Term
| nucleic acids - definition |
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Definition
| biomolecules involved in the transfer of genetic informaiton from existing cells to new cells |
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Term
| what do nucleic acids control |
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Definition
| transfer of genetic information and inherited characteristics |
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Term
| what are the 2 categories of nucleic acids? |
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Definition
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Term
| Where is DNA found and what is it's function? |
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Definition
| the nucleus - serves as the master copy for most of the information in the cell |
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Term
| Where is RNA found and what is it's function? |
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Definition
| in the cytoplasm - it's the template on which information is copied and acts to transfer information from DNA to the rest of the cell |
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Term
| What are the 3 components of nucleotides? |
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Definition
| heterocyclic base, sugar, and phosphate |
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Term
| What are the 2 classes of heterocyclic bases? Define them, |
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Definition
| purines - A & G, found in RNA and DNA * pyrimidines - T,C,U - Uracil is in RNA only and T is in DNA only |
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Term
| What are the 2 sugars found in nucleotides? |
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Definition
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Term
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Definition
| a base and a sugar with no phosphates |
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Term
| What is the approximate size of DNA? |
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Definition
| large - 1x10^8 nucleotides |
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Term
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Definition
| by the phosphate groups at the 5' and 3' positions |
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Term
| What part of DNA is the backbone? What makes DNAs different from each other? |
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Definition
| the sugar-phosphate, the sequence of bases |
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Term
| who proposed the secondary structure of DNA? What is the secondary structure of DNA? |
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Definition
| Watson and Crick - an alpha helix |
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Term
| What is the compositon (base-wise) of DNA |
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Definition
| equal parts A-T and G-C, but the amount of bases vary among organisms |
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Term
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Definition
| hydrogen bonding happens between the purines and pyrimidines (A-T, G-C) |
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Term
| How many H bonds are between A and T, between G and C? |
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Definition
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Term
| What is the storage and transmission of heredity information done by? |
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Definition
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Term
| What is a chromosome made of? |
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Definition
| 1 DNA molecule wrapped around a histone, a basic protein |
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Term
| What are individual sections of DNA called? |
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Definition
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Term
| What is the mechanism for passing along heredity info from 1 generation to the next? |
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Definition
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Term
| What are the 3 steps in DNA replication and what performs each step? |
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Definition
| 1)unwinding of the DNA - DNA helicase 2) synthesis of DNA segments - DNA polymerase 3) closing of the "nicks" - DNA ligase |
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Term
| Where does replication take place? |
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Definition
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Term
| Does replication occur at only one spot at a time on the DNA strand? |
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Definition
| no - many replication forks |
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Term
| What does DNA replication result in? |
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Definition
| 2 double helical strands identical to the original DNA molecule |
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Term
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Definition
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Term
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Definition
| a method for amplifying DNA |
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Term
| What can PCR be used for? |
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Definition
| *detection of anomalies in protein metabolism *detection of viral or bacterial infection * DNA from crime scenes |
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Term
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Definition
| polymerase chain reaction |
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Term
| What are the "ingredients" in PCR? |
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Definition
| DNA, DNA polymerase, buffers, primers, and cofactors |
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Term
| What is the cofactor used in PCR? |
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Definition
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Term
| What are the steps in PCR specifically? |
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Definition
1)unwinding - heat to 94 degrees C, causes DNA to denature
2) anneal primers - cool to 54 degrees C
3) extension - add dNTPs - 2 minutes at 72 degrees C
*repeat process over and over |
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Term
| How does RNA differ from DNA? |
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Definition
1)contains ribose, not deoxyribose
2)usually single stranded, although there are double-stranded regions |
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Term
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Definition
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Term
| What are the 3 types of RNA and what are their functions? |
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Definition
*tRNA - brings amino acids to the site of protein synthesis
*mRNA - carrier of genetic information contained in DNA, used as a pattern to make proteins
*rRNA - platform for protein synthesis, holds mRNA in place and helps assemble proteins |
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Term
| What are the important regions of tRNA? |
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Definition
| the anticodon site - where tRNA and mRNA bind and the 3' end binds amino acids for transport to the site of protein synthesis |
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Term
| What is a tRNA called when an amino acid is attached to its 3' end? |
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Definition
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Term
| What is the phosphatidyl site? |
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Definition
| it's the site of the codon on the mRNA |
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Term
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Definition
| The site where the next amino acid comes in - next to the P site |
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Term
| What is the central dogma of molecular biology? |
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Definition
| *there is a specific DNA gene for every protein expressed |
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Term
| Name and define the 2 steps of gene expression. |
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Definition
| transcription - transfer of info from DNA to RNA and translation - conversion of mRNA code into amoni acid sequence of proteins |
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Term
| Describe transcription - what happens, what's involved. |
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Definition
| DNA unwinds near the gene of interest - RNA polymerase recognizes the start codon - RNA pol catalyzes RNA synthesis from 5' to 3' stops with the termination sequence - RNA moves away and the DNA rewinds |
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Term
| What types of RNA are made by typical genetic expression? |
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Definition
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Term
| How many DNA strands get transcribed? |
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Definition
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Term
| Who discovered the genetic code? |
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Definition
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Term
| What are the 2 amino acids that are not degenerate? |
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Definition
| methionine and tryptophan |
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Term
| What is the start codon and what does it code for? |
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Definition
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Term
| Are most amino acids coded for by 1 codon? |
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Definition
| no - the code is highly degenerate |
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Term
| Where does protein synthesis take place? |
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Definition
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Term
| Describe initiation of protein synthesis. |
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Definition
1)it's initiatied when the mRNA is aligned on the small subunit at the P site on the ribosome containing the initating codon AUG (N-formylmethionine)
2)tRNA with fMet binds to the codon on mRNA by H-bonding
3)this complex binds to large ribosomal subunit - this is now the initating complex |
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Term
| Describe elongation in protein synthesis. |
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Definition
| an AA is added to the peptide chain - peptidyl transferase is used to move the ribosomal unit down the mRNA strand - this is translocation |
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Term
| Describe termination of protein synthesis. |
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Definition
| When the stop codons (UAA, UAG, or UGA) are encountered, there's no tRNA that matches, so protein synthesis stops - the new protein is released from the ribosome and the complex falls apart |
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Term
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Definition
| an incorrect DNA base sequence |
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Term
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Definition
| external influences - ionizing radiation, chemical agents (mutagens) like nitrosamines, nitrous acid, acrolein |
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Term
| What does recombinant DNA allow to happen? |
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Definition
| allows genes to be transferred from 1 life form to antoher |
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Term
| What is the general term for describing recombinant DNA? |
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Definition
| genetically modified organisms |
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Term
| What is an example of recombinant DNA |
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Definition
| insulin - we put the human insulin gene into E. coli and it makes insulin - there are no allergies this way |
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Term
| What are the 3 things used to create recombinant DNA? |
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Definition
| restriction enzymes, plasmids, DNA ligases |
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Term
| What do restriction enzymes do? |
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Definition
| cleave genes in specific places, hydrolyze antibiotic proteins, synthesize toxins, catalyze cleavage of foreign DNA from viruses |
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Term
| What do DNA ligases do in recombinant DNA? |
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Definition
| asemble gene pieces into useful DNA |
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Term
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Definition
| circular double stranded DNA in the cytoplasm of bacteria |
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Term
| What do plasmids do in recombinant DNA? |
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Definition
| serve as vectors for the foreign gene material - these replicate independently of cell chromosomal DNA |
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Term
| How do you make recombinant DNA? |
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Definition
| isolate the plasmid from the bacterium, add restriction enzyme to cleave the plasmid - this creates a segnemt with sticky ends - add the human DNA and cut it with restriction enzyme to also get DNA with sticky ends - put these together and ligate them with DNA ligase |
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Term
| What is the 5' end of a DNA molecule? |
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Definition
| the end with the 5' phosphate group free |
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Term
| What is the 3' end of the DNA molecule? |
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Definition
| the end with the free OH group |
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Term
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Definition
| direct the synthesis of proteins |
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