(4) The attachment of the pyrimidine base to the ribose phosphate ring is catalyzed by orotate phosphoribosyl transferase (OPRT) and PRPP provides the ribose-5-phosphate moeity. Hydrolysis of the PP i that is split off of the PRPP makes this reaction irreversible.
Red Squirrels shed their coats twice a year, switching between a thinner coat in summer and a darker, thicker winter coat. 6. Males may live in an area of up to 17 hectares of woodland... thatâs about the same size as 34 football pitches! 7.
The inhabitants of the cottage are out, but Snow White decides to clean the house in the hopes of securing a place to stay. The animals help as Snow White cleans to Whistle While You Work; squirrels use their tails as dusters, an antlers are used to carry wet clothes, and the turtle's shell is used as a drying rack.