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.
Answer: I think that it would be C because blooms are due to eutrophication, which means that there are high levels of phosphate in the water. Phosphate is a main ingredient in pesticides, which can run-off into rivers.
Answer:
3 ways to understand the differences between compounds and mixtures are described below in explanation.
Explanation:
1. In a mixture, no new product is formed. It is a simple tacking of two molecules without any chemical reaction occurring. For example water and sand. Compound is a new substance formed by chemical reactions occurring between various molecules. For example, carbon and oxygen combine to form carbon dioxide.
2. A compound is always homogeneous whereas a mixture can be homogeneous or heterogeneous.
3. Compounds have a fixed boiling and melting temperature. Whereas, mixtures do not have a definite melting and boiling temperature.
