Human Anatomy and Physiology : Help with Respiratory Proteins and Hormones

Study concepts, example questions & explanations for Human Anatomy and Physiology

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Example Questions

Example Question #1 : Help With Respiratory Proteins And Hormones

Which of the following stabilizes the deoxygenated form of hemoglobin?

Possible Answers:

Increased 2,3-bisphosphoglycerate

All of these stabilize the deoxygenated form of hemoglobin

Increased carbon dioxide

Decreased pH

Increased temperature

Correct answer:

All of these stabilize the deoxygenated form of hemoglobin

Explanation:

Hemoglobin's primary function is to transport oxygen from the lungs to the myoglobin in the tissues that need oxygen. Oxygen is required for aerobic cellular respiration, so the tissues that have high metabolisms require the most oxygen. The byproducts of metabolic processes include acid, heat, carbon dioxide, and 2,3-bisphosphoglycerate (BPG). It should make sense that the byproducts of metabolism (evidence that oxygen is being used) influence hemoglobin to drop off its oxygen. Remember, if we stabilize the deoxygenated form of hemoglobin, it is less reluctant to drop off its oxygen since the oxygenated form of hemoglobin is always more stable than deoxygenated.

For your reference, 2,3-BPG is an isomer of a glycolytic intermediate that sits in the central cavity of hemoglobin. 2,3-BPG carries a large negative charge, and interacts with the basic (positive) amino acid side chains facing the central cavity of the molecule. When positives and negatives are close together, the molecule is stable.

Example Question #594 : Systems Physiology

Surfactant plays a major role in the alveoli of the lungs in that it increases pulmonary __________.

Possible Answers:

resistance

compliance

edema

surface tension and resistance

surface tension

Correct answer:

compliance

Explanation:

The main role of surfactant on the alveoli (the lining of the lungs) is to decrease the surface tension of the lungs. Decreasing the surface tension allows more air to enter the lungs, in other words, it increases the compliance of the lungs.

Example Question #2 : Help With Respiratory Proteins And Hormones

A lecithin-to-sphingomyelin ratio greater than __________ in amniotic fluid indicates fetal lung maturity of the baby.

Possible Answers:

1.25

1.75

1.50

1.0

2.0

Correct answer:

2.0

Explanation:

The lecithin-sphingomyelin ratio is a test used to assess fetal lung maturity. Lecithin and sphingomyelin are both substances that make up surfactant, a soap-like substance that lowers the surface pressure of the alveoli of lungs. When dealing with premature babies, it is important that the lecithin-sphnigomyelin ratio is at least 2.0, which suggests fetal lung maturity. This ratio is obtained by acquiring amniotic fluid through a needle and helps doctors to assess if a premature baby is ready for delivery.

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