Answer:
C. Cohesion of molecules
Explanation:
Cohesion is the interaction of molecules of the same substance together. By the force of cohesion if two drops of water come together they form one. Water has high rates of cohesion due to hydrogen bonds.
This phenomenon also called surface tension and is what allows small insects to stand on water.
Cohesion along with adhesion of water to the walls of the narrow tube generate what is called capillarity. This allows liquids to ascend inside the narrow tubes. As long as the cohesion is less than the adhesion, the liquid will rise until both forces are equal.
Toxicology is the study of poison on living things
An absorption line will appear in a spectrum if an absorbing material is placed between a source and the observer.
The question is incomplete. The complete question is:
Question: Why do organisms without oxygen need to convert pyruvate to lactate?
A) because pyruvate is toxic to the cells
B) in order to regenerate NAD+
C) in order to use lactate in the citric acid cycle
D) because lactate is needed to produce ATP
Answer:
B) in order to regenerate NAD+
Explanation:
Kreb's cycle and electron transport chain (ETC) are the aerobic stages of cellular respiration. ETC regenerates NAD+ and FAD+ by oxidation of NADH and FADH2 produced during glycolysis and Kreb's cycle. Here, oxygen serves as the terminal electron acceptor.
Glycolytic reactions use NAD+ as an electron acceptor and produce NADH. Therefore, a constant supply of NAD+ is required to sustain glycolysis. In absence of oxygen, ETC cannot occur and organisms convert pyruvate into lactate. Pyruvate is reduced in lactate and NADH serves as the electron donor. Thereby, lactate fermentation regenerates NAD+ to continue the process of glycolysis.
<span>A light microscope uses focused light and lenses to magnify an object. Light microscopes come in several forms. (1) Simple light microscopes use a single lens to magnify an object and cannot reach high magnification just like a handheld lens whose highest clear magnification in the best conditions is 25x. (2) Compound light microscopes use two sets of lenses - an objective lens and an eye piece. This is the type of light microscope whose magnification power reaches between 1000x and 2000x.</span>
