RT Book, Section
A1 Skorecki, Karl L.
A1 Cohen, Bruce H.
A2 Loscalzo, Joseph
A2 Fauci, Anthony
A2 Kasper, Dennis
A2 Hauser, Stephen
A2 Longo, Dan
A2 Jameson, J. Larry
SR Print(0)
ID 1190512385
T1 Mitochondrial DNA and Heritable Traits and Diseases
T2 Harrison's Principles of Internal Medicine, 21e
YR 2022
FD 2022
PB McGraw-Hill Education
PP New York, NY
SN 9781264268504
LK accessmedicine.mhmedical.com/content.aspx?aid=1190512385
RD 2024/04/18
AB Mitochondria  are  cytoplasmic  organelles  whose  major  function  is  to  generate  ATP  by  the  process  of  oxidative  phosphorylation  under  aerobic  conditions.  This  process  is  mediated  by  the  respiratory  electron  transport  chain  (ETC)  multiprotein  enzyme  complexes  I–V  and  the  two  electron  carriers,  coenzyme  Q10  (CoQ10)  and  cytochrome  c,  located  in  the  inner  mitochondrial  membrane.  Other  cellular  processes  to  which  mitochondria  make  a  major  contribution  include  apoptosis  (programmed  cell  death)  and  additional  cell  type–specific  functions  (Table  468-1).  The  efficiency  of  the  mitochondrial  ETC  in  ATP  production  is  the  major  determinant  of  overall  body  energy  balance  and  thermogenesis.  In  addition,  mitochondria  are  the  predominant  source  of  reactive  oxygen  species  (ROS),  whose  rate  of  production  is  a  delicate  balance  between  health  and  disease  and  relates  to  the  coupling  of  ATP  production  to  oxygen  consumption.  Given  the  centrality  of  oxidative  phosphorylation  to  the  normal  activities  of  almost  all  cells,  it  is  not  surprising  that  mitochondrial  dysfunction  can  affect  almost  any  organ  system  (Fig.  468-1).  Until  recently,  it  was  thought  that  disruption  of  energy  production  was  the  source  of  the  pathophysiology  in  those  with  mitochondrial  dysfunction,  but  recent  evidence  suggests  that  free  radical  production  and  the  redox  state  of  the  mitochondria  may  play  a  role  as  well.  Thus,  physicians  in  many  disciplines  might  encounter  patients  with  mitochondrial  diseases  and  should  be  aware  of  their  existence  and  characteristics.