Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BISC 101 Final > Gas Exchange > Flashcards

Gas Exchange Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards Psychology 101 flashcards Chemistry 101 flashcards Biology 101 flashcards Organic Chemistry 101 flashcards Sociology 101 flashcards
1
Q

What does Fick’s Law Describe?
What do the Variables represent?

A

Fick’s Law measures the Rate of Diffusion
k = the diffusion constant
A = Area for gas exchange
(P2 - P1) = Difference is Partial Pressure
D = Distance (Thickness)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What percent of oxygen is in the air?

A

Approx 21%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the Air Pressure and Partial Pressure at Sea Level?

A

Air Pressure is 760 mm Hg

21% of that is 760 x 0.21 = 159.6

Therefore the Partial Pressure of Oxygen is approximately 160 mm Hg

mm Hg = millimetres of Mercury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the Partial Pressure of Oxygen at the peak of Mt. Everest?

A

Approximately - 53 mm Hg
because total air pressure is much lower as elevation increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What % of oxygen dissolves in the Blood Plasma?
What happens to the rest of it?

A

1.5% of the oxygen dissolves in the Blood Plasma

The remaining 98.5% binds to hemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is Hemoglobin?

A

Hemoglobin is an Oxygen-transporting Protein found in our RBCs and erythrocytes. (Quaternary Structure)

It has 4 subunits.
Each subunit has a binding site where it can bind with 1 Oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What happens when 1 Oxygen binds to Hemoglobin?

A

The binding of O2 to one subunit changes the affinity of the other subunits:
This is referred to as Cooperative Binding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Draw an Oxygen-Saturation Curve.
What does it show?

A

100% on the y-axis means all 4 O2 have bonded with the Hemoglobin

% of O2 changes slowly near the top and the bottom

There is a rapid increase in the middle
(Sigmoid Curve)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Graph the change in pressure of an animal at rest vs on the move (exercising).
What do you notice?

A

y-axis decreases at a faster rate than the x-axis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What happens to our blood as we exercise? What causes this?
(4)

A

-During exercise, CO2 is produced
-The CO2 dissolves in water and forms Carbonic Acid

-Blood in exercising muscles becomes more acidic

-Change in pH affects the affinity of hemoglobin to O2

-Less O2 available, more likely to release O2 into tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is Carbonic Acid? How is it made?

A

When we exercise, we produce CO2.
That CO2 mixes with H2O to form Carbonic Acid and an extra proton.

Chemical Reaction:

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What happens to oxygen levels as pH decreases?

A

As the pH drops, oxygen becomes less likely to stay bound to hemoglobin

We call this the Bohr Shift.

The Bohr shift makes hemoglobin more likely to release oxygen to tissues at low pH.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What happens to the Carbonic Acid in the RBC?

A

The carbonate is removed from the erythrocyte (RBC) by a protein (antiporter) in the membrane and is replaced with a chloride

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe what happens to Oxygen as Maternal Blood is shared with the Fetus’s Blood.

A

oxygen needs to diffuse from maternal blood to fetal blood.
The fetus has different hemoglobin with higher oxygen affinity
So the graph shift would look something like this.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

True or False
Animals have to take in CO2 and expel O2 to sustain cellular respiration and stay alive

A

FALSE
Animals have to take in O2 and expel CO2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

True or False
Air and water provide very different constraints on the design of gas exchange systems

A

True

17
Q

True or False
Gas exchange is more efficient in the air than underwater.

A

FALSE
we only use 25% of air we inhale, but much more efficient underwater (because aquatic animals HAVE to be efficient due to environmental constraints)

18
Q

True or False
Bird lungs flow air in one direction (more efficient and more complex), whereas human lungs flow air in two directions (less efficient and less complex)

A

TRUE
See? Humans are not necessarily “better” than other animals!

19
Q

True or False
In humans, ventilation occurs by contracting muscles in the throat

A

FALSE
ventilation occurs by changing the pressure (and volume) within the chest (thoracic cavity)

20
Q

True or False
Carbon dioxide is less soluble than oxygen in the blood, making CO2 transport relatively difficult

A

FALSE
CO2 is more soluble and easier to transport than oxygen in the blood

21
Q

True or False
Lower pH decreases the affinity of hemoglobin for O2

A

TRUE

22
Q

True or False
Hemoglobin is more likely to release O2 during times of rest.

A

FALSE
Hemoglobin is more likely to release O2 during times of exercise.

23
Q

What specialized tissue transports gases in large organisms?

A

Blood

24
Q

What is the function of the heart?

A

To generate pressure for transport of gases and nutrients via blood

25
Q

What is happening (physiologically) as inhalation occurs?

A

Intercostal muscles contract, pulling ribs up and out, the diaphragm moves down
increasing the volume and decreasing the pressure to draw air in

26
Q

What is happening (physiologically) as exhalation occurs?

A

The diaphragm and intercostal muscles relax pushing the air out. This is passive unless you are working out (muscles will pull ribs down and in during exercise)

27
Q

What protein and what element in that protein cause your blood to be red?

A

Hemoglobin is the protein, iron is the element the cause the red color in blood

28
Q

What drives the O2 and CO2 diffusion of gases in the circulatory system?

A

Partial pressure gradients

29
Q

When is oxygen pressure the highest, at the unloading of O2 in tissues or loading O2 in lungs?

A

Loading at the lungs

30
Q

How does the oxygen dissociation curve change if the hemoglobin is from a human fetus?

A

Shifts to the Left

31
Q

What are 3 ways to maximize gas exchange by diffusion?

A

1-Large surface area
2-small distance
3-partial-pressure concentration gradient

32
Q

Name AND describe the 4 phases of gas exchange (gas exchange may be used as one of these phases).

A

1- Ventilation- the movement of air/water through or around gas exchange surfaces (skin, trachea, gill, lung, respiratory system)

2- Gas Exchange- diffusion of O2 and CO2 between air/water and blood at the respiratory surface (respiratory system)

3- Circulation- transport of gases throughout the body delivering them to cells/tissues (circulatory system)

4- Cellular respiration OR gas exchange again occurs by diffusion at the tissues between blood and cells

33
Q

Describe differences faced by animals that must undergo gas exchange in the air versus animals that undergo gas exchange in the water

A

-different amounts of oxygen available (21% in the air at sea level, 30x less in the water)

-viscosity and density of the medium (air is less dense and less viscous, water has high density and viscosity)

-ease of ventilation (easy in air, but energetically demanding in water)

34
Q

Describe what happens to CO2 after cellular respiration

A

-Enters the blood stream

-reacts with water to form carbonic acid (using carbonic anhydrase enzyme)

-rapidly dissociates to form bicarbonate ions

35
Q

Describe the effect of CO2 on the affinity of hemoglobin for oxygen in the tissues.

A

Carbon dioxide does not bind to hemoglobin, but it leads indirectly to a change in the oxygen affinity of hemoglobin. The CO2 produced during the citrate cycle is released into the blood and forms bicarbonate:

(In erythrocytes, this reaction is sped up by the enzyme carbonic anhydrase). This lowers the pH in the erythrocytes, which in turn changes the conformation of hemoglobin so that its affinity for oxygen is reduced, i.e., more oxygen is released.

This phenomenon is called the Bohr effect, and it allows increased oxygen supply to tissues when they need it most - the amount of CO2 is a direct consequence of the oxidation of energy-rich molecules (sugars, fats).

36
Q

The oxygen content of water increases linearly with an increase in oxygen partial pressure, while the oxygen content of blood increases in a sigmoidal (S-shaped) fashion. Why?

A

Hemoglobin shows cooperative oxygen binding.

37
Q

Insect trachea comes in direct contact with the internal organs to which they deliver oxygen. What parameter of Fick’s Law does this optimize?

A

D = distance between things or whatever

BISC 101 Final (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions