biology, some confusing concepts

[izzahzainab]

i am having problem in finding out hope you can answer.

1. why do guard cells contain stomata?

2. what type of dissolved SOLIDS can pass through partially permeable membrane?

3. is there such a thing as "starch solution"? is starch soluble?

4. are all enzymes organic?

5. how are skeletal muscles involved in controlling the body temperature?

6 what is the difference between binary fission and mitosis?

 

[scouserlfc]

Well guard cells contain stomata to control the movement of molecules and vapour in and out of the plant.According to one theory guard cells make their own food and take in water and become turgid and therefore swell and become round opening the stomata and CO2 intake occurs.While in night this water has evaporated and therefore the cells return to normal shape closing stomata.

2.Only certain substances pass through well i dont know specifically .

3.Well i think yes a starch solution exists the starch test might be what u r referring or maybe not specify thanks.

4.yup all enzymes are organic and made of Proteins and therefore are denatured.

5.Well skeletal muscle cause Spasmodic contraction of muscles to cause shivering one of the methods to produce heat when it is extremely cold,the muscles when contract produce heat and therefore body heat is tried to mantain.

6.Dont know this havent read it not going to give BIOLOGY this term.
Please point any mistake out :mrgreen:

 

[abcde]

AOA!
1. Technically, guard cells do not 'contain' stomata. A stoma (stomatal pore) is found between two guard cells for the diffusion of gases into and out of the cell. For example, during photosynthesis CO2 enters the leaf through the stomata and O2 leaves the leaf through it, too. Similarly, water vapour leaves the leaf through diffusion during transpiration.
2. Simple molecules such as glucose, amino acids, fatty acids and glycerol can move through partially permeable membrane. So can mineral salts.
3. As far as I know, there isn't. Starch is a polysaccharide and like glycogen and cellulose, it is insoluble in water.
4. Enzymes are made of protein and proteins are organic so yeah, all enzymes are organic. But if you're talking about catalysts, both organic and inorganic catalysts exist.
5. When the body temperature falls below normal, shivering occurs. The spasmodic contraction of the muscles increases body temperature and helps to raise it back to normal. So this is the role of skeletal muscles in controlling body temperature.

 

[abcde]

OMG! When I started out my reply, there was no other solution! Yes, do correct me if I'm wrong!

 

[scouserlfc]

Aw i got 3/5 correct well yeah should I edit my post to confirm i was wrong wait ill thank u to show mine was wrong/

 

[abcde]

6. Binary fission occurs in prokaryotes such as bacteria and cannot be divided into stages like mitosis. I hope I helped if not completely then maybe just a little

 

[scouserlfc]

OMG! When I started out my reply, there was no other solution! Yes, do correct me if I'm wrong!

I was already on it before u came online. :mrgreen: :mrgreen:

 

[izzahzainab]

thanks scouserlfc, and abcde !!
sorry i wanted to ask why guard cells contain "chloroplasts"???
and there is a question in pastpapers, showing a solution. when we add iodine in it, it turns blue black. what was the solution??? the redspot answers "starch solution"....!!! i think its wrong

 

[scouserlfc]

Well for reference u can call it a starch solution but it confuses u only so cll it the Starch test or IODINE test.

 

[VelaneDeBeaute]

Well as far as i know, there is a starch solution but the thing is that there is a chemically prepared starch powder that is dissolved in water and the solution is then boiled. So overall as though it gives the impact that starch is directly dissolved in the water, this isnt the case.
Hope this helps..!!

 

[izzahzainab]

yup, thanku

 

[intelnehalem]

Starch solution can be made by heating starch in water under high temperatures. Therefore technically a starch solution is possible.
Abcde got the rest correct btw
Our syllabus requires minimal knowledge of binary fission- if you know that it is how bacteria reproduce and that it is a form of asexual reproduction , then you are fine

 

[VelaneDeBeaute]

Well if this thread is working out, may i post my questions here too..??!!
(I'm posting them anyway)
1.Like penicillin, mycoprotein is made in a fermenter. However , when mycoprotein is made, there is no stirrer in the fermenter. Why??
2.The microorganisms that you grow in a lab might be harmful for humans. What should you do after you have finished with your experiments of growing microbes in the petri dish?
Thanx in advance 2 those who wud answer..!!

 

[izzahzainab]

there IS a stirrer when mycoprotein is made. read it in my book just now

 

[VelaneDeBeaute]

I read it in mary jones' book...There was this question..!!

 

[insomniac]

well well in single cell proteins production we have rotating spray heads while in the production of penicillin we not only want to mix fungus with nutrients or provide oxygen but also there is a need to roll the fungus in pellets bcoz there is a need to separate the liquid part from the fungus ... this makes it easier by having tools to stir in penicillin production

 

[insomniac]

and yeah the rotating sprays maintain the oxygen supply so there aint a need to stir

 

[VelaneDeBeaute]

wat u said is perfectly clear..!!
i just wanna understand why do we not stir the mixture wen mycoprotein is made..!!
Is it becuz we hve to obtain it as a product so we let it descend to the bottom to extract it out??
In the penicillin one we need to mix the oxygen and nutrient bcuz it helps in producing more penicillin!!
If im ri8 tell me..
if im wrong correct me..!

 

[insomniac]

see penicillin production is by batch process but for mycoprotein the technique is continuous culture ..
for penicillin we need to stir the mixture for the mixing of the fungus with basic needs then turning it to pellets to be bached off ... and collecting liquid penicillin ..
while in mycoprotien u just need to put in the fussarium pump in air and bla bla bla .. and then when its done replace it again with new fussaruium and take out the mycoproytien ..
i think thats the difference ,,, thats how much i knw

 

[insomniac]

so when the air is pumped and the fungus is sprayed there wont be a need for stirring ...