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RNA. 12.3. What is RNA?. Macromolecule made of nucleotides from DNA Used to build proteins 3 types total. RNA is different from DNA. Single stranded Uracil replaces Thymine Ribose instead of deoxyribose Can leave the nucleus. mRNA. m=messenger Long, stringy (like a snake)
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RNA 12.3
What is RNA? • Macromolecule made of nucleotides from DNA • Used to build proteins • 3 types total
RNA is different from DNA • Single stranded • Uracil replaces Thymine • Ribose instead of deoxyribose • Can leave the nucleus
mRNA • m=messenger • Long, stringy (like a snake) • Carries the instructions from the nucleus to the cytoplasm to initiate translation • Contains 3-base sequences called “codons” • Made in transcription
tRNA • t= transfer • Responsible for bringing the amino acids for translation • Contains “anti-codons” that match up with mRNA temporarily • Shaped like a “hair pin” or a T
rRNA • Structurally part of the ribosome organelle • Site of translation • Globular shaped
RNA is made through “Transcription” • RNA is made in the nucleus like DNA replication
What is transcription? • Making of RNA from DNA in the nucleus • Initiation at the promoter site by RNApolymerase opens up the DNA molecule • Elongation adds new RNA bases, including Uracil, down the exposed DNA bases • Termination occurs when RNA polymerase hits the “stop” signal and detaches the new single strand of RNA • http://207.207.4.198/pub/flash/26/transmenu_s.swf
Review the steps • Transcription • Unzip one gene in DNA • Match up bases to one side of a gene in DNA • mRNA detaches from the DNA • mRNA moves out of the nucleus and into the cytoplasm
In RNA: A binds with U C binds with G DNA strand: GAG AAC TAG TAC RNA: CUC UUG AUC AUG
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