Question

The difference between normal prion proteins and those that cause disease (such as mad caw disease) is that:

a. they have very different primary structures
b. they have very different secondary structures
c. they have completely different nucleotides
d. they also function as viruses
e. normal prions also have an RNA genome

Answer 1

Normal prion proteins convert to disease-causing prions when their structure changes from alpha helices to beta-pleated sheets, leading to diseases like Mad Cow Disease.

Step-by-step explanation:

The difference between normal prion proteins and those that cause disease, such as Mad Cow Disease, is related to their structure. Specifically, the normal form of the protein, known as PrPC, can be converted into a disease-causing form, dubbed PrPSc, when it encounters the malformed version. The difference is not in the primary structure or nucleotide sequence but in the secondary and tertiary structures: normal prions contain alpha helices, while the disease-causing prions fold predominantly into beta-pleated sheets and become resistant to proteolysis. Additionally, the abnormal PrPSc can induce other normally-folded prions to become misfolded, producing more rogue proteins and leading to diseases such as Mad Cow Disease in cows and Creutzfeldt-Jakob disease in humans.