164 



Inside the Living Cell 



CH, 



CH 



•♦Acid Group / 



NH 



I 1 



d-Ribo oo - ' phospho-group^ Basic Group ', 



Part of protein molecule 



Figure 3. The riboflavin phosphate molecule showing how it 

 combines with the protein part of the enzyme. 



NH2 



COOH 





SO2NH2 



p-Aminobenzoic Sulfanilamide 

 acid 



Figure 4. A vitamin and its antagonist. 



c c c 



/ \ / \ / \ 

 c c c c 



\ I I / 



C_N N— C 



/ \ / \ 



C Fe C 



\ / \ / 



C— N N— C 



/ \ I \ 



c c c c 



\ / \ / \ / 



c c c 



The central haem part 

 of haemoglobin 



I I I 



c c c 



/ \ / \ / \ 



■c c c c 



\ I \ / 



C— N N— C 



\ / \ 



Co C 



/ \ / 



C— N N— C 



/I I \ 



c c c c 



\ / \ / \ / 



c c c 



I I I 



The central part of 

 Vitamin BI2 



Figure 5. The central parts of the molecules of haemoglobin 

 and vitamin B12. 



