RNA: Ribonucleic Acid 3 types Helps cells make protein Single strand of nucleotides: Ribose sugar Phosphate Nitrogen bases Adenine, uracil, guanine, cytosine Base pair rules Uracil always pairs with Thymine Cytosine always pairs with Guanine m = messenger Found in the nucleus and cytoplasm Makes a copy of DNA to take to ribosome for protein synthesis Codons Every 3 letter base sequence on mRNA 1 codon = 1 amino acid t = transfer Found in the cytoplasm Carries amino acids to the ribosome Anti-codon Complementary 3 base sequence to mRNAs codon amino acid anti-codon r = ribosomal Found in cytoplasm Makes up ribosomes DNA RNA Protein Organisms are a collection of traits! Entire set of DNA for an individual organism is located on 46 chromosomes. Segments of these chromosomes are called ________. Every cell of an organism has the same exact set of DNA Molecular process of converting DNA genes into a trait is called gene expression. Stage 1: Transcription Gene (section of DNA) is converted into mRNA code In nucleus Stage 2: Translation mRNA, tRNA, rRNA link amino acids based on code In cytoplasm How does the cell determine what amino acid goes with the mRNAs codon? CODON = AUG Start in the center and work your way out A U G Amino acid is methionine Try finding the amino acid for the codon CUA LEUCINE Codon Table In multicellular organism not all genes are expressed in all cells. Different parts of the genetic instructions (DNA) are used in each type of cell. For example a liver cell has different genes turned on being expressed than a heart cell. This is called differentiation and happens while the baby is growing inside the womb. Frogs undergo metamorphosis from tad pole to frog. The time this process takes depends on environmental conditions even though the genes are the same. If it has been a dry season or there is a shortage of food, for example, then the tadpole stage may be cut short and development may be quicker