Bio P2 Flashcards
What enzyme does Lac Z code for
Lactase
(B- Galactosidase)
What enzyme does Lac Y code for
Lactose permease
What enzyme does Lac A code for?
Lactose transacetylase
If shown deformed organism in exam Q e.g. double headed cow- What is explanation?
Perhaps Hox/ homeobox genes of organism have been mutated.
Describe the steps in exctracting DNA
sample ground up using pestle and mortar.
sample mixed with detergent
salt is added
protease is added
ice cold ethanol is added down the side of the test tube
(DNA Extraction) Why is sample ground up
To break down cell walls
(DNA extraction) Why is detergent added?
To break down cell membranes, releasing contents of cell.
(DNA Extraction) Why is salt added?
To make the DNA less soluble in water by neutralising charge of phosphate
(DNA extraction) Why is protease added?
To break down proteins associated with DNA (e.g. histones)
(DNA extraction) Why is ethanol added?
Causes a precipitate to form which can be extracted.
What is a sparger?
A device that introduces a gas to a liquid
What are the conditions that must be present for speciation to occur?
- Selection pressure are different from the other population
- Time
- Natural selection
- Mutation/ genetic diversity
Are disulfide bonds involved in the secondary structure of a protein?
NO
Why is it important that the technique used for culturing microorganisms be aseptic?
- To prevent contamination
- To prevent growth of unwanted MO
Precautions that should be taken when preparing a bacterial culture in order to ensure procedure it aseptic (Broth)
- Stopper flask (e.g. with cotton wool)
- Use sterile broth
- Disinfect surfaces
- Have bunsen flame nearby to create upward air flow.
Why (graph or bacterial growth) Is logarithmic scale used for y axis?
Differences would be too big to represent on paper
How can a graph show that a factor is influenced by environmental factors
- If it is bell shaped/ normal distribution
- Continuous data/variation
Why may a cooling system be necessary in a fermenter?
- Fermentation is exothermic
- Increased temperature may denature enzymes
- Cooling inhibits growth of pathogenic bacteria.
Methoss of determining the conc of protein in a solution
- Use colorimeter, compare to calibration curve of known concs
- Biosensor
What digests cell contents during apoptosis?
Enzymes
What removes the products of apoptosis?
Phagocytes
