Sliding Filament Theory

It refers to the process of harvesting chemical energy (ATP) from organic molecules (food) into a form immediately usable by organisms. This process is happening all the time in the cytoplasm and mitochondria. The following equation is used during cellular respiration:

ATP is required to break the attachment of actin to the myosin head. At death, calcium ions leak out of the SR

Cytoplasmic streaming is the organised flow of the cytoplasm and its constituents within a living cell (Shimmen et al., 2004). Organelles and important molecules move through the cytosol along the structure of the cytoskeleton (actin filaments and microtubules) with the aid of myosin I, an actin-binding motor protein that plays a part in various cell functions including cell motility and endocytosis (Flavell et al., 2008). Actin microfilaments (F-actin) are the thinnest filaments of the cytoskeleton,

This energy is used to re-form the bonds between ADP and P to make ATP.

Another example of converted energy we can find in our movement. For this to happen we need the chemical energy first, which makes the electrical energy. This is converted to electrical energy for the nerve production, which goes back to chemical energy for the muscle contraction. At the end, the thermal energy which has the waste energy is converted to kinetic energy which produces the movement.

I wake up to the alarm clock blaring loudly in my ear. Next, I rise slowly

Myofibrils are made up of long proteins that include myosin, titin, and actin while other proteins bind them together. These proteins are arranged into thin and thick filaments that are repetitive along the myofibril in sectors known as sarcomeres. The sliding of actin and myosin filaments along each other is when the muscle is contracting. Dark A-bands and light I-bands reappear along myofibrils. The alignment of myofibrils causes an appearance of the cell to look banded or striated. A myofibril is made up of lots of sarcomeres. As the sarcomeres contract individually the muscle cells and myofibrils shorten in length. The longitudinal section of skeletal muscle exhibits a unique pattern of alternating light and dark bands. The dark staining, A-bands possess a pale region in the middle called the H-zone. In the middle of the H-zone the M-line is found, that displays filamentous structures that can join the thick filaments. The light-staining bands also known as I-bands are divided by thin Z-line. These striated patterns appear because of the presence of myofibrils in the sarcoplasm (IUPUI, 2016).

Actin and myosin filaments can be found in skeletal muscle and are the smallest units that form a sarcomere, which is the smallest contractile unit in muscle (Baechle, 2008). The Sliding Filament Theory states that the actin filaments slide inward on the myosin filaments, pulling on the boundaries of the sarcomere, causing it to shorten the muscle fiber, also known as a concentric muscular contraction (Baechle, 2008). The Sliding Filament Theory is composed of five steps: the “Resting Phase”, the “Excitation-Contraction Coupling Phase”, the “Contraction Phase”, the “Recharge Phase”, and the “Relaxation Phase” (Baechle, 2008). During the Resting Phase, the actin and myosin filaments are lined up with no cross-bridge binding of the two filaments. During the Excitation-Contraction Coupling Phase, Calcium is released from the sarcoplasmic reticulum and binds to troponin, causing a shift in tropomyosin where the binding cites are exposed (Baechle, 2008). When the binding cites are exposed, the myosin cross-bridge head attaches to actin. During the Contraction Phase, ATP bonds break, releasing energy that is used to allow the myosin head to flex, causing the actin filaments to move toward the M-bridge. During the Recharge Phase, there is a continuous repetition of the Excitation-Contraction Coupling Phase and the Contraction Phase in order to produce muscular

Actin and Myosin proteins serve the primary role of producing muscle contraction. Myosin molecules will create pressure in the skeletal muscle, where ATP hydrolysis causes Myosin to bind to Actin. A conformational change of the molecule then result in Myosin being

Calcium ions exposes the binding sites on the actin filaments. Calcium ions binds to the troponin molecule causing tropomyosin to expose positions on the actin filament for the attachment of myosin heads. Cross bridges between myosin heads and actin filaments form. When attachment sites on the actin are exposed, the myosin heads bind to actin to form cross bridges. ADP and Pi are released, and sliding motion of actin results.

The anatomy which the physical structure of the body and physiology which is the normal functions of the body help individuals to move their limbs. Muscles have the power of contraction thus it produce movement of the body and allow the bones to work like hinges. When moving someone/individual it is important to remember that the muscles can only move the joint as far as the bones will allow them.

the energy released is trapped in the form or ATP for usage of all the energy consuming

and using that to produce ATP in a very fast and inefficient way. The Chemical equations are as

(ATP must be generated continuously since muscles store only enough ATP for 1–3 secs of activity)

while releasing energy from it's bonds. This is the energy used by the cell to produce