugar in RNA is _________________ instead of deoxyribose.
RNA is generally ________________-stranded.
RNA contains ______________ in place of thymine.
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Types of RNA
Types of RNA
There are three main types of RNA:
_______________________ RNA
_______________________RNA
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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 instructions for assembling _______________________into proteins.
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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 ________________ and _____________________ RNA (rRNA).
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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, _______________ RNA (tRNA) transfers each amino acid to the ribosome.
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Transcription
Transcription
RNA molecules are ________________ by copying part of a nucleotide sequence of DNA into a complementary sequence in RNA. This process is called __________________________________.
Transcription requires the enzyme RNA ___________________________.
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Transcription
During transcription, RNA polymerase binds to DNA and _________________ the DNA strands.
RNA polymerase then uses one strand of __________________ as a template from which nucleotides are assembled into a strand of RNA.
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Transcription
RNA polymerase binds only to regions of DNA known as__________________________.
Promoters are signals in DNA that indicate to the _________________________ where to bind to make RNA.
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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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RNA Editing
RNA Editing
The DNA of eukaryotic genes contains sequences of nucleotides, called _________________, that are not involved in coding for proteins.
The DNA sequences that code for proteins are called _________________________.
When RNA molecules are formed, introns and exons are ____________________ from DNA.
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RNA Editing
The introns are _____ out of RNA molecules.
The exons are the __________________ together to form mRNA.
Exon
Intron
DNA
Pre-mRNA
mRNA
Many RNA molecules have sections, called introns, edited out of them before they become functional. The remaining pieces, called exons, are spliced together. Then, a cap and tail are added to form the final RNA molecule.
Cap
Tail
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The Genetic Code
The Genetic Code
The genetic code is the “language” of mRNA ____________________________.
The code is written using ___________ “letters” (the bases: A, U, C, and G).
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The Genetic Code
A _________________ 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
Each codon specifies a particular amino acid that is to be placed on the __________________chain.
Some amino acids can be __________________ by more than one codon.
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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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The Genetic Code
There is one codon_______________that can either specify the amino acid methionine or serve as a ______________codon for protein synthesis.
There are three _______________codons that do not code for any amino acid. These “stop” codons signify the end of a polypeptide.
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Translation
Translation
Translation is the ________________ of an mRNA message into a polypeptide chain (protein).
Translation takes place on _____________.
During translation, the cell uses information from _________________ RNA to produce proteins.
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Translation
Messenger RNA is transcribed in the ____________, and then enters the ________________ 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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Translation
Translation begins when an mRNA molecule __________________ to a ribosome.
As each ________________ of the mRNA molecule moves through the ___________________, the proper amino acid is brought into the ribosome by tRNA.
In the ribosome, the amino acid is transferred to the growing polypeptide chain.
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Translation
Each ____________ molecule carries only one kind of amino acid.
In addition to an amino acid, each tRNA molecule has three __________________ bases.
These bases, called the ___________________are complementary to one mRNA codon.
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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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Translation
The process continues until the ribosome reaches a stop codon.
Polypeptide
Ribosome
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
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The Roles of RNA and DNA
The Roles of RNA and DNA
The cell uses the DNA “____________________” to prepare RNA “_______________________The DNA stays in the nucleus.
The RNA molecules go to the protein ______________________sites in the cytoplasm—the ribosomes.
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Genes and Proteins
Genes and Proteins
Genes contain ____________________ for assembling proteins.
Many proteins are enzymes, which _______________________and regulate chemical reactions.
Proteins are each specifically _______________ to build or operate a component of a living cell.
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29. Amino acids within a polypeptide
Genes and Proteins
Codon
Codon
Codon
The sequence of bases in DNA is used as a ______________ for mRNA.
The codons of mRNA specify the __________________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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