Muscle Module Discussion 1 Notes Flashcards
_____________ is the general function of muscle that that functions as a form of storage of sugar and high energy molecules
chemical energy storage
__________________ is a general function of muscle that allows us to produce force and use ATP
Transduction and conversion of chemical energy to mechanical energy
What are the three types of muscle
voluntary striated, unvioluntary striated, involuntary unstraiated
Function and name of voluntary striated muscle
skeletal muscle
locamotion and posture
Function and name of involuntary striated muscle
cardiac muscle
cardiac pump
Function and name of unstriated involuntary muscle
smooth muscle
digestion, visual accommodation, thermoregulation
What is the structure of muscle
whole muscle -> muscle fiber -> myofibril -> sarcomere
What are the structural notes of a muscle fiber
- indiviudal muscle cell
- diameter 50 μm
- length of whole muscle
- multinucleate
What are the structural notes of a myofibril
- contractile organelle
- diameter 1μm
- length whole muscle fiber
What are the structural notes of a sarcomere
- contractile unit
- one sarcomere can contract and produce force on its own
- length 2.1 μm
What are the connective tissue layers in muscle
- Epimyseim: surrounds whole muscle
- perimyseium: surrounds groups of muscle fibers
- endomyseium: surrounds individual muscle fibers
what is the connective tissue of muscles primarily made of
collagen (elastic and strong)
_________ surrounds whole muscle
-Epimyseim:
______________ surrounds groups of muscle fibers
perimyseim
________________ surrounds individual muscle fibers
-endomyseium:
Structural units of a sarcomere:
- Z disc
- M line
- A band
- I band
Structural units of a sarcomere:
___________ beginning and end of sarcomere. Archiores thin filament
Z disc
Structural units of a sarcomere:
__________ is the midline of sarcomere
Midline
Structural units of a sarcomere:
__________________ region containing only thick myfilaments
A band
Structural units of a sarcomere:
_________________ region containing only thin filaments
I band
_____________ are what contain contractile proteins in sarcomere
myofilaments
Length of filaments:
thick filament: length 1.6 μm
thin filament length 1.0 μm
what were experimenters unsure was due to________________
shortening of thin filaments or sliding filaments
An experimenter was done to understand how muscle contraction works
- stimulate the muscle to contract
- measured force generated by the muscle
- Increase in the length of the muscle
Sliding filament hypothesis:
Overall change in length during contraction
- muscle fiber, myofibral, sarcomere gets shorter
- filament do not change, they overlap
____________________ are structural connections between thick and thin filaments. Thought to be motors producing force during contraction
structural connections
Thin filaments are made of
- G action
- Trpomyosin
- ttroponin Complex
In thin filaments:
______________:
-Is globular
-forms an alpha helical polymer
-7G actin make up one turn of the alpha helix
-a polymer associated to make a double strand of F actin
G actin
How many G actin make up one turn of the alpha helix
7 G actin
In thin filaments: \_\_\_\_\_\_\_\_\_\_\_\_ -Is long and helical -7 G actin long -associated with F actin
Tropomyosin
In thin filaments:
______________
-50 long
-spherical
Troponin Complex
What make a thick filament?
- Myosin heavy chain
- myosin light chain
In thick filaments?: \_\_\_\_\_\_\_\_\_\_\_\_: -head of ATP -Tail of alpha helix -form dimers
myosin heavy chains
In thick filaments?:
______________________
-self autonomous (assemble by themselves)
-staggered one after another
-antiparallel on either side of each other fragmenting in either direction
myosin light chains
_____________ where the thick filament myosin head is attached to thin filament G actin
cross bridge
Purpose of cross bridge cycle is to _____________ with ______________
cause a force production
with ATP and CA2+
In the cross bridge cycle:
during the _________________
-low Ca levels, myosin heavy chain head is relaxed, and ATP is hydrolyzed
-cross bridge is not formed
relaxed state
what is the first step of the cross bridge cycle
- an increase in intracellular Ca2+
How are cross bridge formed
- myosin heavy chain head binds to thin filament
- ATP is still hydrolyzed in form of ADP and P
What is the power stroke aka tiger state
- realse of ADP and P which causes conformational changes in the MHC head
- MHC head remains bound but changes its angle at hinge region
what happens in the cross bridge cycle after the power stroke
- release of head from thin strand
- ATP binds to MHC
- MHC dissociated from thin filaments still at angle
What is the final step of the cross bridge cycle
hydrolysis of ATP
-this causes MHC head to be relaxed again and go back to relaxed state
one cross bridge cycle is an unload in muscle that takes _________________
50 msecs
MHC head ____________ on each half of sarcomere
moves 10nm
Power streak causes __________________ and ___________________
- moves Z disc toward M line
- causes 20 nm total per sarcomere
efficency is ______________ of chemical energy is transduced Into mechanical energy
45% of energy
_____________ is the hydrolysis of ATP breaking its phosphate bond
chemical energy
Where is the chemical energy stored ____________
MHC head
what happens to the chemical energy
it is released as mechanical energy when the MHC head moves
what happens to chemical energy
55% is lost as heat aka thermoregulation
