Part 2 Flashcards
There are 4 functions of the Skeletal Muscles..
Supports the body ( contraction of skeletal muscles opposes the force of gravity allowing us to stand up and remain upright)
Makes bones move ( Moves the muscles attach to our bones making them move (arms, legs, eyes, facial expression and breathing))
Maintain constant body temperature ( causes ATP break down which releases heat )
Protect internal organs and stabilize joints (cover the bones that protect the organs and holds it together)
Muscle contraction involves the action of two myofilaments..
actin (thin) and myosin (thick)
The actin myofilament Is composed of..
globular actin proteins
The myosin myofilament is composed of..
myosin molecules
The sliding filament theory helps scientist explain how muscle contraction occurs. Thin and thick myofilaments (actin and myosin) do not change i..
in length
The thick myofilament (myosin) is stationary but..
the thin myofilament (actin) slides close together to shorten the sarcomere (contracting).
Explain the 4 process that occur when muscles contract..
The myosin has little heads sticking out of its thick myofilement, these heads then get attached to the actin.
The myosin head then flexes, and moves the actin closer (shortening the sarcomere)
The myosin head then release and unflex, which requires ATP
the myosin head then get attached to the actin further along the myofilament
What role does Calcium play in muscle contraction?
Calcium allows the muscles to contract as it binds to the troponin, lifting the tropomyosin that surrounds the ACTIN allowing the myosin heads to bind with the actin
When muscles are in relaxation, myosin heads can not get to the actin, what is the caused of this?
A cage like barrier called the tropomyosin surrounds the actin preventing the myosin heads to be attached to the actin.
ATP that is produce for exercise only last a few seconds. The muscle then acquire new ATP in 3 different ways, depending on the availability of oxygen..
The breakdown of a molecule called creatine phosphate (anaerobic (without oxygen)). This broken down molecule is used first to acquire ATP before it enters the mitochondria.
Aerobic (with oxygen) Cellular Respiration (can only occur if oxygen is available)
Fermentation (ANAEROBIC). This occurs when performing excessive exercise that oxygen cannot be delivered fast enough to working muscles. This causes an oxygen deficit.
The process and role of energy when muscles contract…
When a stimulus occurs causing muscle to contract, it starts it contracting by breaking down a molecule called creatine phosphate into Creatine + P
To keep contracting, the muscles either continues aerobic cellular respiration (most preferred method) or carries out to fermentation which leads to fatigue. Glucose becomes pyruvate which goes to either methods
When muscles is in its relaxation state, creatine phosphate..
builds up. When muscles is at rest, it builds up Creatine Phosphate which is a HIGH energy compound.
When muscles contract, ATP is..
broken down into ADP + P
One of the ways muscles use to acquire ATP, creatine phosphate is the fastest way to make ATP available to muscles. it provides enough energy for about..
8 seconds of intense activity
When ATP unflexes the myosin heads diattaching from the actin, the ATP turns into ADP + P. When muscles contract, this ADP + P is turned into ATP combined with Creatine + P to form..
Creatine Kinase which then turns into energy muscle can use.
