(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.
Cats moult fur around spring-summer time to get rid of their winter coat. Cats have thicker fur during the colder winter months to keep them warm, then around spring and summer they shed some of their fur to get a thinner coat for the warmer summer months. Some cats need brushing during moulting, since dead hairs can get trapped in the cat's fur.