· 2: the two subunits assemble the enzyme and recognize regulatory factors. Each subunit has two domains: CTD (C-Terminal domain) binds the UP element of the extended promoter, and NTD (N-terminal domain) binds the rest of the polymerase. · : this has the polymerase activity (catalyzes the synthesis of RNA) which includes chain initiation and elongation. · ': binds to DNA (nonspecifically). · : restores denatured RNA polymerase to its functional form in vitro. It has been observed to offer a protective/chaperone function to the ' subunit in Mycobacterium smegmatis. Now known to promote assembly. In order to bind promoter-specific regions, the core enzyme requires another subunit, sigma (). The sigma factor greatly reduces the affinity of RNAP for nonspecific DNA while increasing specificity for certain promoter regions, depending on the sigma factor
steady became constant at, 3 hours / 4.3 (a.u) ; if no figs in description, e.g. ‘rose then constant’ award 1 mark max 2 (ii) (increased as) enzyme working / rate of reaction high / reaction proceeding ; (increased as) substrate converted into, drug / product ; (levelled off / became constant, after the) enzyme, became inactive / was denatured; (levelled off / became constant) because product inhibits, reaction / enzyme ; R references to enzyme or substrate being used up R T ºC limiting 2 (b) pH ; degree of mixing ; enzyme concentration ; AVP ; e.g. ref to concentration of inhibitors 1 max (c) max of 2 marks for predicting or explaining
globin fraction is in its native state (undena- tured). Over time, these reducing equivalents Color are depleted and the pigment is irreversibly Color and appearance of fresh meat are major oxidized. Oxidation also occurs rapidly if the factors in consumer purchase decisions globin moiety is denatured by rapidly declin- because they are presumed to be indicators ing pH while the carcass is “hot” or by exces- of meat freshness and quality (Brewer et al. sively low ultimate pH. 2002). Meat color is due to the concentration In pigs, color variations may have been of heme pigments (myoglobin, hemoglobin), inadvertently selected for as pigs were bred
annaabi.ee 
