Questions tagged [digestive-system]

Organs that play a role in digestion and/or absorption of nutrients: breaking down of food into smaller components that can be absorbed and used as for sources of energy, cellular/tissue building blocks, or cofactors for vital biochemical reactions.

Filter by
Sorted by
Tagged with
21 votes
2 answers

What inactivates pepsin in infants?

In infants, rennin helps in digestion of milk. Pepsin is also present in their stomach. Why do infants need rennin for milk digestion, at the first place? Why does pepsin not act on the milk ...
Mesentery's user avatar
  • 3,277
11 votes
3 answers

Do humans produce rennin?

At school, we've been taught that human infants produce rennin/chymosin (which aids in the digestion of milk). More specifically, it is the peptic cells in the stomach which secrete prorennin, the ...
paracetamol's user avatar
  • 1,569
26 votes
3 answers

Are humans the only animal that requires "clean water"?

I've seen a number of animals - dogs, cats, squirrels, ducks and geese, etc drink from puddles, some of them were muddy, others had green flora growing under water. Same goes for lakes and rivers. A ...
Alex Stone's user avatar
  • 6,517
17 votes
4 answers

What nutrients can humans absorb in the mouth?

For instance, I realise being able to absorb simple sugars in the mouth is pivotal in the rapid action of oral glucose gel. Thus I was wondering what nutrients in general can be absorbed directly ...
mchen's user avatar
  • 273
7 votes
3 answers

Is there evidence to suggest that nutrients in vitamin capsules are not as readily absorbed as the same nutrients in whole foods?

I recently fell ill with a cold, and began to take a vitamin C capsule each day to help my immune system. When I noticed no change in my condition, I began to incorporate an abundance of citrus into ...
Andrew's user avatar
  • 235
5 votes
1 answer

How does botulinum toxin enter the blood stream from the digestive tract?

To my understanding, large polypeptides such as botulinum toxin cannot pass the intestinal lining intact. How, then, can it enter the bloodstream and cause botulism poisoning?
Nick's user avatar
  • 153
5 votes
1 answer

Do intestinal flora have the same DNA as their host?

Please bear with me, this is not my professional field and I might be mixing things up. In an explanation why seeds won't start growing in one's intestines, the explanation given was that foreign ...
Louis Somers's user avatar
11 votes
2 answers

Does freezing microorganisms such as probiotics kill them?

Does freezing microorganisms such as probiotics kill them? If not, what is the process that allows them to "come back to life" after the temperatures are increased? As an example, lets say you ...
End Anti-Semitic Hate's user avatar
10 votes
2 answers

Why do people say that trans fatty acids are bad for your health?

I've heard from several sources that trans FAs are bad for you and their consumption will lead to cardiac problems, and that they are indigestible. But I also learned from biochemistry that they are ...
zeller's user avatar
  • 749
6 votes
2 answers

Do omnivore mammals vary food preferences based on dietary needs?

I'm wandering if mammals that can eat many different kinds of food (omnivores) vary their preference for food not only based on the availability, but also based on dietary needs? I'm looking at this ...
Alex Stone's user avatar
  • 6,517
5 votes
1 answer

How does the human stomach handle a mix of digested and undigested food?

As I understand it, the stomach digests the bolus into chyme and then passes the latter on to the small intestine. This process takes between 40 minutes and a few hours. However, what happens when ...
user avatar
5 votes
1 answer

What is an simple way to burn glucose for visible effect?

I want to make a partially working model of the digestive system that could digest complex carbohydrates. My ultimate goal is to be able to cut up some bread, put it into the model, operate it, and ...
technillogue's user avatar
2 votes
1 answer

Energetics and Products of Pepsin/HCl Protein Digestion

What are the energetics of protein digestion during which the enzyme pepsin is "activated" (whatever that means) by HCl? I've looked and been unable to find anything like a chemical equation that ...
James Bowery's user avatar
1 vote
1 answer

What is the biological basis for tiredness after eating? [duplicate]

I can sometimes feel quite drowsy after some "meals" (e.g. a cold cut & cheese sandwich with juice on the side) and less drowsy (or maybe less often) after others (such as a salad). This ...
user avatar
1 vote
1 answer

Is there nutrient absorption in the large intestine of hindgut fermenters?

In hindgut fermenters, plants are digested in the caecum by microbes. I want to know whether hindgut fermenters can absorb the nutrients obtained from the digestion in the large intestine because the ...
quibble's user avatar
  • 662
0 votes
2 answers

Gastric and intestinal gas exchange

A very long time ago, I happened across research into using an oxygenated liquid in the stomach and or intestinal cavity. I wondered what further results came about of that research, and am having ...
Keith Reynolds's user avatar
-1 votes
1 answer

Why porifera is classified to have an incomplete digestive system although it has no organs?

Why are we using the term "incomplete" for digestive system only? We could have also said that for circulatory system that it is either incomplete or present as a simple system. What I mean ...
Lakshya Kumar Singh's user avatar