Genetics Test

Time to apply what I've learned the last month (sigh... its only been 4 weeks of school?!!?).  I never like this part of learning... time restraints to solve questions.  Panic level just went up...

So, genetics.  Everything began somewhere, so let's start with the history:

1928: Griffith --> proteins do NOT carry traits

1952: Hershey and Chase --> DNA is the genetic material. Proteins are NOT the hereditary material

pyramidine - single ringed: cytosine, thymine

purine - double ringed: adenine, guanine

adenine = thymine

guanine ≡ cytosine

nucleotide = phosphate backbone, sugar, base

 

(difference of an OH group on carbon 2)

Bond types:

• glycosyl: sugar + nitrogenous base (CN) - intramolecular
• hydrogen bond: complementary nitrogenous bases; between nucleotides - intermolecular
• phosphodiester: sugar + phosphate (POC) - intramolecular

DNA replication is semi-conservative

1. helicase: unwinds DNA at replication fork
2. single-strand binding proteins (ssbps): attach to unpaired strands until replication begins
3. gyrase: enzyme that releases tension of unwinding but cutting the DNA strands and putting them back together again
4. primase: makes RNA primers --> signals elongation to
5. DNA polymerase III: elongates new DNA strands
6. DNA polymerase I: proofreads + converts RNA primers into DNA
7. ligase: joins gaps between Okazaki fragments (on lagging strand only)

DNA elongates ONLY in the 5' --> 3' direction

Template strand read 3' --> 5', creating a 5' --> 3' RNA strand

1. 5' TATA 3' box
2. transcription factors --> signals transcription to
3. RNA polymerase II: transcribes (don't want to stay in Toronto, but should go to University. Or else suffer getting disowned...) until
4. AATAA in the coding strand
5. 5'G cap
6. poly(A) tail
7. spliceosomes = snRNPs + snRNA: splice pre-RNA --> RNA
8. introns are OUT, exons are IN

This is pre-RNA/mRNA:

This is tRNA:

It is NOT from DNA. It floats.

RNA read in threes beginning at AUG --> Met

1. 5' AUG 3'
2. 40S ribosomal unit + 60S ribosomal unit = 80S ribosomal unit
3. P (Met), new tRNA at A, animo acid attaches to the one at A-->P-->E
4. stop codons (UAA, UGA, UAG)

Point mutation: change of ONE base pair of a gene

• base-pair substitution:
• silent mutation: no effect
• missense mutation: change amino acid
• nonsense mutation: stop codon
• frameshift mutation:
• insertion
• deletion
• inversion

(And now I have made my 10 points worth)