Term
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Definition
| the single stranded binding proteins prevent the strands of DNA from annealing during DNA replication |
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Term
| How does DNA Polyermase (III) know where to begin synthesis? |
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Definition
| short strands of RNA are laid down as markers by RNA primase |
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Term
| In what direction is DNA read during replication? |
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Definition
| 3' to 5' direction, therefore new nucleotide synthesized in 5' to 3' direction |
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Term
| What are Okazaki fragments? |
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Definition
| Small fragments of copied DNA synthesized on the 5' to 3' end of the DNA |
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Term
| What are the three types of RNA? |
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Definition
- mRNA - messenger RNA
- tRNA - transport RNA
- rRNA - ribosomal RNA
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Term
| What are the three steps in transcription? |
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Definition
- Initiation - RNA polymerase binds to DNA at TATA box
- Elongation - RNA polymerase builds RNA transcript in 5 ' to 3' direction
- Termination - RNA polymerase passes termination gene and releases the new transcript
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Term
| What are the three post transcription modification applied to the mRNA |
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Definition
- 5' cap - protects mRNA and acts as initiation site for ribosome
- poly-A-tail - protects mRNA from degredation
- removal of introns - splicesomes remove all non-coding reigons of mRNA
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Term
| What are the three phases of translation |
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Definition
- Initiation - ribosome bonds to mRNA at acceptor slot at the AUG start codon
- Elongation
- Termination - stop codon tells ribosome to disassociate
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Term
| What are the four steps in elongation during translation? |
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Definition
- tRNA enters acceptor site
- peptide bond forms between amino acids
- tRNA moves to peptide site allowing new tRNA to enter acceptor site
- new amino acid added to a chain while tRNA exits through ejection site
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Term
| What are the three types of base pair mutations? |
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Definition
- Silent mutation - mutation on 3rd nucleotide of the codon, has no effect on amino acid chain
- Missense mutation - mutation on one nucleotide of the codon resulting in one amino acid being altered
- Nonsense mutation - converts an amino acid codon into the stop codon resulting in an all new protein
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Term
| What is a frameshift mutation? |
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Definition
| an addition or deletion of one or more base pairs resulting in the whole amino acid chain being altered |
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Term
| How is a mutation induced? |
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Definition
- Spontaneous - random change
- Mutagen - environmental cause (radiation, chemicals, virus)
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Term
| How are mistakes in DNA replication fixed? |
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Definition
- DNA polymerase immediately able to recognise and fix a single mutation
- enzymes called exonucleases excise multiple mistakes while polymerase fixes them
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Term
| What are the three steps of PCR? |
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Definition
- Denaturation: original strands, primers placed in water - heated to 95oC for one minute
- Annealing: RNA primers anneal to denatured DNA - 60oC for one minute
- Replication: 72oC for one minute - taq-polymerase replicates DNA faster
steps repeated 20-30 times |
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Term
| What neurotransmitter is involved during a synaps? |
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Definition
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