Answer:
A. NADH and FADH2 both donate electrons at the same location.
Explanation:
In the respiratory chain, four large protein complexes inserted into the mitochondrial inner membrane transport NADH and FADH₂ electrons (formed in glycolysis and the Krebs cycle) to oxygen gas, reducing them to NAD⁺ and FAD, respectively.
These electrons have great affinity for oxygen gas and, when combined with it, reduce it to water molecules at the end of the reaction.
Oxygen gas effectively participates in cellular respiration at this stage, so its absence would imply interruption of the process.
NADH and FADH₂ electrons, when attracted to oxygen, travel a path through protein complexes, releasing energy in this process.
The energy released by the NADH and FADH₂ electrons in the respiratory chain in theory yields <u>34</u> <u>ATP</u>, however, under normal conditions an average of 26 ATP molecules is formed.
If we consider that these 26 molecules are added to the two ATP formed in glycolysis and two ATP formed in the Krebs cycle, it can be said that cellular respiration reaches a maximum yield of 30 ATP per glucose molecule, although theoretically this number was 38 ATP per glucose molecule.
Structurally, DNA and RNA are nearly identical. As mentioned earlier, however, there are three fundamental differences that account for the very different functions of the two molecules. RNA has a ribose sugar instead of a deoxyribose sugar like DNA. RNA nucleotides have a uracil base instead of thymine.
An open circulatory system simply
means that the blood flows out of vessels and into the spaces or sinuses. Invertebrates,
insects and crustaceans has an open circulatory system where pump blood goes
into a hemocoel and diffusing back to the circulatory system between cells. In
other animals, the heart pumps the blood into the body cavities, spaces or
sinuses, where the blood surrounds the tissues.
Options for part A are as follows:
A) A mutation in the operator sequence
B) A mutation in the lac-Z gene
C) A mutation in the lac-Y gene
D) A super repressor mutation
Answer:
The correct answer:
Part a - A mutation in the operator sequence
Part b - It ensures that a cell dedicates resources to the production of enzymes involved in lactose metabolism only when lactose is available in the environment
Part C. true.
Explanation:
part a:
If there is a mutation in the operator sequence leads to prevent binding of the repressor which leads to allowing constitutive expression of the genes various conditions.
part b:
The biological role of the lac operon makes sure that the cell dedicates resources to the production of enzymes involved in lactose metabolism only when lactose is available in the environment
Part c:
RNA polymerase cannot transcribe the structural genes due to the repressor binds to the lac operator, therefore, the proper function of the lac operon is possible when the placement of the operator sequence between the promotor and the structural genes.
