Unit 1: Chapter 18 Flashcards
Who is Chargaff
Amount of nucleotides are equal to its corresponding partner
Partners:
Adenine=Thymine
Guanine=Cytosine
*Total amount should add up to 100%
Franklin
- Used X-ray photography to analyze the DNA structure
- Found the double helix
- Nitrogenous base on the inside whilst sugar phosphate on the outside
Watson and Crick
- Produced the structure of the DNA
- Mixed of Chargaff and Franklin’s idea
Griffith then Hershey and Chase
Griffith - thought that bacteria can transfer genetic information
Hershey and Chase experiment with rats
- resulted in viral DNA not protein, enters the bacteria cell
Difference between DNA and RNA
DNA:
- 5Carbon sugar, phosphate group, 1 of 4 nitrogenous base
- double stranded
- Has nucleotides: Adenine, Thymine, Guanine, Cytosine
RNA:
- Uracil (U) instead of Thymine
- Single stranded
Why can’t nucleotides have different partners
- A (Adenine) and G (Guanine) are double ringed therefore bigger than
- T (Thymine) and C (Cytosine) whom str single
*Mixing their partners can make them too big therefore can be messy
What is a Gene and Genome
Gene = small part of DNA
Genome= sum of all DNA
What is a coding genome and non-coding genome
Coding genome - portion of DNA that codes for a protein. If disrupted it can cause many problems within the gene
Non-Coding - Do not code for any protein and can be taken off without disrupting the protein chains. No harm will happen
What is semi-conservative replication
- When a gene splits in half then new daughter strands replicate the two
- Now has a original strand and daughter strands
What does elongation mean
- to grow or make larger
- basically DNA replication
What is the process of DNA elongation/extending
- Helicase - an enzyme binds to the DNA then unwinds it creating a Y-shape
- DNA polymerase - synthesizes the DNA by copying or replicating it
- The replicated DNA then gets added to the 3 prime end
Difference between Leading and Lagging Strand
- Leading - 5 prime to 3 prime direction. basically adds the replicated DNA at the 3 prime end
- Lagging - when DNA ligase adds the replicated DNA at the 5 prime end but in short strands. Which are called the Okazaki Fragments
What is transcription
- DNA is transcribed to make mRNA (basically opposite letters)
- occurs in the nucleus
What is Translation
- directs protein synthesis with the help of tRNA (again opposite of mRNA)
- Occurs in cytoplasm
What is a codon
- set of 3 letters that correspond to an amino acid
What are important keys about the amino acids. Is there starting and ending ones
- AUG is the starting codon
- Then there are 3 stop codons
What is anti-sense vs. sense strand
anti sense - gets replicated by mRNA
How does Translation occur
- When the mRNA binds with the tRNA (which holds the anti codon and amino acid)
Types of Mutationz
Point Mutation - change in single base of a gene
- Silent - Change in letter but same protein
- Mis-sense - Change in letter and change in protein
- Non-sense - change in letter but to a stop codon. dangerous
Frameshift - usually results in a non-sense mutation
- addition/insertion
- deletion
*adjusting codon sequence
Gel Electrophoresis
- DNA fingerprint - patterns of bands for each person. unique
- smaller fragments of DNA travel the farthest. The darker it is the more fragments which should be heavy and does not move far
What are the two major gene theraphy
- somatic gene theraphy - somatic cell / body cells
- germline therapy - modifying genetic information in egg and sperm to eliminate inherited genetic information
