Because there is no indication of what's the highlighted structure I'm going to tell you where all the four muscles of the quadriceps femoris originate from.
The vastus lateralis originates on the greater trochanter and the lateral lip of linea aspera. The vastus intermedius originates on the lateral and anterior surfaces of the femur's body. The vastus medialis originates on the medial lip of the linea aspera and the intertrochanteric line. R<span>ectus femoris originates, </span>superior to the acetabulum, on <span>the ilium.</span>
<span>Enzymes are used up as a part of the reaction and cannot be used again. Enzymes can be any shape to bind to the substrate. Enzymes are catalysts that lower the activation energy allowing the reaction to occur. Enzymes are formed into lipids. 3. Which macromolecule is most likely to be broken down for quick energy? nucleic acid carbohydrate phospholipid protein
The Central Role of Enzymes as Biological Catalysts. A fundamental task of proteins is to act as enzymes—catalysts that increase the rate of virtually all the chemical reactions within cells. Although RNAs are capable of catalyzing some reactions, most biological reactions are catalyzed by proteins.</span>
Answer:
The correct answer will be options
1. The position of the tropomyosin threads shift
2. Exposing myosin binding sites
3. Allowing the myosin head to attach to the actin filament
Explanation:
Calcium plays an important role in the contraction of muscles especially in the formation of the cross-bridge between myosin and actin filaments.
In the presence of calcium, myosin head binds the actin filament as calcium binds to the troponin which changes the configuration of the troponin which releases the tropomyosin from the myosin-binding site on actin.
Once the myosin binding site is freed, myosin binds the site and causes muscle contraction due to ATP hydrolysis.
Thus, the selected options are the correct answer.
B)
Both occur in only one direction.
Check the following: heterogeneous mixtures; may have a uniform appearance; <span>are made up of at least two substances</span>
