<span>A to recycle carbon dioxide in the atmosphere</span>
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.
The answer is In the last trimester of pregnancy. While the senses
of the fetus start to develop in the 8th week, the different sense mature
at different stages. Vision is the last sense to mature. After the 26th
week, after the eyelids of the fetus have
fully developed, the fetus begins to blink (even experience REM while involves rapid
eyelid movements ).
Answer: Tay-Sachs a disease caused by an absence of an enzyme that break down fatty substance causing damaged to nerve cells
They form a spore when they run out of food.
