bio 241 Flashcards
What is a hypothesis?
A possible answer to a question
Hypothesis’s cannot be proven because future experiments may reject them
they can be rejected or we can fail to prove them
What is a null hypothesis
Assumes that the experimental treatment has no effect or no significant difference between the control and experimental group
What is an alternate hypothesis
There is a significant difference between control and ecperimental group
When null hypothesis is rejected then alternate hypothesis is considered
What is an independent variable?
This is the variable that is manipulated in the experiment
Cause
What is an dependent variable?
THe factor that changes because of the indpendent variable
effect
What are controled variables
The factors the don’t change between control and experimental treatment
AKA Constants
What is the control treatment
Confirms tour experimental setup has no effect on dependent variable
ex, normal reaction occuring without enzyme
What is experimental treatment ?
In this treatment the independent variable is manipulated
ex: adding different concentrations of enzyme to reaction
What is the purpose of replication?
Repeating a experiment multiple times should give you consistent results to have an accurate conclusion
were results a coincidence?
What is a sample mean
Our experiement is limited to a specific normal of organisms so a sample mean is a estimate of the population mean
Average
sum of all treatment divided by number of treatments
How can variability be reduced
By increasing sample size and having multiple replicates
What is the standard error of mean
Takes in account variability in data in relation to size of group
sum of all (mean-measurement in treatment)^2/ number of treatments( number of treatments-1)
When do we use a line or bar graph?
Line graph- Both x and y axis are numerical and continous
Bar graph-when x axis are non numerical (like names) discontinous, and y axis are continous
When do we use a line or bar graph?
Line graph- Both x and y axis are numerical and continous
Bar graph-when x axis are non numerical (like names) discontinous, and y axis are continous
How do we calculate total magnification
Magnification of objective lens x10
Lens on microsope =Ocular lens has 10x magnification
How to measure a specimen
10x objective lens=ocular divisionsx10um
40x objective lens=ocular divisionsx2.5um
100x objective lens=objective lens x1um
ocular divisions is measurment on ruler in microscope
What are enzyme kinetics
Study of how fast an enzyme conversts substrates to products
What is enzyme activity
The rate or velocity of the reaction catalyzed by the enzyme
How can we measure enzyme activity
This is measured by adding enzyme and substrate into a test tube and then measuring the increase of the amount of product as the reaction occurs
How can we measure the changing concentration of substrate or product
If substrate or product is a pigment we can use a spectophotometer. Otherwise we can add a indicator that will let us calculate absorbance
How does a spectophotmeter work
They measure how much light is absorbed by a solution
The higher the concentration of the coloured pigment molecules or indicator in the solution the greater tha absorbance.
We then use a standard curve to measure the concentration of pigment in solution
How to use spectophotometer standard curve to convert absorbance to concentrations
- Locate point on y axis that corresponds to the measured absorbance
- Draw a straight line from the point over the standard curve
- Draw straight line down the axis
PIcture in notes
What enzyme was used in the lab?
Lab 1
B-galactosidase which is an enzyme used to treat lactose intolerance. It breaks the bonds between galactose and gluose in lactate molecules
We need alot of b-galactosidase to break down milk
Why is a blank used to zero spectophotometer
It is used to so that you only calculate pigment in the product and not any other molecules that may have pigment
What substrate do we use in the lab
lab 1
We use ONPG which is similar to lactose but it contains glucose and o-nitrophenol. O-nitrophenol has a yellow color so it can be used to calculate enzyme activity
Why do we use Na2CO3
Lab 1
To create a more yellow color. When o-nitrophenol reacts woth Na2CO3 it becomes o-nitophenolate which is more yellow
Sodium carbonate also deactivates the enzyme
What is the optimal wave length
The optimum wavelength should cause maximum absorbance
you should see the greatest difference overtime
What is Vmax
The maximum rate of reaction for a given enzyme and substrate
What is Km
Km of a substrate concentration in which reaction proceed at half of it’s maximum rate 1/2 Vmax
Michealis mentin plot vs line weaver plot
In michaelis menten plot the Vmax is an asymptote so the curve never reaches Vmax So instead we use line weaver plot
What is the km and vmax of competitive inhibitor
In competitive inhibition vmax is the same since eventually substrate outcompetes inhibitor but km is the sameWhat is the km and vmax of competitive inhibitor
What is the km and vmax of non competitive inhibitor
In non competitive inhibition vmax is reduced but km remains the same
How to calculat vmax on lineweave plot
If y=Mx+b
Vmax=1/b
How to calculate Km on lineweaver plot
If y=Mx+b
Km= M. Vmax
How do dilutions work?
Dilutions are made by pipetting a volume of an undiluted or stock solution into a volume of solution (dilutent
what is the formula for dilutions
D= volume of original solution/(volume of original solution+volume of diluent)
How do we calculate concentration of diluted sample
c1v1=c2v2
How to calculate dilution factor
Original solution+volume of dilutent
it means total volume of solutiojn
What did Robert hill discover?
Robert hill discovered de that isolated chloroplast produce oxygen when they are exposed to light and provided an electron acceptor even if CO2 is missing.
This means O2 doesn’t actually come from CO2
What is the hill reaction?
Reduction of an electron acceptor by electrons and a proton from water
What is the role of DCPIP?
DCPIP a stronger oxidizing agent then NADP+ and it accepts electrons from ferredoxin
What Color is DCPIP?
It is blue when oxidized and colourless when reduced so we can measure the rate of electron flow by looking at the loss of colour in DCPIP
Why do we cover tube 3 with aluminum foil?
It is the dark control so we want no light getting in
WHat is the role of DCMU?
DCMU is an inhibitor that inhibits photosystem 2 and the light dependent reaction. SO it only inhibits part of photosynthesis.
Why do we use a heat sink
The lamp provides heat and light to the reaction, but temperature is one of our controls so the water absorbs heat coming from lamp so that light is the only factor effecting treatments
What are the results (DCMU)
Lab 6
With increased concentrations of DCMU cyclic flow occurs so DCPIP concentrations
What are biofuels
Alternative sources of energy that are meant to be more sustainable
Name one con for use of ethanol ?
There is not enough corn production to form a sustainable amount of ethanol. SO ethanol would not be able to replace diesel.
Fertilizers used to grow corn would also cause eutrophication
Name one of the pros of use of ethanol production ?
Ethanol can be used to replace diesel
How is bioethanol produced?
It is produced when carbohydrates are fermented by yeasts (glycolysis and then alcohol fermentation)
What causes bread to rise?
The carbon dioxide formed through alcohol fermentation (performed by yeast) Ethanol is also formed but it evaporates when we bake bread
How can we measure rate of ethanol production?
Since during fermentation both co2 and ethanol are produced. We can measure ethanol production by measuring co2 produced. They are directly related
What role do yeast play?
When yeast are provided with a source of carbohydrates it uses it as a source of energy and carbon. For example glucose
Yeast breaks down carbohydrates to release energy that can be used for alchol fermentation.
How can carbohydrates other then glucose be used?
They can be used after they are broken down to simple sugars. (Rate of reaction will be longer)
cpmplex sugars startches
Which plant material was the best for ethanol production ?
Sugar beets have the highest sugar content so they produced the most co2(ethanol). Oats contained the most complex carbohydrates so they would need to be broken down so rate of co2 production is slow
What is the difference between volume of co2 produced and rate of co2 production?
Volume of co2 is the total amount of co2. Rate of co2 produced is the speed of co2 production
How can we prepare series dilution
Transfer 1 mL of stock to first tube, mix, transfer 1 mL to next, mix, and so on for rest.
Keystone species
spe
species controls the community structure despite its relatively non proportional population
Competitive dominance
a species is beter at obttaining or holding space than another. Abe to displace another species
Primary producers
use energy from the sun to produce their own food (rather than consuming other organisms) Occupy lowest trophic level
Trophic level
A step on the food chain or food web, Starts from primary produces, then primary consumers and so on
How microcosm models aquatic environment
Phytoplankton (aquatic photoautotrophs including cyanobacterial algae & eukaryotic algae) + zooplankton in the lower chamber along with the aquatic plants.
Allows us to replicate runoff.
How microcosm models terrestrial environment
Plants in the upper chamber with soil. Runoff can occur via bottle hole at the bottom.
Air holes for gas exchange in both upper and lower chambers.
