You are right, the correct answer is all of these supplies are required for such a long trip.

Food - You would have to decide not only the quantity of food to prepare but also the quality of food to be packed.

Quantity - What two factors would you need to know to determine the quantity of food to be packed? The duration of the trip and the number of individuals on the spacecraft, of course.

Quality - In an earlier miniunit you learned that living organisms consist of relative few elements (99% C,H,O, P, and N) which are the basis of only few classes of macromolecules (proteins, carbohydrates, lipids, and nucleic acids). The foods required on this long trip must include a balance of these macromolecules to meet the needs of the human beings aboard the spacecraft.

Which food groups contain nitrogen?

a. carbohydrates

b. lipids

c. proteins

d. nucleic acids

e. both c and d

Oxygen - The only source of oxygen that human beings can use is molecular oxygen (O2 ). In an earlier miniunit you learned that oxygen is used to break down energy rich molecules into energy poor molecules producing biological usable energy ATP and forming small organic molecules that can be synthesized into the larger macromolecules of that organism. You also learned that during the process carbon dioxide is produced as a waste product which in high concentrations may be toxic.

What is the name of this process?

a. photosynthesis

b. hydrolysis

c. respiration

d. reduction

What is the percent oxygen in air?

a. 5%

b. 20%

c. 70%

d. 99%

Water - In the laboratory you learned that the universal solvent in living cells and organelles is water and that 88 % of living tissue is water. Living cells must have a balanced equilibrium between the interior and the exterior part of a cell.

Energy - Energy used by living organisms must be in the form of ATP which is a biological macromolecule that can only be produced by living organisms through the breakdown of energy rich molecules such as glucose. This process is called cellular respiration.. You also learned that plants through the process of photosynthesis can convert sunlight energy into chemical energy and store it in energy rich molecules (glucose, starch).

Identify where these two process occur in the figure to the left. Plants convert light energy into energy rich molecules (glucose/starch), animal eat these molecules and convert the stored energy into biological usuable energy (ATP).

Identify the pigment found in plants that absorb light energy and converts it into chemical energy through a process called photosynthesis..

a. anthocyanin

b. aqua blue

c. carotene

d. chlorophyll

By now you can see that it is going be quite a task, if not impossible, to pack this quantity and quality of supplies for this trip.

It may surprise you there already exists a spaceship that has been traveling millions of years with millions of human beings aboard. The name of this spaceship is Earth. This spaceship would be a good model to study to solve some of the problems you may have in packing the Big Blue spaceship. Miniunit Zeta explains how the spaceship Earth has solved many of the problems mentioned earlier. It will also describe some of the limitations and problems it has in maintaining a balance of its supplies food, oxygen, water, and energy.