Answer any of the following questions by Shuguang Zhang:
- How many molecules of amino acids do you take with a piece of 500 grams of meat? (on average an amino acid is ~100 Daltons)
1 mole of amino acid= 100 g then number of moles in 500g meat would be 5 mole
But I feel It will highly depend on the type of meat i.e. there are some meats which are much leaner in nature having a higher amino acid profile while some have more fat amount. This make the question a bit tricky. Also not all parts can be leaner, so the variation is there as well.
So lets assume, its 500g poultry meat (Chicken, turkey etc.) 500G chicken breast would have around 145g (could be higher, taking a lower number to account for fat) protein that's 29% of the total weight
on avg an amino acid mol is 100 daltons
total moles in 500g chicken = amount of protein in grams/ 1 mol in daltons = 145/100 = 1.45 mol
Amount of amino acid molecules in 500g chicken breast = 1.45 * Avogadro number =1.45 * 6.022 * 10^23 = 8.7319 * 10^23
I think this number will be lower in red meats, due to higher fat content.
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- Why humans eat beef but do not become a cow, eat fish but do not become fish?
I mean we obviously aren't some extraterrestrial species who have an ability to become what they eat (even if that's a very famous saying) . Humans consume the meat of these animals which is mainly classified into macros i.e. carbohydrates, fats and proteins( and many micronutrients) Our body processed these macros to function and survive like carbs for energy, fats for hormones and protein for the wear and tear of our body. Even if we are consuming other animals or any other omnivores or carnivores are consuming animals wouldn't mean that they would become them, as the digestion system works to process these meats and there isn't a system that would have somehow formed a chimera of me and a chicken after I eat a chicken salad! at least not in nature **
- Why there are only 20 natural amino acids?
That's an interesting question but before answering it I would like to admire the fact that there are just 20 natural amino acids and still we all differ from each other so much. I mean protein is what makes the life, protein is everywhere. 20 Amino acids and my cat is completely different from me, there is a fly, my cat, me and a cactus in my room and we are nothing alike structurally . I think its fascinating. To come to that question, I think its exactly like how we approach Physics and chemistry, there are some rules which cannot be changed. like the gravitational constant being 9.8 m/g or Hydrogen being the first on the periodic table due to its atomic number and electronic configuration. 20 amino acids is all we need, no more or no less and having more would have disrupted the flow of nature We may find some new ones maybe someday in future, who knows ** - Can you make other non-natural amino acids? Design some new amino acids.
Okay so for this I will require an already existing amino acid, to use as a precursor,I will choose a simple one
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So this is proline, pretty basic right? lets make it a bit complicated **
I doubled the peptides, Let's call this one Pro-proline. đ
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Where did amino acids come from before enzymes that make them, and before life started?
Wow, this is a classic chicken and egg scenario. but I have read something that may be an answer to this.
the miller urey experiment, where these scientists tried to simulate how earth must have been in the very early times, millions years ago had observed the existence of amino acids due to what reactions that took place on earth. mainly an interaction between lightening and early earth elements like water ammonia etc.
These permutation and combinations millions years ago must have created amino acids requires to make enzymes and then the enzymes carries the torch forward and so on.
If you make an alpha-helix using D-amino acids, what handedness (right or left) would you expect?
D-amino acids are mirror images of L-amino acids, so i think they would create a left-handed alpha-helix instead of the original helices.
- Can you discover additional helices in proteins?
Yes there is already a known concept such as pi helices **
- Why most molecular helices are right-handed?
amino acids occurring in nature are L- amino acids which have a right handed symmetry that might be the reason behind the molecular helices being righthanded **
- Why do beta-sheets tend to aggregate?
beta-pleated sheets easily interact with each other and form aggregates this is due to the presence of H bonds, flat surface. this can lead to them sticking on top of each other and then forming aggregates ** - What is the driving force for b-sheet aggregation?
Hydrogen bonding and side chain interactions
- Why many amyloid diseases form b-sheet?
Big aggregates can form due to the physical nature of b sheets as they interact with each other , this can lead to harmful buildup mainly in neurodegenerative diseases. Its incorrect folding and flap surface facing each other ** - *Can you use amyloid b-sheets as materials?
As harmful their physical structure can be I think it can be used for some novel purposes, as they are flat and thin they may be integrated in systems that require extremely fine and fibrous materials.*
- Design a b-sheet motif that forms a well-ordered structure.
| Requirements | components |
|---|---|
| stability | beta sheets antiparellel to each other |
| sequence | amino acid residues and less glycine as it reduces rigidity |
| hydrophobic nature | hydrophobic amino acids in side chains |
