RT Book, Section
A1 Ryan, Kenneth J.
SR Print(0)
ID 1148678022
T1 Sarcomastigophora—The Flagellates
T2 Sherris Medical Microbiology, 7e
YR 2017
FD 2017
PB McGraw-Hill Education
PP New York, NY
SN 9781259859809
LK accessmedicine.mhmedical.com/content.aspx?aid=1148678022
RD 2024/04/19
AB The  flagellated  protozoa  are  widespread  in  nature,  multiply  by  binary  fission,  and  move  about  by  means  of  a  primary  organelle  of  locomotion,  the  flagellum.  This  organelle  arises  from  an  intracellular  focus  known  as  a  kinetosome  (basal  body),  extends  to  the  cell  wall  as  a  filamentous  axoneme  composed  of  microtubules  arranged  in  the  typical  9  pairs  +  2  central  microtubular  pattern,  and  continues  extracellularly  as  the  free  flagellum.  A  pair  of  dynein  arms  extends  from  each  outer  microtubule  of  a  pair  to  an  adjacent  microtubular  pair  and  is  responsible  for  flagellar  beating  through  ATP  hydrolysis.  The  long,  whip-like  free  flagella  may  be  single  or  multiple.  The  number  is  distinctive  for  individual  species.  When  more  than  one  flagellum  is  present,  each  has  its  own  associated  basal  body  and  axoneme.  The  entire  flagellar  unit  and  any  associated  organelles  are  referred  to  as  a  mastigont  system.