<span>As there are many kinds of deserts, some hot, some cold even arid deserts are the classic hot deserts, but there are also cold and coastal deserts where temperatures do not get so high. The element common to all of these types of deserts, however, is their lack of rainfall. In that sense the rainfall is a characteristic that determines if it's a desert.</span>
The system is called Taxonomy and was made by Swedish botanist Carlous Linnaeus
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.
This produces several negative effects on the biodiversity of the river ecosystem.
<u>Explanation:</u>
The Susquehanna river is polluted by the excess release of nutrients like phosphorous and nitrogen from agricultural land and sewage treatment plants. This can adversely affect the health of the river. The excess of nutrients will accelerate the growth of algae in the river.
The dead algae that settle at the bottom of the river decay by consuming the oxygen present in the river. This will reduce the amount of dissolved oxygen in the river and affect aquatic life.
Thick algal growth partially prevents the penetration of sunlight into the water and this affects the growth of submerged plants which are food to the fish.
