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36 Cards in this Set
- Front
- Back
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What makes up a nucleotide? |
A phosphate, deoxyribose sugar and a base |
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Structure of the DNA? |
Two strands of antiparallel nucleotides, in a double helix structure. 4 complementary base pairs. |
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What are the 4 complementary base pairs? |
Adenine, thymine, guanine and cytosine. A->T. C->G |
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What organisms contain prokaryotes(circular chromosomes)? |
Bacteria, as they lack a membrane bound nucleus. Eukaryotes(linear chromosomes) are animal and plant cells, for example. |
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What is required for DNA replication? |
A DNA template, Primers Supply of 4 dna nucleotides Dna Polymerase and ligase Atp |
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Replication. What happens in step 1? |
Double helix unwinds ; hydrogen bonds between bases break,unzipping the molecule. |
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Step 2? |
A primer binds to the 3'end of the strand. |
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Step 3? |
Free DNA Nucleotides align themselves so their bases bond with the exposed complementary base pairs. |
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Step 4? |
Dna Polymerase catalyses formation of the sugar phosphate group between the 3' end of the primer and the adjacent nucleotide. |
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Step 5? |
Dna polymerase moves along the growing strand CONTINUOUSLY adding nucleotides to the 3'end of the strand. |
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What is the continuous strand called? |
The leading strand. |
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What is the discontinuous strand called? |
The lagging strand |
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What is the polymerase chain reaction? |
A method of amplifying a small segment of dna in vitro. |
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What is needed for PCR? |
Dna template Dna nucleotides Primers Heat tolerant Dna polymerase |
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What is step 1 of PCR? |
Dna template heated to 95° to denatured it. Breaks the hydrogen bonds between bases, seperately the strands. |
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What is step 2 of PCR? |
Cooled to 55° to allow primers to bind by forming hydrogen bonds between complementary base pairs |
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What happens in step 3 of PCR? |
Heated again to 72° to allow heat tolerant Dna polymerase to add nucleotides to the 3'end of the primers. |
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What is protein made of? |
Carbon, hydrogen, oxygen and nitrogen |
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Structure of RNA |
Phosphate group: Ribose sugar: base |
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What bases are in RNA? |
Adenine, Guanine, Cytosine and Uracil |
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Transcription requirements?? |
Dna template, RNA nucleotides, RNA polymerase (unwinds and unzips double helix) |
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Where does transcription start? |
At a 'promoter' region |
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What does RNA polymerase do in transcription? |
Attaches to the promoter and unzips the DNA molecule |
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Terminator sequence does what? |
Acts as a 'stop' barrier to stop RNA nucleotides being added to the 3' end by RNA polymerase. |
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What regions of DNA are coding regions? |
Exons |
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What regions of DNA are non-coding regions? |
Introns |
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What is Splicing? |
When the introns are removed from the gene, to only leave exons |
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What are stem cells? |
Cells which have the potential to become almost any cell required by the body |
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What are embryonic stem cells? |
Cells which have the ability to become ANY cell in the body. Although it means a fetus must be sacrificed. |
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What are the 3 Single gene mutations? |
Substitution Insertion Deletion |
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What is substitution? |
Where one nucleotide is swapped with another. Result in a wrong amino acid being produced. |
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Insertion? |
A insertion of one or more nucleotides. Changes all the codon, therefore the sequence of amino acids. Non functional protein produced. |
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Deletion? |
One nucleotide is deleted, changes the sequence of all codon and the protein will not function. |
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What molecule holds the dna together? |
A Histone protein |
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What bonds form between bases? |
Weak hydrogen bonds |
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A cellular process which DNA replication is essential? |
Polymerase chain reaction. |
