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51 Cards in this Set
- Front
- Back
Nucleotides |
Monomers of nucleic acids |
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Polynucleotide |
A chain of monomers made up of nucleic acids |
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Sugar-Phosphate Backbone |
An arrangement of sugar group to phosphate group that makes up the back of DNA. Nitrogen bases attach to the sugar. |
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4 Nitrogen bases |
Thymine and Cytosin (single ring) and Adenine and guanine (double ring). Uracil replaces thymine in RNA. |
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What's in a DNA nucleotide? |
1.) Phosphate group 2.) Sugar (deoxyribose) 3.) Nitrogen base (Thyamine, Guanine, Adenine, Cytosine) |
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Purines |
Have two rings of carbon they're Adenine and Guanine |
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Pyrimidines |
Have one ring of carbon they're Cytosine and Thyamine |
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Uracil |
Replaces Thyamine in the various RNA sequences (tRNA and mRNA). |
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Nitrogen base pairs |
Cytosine and Guanine share a triple bond, Adenine and Thyamine share a double bond. |
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DNA double helix |
Base pairs need to have one double ring and one single ring to ensure that all of the pairs are the same length. Hydrogen bonds can only be formed between specific combinations of these pairs. |
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DNA Polymerases |
The enzymes responsible for making new covalent bonds between the nucleotides of a new DNA strand
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How does complimentary base pairing make it possible for DNA replication |
Because it's always going to be the same pair on either side (one strand will get an A from T and vice versa). When the new strand comes together it will be an exact copy. |
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Transcription |
Transfer of DNA to RNA |
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Translation |
Transfer of RNA into a polypeptide strand |
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Codon |
3 nucleotide bases that when placed together refer to a specific polypeptide. |
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AUG |
Start codon (Met) |
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UAA, UAG, UGA |
Stop codon |
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Stages of Transcription |
1.) Initiation 2.) RNA Elongation 3.) Termination |
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Initiation of Transcription (1) |
Involves the attachment of the promoter and RNA polymerase to each other. |
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Promoter |
A sequence of nucleotides that tell you where to start the RNA replicaiton. |
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RNA Elongation (2) |
RNA grows longer and begins to separate when it gets to a certain length. This allows the DNA to reattach itself in certain areas. |
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Termination of Transcription (3) |
RNA polymerase reaches a sequence of nucleotides that are called a terminator. This is where it detaches allowing the DNA to come back together. |
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RNA Process Cap and Tail |
Cap and Tail are additions to the end of the RNA strands to help protect it from attack as well as aid in recognition |
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RNA Process Exons and Introns |
Exons are the parts of RNA that express genes while Introns are fillers. RNA splicing removes the introns leaving the exons. |
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RNA splicing |
The process of removing Introns just leaving exons left over for RNA. |
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Anticondon |
A triplet that is complimentary to the codon on mRNA |
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Ribosomes |
Organelle in the cytoplasm that dictates the actions of mRNA and rRNA to form polypetides. |
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Translation - Initiation (1) |
-mRNA binds to the small ribosomal subunit, tRNA start codon brings met (start of the polypeptide). - Large ribosomal subunit than comes and binds creating a functional group |
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Translation (2) |
-The anticodon of the incoming tRNA molecule comes and binds to the mRNA codon in the A site -The polypeptide leaves the the tRNA in the P site and it attaches that the one in the A site - The P site tRNA now leaves the subunit and the ribosome moves the A site to the P site. |
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Termination (3) |
Once it reaches a stop codon in the A site and it's released. The ribosome than splits again. |
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Summary of DNA/RNA |
1.) Transcription 2.) RNA Processing 3.) Amino Acid Attachment 4.) Initiation of Translation 5.) Elongation 6.) Termination |
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Mutation |
Any changes in a nucleotide sequence that was not intended |
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Mutation - Base Substitution |
Change one of the nucleotides. May or may not effect the expression of the protein |
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Mutation - Nucleotide Deletion |
Delete a nucleotide. This can be more harmful since it can effect the codon that lost the nucleotide as well as all of the ones after that |
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Mutation - Nucleotide Insertion |
Add a nucleotide. This is the same as deletion |
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Mutagens |
Physical and chemical agents that cause mutations in DNA and RNA sequences. EX: X-rays |
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Virus |
An infectious particle that is basically just a gene. Viruses cannot reproduce on their own instead they need a host to splice with |
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Baceriophages or phages |
Cells that are designed to infect bacteria cells. They have 3 legs that bend when they touch the bacteria allowing the middle portion to coil like a spring and release to puncture the cell. |
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Lytic Cycle |
Reproductive cycle of a phage once it enters a bacteria. Many copies are produced |
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Lysogenic Cycle |
Virus DNA reproduces without the production of a phage or death of the host cell |
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LYTIC CYCLE |
1.) Phage attaches to cell 2.) Phage DNA circulates 3.) New phage DNA and proteins are synthesized 4.) Phages are released and allowed to infect other cells |
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LYSOGENIC CYCLE |
1.) Phage attaches to cell 2.) Phage DNA circulates 3.) Phage DNA inserts into DNA (The phage sequence is called a prophage) 4.) Lysogenic bacterium reproduces naturally spreading the infected DNA 4A.) Occasionally the prophage leaves the chromosome |
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Plant Viruses |
Most have RNA not DNA as the genetic code. Plant viruses must get past the tough epidermal of the plant making those that are damaged by wind, temperature etc... more susceptible |
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Animal Viruses Reproductive Process |
1.) Virus enters and allows the protein coated RNA to escape in the cytoplasm.
2.) Enzymes remove proteins 3.) Enzymes from the virus synthesize new RNA strands from the original 4.) Some of these will make new mRNA strands 4A.) Others will be a template for more RNA 5.) New coat proteins ensemble around the new viral RNA 6.) The virus leaves the cell disguised in the plasma membrane |
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AIDS and HIV |
Is a retrovirus that reproduces backwards RNA to DNA |
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Reverse Transcriptase |
An enzyme that catalyses reverse transcription the synthesis of DNA from an RNA template. |
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Steps of reproduction of HIV/AIDS |
1.) Uses RNA to make DNA strands 2.) Adds a second complimentary DNA strand 3.) These strands enter the cell and insert itself into the Chromosomes and becomes and provirus 4.) This provirus is transcribed into RNA 5.) Translated into viral proteins 6.) New virus are made and leave the cell to infect other cells |
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Ways to slow HIV/AIDS (2 methods) |
1.) Helps inhibit the actions of enzymes called proteases which make proteins for HIV 2.) Inhibit the actions of reverse transcriptase |
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Prions |
Cause brain diseases. It cause misfolding of proteins, as it enters a cell it manipulates the proteins causing them to fold differently, they than clump together and cause loss of tissue and other problems. |
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Viroids |
Small RNA molecules that infect plants and interfere with regulatory systems that control growth |
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Emerging Viruses |
New viruses that suddenly become apparent to medical personal and scientists. |