Biochemistry/Microbiology Challenge Question.

[Survivor39]

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Originally Posted by nit

haha, one semester of concepts in biology 1001 and I'm on my way to becoming biologist! Hmm, yeh lactic acid results from the fermentation of pyruvate mainly in animal cells. That whole cycling idea of NAD while producing ATP is really neat. Talk about efficiency.

what's with all the Med people invading this thread??!
I hate metabolism. Why are there so many enzymes for everything Especially the cycling of NAD+. I hate that you can cycle it via latate fermentation, via the glycerrole 3-phosphate shuttle, or via malate-aspartate shuttle. I mean come on.. you found that neat. :P

[Budz]

Just taking a wild guess but.
Lemon which is acidic (Ph < 7)

Affects naturally occuring enzymes found in seafood, the alterations of charges around the Enzyme causes 'denaturing' the enzymes no longer catalyse chemical reactions which im guessing deteriorate the food...

But i actully think we as in everyday humans who know nothing about bio chemistry add lemon to food becase it tastes good - "sharper than normal"

[Budz]

Um Why Antibiotics only target pathogen well to be precise bacteria..

I am also only guessing but isnt it because it is only toxic to bacteriums. You could also ask why some antibiotices affect certain species of bacteria and other dont.

I was always under the impression that some fungi secrete chemicals which were found to inhibit bacterial growth. After the testing upon various organisms it was concluded that only certain species of bacteria was affected by certain antibiotics.

If no well my next best guess would be somethign to do with bacterium's lack of a nucleus. lol.

And if not then i guess the antigens (chemical signature) of certain bacteria allow for attraction of ceratin antibiotics

why am i (braceting) lol im talkin to Uni students lol

[Budz]

For Survivor 39 -
Although i have searched everywhere for a worth while carreer future... It is impossible to decide the science i enjoy the best..
So i was thinking of doin a combined Bachelor in engineerin and Science but what major in the engineering would be science based

Also what majors should i pick if i would eventually wish to do nanotechnology.

I know that there is a seperate degree but id prefer a combined just in case...
Thanx

[Survivor39]

Originally Posted by Budz

Just taking a wild guess but.
Lemon which is acidic (Ph < 7)

Affects naturally occuring enzymes found in seafood, the alterations of charges around the Enzyme causes 'denaturing' the enzymes no longer catalyse chemical reactions which im guessing deteriorate the food...

But i actully think we as in everyday humans who know nothing about bio chemistry add lemon to food becase it tastes good - "sharper than normal"

Everyday people do actually think that adding lemon because it taste good. But this is not the case in a microbiological pespective. You add lemon to seafoos, especially oysters, because the lowring of pH denature enzymes found in bacteria (not the food itself). Seafood contain a range of bacteria, possibly pathogenic, such as Vibrio species, which are suitable to the high salt content of the sea water. Then you have your other nasty Protozoa (Giardia and Cryptosporidium) etc etc.

Bascially the lowering of pH is used to kill microorganisms. So no matter whether you eat your seafood raw or cooked, the chance of you getting food infection and food intoxication descreases.

[Survivor39]

Originally Posted by Budz

I am also only guessing but isnt it because it is only toxic to bacteriums. You could also ask why some antibiotices affect certain species of bacteria and other dont.

But why is it only toxic to bacteria??

Originally Posted by Budz

I was always under the impression that some fungi secrete chemicals which were found to inhibit bacterial growth. After the testing upon various organisms it was concluded that only certain species of bacteria was affected by certain antibiotics.

Yes, fungi do secrete chemicals which inhibit bacterial growth. That was how penicillin was discovered. But how, that it only inhibit bacterial cells, not human cells??

Originally Posted by Budz

If no well my next best guess would be somethign to do with bacterium's lack of a nucleus. lol.

No

Originally Posted by Budz

And if not then i guess the antigens (chemical signature) of certain bacteria allow for attraction of ceratin antibiotics

Not really.

The answer is that antibiotic attack bacteria mainly because of their cell walls, and their ribosomes.

Human cells do not consist a thick layer of cell walls. Bacteria do. Certain antibiotics target the cell walls because of their unique chemical structure. The bacterial cell wall is composed of layers of peptidoglycans, which crosslinks with each other via a chain amino acids. Therefore, antibiotics can:
Target peptidoglycan chain, OR
Target the crosslinks between the peptidoglycan, that is the amino acids.

But you might ask, why do antibiotics only target amino acids on bacteria? That is because we, humans have 20 amino acids, and bacteria have more than 20. Antibiotics target bacterial amino acids that do not exist in human, such as mesodiaminopimelic acid.

Hence cell wall is destroyed, bacteria burst and die. Examples of antibiotic that target cell walls - penicillin.

For ribosomes, bacteria have different ribosomal arrangement like 70S compared to human 80S which I dont want to go into too much detail to freak you out from doing science . Yeah, so antibiotic kill the 70S ribosomes and hence no protein synthesis, bacteria die. And plus, they could target bacterial amino acid on ribosomes as well.

[Survivor39]

Originally Posted by Budz

For Survivor 39 -
Although i have searched everywhere for a worth while carreer future... It is impossible to decide the science i enjoy the best..
So i was thinking of doin a combined Bachelor in engineerin and Science but what major in the engineering would be science based

Also what majors should i pick if i would eventually wish to do nanotechnology.

I know that there is a seperate degree but id prefer a combined just in case...
Thanx

Well, all branches of engineering are considered science-based. But I guess chemical engineering has the most science. For more biological based, do biomedical engineering. For physics-based, do mechanical. All other branch such as mining, computing, environmental, they are pretty even in terms of how much science is taugh I guess.

if you wish to do nano, at UNSW, the major is already picked for you, that is nano! That itself is a major.

If you have no idea, just try every subjects in first year (Bio, chem, phy, geo, psyc, food, biotech) within your B Sc units. And see what you like best at uni.

[Survivor39]

howcome no one bothers to answer the anatomy question

Ok, there are 5 skin layers in the epidermis for thick skin (palm and sole). 4 in thin skin (all over your body except palms of your hand and soles of your feet).

Form daily activity, abrasion actually slough the uppermost layer off. However, what you lose is not living cells, but keratins on the uppermost layer. These are cells, which are dead, and whose nuclei and organelles are replaced by keratin protein. And the process of keratinisation occurs constantly to replace the sloughed cells on the upperlayer from lower layers.

[Budz]

Thanx heaps...
although when u said there is already a major at UNSW... is that in a BSc or BE
or is it simply a Bachelor of Nano

Because as i said id prefer to do a combined degree to keep my options open i guess..
thanx Survivor.

[Survivor39]

Originally Posted by Budz

Thanx heaps...
although when u said there is already a major at UNSW... is that in a BSc or BE
or is it simply a Bachelor of Nano

Because as i said id prefer to do a combined degree to keep my options open i guess..
thanx Survivor.

For your science degree, if you want to major in nano, you need to do B Science (Nanotechnology), a 4 year program.

You cannot major in Nano in a normal 3 year B Sc degree for some reason, unfortunately. Some units are restricted to Nanotech students, and you cannot do them in normal B Sc. So there's a slight problem in majoring in nano in your B Sc combining with engineering.

[Budz]

Thanx.. yeah, i was just notified that i was unable to do a combined degree in engineering and science with an eventual career prospect of nanotech.

[simplistic]

1st one--> build up of lactic acid thus enzymes cannot function lower metabolism thus not enough energy to continue
2nd one--> lemon = acid thus kill the micobes on it (the usual enzymes thing thus microbes die)
3rd one-->no idea .. they r chemicals naturally derived from othe bacteria thus kill bacteria ..
4th one--> is it 3 or 5 .. cant remmeber did it in yr 11 umm duno the nxt thing probably yeah but isnt it 1st the dead cells on the top ?
thye r liek rubbed off from day to day activites but like from mitosis in the bottom layer the whole layer is maintained

[simplistic]

oh lol uve alredi answered them maybe nxt time i should read the whole thread ..
well at lweast i was close this time

[mr EaZy]

Originally Posted by Survivor39

For biochemistry lover:

1. After vigorous excercise or running, why do you tend to stop and cannot continue? Answer from a biochemical perspective. (hint: What happens in your metabolism?)
.

of the top of my head,
is it because the reaction rate slowed down over time, and as too many bi-products and waste products accumulate/saturate in the cell at or near the active sites where chemical reactions occur, the body can no longer react at the rate it once did and tends to slow down; our body's exterior responding by moving into a position to maximise air intake, burn more carbs (but rate rate of burning is too slow). if it needs to carry on running or whatever- it'll exert itself with adrenaline, but if it doesnt, then the psychological forces acting on the body convince the mind to give it a break.

lol after 2 years of no science, this is all i can come up with.