In active cells, pO_2 may be 10 torr at the cell surface and 1 torr at the mitochondria (the organelles where oxidative metabolism occurs).
A) How does myoglobin (p_50 = 2.8 torr, where p_50 is the partial pressure of oxygen required to 50% saturate myoglobin) facilitate the diffusion of O_2 through these cells? (Myoglobin does not just pick up the O_2 at the cell membrane and carry it over to the mitochondrial membrane.)
B) Active muscles consume O_2 much faster than do other tissues. Would myoglobin also be an effective O_2 - transport protein in other tissues? Explain.

a. Oxygen binds to it when it attains a partial saturation of 0.5

b. Yes.

Explanation:

Myoglobin -  is a small globular protein, containing a heme group, that carries oxygen to muscles.

In this case we see how a specialized oxygen storage

protein, myoglobin, is used to store the oxygen and to facilitate its

diffusion within cells.

a) For oxygen binding in this proteins the KD or the “p50” – the amount of oxygen required to give

a fractional saturation of Y=0.5. In the case of myoglobin, the KD is 2-3 torr. In the case above we have a KD of 2.8 which is sufficient for the fractional saturation binding to be activated.

The fractional saturation seems to be sufficient for a noncooperative binding of O2 to carry oxygen from the capillaries to sites of usage like the mitochondria.

It binds 1 molecule of oxygen molecule per molecule of protein.

b. Myoglobin is an intracellular protein propagated in such a way that it is found in skeletal and cardiac muscle cells and is associated to the transport of oxygen from the cytoplasm to the mitochondria where oxygen is used. It is hence a reliable oxygen depot and transporter.

d concave shape of wave rock

explanation:

the concave shape of wave rock is a very good evidence that supports the evolution of earth due to chemical weathering. if we talk about structure of   wave rock, studies have estimated that it is around 2.7 billion years old. it also serves as the foundation of evidence that it was the place where australian continent began to form.

how the structure of wave rock was created?

studies suggest that structure of wave rock was created when the surrounded area was started to weather due to which deposition of material started on the part of land which now contains wave rock.

the structure of wave rock is considered to be one of the best-known landforms in australia. at the height of around 15 cm, there can be found flared slopes which formulate the margins of hyden rock. it is now assumed by geologists that wave rock was created by subsurface water-induced weathering and not by glaciers, waves or wind.

due to deposition of material over the period of long time, the wave rock became tougher and tougher due to weathering from surrounding terrain. this makes it a physical evidence that supports   the evolution of earth due to chemical weathering.

hope it !