Lab Test 2 Flashcards
(39 cards)
Horizontal gene transfer
Sharing of DNA between organisms that are not in a parent–offspring relationship
Transgenesis
The deliberate introduction of a gene from one species into another by genetic engineering techniques
Transformation
Genetic modification of a bacterium, natural or artificial.
Plasmid
Small circular extrachromosomal DNA that contains genes for traits that may help the bacteria survive under specific conditions. Plasmids replicate independently of the chromosomes.
pGLO Genes
- GFP (green fluorescent protein)
- beta lactamase (bla gene), which will make the bacteria resistant to ampicillin
- ara C protein
Bacteria Promoter
Recruits RNA polymerase & directs transcription of a linked transcription unit in bacteria. These promoters in bacteria are always active.
Beta-Lactamase in pGLO
Makes bacteria resistant to ampicillin. Expression of the enzyme acts as a selectable marker. A selectable marker allows you to select for cells that took in the plasmid & are expressing its genes.
GFP
GFP fluoresces bright green when exposed to UV light..
Marker of transformation
GFP Regulation in pGLO
- araC produces AraC regulatory protein
- in absence of arabinose, represses transcription of mRNA from the P promoter (GFP)
- arabinose binds to AraC, changing its conformation
- modified AraC enables transcription of mRNA from promoter (GFP)
Operon
Gene regulated system
Allows genes to respond to stimulus from environment to modify its pathways, eliminated wasteful overproduction
Assays for transformation experiment
-pGLO LB
- Positive control group for growth
-pGLO LB/amp
- Negative control group for growth
+pGLO LB/amp
- Negative control group for fluorescence
+pGLO LB/amp/ara
- Experimental group
Steps in Transformation
+ CaCl2 solution
+ E-Coli bacteria
+ pGLO plasmids (only in +)
Incubate (10 minutes on ice)
Heat shock (50 seconds)
Recovery (2 minutes)
+ LB broth
+ arabinose (only ara)
Incubate (30 minutes)
Plate
CaCl2 Role in Transformation
- Makes cells artificially competent when heat shocked
- Ca+2 cations neutralizes negative changes on DNA backbone and phospholipids, making the cell more permeable
Glucose respiration equations
C6H12O6 + 6O2 -> 6CO2 + 6H2O + 36-38ATP (aerobic respiration)
C6H12O6 -> 2C2H5OH + 2CO2 + 2ATP (alcohol fermentation)
C6H12O6 -> 2C3H6O3 + 2ATP (lactase fermentation)
Yeast metabolic potential
- Monosaccharides - immediately
- yes - Sucrose - most have sucrase, so similar to glucose
- yes
- Maltose - slow process, need to translate permease & maltase
- yes
- Lactose - does not have lactase
- none, unless given latase
- Starch - does not have amylase
- none
Pea Respiration Experiment
- Germinating pea seedlings
- Covered in Aluminum to avoid photosynthesis
- Soda lime to absorb CO2 gas produced by seedlings
- Pressure sensor to measure O2 uptake
- Starch likely main substrate, so RQ quotient of 1
Fermentation experiment variables
Independent: - type of substrate (sugar)
Dependent: - pressure per minute per grams of yeast (kPa / min / g)
Fermentation process reaction
- Pyruvate is direct fermentation substrate
- Pyruvate is reduced to ethanol or lactose
- NAD+ is regenerated as a result
Rate of glucose utilization from anaerobic to aerobic conditions
Rate of glucose utilization would decrease, because organism wouldn’t need as much glucose for the same amount of energy
Respiratory Quotient
- RQ
- rate of CO2 production over O2 uptake
- is 1 for carbohydrates
- is lower for fats (more hydrocarbons)
Mesophyte
Plant type
Moderate habitat
Basis of comparison
Vascular bundle
Veins
Comprised of:
- xylem (upper portion)
- phloem (lower portion)
Mesophyll
Between upper and lower epidermis Primary photosynthetic tissue - Palisade mesophyll, near upper layer - Spongy mesophyll, irregular cells, near lower, many intercellular spaces Upper epidermis is 1 cell thick Upper epidermis has no chloroplasts Lower epidermis usually has some chloroplasts Guard cells have chloroplasts
Cuticle
Waxy layer on upper and lower leaf portions
Prevents water evaporation
