Unit 1 Flashcards
SDS
Safety Data Sheet, communicates hazards of chemical products
Proved DNA is the Model of Heredity
Hershey and Chase in 1953
99.9% of our Genome
Is the same from person to person
Polymorphism
DNA sequence that is highly variable from person to person
PPE in Different BSL’s
1) Gloves, goggles, lab coat, hair up, working on open bench
2) Lab coat that does not leave facility, working in BSC
3) Breathe filtered air
4) Wear pressurized suits and breathe filtered air from a different room
BSL Requirements and Organisms
1) Basic rules, not known to cause diseases
2) Restricted access and training required, small to moderate risk
3/4) Very extensive rules and training, pathogens known to kill people
SDS Diamond Numbers
Left blue box - health hazard
Top red box - flammability
Right yellow box - instability hazard
Bottom white box - specific hazard
Consequences of Violating Safety Rules
Injury, grade, no more labs, school discipline
Why Not to Blow Out a Micropipette When Measuring
Pushes out all liquid
How Far Into the Liquid Do You Put the Micropipette Tip
Just enough, not all the way to the bottom/immersed but in the liquid
Three Ways to Improve Accuracy of Micropipetting
1) Hold the liquid at eye level
2) Don’t include air bubbles
3) Use the most specific micropipette
Conversions
1 L = 1,000 mL
1 mL = 1,000 uL
1 L = 1,000,000 uL
Most Common Sources of Contamination
Dust, the bench top, the air, and people
Two Reasons to Follow Sterile Procedures
1) Prevent contaminants from entering a culture
2) Preventing contaminants from causing effects to humans in the lab or escaping
Aseptic
Preventing infection
Autoclave
Use high temperature and high pressure to kill organisms
Types of Disinfectants
Bleach, alcohol (95% or 70%), hand sanitizer, Lysol
Another Option for an Autoclave
Pressure cooker, glass bead sterilization, idk
Original Key DNA Experiments
Meischner discovered DNA, Garrod discovered link between proteins and heredity
DNA Not Protein Experiment
Hershey and Chase grew bacteriophages with radioactive phosphorous (DNA), and radioactive sulphur (protein but NOT DNA)
Why Protein was Thought of heredity Before DNA
More complex than DNA (proteins have 20 different types of amino acids, four levels of folding and DNA has four different types of nucleotides), proteins were associated with genetic disease.
Three Parts of DNA
1) Deoxyribose/five carbon sugar
2) Phosphate group
3) Nitrogenous base
Sugar in RNA VS DNA
Ribose VS deoxyribose
Chargaff’s Rule
A = T, C = G
Sugar Phosphate Backbone
Joins together nucleotides in a DNA sequence, determines direction
Determining Direction of DNA
Leading strand is 5 prime to 3 prime, found by phosphate is 5 prime
How Did Watson and Crick Find Structure of DNA
Not officially working on DNA, used tin models of DNA to show location of bonds, given photo 51, got it wrong (inside out), found that hydrophobic bases on inside and hydrophilic sugar/phosphates on outside
Key People in Watson and Crick Discovery
Wilkins and Franklin helped with X-Ray crystallography, famous photo 51, and double helix
Type of Bonds in Nitrogen Base Pairs
Weak hydrogen bonds
Nucleotide
Building block of nucleic acids
Pyrimidine VS Purine
One carbon nitrogen ring VS two carbon nitrogen rings, T and C VS A and G
Why Does One Pyrimidine Bond with One Purine
Structure of purines allows to make hydrogen bonds with pyrimidines, adenine bonds with thymine because both have two binding sites so double hydrogen bonds
DNA Profiling
Comparing DNA to establish or rule out identity, relationships, or ancestry
Restriction Enzymes
Cut DNA, found naturally in bacteria
Why Bacterial DNA is Not Cut With Their Own Restriction Enzymes
Protective methyl groups (such as CH3) protect bacterial DNA from the enzymes
Why Incubate During the Outbreak Lab at 37 Degrees Celsius
Restriction digest occurs with these enzymes at this point
Gel Electrophoresis
Uses electricity to separate DNA fragments by size as they migrate through a gel matrix
Overall Charge of DNA
Negative
Differences in Bands of DNA
Protein contamination can cause wider, brighter bands with a strong, smeared tail
Amount of Polymorphic Regions FBI uses in DNA Profiles
13
How Likely is it Two People Have the Same DNA Profile
Less than one in one hundred billion
Why Did You Make a 1% Agarose Gel in the DIY Gel Electrophoresis Lab
A gel with a lower percentage of agarose will have larger pores
Why Did You Add a Running Buffer in the DIY Gel Electrophoresis Lab
To conduct the electricity through the solution and gel so that the DNA, RNA, or proteins can migrate through the gel
How Much Voltage Did You Use in the DIY Gel Electrophoresis Lab
45 V
What Would Have Happened if You Used a Higher Electricity in the DIY Gel Electrophoresis Lab
1) Faster results
2) Higher heat/melt the gel
3) Fragments can be distorted
