Biology- Review Essay of Dna and Genes

Only available on StudyMode
  • Download(s) : 161
  • Published : March 11, 2008
Open Document
Text Preview
In chapter 11, we learned about DNA and Genes (11.1—DNA: The Molecule of Heredity; 11.2—From DNA to Protein; 11.3—Genetic changes). DNA (deoxyribonucleic acid), which is in a shape called a double helix, developed its name from the simple sugar in DNA (deoxyribose). The phosphate group is composed of one atom of phosphorus surrounded by four oxygen atoms. A nitrogen base is a carbon ring structure that contains one or more atoms of nitrogen. Next to cover is DNA replication in which enzyme breaks the hydrogen bonds with the DNA unzipping. Another enzyme bonds floating nucleotides to the single strands to make two new DNA. Each DNA will have an old strand and a new strand. RNA—which is a nucleic acid, a nucleotide—differs from DNA in three ways: 1. sugar is ribose; 2. there is a single strand of nucleotides, not two; 3. and uracil instead of thymine. There are three types of RNA: 1. mRNA—messenger—takes the message from DNA to the ribosome; 2. rRNA—ribosomal—the ribosomes are made of RNA; 3. tRNA—transfer—brings amino acids to the mRNA, about 80 nucleotides long. There are two different types of processes called transcription, and translation. Transcription is a process in the nucleus where enzymes transcribe the message in DNA to RNA strand, the enzyme then unzips part of the DNA, and free RNA nucleotides attach to DNA to form RNA, the mRNA then breaks away and go to the ribosome. The next process is Translation, which is a process of converting the information in mRNA into a protein, the mRNA attaches to the protein, and the tRNA brings the amino acid to the ribosome.

In section 3 of chapter 11, we learned about Genetic Changes. Starting out with mutations, which is any change in DNA sequence that also changes the protein, DNA changes. There are two types of mutations: point mutations and frameshift mutations. Point mutations are a change in a single base pair in DNA (changes only one amino acid). Frameshift mutations are a mutation in which a single base is...
tracking img