Muscles sliding filament theory

Sliding filmament theory

Sliding filmament theory

The shortening of myofibril or sarcomere in order for muscle contraction to occur

First step of sliding filament theory is when

myosin and G actin bond forming a cross bridge

When myosin and G actin bond, they form what is callled a

Cross bridge

In order for myosin head to bind to G actin, it has to be in a specific shape, and it can change shape because it is a

Protein

In step 1 of the sliding filament theory, when the myosin head is able to bond to the G actin, which shape is it in

High energy shape

In step 1 of the sliding filament theory, What is already attached to the myosin head when it bonds with G actin

ADP + Po4

First step of sliding filament theory- formation of a cross bridge:

-myosin head is in high energy shape

-myosin head has an ADP and PO4 attached to it

-bonds to G actin

As soon as actin and myosin bond, we go to the SECOND stage, which is

Power stroke

What initiates the power stroke?

Actin and myosin bonding

During the second stage- Power stroke

Myosin head changes its shape in order to be able to pull on the actin

During the second stage- Power stroke: when myosin is pulling on actin, it is pulling

Z line toward M line to shorten the sarcomere

During the second stage- Power stroke: when myosin is pulling actin, what happens to sarcomer?

The sarcomere will shorten

During stage 2- power stroke: the third step is

The ADP +PO4falls off the myosin head

During the second stage- Power stroke: what causes myosin head to change to the low energy shape

After Po4 binds falls off; causing ATP to bind to the myosin head

During the second stage- Power stroke: What can’t happen in the low energy shape of myosin

It cannot bind to G actin

Which enzyme lives on the myosin head all the time

ATPase

ATPase enzyme has the ability to

Break down ATP

During the second stage- Power stroke: ATPase breaks down ___ into ___

ATP, ADP +PO4

During the second stage- Power stroke: what does the breakdown of ATP cause

Allows myosin head to go back into the high energy shape

During the second stage- Power stroke: Due to the real down of ATP the myosin head goes back to the high energy shape. This ends up being the …

Original ADP+PO4 from the beginning

How do you get rid of ACh-Acetylcholine that is already in neuromuscular junction

Enzymatic degradation only

Ca++ ATPase pump

Actively transports ca++ off of troponin back into sarcoplasmic reticulum where it came from.

After Ca++ ATPase Pump transports Ca++ back from troponin into sarcoplasmic reticulum, what does troponin do?

Troponin puts tropomyosin back in between actin and myosin. They can’t bind anymore, so muscle relaxes.

The more actin and myosin in the muscle cell, the

Stronger your force of contraction will be

When you’re picking something up, what is our brain trying to figure out?

How much actin and myosin should we have bond to pick something up to not waste too much energy

Connective tissue helps to

Make all cells move together

What is the quanta of muscle cells and why is it important?

Quanta of muscle cells refer to the basic units of contraction in muscle fibers, specifically the minimal functional unit that can produce a contraction. They are important because they determine the muscle's force production and play a crucial role in how muscles respond to stimuli, contributing to overall muscle functionality and performance.

What is quanta of muscle cells and why is it important

Small twitch of electricity in muscle cells that is constantly happening. If it does not happen, it will atrophy or fall apart

Quanta of muscle cells keeps our muscles

Healthy and producing proteins all day long

What is the piezoelectric effect?

The piezoelectric effect is the generation of electric charge in certain materials when they are mechanically stressed or deformed.

Rigor mortis is caused by

No more ATP production

Rigor mortis meaning

Stiffness after death

What causes myosin to change shape and let go of tropomyosin

ATP

Explain what happens during rigor mortis

Resting membrane potential reaches 0. All Ca++ gates flood open, and Ca++ causes troponin to remove tropomyosin allowing myosin and actin to bond and contract. However, since no ATP, myosin cannot let go.

How long does rigor mortis last

24-36 hours

The more terminal butons that attach to a muse fiber,

The Bettie we have control of that muscle (more fine motor skills)