Nutrition: Proteins
Nutrition: Proteins

This free course is available to start right now. Review the full course description and key learning outcomes and create an account and enrol if you want a free statement of participation.

Free course

Nutrition: Proteins

1.7.2 Too much protein

There is no way of storing large quantities of amino acids in the human body and so if more are present in the blood than are needed, the surplus ones have to be broken down and removed from the body. The liver carries out this crucially important function. The amino (nitrogen-containing) part of the amino acid is converted into a substance called urea, which contains the unwanted nitrogen. The urea is then carried round in the bloodstream to the kidneys where it is removed and then excreted from the body dissolved in water in the urine. All animals have to undertake a similar process to get rid of their excess amino acids, though the form of the nitrogen-containing waste product depends on how much water is available to dilute it. Fish produce ammonia, which is soluble and needs large amounts of water to remove it from the body, and can be toxic at high concentrations in the blood. Ammonia (in solution) is lost via their gills. Birds, which often do not have easy access to water, produce a semi-solid white sludge of uric acid. The remaining (carbon-containing) part of the amino acid can be broken down in humans and other animals, to provide energy or it can be stored by being converted to carbohydrate or fat, depending on the identity of the R group.

SK183_1

Take your learning further

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has over 40 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses.

If you are new to university level study, find out more about the types of qualifications we offer, including our entry level Access courses and Certificates.

Not ready for University study then browse over 900 free courses on OpenLearn and sign up to our newsletter to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus