40. which of the following statements regarding substrate-level phosphorylation is correct?
a. does not involve phosphate transfer
b. does not produce atp
c. depends one distinct enzyme type
d. occurs twice in glycolysis

c. Depends one distinct enzyme type

Explanation:

Glycolysis is the common metabolic pathway to all living things and consists of the incomplete oxidation of the glucose in pyruvate and occurs in the cytosol of eukaryotes and prokaryotes. During the substrate-level phosphorylation ATP is generated when a high energy P is directly transferred from a compound phosphorylated (substrate) to ADP. P got its energy during an initial reaction, in which the substrate itself is oxidized. During this process one distinct enzyme (Succinyl CoA) type is used.

stress fractures occur largely in the feet and legs and are common in sports that require repetitive impact, primarily running/jumping sports such as gymnastics or track and field.

cells use diffusion to get substances in and out of themselves. that diffusion will occur across the cell membrane or the outer covering of the cell. because we are talking about the surface of the cell, surface area and volume are  important factors here. as a cell increases in size, its surface area and volume increase as well.  we call that the surface area to volume ratio (sa: vol).  but the catch is that  volume increases at a greater rate than surface  area. in other words, as a cell gets bigger, the sa: vol gets smaller. so a really small cell like bacteria is mostly cell membrane (surface) with very little contents (volume). a really big cell like an egg, is mostly insides with a super thin membrane. so what ends up happening is that the cell cannot efficiently diffuse all of the stuff it needs in/out to survive. therefore cell size is limited to about 100mm. so how do we make organisms bigger than 100mm? cells divide! by dividing and becoming multicellular, organisms are able to grow!   check out the diagrams i attached to see the effect of sa: vol. i hope this ! good luck!