What Is the Best Description of a Secondary Active Transport

question 67

Multiple Choice

What is the best description of a secondary active transport process that cotransports an amino acid with Na+?

• A) Both Na+ and the amino acid bind on the side of the membrane where the Na+ concentration is lowest, and undergo net movement to the other side of the membrane.
• B) Na+ and the amino acid bind to opposite sides of the membrane, and Na+ undergoes net transport from the side of the membrane with higher Na+ concentration toward the side with lower concentration, while the amino acid moves in the opposite direction.
• C) Both Na+ and the amino acid bind on the side of the membrane where the Na+ concentration is higher, and both are transported to the side of the membrane where the Na+ concentration is lower.
• D) Both Na+ and the amino acid bind to the side of the membrane where the amino acid concentration is highest and are transported toward the side of the membrane where the amino acid concentration is lower.
• E) Na+ and the amino acid bind to opposite sides of the membrane, and the amino acid undergoes net transport from the side of the membrane with lower Na+ concentration to the side of the membrane where the Na+ concentration is higher.

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Definitions:

Watery Sac

A fluid-filled bladder or cyst that can form in various parts of the body, often benign.

Primitive Streak

Ectodermal ridge in the midline of the embryonic disk, from which arises the mesoderm by the inward and then lateral migration of cells.

Epiblast Cells

Cells in the early embryo that give rise to the tissues of the body.

Mesoderm

Middle of the three germ layers of an embryo.