Protein Function and intro to enzymes Flashcards
What are cofactors?
One or more inorganic ions that help with enzyme fucntion
What are coenzymes?
Complex organic or metalloorganic molecules, often derived from vitamins, that act as transient carriers of specific atoms or functional groups
What are prosthetic groups?
Coenzymes that are tightly bound to and remain associated with enzyme during the entire catalytic cycle
Explain how Phenylketonuria occurs.
Deficiency in phenylalanine hydroxylase which metabolises F to Y
What happens if phenylketonuria remains untreated?
F accumulates which is converted into phenylpyruvate
This causes problems with brain development, leading to progressive mental retardation and seizures
How do we treat phenylketonuria?
Diet low in Phe and high in Tyr
Damage done is irreversible
Explain how scurvy occurs.
Insufficient hydroxylation of collagen
Vitamin C is necessary to keep prolyl hydroxylase reduced in its active state
Collagen synthesised in the absence of ascorbic acid is insufficiently hydroxylated making it not fold properly
What is the role of kinases?
Attach a phosphoryl group to the OH group of specific amino acids in proteins
What amino acids can be phosphorylated?
Serine
Threonine
Tyrosine
What is the role of phosphatases?
Reverse the phosphorylation process
What is myristoylation?
Attachment of a fatty myristoyl group to proteins facilitating membrane association of proteins produced on free ribosomes
What is ubiquination?
Attachment of a small protein called ubiquitin that ends a protein’s life
Ubiquination leads to protein turnover
