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.
Explanation:
This electron exchange results in an electrostatic attraction between the two atoms called an ionic bond. An atom that loses one or more valence electrons to become a positively charged ion is known as a cation, while an atom that gains electrons and becomes negatively charged is known as an anion.
Answer: In Meiosis,chromosomes in a diploid cell resegregate, to give four haploid cells. Genetic diversity takes place during this early step of meiosis. DNA replication takes place before Early Meiosis commence. Pairing of homologous chromosomes which forms synapses is unique to Meiosis.
Explanation: Meiosis is a type of cell division which aides the formation of reproductive materials like the GAMETES SUCH AS SPERM CELLS AND EGGS,During Meiosis cell division takes place which reduces the number of chromosomes in the parent cell by half and produces four daughter cells, Meiosis is essential to guarantee genetic diversity in living organisms.
A Punnett square allows the prediction of the percentages of phenotypes in the offspring of a cross from known genotypes. A Punnett square can be used to determine a missing genotype based on the other genotypes involved in a cross.
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