Effect of CO2 concentration of photosynthesis

[NN900]

Hello, there
Can someone please explain to me in detail how an increase in Co2 concentration results in an increase in photosynthetic rate?
This is what I got from the internet "An increase in the carbon dioxide concentration increases the rate at which carbon is incorporated into carbohydrate in the light-independent reaction, and so the rate of photosynthesis generally increases until limited by another factor." But, it is not really in-depth for me to use when analysing the graph.

Kind regards.

[RaspberryTau]

Hey There!

Here's my understanding:
- CO2 is a reactant in photosynthesis, and is a substrate for some enzyme
- An increase in substrate concentration (or reactant concentration) increases the rate of the reaction
- This is because more enzyme-substrate collisions occur per second. (The frequency of enzyme-substrate collisions increases)
- Hence the rate of reaction increases

In photosynthesis there is the light-dependent stage (where water is split by sunlight) and the light independent stage (where carbon dioxide is mushed together to form glucose in the Krebs Cycle). So you would be increasing the rate of the light independent stage.

The graph would plateau because of either a limiting factor (eg sunlight/water) or because the enzyme has become "saturated".

Hope this helps!
- 

Edit: increasing the rate of the light-independent stage (not dependent).

[NN900]

Hey There!

Here's my understanding:
- CO2 is a reactant in photosynthesis, and is a substrate for some enzyme
- An increase in substrate concentration (or reactant concentration) increases the rate of the reaction
- This is because more enzyme-substrate collisions occur per second. (The frequency of enzyme-substrate collisions increases)
- Hence the rate of reaction increases

In photosynthesis there is the light-dependent stage (where water is split by sunlight) and the light independent stage (where carbon dioxide is mushed together to form glucose in the Krebs Cycle). So you would be increasing the rate of the light dependent stage.

The graph would plateau because of either a limiting factor (eg sunlight/water) or because the enzyme has become "saturated".

Hope this helps!
- 

Hello, RaspberryTau
Thank you so much for your help! This is very useful 
Have a good evening

[RaspberryTau]

And to you! Glad I could help

[NN900]

Hello, there
Can someone please help me with analysing this particular graph?
This is an experiment testing the burning of biofuels and how different concentrations can affect this. Does this have anything to do with anaerobic fermentation and how does it happen?

(Note that the numbers on top of the bar graph are the average time taken for the burning time) - Just ignore Fuel (mL) it does not really relevant to the interpretation of this graph.

Kind regards.

[Billuminati]

Hello, there
Can someone please help me with analysing this particular graph?
This is an experiment testing the burning of biofuels and how different concentrations can affect this. Does this have anything to do with anaerobic fermentation and how does it happen?

(Note that the numbers on top of the bar graph are the average time taken for the burning time) - Just ignore Fuel (mL) it does not really relevant to the interpretation of this graph.

Kind regards.

I don’t really understand this graph, is this supposed to be a calorimetry experiment? If so why is the dependent variable “burning time” instead of “energy released”? What are the units of concentration and what is the identity of the biofuel (I’m guessing bioethanol from anaerobic fermentation from context of the post)? Also why is there a burning time at 0 concentration units of biofuel/diesel if you’re not actually burning a fuel? FYI different fuels have different burning rates so you can’t validly conclude that there is less of Fuel X present just because it burns out quicker than Fuel Y

[NN900]

I don’t really understand this graph, is this supposed to be a calorimetry experiment? If so why is the dependent variable “burning time” instead of “energy released”? What are the units of concentration and what is the identity of the biofuel (I’m guessing bioethanol from anaerobic fermentation from context of the post)? Also why is there a burning time at 0 concentration units of biofuel/diesel if you’re not actually burning a fuel? FYI different fuels have different burning rates so you can’t validly conclude that there is less of Fuel X present just because it burns out quicker than Fuel Y

Hello, Billuminati
Sorry for not making it clear, this practical task is about testing the burning time of (methanol oild) and (canola oil).
But I don't know why methanol oil burn longer than canola oil, like what are the causes for this?

Cheers.

[Billuminati]

Hello, Billuminati
Sorry for not making it clear, this practical task is about testing the burning time of (methanol oild) and (canola oil).
But I don't know why methanol oil burn longer than canola oil, like what are the causes for this?

Cheers.

Like I said burning time is pretty meaningless on its own without info on other factors like rate of combustion. The disparity of burning time could just be caused by the fact that canola oil has a faster rate of combustion than "methanol oil". "Methanol oil" doesn't make sense either since methanol is an alcohol, is it supposed to say methyl esters of fatty acids ie biodiesel or is it supposed to be like E10 fuel where you have a fossil fuel doped with alcohols?

[Bri MT]

Hello, there
Can someone please help me with analysing this particular graph?
This is an experiment testing the burning of biofuels and how different concentrations can affect this. Does this have anything to do with anaerobic fermentation and how does it happen?

(Note that the numbers on top of the bar graph are the average time taken for the burning time) - Just ignore Fuel (mL) it does not really relevant to the interpretation of this graph.

Kind regards.

I looked at this last night, I've looked at it again now and I'm still confused. There is not enough information provided to interpret this data - is the 0.5 indicating that half the amount (volume? mass?) was used? a proportion mixed with something else?

Also, although the title seems to clarify this a y-axis really should be provided for scientific display of data.

You mentioned different concentrations - different concentrations of what?


Not meaning this as an attack at all; I'm just trying to help you express the information so that we can better understand what is going on

[NN900]

I looked at this last night, I've looked at it again now and I'm still confused. There is not enough information provided to interpret this data - is the 0.5 indicating that half the amount (volume? mass?) was used? a proportion mixed with something else?

Also, although the title seems to clarify this a y-axis really should be provided for scientific display of data.

You mentioned different concentrations - different concentrations of what?


Not meaning this as an attack at all; I'm just trying to help you express the information so that we can better understand what is going on

Hello, Bri MT
I'm apologised for not making my question clear enough, maybe the instructions of this experiment will help make the context of this experiment become more clear.

Kind regards.

[NN900]

Like I said burning time is pretty meaningless on its own without info on other factors like rate of combustion. The disparity of burning time could just be caused by the fact that canola oil has a faster rate of combustion than "methanol oil". "Methanol oil" doesn't make sense either since methanol is an alcohol, is it supposed to say methyl esters of fatty acids ie biodiesel or is it supposed to be like E10 fuel where you have a fossil fuel doped with alcohols?

I'm so sorry for not clarifying my question properly.
I was just trying to understand the reason why the burning time for biofuel is shorter than commercial fuel? (My teacher say that it has something relates to esters and vaporisation-in term of chemistry). But, this is for biology, so I don't really know how to explain it in biology context.

Kind regards.

[Billuminati]

I'm so sorry for not clarifying my question properly.
I was just trying to understand the reason why the burning time for biofuel is shorter than commercial fuel? (My teacher say that it has something relates to esters and vaporisation-in term of chemistry). But, this is for biology, so I don't really know how to explain it in biology context.

Kind regards.

Now it's much clearer when you mention your methodology. This is a classic transesterification reaction to produce biodiesel. Petrodiesel burns for longer (assuming same rate of combustion) since it has a lower flashpoint than biodiesel. It's because biodiesel is a lot more polar (dispersion forces + dipole-dipole interactions from ester functional group) than petrodiesel (dispersion forces only as they're long chain alkanes and arenes). Lower flashpoint of petrodiesel = easier ignition since you don't need to heat the fuel as much to get flammable volatile vapours necessary to kick start combustion

No idea why you're doing this experiment in a bio class and not chem class. Maybe your teacher wants to illustrate the structure of biomacromolecules like lipids ie triglycerides which is a topic taught in U3 bio.

Overall the experiment is kinda dodgy cuz again you don't know if both fuels burn at the same rate. Also you should be taking away the burning time of cotton ball without any fuel from your other burning times cuz that's your negative control, it's like zeroing the scale before weighing. You shouldn't refer to quantity of fuel as concentration since the units your methods mention are mL, which is a unit for volume

[NN900]

Now it's much clearer when you mention your methodology. This is a classic transesterification reaction to produce biodiesel. Petrodiesel burns for longer (assuming same rate of combustion) since it has a lower flashpoint than biodiesel. It's because biodiesel is a lot more polar (dispersion forces + dipole-dipole interactions from ester functional group) than petrodiesel (dispersion forces only as they're long chain alkanes and arenes). Lower flashpoint of petrodiesel = easier ignition since you don't need to heat the fuel as much to get flammable volatile vapours necessary to kick start combustion

No idea why you're doing this experiment in a bio class and not chem class. Maybe your teacher wants to illustrate the structure of biomacromolecules like lipids ie triglycerides which is a topic taught in U3 bio.

Overall the experiment is kinda dodgy cuz again you don't know if both fuels burn at the same rate. Also you should be taking away the burning time of cotton ball without any fuel from your other burning times cuz that's your negative control, it's like zeroing the scale before weighing. You shouldn't refer to quantity of fuel as concentration since the units your methods mention are mL, which is a unit for volume

Hello, Billuminati
Thank you so much for taking a lot of your times to help me out with this question 
Hope you have a wonderful weekend!