Muscle- Part 2 Flashcards
What does the sliding of myosin along actin result in?
Shortening of the Sacromere = contraction
Excitation-contraction coupling:
Step 1: ATP binding releases the myosin head from _____?
Actin
Excitation-contraction coupling:
Step 2- What does the hydrolysis of ATP to ADP straighten?
Myosin head
Excitation-contraction coupling:
Step 3- Where does the myosin head bind?
Actin
Excitation-contraction coupling:
Step 4- What happens to the myosin head when ADP is released?
It bends
Excitation-contraction coupling:
What results from low ATP levels and calcium leakage?
Rigor mortis
What is the protein that Ca++ binds to that causes allosteric changes?
Troponin
When Ca++ binds to troponin, what happens that will cause tropomyosin to move away, uncovering the myosin binding sites on the actin filament?
Allosteric change
What are the 4 energy sources for muscle work?
1- ATP, creatine kinase
2- Anaerobic Glycolysis
3- Aerobic Glycolysis
4- Beta-oxidation of fatty acids
What is the name of the Ca++ voltage gated channel located on the SR?
Ryanodine receptor
What is the name of the Ca++ channel located on the T-tubule?
Dihydropyridine receptor (DHP)
What is muscle contraction done by?
Excitation-contraction coupling
What is needed for the myosin head to get out of actin filament?
Release of ADP
If you only need to move for 10-20 seconds, which energy source will you use?
ATP, creatine kinase
If you need energy for a few minutes, what will be the energy source?
Anaerobic glycolysis
If you need energy for a few hours, what will be the energy source?
Aerobic glycolysis
If you need energy for a few days, what will be the energy source?
Beta oxidation of fatty acids
What are free radicals?
Free electron and take them from other cells
What is the result of high levels of free radicals?
Oxidative stress
Where are 3 places free radicals take cells from?
Membrane lipids
DNA
Proteins
What are 2 examples of free radical regulators?
Vitamin E
Selenium
