Presentation on theme: "3 types: mRNA – used in transcription tRNA – used in translation rRNA – makes up ribosomes Composed of nucleotides 5 carbon sugar = ribose phosphate."— Presentation transcript:
3 types: mRNA – used in transcription tRNA – used in translation rRNA – makes up ribosomes Composed of nucleotides 5 carbon sugar = ribose phosphate group nitrogen bases (no Thymine…uses Uracil) A,U,C,G RNA has a Single strand
The information that tells a cell which proteins to make is encoded in the DNA by the arrangement of nucleotides. DNA is in the nucleus. Proteins are made in the cytoplasm on ribosomes. Problem: The message on DNA has to be carried to the ribosomes.
Solution: The message from DNA is carried to the ribosomes using RNA. The process of copying the DNA message in the nucleus onto RNA to be carried to the ribosomes is called TRANSCRIPTION.
Copying the information on DNA to a strand of messenger RNA (mRNA)
Starts in the nucleus DNA opens One side of DNA is a template Makes a section of mRNA
1) RNA polymerase unzips DNA double strand. 1) New RNA nucleotides are attached to one side of DNA. 2) mRNA is removed, DNA reforms, mRNA leaves the nucleus.
Base pair rule is still used but there is never any thymine in RNA so: (A-U & C-G). DNA can never leave the nucleus, so mRNA serves as the messenger to the ribosome RNA has one strand while DNA has 2. mRNA leaves the nucleus and travels to the ribosome to start Translation.
1) Made of amino acids 2) There are only 20 amino acids to make up 100s of proteins 3) Proteins are a major component of cells 4) Proteins are made on ribosomes
Amino acids are added to a protein based on 3- nucleotide sequences called codons. Codons are “read” on the ribosome and the appropriate amino acid is added to the protein chain by tRNA. Each tRNA molecule has an “anticodon” that matches with the nucleotide sequence on the mRNA strand.
…process of making protein from information carried by mRNA. …occurs on the ribosome