g The Electron Transport Complex (ETC) consists of four proteins. How many of these proteins directly contribute to the proton gradient by moving protons across the membrane?

Three proteins directly contribute to the proton gradient by moving protons across the membrane

Explanation:

The Electron transport chain is a group of proteins and molecules incrusted in the internal mitochondrial membrane and organized into four complexes, I, II, III, and IV. These complexes contain the electron transporters and the enzymes necessary to catalyze the electron transference from one complex to the other. Complex I contains the flavine mononucleotide -FMN- that receives electrons from the NADH. The coenzyme Q, located in the lipidic interior of the membrane, conducts electrons from complex I and II to complex III. The complex III contains cytochrome b, from where electrons go to cytochrome c, which is a peripheric membrane protein. Electrons travel from cytochrome c to cytochromes a and a3, located in the complex IV. Finally, they go back to the matrix, where they combine to H+ ions and oxygen, to form the water molecule. As electrons are transported through the chain, protons are bombed through three proteinic complexes from the matrix to the intermembrane space. These are complexes I, III and IV.  

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 !

the cell cycle is the final answer! : )