Muscle Metabolism

Muscle Metabolism

Know your Muscles from within

Muscles need energy to contract. Where do muscles get the energy that they need? The energy molecule muscles use is called ATP (Adenosine triphosphate). Muscles use ATP to contract. But how do muscles use that ATP and what is the source of ATP?

Guiding Questions

How do muscles use ATP?

ATP

+ info

ATP is like a recharageable battery. The molecule can be used for energy and then recharged.

Watch this short video on muscle contraction.

Focus on how the muscle protein use ATP

1. CP

3. Aerobic

2. Glycolysis

Sources of ATP for muscles:

Liver

Muscles

Help! I'm running out of glucose

Where does your body store glycogen? Glycogen is a large, complex chain of glucose units. As your muscle run out of glucsoe, the glycogen molecules can be broken down .

Notice the timeframes for each energy source and how your body shifts to different energy sources to supply your muscles with energy over time.

As long as you can get oxygen to your mitochondria, each glucose molecule can give you up to 36 ATP. Without oxygen, glycolysis only gives 2 ATP, so you hit the wall!

Notice that a switch to aerobic respiration means less ATP and the burning sensation of lactic acid.

-2 ATP-Lactic acid

Anaerobic

-36 ATP-carbon dioxide -water

Glucose

Muscle Metabolism

Pyruvic acid

Aerobic

Slow Twitch

Slow twitch fibers are helpful for sustained contractions. These cells have lots of mitochondria, tend to be a dark red color and a steady blood supply.

Fast Twitch

Fast twitch are for powerful and quick contractions. These cells are larger and use anaerobic respiration. Fast twitch cells tend to be white in color.

VS

Exercises like power lifting, sprinting, and plyometrics help to build fast twitch fibers.

Which muscle fiber type do you want?

Exercises like jogging, biking, and jump rope will help to develop the slow-twitch, fatigue resistnace fibers.

Liver You can store glycogen in your liver. When you are exercising your body uses this store of glycogen. The glycogen is broken into glucose and the glucose is released into your blood. Your blood takes the glucose to the muscles.

Muscles... You store some glycogen in your muscles. First you exhaust the ATP in your muscles. Next, the ATP is recharged by CP. Then you use glycogen in your muscles as a source of glucose.

ATP is like a rechargable battery Most of the energy in ATP is stored between the second and third phosphate. The energy is released when the chemical bond is broken.