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25 Cards in this Set
- Front
- Back
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What is the basic structure of DNA?
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Deoxyribonucleic Acid (DNA) A double-stranded, helical nucleic acid molecule, consisting of the nucleotide monomers with a deoxyribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and thymine (T); capable of being replicated and determining the inherited structure of a cell’s protein.
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How does DNA replicate?
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Semi-Conservatively - The two strands of the parental molecule seperate, and each functions as a temolate for sythesis of a new complimentary strand.
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What do we call that form of replication for DNA?
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Semi-Conservatively
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How did scientists figure out that DNA was the molecule that carried the instructions for traits?
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Using the Griffith's Transformation Experiment
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How were viruses used to illustrate DNA was the molecule that carried the instructions for traits?
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Treated the heated virulents with different enzymes to stop certain processes and when they stopped the nucleic acids it showed that the virulent was no longer able to be transformed.
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What are Purines and Pyrimidines?
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They are nitrogen Bases used in DNA. Purines are Adenine (A), and Guanine (G). Pyrimidines are Thymine (T), Cytosine (C), and in RNA Uracil (U) (in place of Thymine)
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How are DNA and RNA different?
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DNA:
Stores genetic code Deoxyribose sugar Double-stranded A, G, T, C bases Complementary base pairs C = G and A = T RNA: Translates genetic code Ribose sugar Single-stranded A, G, U, C bases |
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What are the different forms of RNA?
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Messanger RNA (mRNA):
Carries message from DNA in nucleus to ribosomes in cytoplasm Codon = nucleotide sequence that codes for a protein (Always starts with AUG) Ribosomal (rRNA): Helps form ribosomes (protein factories) Transfer (tRNA): Transfers amino acids to ribosomes during protein synthesis Anticodon = nucleotide code complementary to mRNA (Always ends with UAG, UAA, or UGA) |
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What are Chargaff’s rules?
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The amount of A, T, G, & C in DNA varies between species.
Within a species: # of A = # of T # of C = # of G |
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Who is Rosalind Franklin?
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She is the one who discovered that DNA was a double helix using an X-Ray Diffraction. Rosalind Franklin showed:
DNA is a helix One part of helix is repeated = paired bases |
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What are the enzymes involved in DNA replication?
What do they do? |
Helicase - Unzips the DNA
DNA polymerase: Adds & joins nucleotides Removes primers DNA Ligase: Joins Okazaki fragments |
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What is the replication fork, the leading strand and the lagging strand?
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Replication Fork = site of DNA replication
Leading strand (continuous) = copied toward fork Lagging strand (Okazaki fragments 100-200 bases) copied in segments away from fork |
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What is an Okasaki fragment?
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Okazaki fragments = 100-200 bases used in the lagging strands
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How is prokaryotic replication different?
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Have 1 circular DNA loop
1 origin of replication Can occur in both directions 1 million base pairs per minute Complete DNA replication in 20-40 minutes |
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How does DNA polymerase work?
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DNA polymerases = elongation
Leading strand = copied continuously into the fork from a single primer. |
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What are the roles that DNA plays and how is the structure conducive to those roles?
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Stores information for development & metabolic activity of cells
Can be replicated and transmitted to offspring Can undergo mutations to create genetic variability Nucleic acid = deoxyribonucleic acid (DNA) Phosphate Ribose sugar (deoxyribose) Nucleotides = bases Composed of 4 repeating units (nucleotides) = A, T, C, G Chromosomes contain: 60% protein (histones) 40% nucleic acids (DNA) |
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What are the 5’ and 3’ ends?
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5' is the Phosphate side and the 3' is the OH or hydroxyl side.
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What is transcription?
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Process that copies DNA to form messenger RNA (mRNA)
and occurs in nucleus. |
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What are the modifications that take place after the primary transcript is made?
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Translation: process that uses the code carried by messenger RNA to build chains of amino acids = proteins
Occurs in cytoplasm (ribosomes). |
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What is the structure of the ribosome? What are the p, a and e sites?
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Large sub unit and small sub unit.
A site = amino acid site (Far Right) P site = peptide site (Middle) E site = exit site (Far Left) |
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What are the main steps of translation? What happens at each step?
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Large subunit joins with small subunit and mRNA codons base pair with tRNA anti-codons.
Initiation = start codon (AUG) initiates translation of mRNA into amino acids GTP to help move things along. (Changes to GDP) Elongation = polypeptide chain extends as aa = transferred from tRNA Termination = stops polypeptide formation & releases it from ribosome GTP to help move things along. (Changes to GDP) |
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Would you be able to translate a sequence from DNA to mRNA to a sequence of amino acids? (of course you would be provided with a genetic code table).
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1st is on the far left of the table, next is on the top then the last one is on the far right.
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What is a codon? What is an anticodon?
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Codon = nucleotide sequence that codes for a protein
Anticodon = nucleotide code complementary to mRNA codon (base triplet) |
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What is tRNA and how does it work in translation?
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Transfer (tRNA): Transfers amino acids to ribosomes during protein synthesis
Anticodon = nucleotide code complementary to mRNA |
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Where does translation take place?
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In the cytoplasm.
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