RNA has ribose backbone, uses uracil instead of thymine. Adding 2 phosphate radicals to form a triphosphate. RNA polymerase identfies & binds to dna promoter, moves down dna while unwinding dna while adding nucleotides to end of newly forming rna chain by breaking 2 phosphate bonds to create covalent linkage between phosphate & ribose. It continues until chain-terminating sequence in the DNA.
MRNA: It carries genetic information from nucleus to cytoplasm w/ codons exactly complimentary to DNA - long single rna strand suspended in cytoplasm trna: - transports activated amino acids to ribosomes to be used in protein assembly.- ~80 nucleotides long, shaped like a clover leaf. Longer stem is 3 end and is where amino acid binding occurs. Anticodon region matches with specific rna codon to deliver amino acid RRNA: - 60% of the ribosome, ~75 proteins - structure on which protein is synthesized - interacts with other forms of rna (mrna encodes codon, trna delivers amino acid) ribosome: - 2 units: small subunit (1 rna molecule ~33 proteins) & large subunit (3 rna molecules ~49 proteins) - mrna/trna first bind small subunit during protein synthesis - large subunit provides enzymes for peptide bonding - encoded by dna found on 5 chromosomal pairs, many duplicates of genes due to large amount of rrna required. RRNA collects in nucleolus, size roughly related to amount of protein being synthesized by host cell. Proteins also bind rrna in nucleolus. Ribosomes are further processed in cytoplasm.
