3.1.2 The digestive system provides an interface with the environment. Digestion involves enzymic hydrolysis producing smaller molecules that can be absorbed and assimilated.
- The gross structure of the human digestive system limited to oesophagus, stomach, small and large intestines, and rectum. The glands associated with this system limited to the salivary glands and the pancreas.
- Digestion is the process in which large molecules are hydrolysed by enzymes to produce smaller molecules that can be absorbed and assimilated.
In GCE AQA Biology, you’ll be expected to know about the human digestive system 🍽️. The entire digestive system is made up of a long, continuous tube (alimentary canal) and its associated glands and organs. Its function is to carry out digestion:
Digestion: Large, insoluble molecules are hydrolyzed by enzymes to produce smaller molecules that are absorbed and assimilated 🍔
- Large, insoluble molecules: e.g. starch, proteins
- Hydrolyzed: splitting up of molecules, by adding water to the chemical bonds that hold atoms together 🚰
- Enzymes: biological catalysts, often produced by the associated glands
- Absorption: movement from the small intestine into the blood/lymph, by passing through cells and membranes on the surfaces of intestines
- Assimilation: the body using the products of digestion to make molecules the body needs
The following is a labelled diagram of the human digestive system:
As a GCE AQA Biology student, you should be able to identify and label the following parts of the alimentary canal and its associated organs:
That's it for today! 🎉
References
1. Toole, G., & Toole, S. (2015). Aqa biology A level. Oxford: Oxford University Press.
2. Photo of digestive system retrieved from https://www.rtmagazine.com/disorders-diseases/infectious-diseases/other-infections/covid-19-gastrointestinal-symptoms/
3. DIagram of digestive system retrieved from https://www.tes.com/teaching-resource/digestive-system-new-spec-aqa-11661580