Structure of hemoglobin and how does oxygen bind to it

Which two molecules generated by the krebs cycle pass their high-energy electrons to the electron transport chain? a. nadh b. c6h12o6 c. fadh2 d. nad+

Which of the following statements is a scientific claim? a. the early solar system had large amounts of water; so, the oldest objects in the solar system should also be abundant in water. b. earth is shaped like a sphere even if not all of the scientific observations related to its shape support this idea. c. the mass of the universe is much greater than current models predict; it is not possible to explain this inconsistency. d. planet earth is abundant in water, but there is no way to scientifically determine from where earth's water originated.

Humans have to eat food to get the nutrients that keep us alive, but plants use the sun to power photosynthesis