2 Genes, segment of DNA, are coded DNA instructions that control the production of proteins. Genetic messages can be decoded and used in protein synthesis by copying part of the nucleotide sequence from DNA into mRNA.mRNA contains coded information for making proteins.
3 The Structure of RNAThere are three main differences between RNA and DNA:The sugar in RNA is ribose instead of deoxyribose.RNA is generally single-stranded.RNA contains uracil in place of thymine.
4 Types of RNAThere are three main types of RNA:messenger RNAribosomal RNAtransfer RNA
5 Types of RNAThe three main types of RNA are messenger RNA, ribosomal RNA, and transfer RNA.Messenger RNA (mRNA) carries copies of instructions for assembling amino acids into proteins.
6 Ribosomes are made up of proteins and ribosomal RNA (rRNA). 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).
7 Amino acidThe three main types of RNA are messenger RNA, ribosomal RNA, and transfer RNA.Transfer RNADuring protein construction, transfer RNA (tRNA) transfers each amino acid to the ribosome.
8 Protein Synthesis DNA molecule DNA strand (template) 3¢ 5¢ TRANSCRIPTIONmRNA5¢3¢CodonTRANSLATIONProteinAmino acid
9 Transcription DNA is copied in the form of RNA This first process is called transcription.The process begins at a section of DNA called a promoter.
10 RNARNA polymeraseDNADuring transcription, RNA polymerase uses one strand of DNA as a template to assemble nucleotides into a strand of RNA.
11 RNA EditingSome DNA within a gene is not needed to produce a protein. These areas are called introns.The DNA sequences that code for proteins are called exons.
12 The introns are cut out of RNA molecules. ExonIntronDNAThe introns are cut out of RNA molecules.The exons are the spliced together to form mRNA.Pre-mRNAmRNAMany 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.CapTail
13 The Genetic CodeThe genetic code is the “language” of mRNA instructions.The code is written using four “letters” (the bases: A, U, C, and G).
14 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.
15 The Genetic CodeThe 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.
16 TranslationTranslation is the decoding of an mRNA message into a polypeptide chain (protein) on ribosomes.During translation, the cell uses information from messenger RNA to produce proteins.NucleusmRNA
17 The ribosome binds new tRNA molecules and amino acids as it moves along the mRNA and the anticodons of tRNA match the mRNA codons.LysinePhenylalaninetRNAMethionineRibosomeDuring 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.mRNAStart codon
18 Protein Synthesis Translation direction Lysine tRNA mRNA 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.mRNATranslation directionRibosome
19 The process continues until the ribosome reaches a stop codon. PolypeptideRibosometRNADuring 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
20 Amino acids within a polypeptide CodonCodonCodonDNAmRNAProteinSingle strand of DNACodonCodonCodonmRNAThis 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.AlanineArginineLeucineAmino acids within a polypeptide