Unit 5 was all about DNA. We learned about the structure of DNA and the nitrogenous bases. DNA is a double-helix (essentially like a twisted ladder) and is made up of nucleotides. DNA is also antiparallel running in opposite 5' to 3' directions. The nitrogen bases are purines (adenine and guanine) which have double rings and pyrimidines (thymine and cytosine) which have single rings. Adenine (A) always matches up with thymine (T) and guanine (G) always matches up with cytosine (C).
To copy DNA, the enzyme helicase unzips the DNA by breaking the hydrogen bonds between the nitrogen bases. Then DNA polymerase matches nucleotides to each strand, resulting in two identical DNA molecules, each one having one strand from the original DNA.
Proteins are made when information goes from the DNA to the RNA to the protein through transcription and then translation. Transcription is the process where RNA polymerase reads and copies the DNA code and matches nucleotides to make an RNA strand. Then the mRNA moves to the cytoplasm where translation occurs and it arrives at the ribosome. The ribosome reads the mRNA three bases at a time and translates DNA language into RNA language (the same thing but the T is replaced by a U). Each 3 base sequence is called a codon, which codes for one amino acid each. A long chain of amino acids is produced until the ribosome reaches a stop codon.
Mutations in DNA are causes by mutagens, and can cause anything from fatal mutations to no effect. Point mutations are mutations that change one or two base pairs in DNA. Substitution is a type of point mutation in which one nucleotide is substituted for another. Frameshift mutations and types of point mutations and include deletion and insertion. Deletion is where a base pair is removed from the code and insertion is where an extra base pair is added to the code. Other mutations include inversion and translocation which changes a large section of DNA all at once.
The reason why characteristics develop in the appropriate places at the appropriate times is because of gene expression and regulation, which ensures that even though all genes are present in all cells, genes can turn on or off in appropriate places.
My strengths form this unit include knowing the nitrogen bases really well and how to translate DNA into RNA language.I also understood the concept of translation fairly quick. My weaknesses include understanding how DNA replicates itself and distinguishing the different types of mutations. Before this unit, I didn't know much about DNA and never really thought about DNA replication or the production of proteins.
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| DNA extraction lab |
Proteins are made when information goes from the DNA to the RNA to the protein through transcription and then translation. Transcription is the process where RNA polymerase reads and copies the DNA code and matches nucleotides to make an RNA strand. Then the mRNA moves to the cytoplasm where translation occurs and it arrives at the ribosome. The ribosome reads the mRNA three bases at a time and translates DNA language into RNA language (the same thing but the T is replaced by a U). Each 3 base sequence is called a codon, which codes for one amino acid each. A long chain of amino acids is produced until the ribosome reaches a stop codon.
Mutations in DNA are causes by mutagens, and can cause anything from fatal mutations to no effect. Point mutations are mutations that change one or two base pairs in DNA. Substitution is a type of point mutation in which one nucleotide is substituted for another. Frameshift mutations and types of point mutations and include deletion and insertion. Deletion is where a base pair is removed from the code and insertion is where an extra base pair is added to the code. Other mutations include inversion and translocation which changes a large section of DNA all at once.
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| Mutation of deletion in the beginning of a DNA sequence |
My strengths form this unit include knowing the nitrogen bases really well and how to translate DNA into RNA language.I also understood the concept of translation fairly quick. My weaknesses include understanding how DNA replicates itself and distinguishing the different types of mutations. Before this unit, I didn't know much about DNA and never really thought about DNA replication or the production of proteins.
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