How are glucose molecules absorbed in the gut?

Food consists of many types of molecules, these are: polysaccharides (a chain of single molecular units); dissacharides (a pair of single molecular units) and monosaccharides (the individual units themselves). Glucose can be present in a polysaccharide chain (e.g. starch), a dissacharide (e.g. maltose) and a monosaccharide (glucose itself). Before any absorption takes place, the poly- and di-saccharides first need to be broken down, by their associated enzymes, into glucose.

Glucose enters the small intestine and is absorbed by a process called "co-transport". Co-transport is when two molecules are transported across a membrane at the same time through a carrier protein. In this case, it is glucose with a sodium ion. The sodium moves into the cell through the sodium-glucose cotransporter protein, carrying glucose along with it. This process requires energy (as ATP), which is produced by the sodium/potassium pump. The glucose is now in the cell and is phosphorylated to maintain the flow of glucose into the cell. This glucose molecule now moves into the blood through a glucose carrier protein.

Answered by Abdul Nasir W. Biology tutor

2359 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

Explain how an action potential is generated


How does the heart pump blood around the body?


Describe the process of atherosclerosis and the effect it has on the properties of the blood vessel


Describe the process of translation


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2024

Terms & Conditions|Privacy Policy