1. Contraction
2. Actin
3. Tendons
4. Epidermis
5. Dermis
6. Acne
7. A nerve signal from the brain arrives at the intersection of the nerve and muscle cells and releases acetylcholine from the neuron. This triggers chemical changes in the muscle cell involving ions, including Ca2+. Calcium triggers the thick filaments, made of myosin, to attach to the thin filaments, made of actin, in the muscle cell, and the myosin pulls the actin toward the center of the muscle cell. ATP causes the release of the actin fibers, allowing the muscle to relax and the process to begin again.
For Penn Foster.
Answer:
has a particular shape that matches the substrate
Explanation:
Enzymes are proteinous biological catalyst i.e. they speed up the rate of biochemical reactions in living systems. Like every other catalyst, enzymes reduce the activation energy of the reactions they are involved in without getting used up in the process.
Enzymes operate by binding to a substrate molecule i.e. the reactant and form a bond with them in order to synthesize a product. However, enzymes are substrate-specific i.e. they are very particular about the substrate they bind to. This property is due to the shape of the enzyme which matches a particular substrate.
Enzymes, like every other protein molecules, are made up of amino acid subunits, which are responsible for the shape that determines the specificity of the protein.
Hello There!
The correct answer is A i'd say. This is due to a process called diffusion.
Hope This Helps You!
Good Luck :)
