Mechanism and chemical changes occuring during muscle contraction
-
Upload
deepika-vellore-shankar -
Category
Health & Medicine
-
view
111 -
download
5
Transcript of Mechanism and chemical changes occuring during muscle contraction
![Page 1: Mechanism and chemical changes occuring during muscle contraction](https://reader033.fdocuments.us/reader033/viewer/2022061411/55d70317bb61eb840e8b462c/html5/thumbnails/1.jpg)
MECHANISM AND MECHANISM AND CHEMICAL CHANGES CHEMICAL CHANGES DURING MUSCLE DURING MUSCLE CONTRACTIONCONTRACTION
By Deepika of B.Sc final year
![Page 2: Mechanism and chemical changes occuring during muscle contraction](https://reader033.fdocuments.us/reader033/viewer/2022061411/55d70317bb61eb840e8b462c/html5/thumbnails/2.jpg)
Myofibril
A Band ,I band
H zone
Z line
Sarcomere
Muscle proteins – contractile property
2 essential proteins are involved
Actin and Myosin
![Page 3: Mechanism and chemical changes occuring during muscle contraction](https://reader033.fdocuments.us/reader033/viewer/2022061411/55d70317bb61eb840e8b462c/html5/thumbnails/3.jpg)
MYOSIN
Assembled myosin filament
Light meromyosin
Heavy Meromyosin
Head –
ATPase active site, actin binding site
![Page 4: Mechanism and chemical changes occuring during muscle contraction](https://reader033.fdocuments.us/reader033/viewer/2022061411/55d70317bb61eb840e8b462c/html5/thumbnails/4.jpg)
ACTIN
Assembled actin filament
F – actin , G – actin
Tropomyosin
Troponin – 3
TN – I – inhibitory protein
TN – C - Site of Ca attachment
TN – T – Prevents bridges between actin and myosin
![Page 5: Mechanism and chemical changes occuring during muscle contraction](https://reader033.fdocuments.us/reader033/viewer/2022061411/55d70317bb61eb840e8b462c/html5/thumbnails/5.jpg)
SLIDING FILAMENT MECHANISM OF MUSCLE CONTRACTION
Huxley and Hanson
1. 2 sets of filaments
2. Thin filaments slide over thick filaments
3. There is no change in A band
I band and H zone dec or disappear
![Page 6: Mechanism and chemical changes occuring during muscle contraction](https://reader033.fdocuments.us/reader033/viewer/2022061411/55d70317bb61eb840e8b462c/html5/thumbnails/6.jpg)
SERIES OF EVENTS IN CONTRACTION
Step 1 : Depolarization of sarcolemma
![Page 7: Mechanism and chemical changes occuring during muscle contraction](https://reader033.fdocuments.us/reader033/viewer/2022061411/55d70317bb61eb840e8b462c/html5/thumbnails/7.jpg)
Step 2 : Release of Ca ions
Step 3 : Conformational changes in actin
![Page 8: Mechanism and chemical changes occuring during muscle contraction](https://reader033.fdocuments.us/reader033/viewer/2022061411/55d70317bb61eb840e8b462c/html5/thumbnails/8.jpg)
Step 4 : Formation of Actomyosin complex
Step 5 : Interaction of thick and thin
filaments
• Power stroke
![Page 9: Mechanism and chemical changes occuring during muscle contraction](https://reader033.fdocuments.us/reader033/viewer/2022061411/55d70317bb61eb840e8b462c/html5/thumbnails/9.jpg)
Ratchet mechanism
Walk along mechanism
![Page 10: Mechanism and chemical changes occuring during muscle contraction](https://reader033.fdocuments.us/reader033/viewer/2022061411/55d70317bb61eb840e8b462c/html5/thumbnails/10.jpg)
ROLE OF CALCIUM
Ca
Troponin
Tropomyosin
Actin
Myosin
![Page 11: Mechanism and chemical changes occuring during muscle contraction](https://reader033.fdocuments.us/reader033/viewer/2022061411/55d70317bb61eb840e8b462c/html5/thumbnails/11.jpg)
CHEMICAL CHANGES DURING MUSCLE CONTRACTION
ATP utilization
• Polymerization of G-action to F-actin
G-actin + ATP F-actin + ADP + iP
• Formation and dissociation of Actomyosin
Actin + Myosin Actomyosin
ATP ADP
ATPase
![Page 12: Mechanism and chemical changes occuring during muscle contraction](https://reader033.fdocuments.us/reader033/viewer/2022061411/55d70317bb61eb840e8b462c/html5/thumbnails/12.jpg)
REPHOSPHORYLATION OF ATP
1.Phosphagen
Creatine phosphate
Creatine phosphate + ADP ATP + Creatine
2 .Breakdown of muscle carbohydrate
![Page 13: Mechanism and chemical changes occuring during muscle contraction](https://reader033.fdocuments.us/reader033/viewer/2022061411/55d70317bb61eb840e8b462c/html5/thumbnails/13.jpg)
Lactic acid formation
Muscle fatigue
Oxygen debt
Cori cycle
4/5th of lactic acid = glycogen
1/5th of lactic acid = water + Carbondioxide
![Page 14: Mechanism and chemical changes occuring during muscle contraction](https://reader033.fdocuments.us/reader033/viewer/2022061411/55d70317bb61eb840e8b462c/html5/thumbnails/14.jpg)
Thanku…….