Gaseous Exchange Questions for Your Exam

Cells and molecules in the environment are constantly moving and changing, for cells to function properly there is a need for equilibrium to be met. The size of the cell and the solution outside of the cell affects the rate of diffusion and osmosis in the cell. Cells are constantly trying to reach an equilibrium with the molecules and substances around it, which is why there are such terms as: hypertonic, hypotonic and isotonic. The procedures allowed testing of whether or not surface area or volume increased diffusion and how different substance control diffusion. Cells are constantly moving to reach equilibrium through diffusion and osmosis.

2. Explain your observations in detail in terms of concentration gradient, diffusion, osmosis, osmotic pressure, passive transport, and active transport.

Exhalation, (breathing out), is the opposite of inhalation and occurs when the inspiratory muscles relax causing the diaphragm to depress which decreases the lung volume. This decrease in volume causes the alveolar pressure to increase therefore the carbon dioxide in the lungs flows from a high pressure to a lower pressure in the atmosphere. (Tortora & Derrickson, 2011)

1. What can you infer about the surface area and/or diffusion distance for gas exchange in Sam’s lungs?

What two parameters are responsible for creating the movement (filtration and reabsorption) of fluid across the capillary wall?

The cardiovascular system is a network of the heart, blood vessels and the blood. It circulates blood throughout the blood vessels in our body in order to provide individual cells with oxygen and nutrients, and help to dispose of metabolic waste. Capillaries, which are the smallest blood vessels, have extremely thin walls. This is so diffusion can happen more efficiently. Every cell has capillaries passing through very close so there is a shorter distance for diffusion to occur. During my experiment, it showed that the larger the agar cube, the more of remaining agar which was left to be diffused. It also showed that the smaller the agar cube, the less remaining agar was left to be diffused. The findings from my experiment prove that the smaller

The presence of fluid in the alveolar space could potentially cause the lung capacity to be effected as well.

Gas exchange is when oxygen is delivered from the lungs to the blood stream and carbon dioxide is taken out of the bloodstream and into the lungs. Gas exchange occurs within the lungs between the alveoli and capillaries which are in the walls of the alveoli. The walls of the alveoli share a membrane with the capillaries in which oxygen and carbon dioxide move freely between the respiratory system and the bloodstream. Oxygen molecules attach to red blood cells, which travel back to the heart. At the same time, the carbon dioxide in the alveoli are exhaled out of the body.

There is a small amount of carbon dioxide and more oxygen in the body because of gases exchange this is where oxygen form the lungs is transferred in to the blood and carried to the heart and when carbon dioxide is carried in to the lungs forms the blood and is exacted outwards by breathing. Mitochondria also need oxygen to create carbon dioxide for the body so the gas exchange can happen again. Outside the body there is a smaller amount of oxygen but it is still higher than CO2.

29. If all the 280 million molecules of hemoglobin contained in RBCs were free in the plasma,

Also he’s oxygen diffusion rate has increased due to the more oxygen which is absorbed by the alveoli and then circulated around the body.

which it is absorbed by alveoli. Alveoli is where gas exchange happens by tiny air sacs. THC

Small air sacks called alveoli are at the tips of the bronchioles. When air reaches them, the oxygen concentration is high, which causes diffusion into red blood cells travelling through pulmonary capillaries (7). The red blood cells then distribute the new oxygen to the rest of the body. When they reach the alveoli again, they exchange carbon dioxide (a form of cell waste) for new oxygen, and repeat the process. The carbon dioxide is moved through the bronchioles, bronchi, and trachea in the form of exhalation.

movement of water in tissues and maintain the fluidity of mucus and other secretions [3].

Diffusion is an automated process by where the levels of oxygen, water and carbon dioxide pass over a ‘semi-permeable membrane’ between the walls of the cells and blood vessels to create a level environment. This membrane only allows these three elements to pass whilst retaining other elements such as blood cells, hence semi-permeable. The high concentration on one side of the cells transfers through this membrane until the level is equal on both sides.