Which Statement About Cardiac Muscle Cells Is True

question 215

Multiple Choice

Which statement about cardiac muscle cells is true?

• A) The DHP proteins are in the sarcoplasmic reticulum membrane.
• B) There is a physical connection between DHP and ryanodine receptors.
• C) The T tubules are smaller than those of skeletal muscle cells.
• D) Ryanodine receptors are ion-gated Na⁺ channels.
• E) Extracellular Ca²⁺ flows into the cytoplasm through DHP channels and then opens calcium channels in the sarcoplasmic reticulum.

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Definitions:

Meso Compound

A molecule with multiple chiral centers that is superimposable on its mirror image due to an internal plane of symmetry.

Stereochemical Relationship

Stereochemical relationship refers to the spatial orientation and arrangement of atoms or groups within molecules, determining their stereochemistry.

Diastereomers

Stereoisomers that are not mirror images of each other, having two or more stereocenters.

Optical Activity

The property of chiral molecules to rotate plane-polarized light, a phenomenon measured using polarimetry.