biology unit 14

comparing RNA and DNA: ==RNA== helped to put the genetic code into action. RNA is a nucleic acid that consists of a long chain of nucleotides. Each nucleotide consists of a 5-carbon sugar, a phosphate group, and a nitrogenous base.

3 DIFFERENCES- Deoxyribose sugar (DNA) + Ribose sugar (RNA), single stranded (RNA) + double stranded (DNA), contains uracil (RNA).

three main types of RNA: RNA has many roles, one of them being protein synthesis. RNA controls the assembly of amino acids into proteins. There are three types of RNA: messenger, ribosomal and transfer.

==Messenger RNA==- The molecules of RNA that carry copies of instructions for assembling amino acids into proteins. They carry from the nucleus to ribosomes.

==Ribosomal RNA-== proteins are assembled on ribosomes, which are small organelles composed of two subunits. The subunits are made of several rRNA molecules and as many as 80 different proteins.

==Transfer RNA==- type of RNA molecule that carriers amino acids to the ribosome and matches them to the coded mRNA message.

rna synthesis- A single DNA molecule can contain hundred of even thousands of genes.

==TRANSCRIPTION-== the process of copying a base sequence from DNA to mRNA. Transcription is carried out by an enzyme called RNA polymerASE. It first binds to DNA and separates the DNA strands. It then uses that strand to assemble nucleotides into a complementary strand of RNA. The product in mRNA which will be used to find the amino acids. RNA polymerases know where to start because of the ==promoter==. A region of DNA with a base sequence that can bind to RNA polymerase. Sometimes RNA strands need to be edited, products of this are called ==introns== and ==exons==. The portions that are cut out and discarded are called introns. The remaining pieces are called extrons. mRNA does NOT use thymine it instead uses uracil.

genetic code or something- Proteins are created by joining amino acids together and forming a ==polypeptide== ==bond==. There are twenty different amino acids. A ==codon== is three consecutive bases that are worth(?) one amino acid. To read these so called genetic codes you need stop and start codons. Which are exactly what they sound like.

==TRANSLATION==- begins when a ribosome attaches to an mRNA molecule in the cytoplasm. As each codon passes through the ribosome, several tRNAs bring proper amino acids through the ribosomes. tRNAs have anticodons on their ends which is the complementary pair to the mRNA. rRNA molecules hold ribosomal proteins in place

Section Reviews: Introns are the parts are are cut. They are moved into the garbage. Exons are the remaining parts that are spliced together.

14.1/14.2 Notes: RNA is a nucleic acid that is made up of a chain of nucleotides. 3 ways RNA is different than DNA are the sugars, the strands, and uracil. Some more differences are the locations. Some similarities are the nucleotides they are made of, adenine cytosine and guanine, the sugars, and the same production of genetic code. DNA makes RNA. RNA codes for amino acids. DNA is in the nucleus of eukaryote celss (prokaryotes don’t have nucleuses). Ribosomes are found in the cytoplasm. mRNA transcribes genetic information in DNA, then is sent to the ribosomes to be translated into a protein. tRNA carries in correct amino acids for protein production. rRNA is found making up the subunits (ribosomes) where proteins are produced. Copying a base sequence from DNA to RNA is known as transcription. The enzyme that separates and transcribes the gene is called the RNA polymerase. Proteins are produced in/on the ribosomes in cells. There are 20 types of amino acids. By combining them in a different ways polypeptide chains are formed (which are proteins). Methionine is the start codon. Start and stop codons tell the tRNA when to start grabbing amino acids and when to stop. The process of reading the mRNA code and converting it into amino acids/ protein language is known as translation. steps of somethign i believe trannslation: 1. ribosomes attache to mRNA molecule. tRNA molecules carry amino acids. 2. Peptide bond forms, breaks the bond by holding tRNA molecule. 3. Polypeptide forms stop codon releases it.