In many cases, the activity of an enzyme is regulated by Negative feedback where the end product acts as a non competitive inhibitor.
In feedback inhibition the end product of a metabolic pathway acts on the key enzyme regulating entry to that pathway, keeping more of the end product from being produced. The feedback inhibition acts at the first committed step of the pathway, meaning the first step that's effectively irreversible. The pathway steps regulated by feedback inhibition are often catalyzed by allosteric enzymes.
Arteries are blood carrying vessels which have thick, elastic, muscular walls, have no valves and in which blood flows under high pressure. The make up of arteries is unique to their function of transporting blood under high pressure.
All arteries carry oxygenated blood from the heart to all other parts of the body, with the exception of the pulmonary artery which carries de-oxygenated blood from the heart to the lungs. It is the only artery that transports blood which has not been oxygenated.
Answer: All the statements of the question are correct.
Sickle cell disease is an autosomal recessive disorder that is characterized by formation of defective hemoglobin protein, which results in sickle shaped RBC ( red blood cell).
This disease is caused by mutation in the gene that is responsible for the protein hemoglobin ( which transport oxygen throughout body).
It is inherited by the offspring when both the mutated copy of genes ( one from each parent) are passed to him.
Carriers of the disease exhibit increased resistance to malarial parasites by controlling the level of free haem in the blood ( through enzyme heme oxygenase that produces a toxic carbon monoxide gas). The resistance thus developed, is a mutation.
Therefore, all the statements in the given question are correct.
Option C, animals moved from the sea to the land is the right answer.
The Paleozoic Era in the history of the earth was a time of major change on Earth. This was the period that ran about 542 to 251 million years ago. The period commenced with the split of a single super-continent and the development of another. Plants grew extensively. Moreover, the primary vertebral animals conquered the land.
Answer: 12
Explanation: the reaction is: C6H12O6 + 6 H2O + 6 O2 -> 6 CO2 + 12 H2O + 38 ATP + heat
Because of the 2 glucose molecules you multiply the stoichiometry with a factor 2 so: 2 x 6 O2 = 12 O2
