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22 Cards in this Set
- Front
- Back
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What are DNA's monomers? |
Nucleotides. |
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What is the structure of a nucleotide? |
A nitrogenous base, a deoxyribose sugar and a phosphate group. |
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What are the 4 nitrogenous bases in a nucleotide? |
Adenine, thymine, cytosine and guanine. |
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What is semi-conservative DNA replication? (6 steps) |
1 - The double helix unwinds. 2 - DNA Helicase breaks the hydrogen bonds between nucleotides. 3 - Free nucleotides in the cytoplasm align up against the template strands via complementary base pairing. 4 - Hydrogen bonds between the bases reform. 5 - DNA Polymerase joins the backbone together via a condensation reaction where a phosphodiester bond forms. 6 - Each new molecule of DNA contains one new and one old strand. |
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Which two nitrogenous bases are purines? |
Adenine and Guanine. |
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Which two nitrogenous bases are pyrimidines? |
Cytosine and Thymine. |
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What is the genetic code? |
A sequence of base triplets in DNA or mRNA which codes for a specific amino acid therefore, the primary structure of a protein too. |
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What is the degenerate code? |
More than one DNA triplet or codon that codes for the same amino acid. |
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What is the non-overlapping code? |
Each base forms part of only one triplet. |
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What is the universal code? |
The same specific base triplets code for the same amino acid in all organisms. |
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What is the difference between a purine and pyrimidine? |
A purine is double ringed and a pyrimidine is single ringed. |
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How many hydrogen bonds form between Adenine and Thymine? |
2 |
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How many hydrogen bonds form between Cytosine and Guanine? |
3 |
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How do you extract and purify DNA? |
1 - Grind up the sample 2 - Mix with detergent 3 - Add salt 4 - Add protease enzyme 5 - Add ice cold ethanol |
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What is a gene? |
A sequence of DNA Nucleotides that codes for the primary structure of a particular protein. |
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What is an allele? |
An allele is a different version of the same gene. |
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What is Transcription? (5 steps) |
1 - RNA polymerase binds to the DNA cause the helix to unwind and the hydrogen bonds to break. 2 - One strand of the DNA becomes the template strand and RNA polymerase lines up the free nucleotides in the cytoplasm by complementary base pairing. 3 - RNA Polymerase joins the nucleotides by a condensation reaction to form a phosphodiester bond. A molecule of mRNA is made. 4 - The mRNA leaves the nucleus via a nuclear pore and attaches to a ribosome. 5 - The hydrogen bonds reform between the two DNA strands as the RNA polymerase moves along the DNA. |
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What is Translation? (7 steps) |
1 - mRNA attaches to a ribosome. 2 - The ribosome exposes the first 2 codons on the mRNA. 3 - tRNA molecules bring specific amino acids to the ribosome. 4 - The codon on the mRNA and the anticodon on the tRNA joins up by complementary base pairing. 5 - Each specific amino acid is attached by a condensation reaction and peptide bonds forming between amino acids. 6 - The first tRNA molecules detaches and the mRNA molecules moves along the ribosome, exposing the next codon. 7 - This process continues until a STOP codon is read, forming a polypeptide chain. |
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What are the differences and similarities between DNA, mRNA and tRNA? (5 things) |
1- DNA is double stranded whereas, tRNA and mRNA is single stranded. 2 - DNA contains a deoxyribose sugar whereas, tRNA and mRNA contains a ribose sugar. 3 - DNA and tRNA contains hydrogen bonds whereas, mRNA doesn't. 4 - mRNA and tRNA contains the nitrogenous bases of Adenine, Guanine, Cytosine and Uracil whereas, DNA contains Thymine instead of Uracil. 5 - All of them contain phosphodiester bonds. |
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What are the number of DNA nucleotide bases that code for a single amino acid? |
3 |
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Why is DNA replication considered to be semi-conservative? |
Because one strand is from the original DNA and the other strand is newly formed. Each strand is copied as it acts as a template strand. |
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Why is complementary base pairing important in DNA replication? |
Because it reduces the occurrence of mutations and DNA can be replicated without error. |
