Respiratory

Question 1

What are the two methods of transporting oxygen in the blood?

Answer 1

Via hemoglobin of erythrocytes and dissolved in blood

Question 2

What percent of oxygen is transported in the blood directly in the bloodstream? By hemoglobin?

Answer 2

~1.5%; ~98.5%

Question 3

What is the portion of hemoglobin that contains iron to bind to oxygen? How many iron irons does each hemoglobin molecule have?

Answer 3

Heme; four iron ions to carry up to four oxygen molecules at a time

Question 4

What is oxyhemoglobin?

Answer 4

When oxygen binds to hemoglobin

Question 5

What is a conformational change and when does it occur? What does this allow?

Answer 5

Occurs when the first oxygen molecule binds at the alveoli; allows the second molecule of oxygen to bind more readily. (increasing affinity for oxygen)

Question 6

Does hemoglobin have increasing or decreasing affinity at the tissues?

Answer 6

Decreasing affinity for easy dissociation

Question 7

What does it mean for a hemoglobin to be 100% saturated? What are the normal values?

Answer 7

When all four heme sites are occupied; 95-100%

Question 8

What is it called when 1-3 heme sites are occupied?

Answer 8

Partially saturated

Question 9

Where do we prefer to be more saturated: lungs or tissues?

Answer 9

Lungs, to keep pulling in oxygen

Question 10

Why is it important to be less saturated in veins and contracting skeletal muscles?

Answer 10

To be able to drop off oxygen more efficiently

Question 11

Where is percent saturation lowest in the body: systemic arteries, systemic veins, or contracting skeletal muscles? Why?

Answer 11

Contracting skeletal muscles; since muscles are at work, more mitochondria is present and more oxygen needs to be used/dropped off.

Question 12

What happens to the affinity of heme in the oxygen-Hb saturation curve as partial pressure of oxygen increases?

Answer 12

There is a greater number of oxygen bound to heme (vice versa: lower partial pressure of oxygen means fewer oxygen molecules bound to heme)

Question 13

What is the partial pressure of oxygen inside arteries and capillaries?

Answer 13

~100 mmHg

Question 14

Where is the lowest partial pressure of oxygen located? (~40 mmHg)?

Answer 14

Inside veins

Question 15

Do highly active tissues (exercising muscle) have higher or lower partial pressure of oxygen than less active tissue (adipose)?

Answer 15

Highly active tissue = more oxygen used so lower affinity and LOWER PARTIAL PRESSURE (~20 mmHg in highly active vs ~55-60 mmHg in less active)

Question 16

What causes hemoglobin and oxygen to dissociate faster, higher temperature or lower temperature? Why?

Answer 16

Higher temperature, as that means more movement is occuring and we need more oxygen to sustain working tissues.

Question 17

Lower temperature shifts the oxygen-Hb dissociation curve to the left: true or false?

Answer 17

True.

Question 18

What does elevated 2,3-diphosphoglycerate (DPG) mean for oxygen and hemoglobin?

Answer 18

Higher DPG means making more ATP via glycolysis, so more movement and hence more dissociation.

Question 19

Does dropping off oxygen make the blood more or less acidic? What happens to pH?

Answer 19

Less acidic; dropping off oxygen means raising pH and correcting for acidosis (low pH)

Question 20

What relationship does the Bohr effect describe?

Answer 20

pH and oxygen’s affinity for hemoglobin.

Question 21

During exercise, what happens to the oxygen-Hb dissociation curve? What factors affect it?

Answer 21

Curve shifts right because affinity for oxygen decreases; exercise means more carbon dioxide, more H+ produced, more DPG, and higher temperature

Question 22

What are the three methods CO2 is transported in the blood?

Answer 22

Bicarbonate, blood plasma, hemoglobin

Question 23

70% of CO2 is transported in the blood via?

Answer 23

Bicarbonate

Question 24

What term describes the exchange of chloride ions for bicarbonate when too much bicarbonate builds up in the erythrocytes and it needs to move down its concentration gradient into the plasma?

Answer 24

The chloride shift.

Question 25

At the pulmonary capillaries, the chemical reaction that produced bicarbonate now produces what?

Answer 25

CO2 and water.

Question 26

~7% of CO2 dissolves in what? Why?

Answer 26

Plasma; so that it can be detected by chemoreceptors