Define slow oxidative fibers relationship

Type 1 and type 2 muscle fibers (video) | Khan Academy

define slow oxidative fibers relationship

Describe the types of skeletal muscle fibers; Explain fast and slow muscle fibers Slow oxidative (SO) fibers contract relatively slowly and use aerobic. Oxidative fibers primarily use oxidative phosphorylation to generate ATP. Fast glycolytic fibers fatigue rapidly, while slow oxidative fibers are highly resistant to. All values are expressed as a fold-change relative to ST oxidative fibers a positive correlation between the proportion of ST fibers and the best 6-mile performance time was noted The darkly stained fibers are relatively slow in contractile rate and are ST. Genes That Define Skeletal Muscle Phenotype.

define slow oxidative fibers relationship

So what I do is I get back at them. I come up with one golden rule. And this one golden rule will help me go through a table, like we're about to do right here, to differentiate between type 1 and type 2 muscle fibers. So the golden rule I'm going to have for this table here is that mitochondria-- whoops, look how I wrote that "i" there.

Mitochondria are present in greater quantities in your type 1 muscle fibers, type 1.

define slow oxidative fibers relationship

So mitochondria are more prevalent in type 1 muscle fibers than in type 2. And just based on that knowledge alone, we should be able to go through and fill out this table. All right, so let's start from the top. I may have alluded to it here through the way I wrote this out, but the color type 1 muscle fibers are often noted as?

And why do you think that is? Well, what are mitochondria used for? Mitochondria are used in biochemical processes that help us make energy.

  • Muscle Fiber Types

And the main process they function in that I'm going to reference a couple of times is called oxidative phosphorylation. Now, what is that term mean to you? What does that suggest?

What are the two things that are probably involved in oxidative phosphorylation? So just as the name suggests, oxidative means oxygen is going to be involved here. And then phosphorylation means that something is going to receive a phosphate group.

Skeletal Muscle Fiber Type: Influence on Contractile and Metabolic Properties

Phosphoryl- -ation, something will receive a phosphate group. So the oxidative part applies here to red, the same way that the color red shows up in our arteries. Why are arteries red, and why are veins blue? Well, arteries have more oxygen than veins do.

Type 1 and type 2 muscle fibers

And because of that, the color of our type 1 muscle fibers will be red because they produce more energy from oxygen than type 2 muscle fibers do. More oxygen is present in type 1, so they're red. And so we could say then that our type 2 muscle fibers will be white. All right, what about the speed of contraction that we see here?

How fast do type 1 muscle fibers contract? Well, let's think about the process of making energy with mitochondria. If type 1 muscle fibers rely on mitochondria for energy, think about all the processes that have to go into making energy through oxidative phosphorylation.

You can't just do this right away. You have to have glycolysis happen.

define slow oxidative fibers relationship

You have to have the Krebs cycle occur. Slow oxidative SO fibers contract relatively slowly and use aerobic respiration oxygen and glucose to produce ATP. Fast oxidative FO fibers have relatively fast contractions and primarily use aerobic respiration to generate ATP.

Fast fibers hydrolyze ATP approximately twice as rapidly as slow fibers, resulting in much quicker cross-bridge cycling which pulls the thin filaments toward the center of the sarcomeres at a faster rate.

Skeletal Muscle Fiber Type: Influence on Contractile and Metabolic Properties

The primary metabolic pathway used by a muscle fiber determines whether the fiber is classified as oxidative or glycolytic. More ATP can be produced during each metabolic cycle, making the fiber more resistant to fatigue. As a result, glycolytic fibers fatigue at a quicker rate. Slow oxidative fibers have structural elements that maximize their ability to generate ATP through aerobic metabolism.

These fibers have fast contraction times and maintain some, though not a great amount of their force production with repeated activity.

Muscle Physiology - Fiber Types

With the development of techniques capable of identifying specific proteins or even isoforms of the same familyspecifically, antibody techniques and gel electrophoresis, it has been found that these functional properties are closely related to the myosin heavy chain MHC isoform.

In fact, most of the proteins of the contractile machinery exist in several isoforms, with one or two being associated with each MHC. It should be noted that there is not a one-for-one correspondence between the functional classification and the MHC based classification schemes: These are relatively uncommon, though. There are at least nine different mammalian MHC isoforms. Two are developmental, termed embryonic and neonatal, based on the time of their expression.