Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
21 Cards in this Set
- Front
- Back
|
describe the micro anatomy of a skeletal muscle |
|
|
|
what are the 3 types of filament muscle? |
actin (thin) myosin (thick) and titin |
|
|
a myosin molecule consists of a two parts; the head and the tail, how many heads does a myosin molecule have? and what are the letters associated with the head and tail? |
-myosin has 2 heads -head --> S1 -tail --> S2 |
|
|
what is the arrangement in which 2 myosin molecules wrap around each other known as? |
helical arrangement |
|
|
what energy compound is found in myosin heads that is released when myosin and actin join together? |
ADP + inorganic phosphate |
|
|
name the 3 (relevant) structures found in an actin molecule |
troponin complex - 3 proteins (C,T&I) which hold the tropomyosin in place tropomyosin G actin |
|
|
What is the role of troponin C? |
this is the part Where Calcium binds to the troponin it makes a conformational change |
|
|
What is the role of troponin T? |
-the troponin C makes a conformational change to the troponin (through the action of Calcium) -this conformational change pulls on troponin t and transduces the effect on calcium by pulling on troponin I |
|
|
What is the role of troponin I? |
troponin I is the inhibitory troponin - it is attached to tropomyosin so when troponin I is pulled away, so is tropomyosin |
|
|
when actin and myosin join, what happens to the ATP which is associated with shortening of muscle |
the ATP is metabolised/hydrolysed |
|
|
what is the role of ATP in the myosin heads? |
detaches myosin heads and energizes them for another contaction |
|
|
define power stroke in muscle contraction |
-The power stroke occurs at the release of phosphate from the myosin molecule after the ATP hydrolysis while myosin is tightly bound to actin. -The effect of this release is a conformational change in the molecule that pulls against the actin. The release of the ADP molecule and binding of a new ATP molecule will release myosin from actin. -ATP hydrolysis within the myosin will cause it to bind to actin again to repeat the cycle. The combined effect of the myriad power strokes causes the muscle to contract. |
|
|
what is the molecule which is capable of storing ATP energy, and in what form? |
creatine in the form of creatine phosphate |
|
|
define muscle atrophy |
the weakening and shrinking of a muscle |
|
|
what can cause muscle atrophy? |
-immobilisation -loss of neural stimulation |
|
|
define muscle hypertrophy |
enlargement of muscle through -enlargement of cells within muscle -more capillaries -more mitochondria |
|
|
what is causes muscle hypertrophy |
-strenuous exercise -steroid hormones |
|
|
define isometric contraction |
-contraction in which there is no movement -muscle length does not change even tho the muscle is contracted |
|
|
when is isometric contraction used |
-standing -sitting -posture |
|
|
define isotonic contraction |
-produces movement -muscle length changes when the muscle is contracted |
|
|
when is isotonic contraction used? |
-walking -in concentric/eccentric movements (the different types of isotonic movements) |
