Answer:
Many scientists favor the RNA world hypothesis, in which RNA, not DNA, was the first genetic molecule of life on Earth. Other ideas include the pre-RNA world hypothesis and the metabolism-first hypothesis. Organic compounds could have been delivered to early Earth by meteorites and other celestial objects
Answer:
Some cells function best at a pH of 5, while others are better at pH 7. ... control what crossed their membranes, either no molecules would make it across, ... Various types of cell transport are summarized in the concept map in ... Figure 5.7.5 demonstrates the specific outcomes of osmosis in red ...
Explanation:
Lipophilic hormones,
intuitive as the name suggests, tend to dissolve
well in lipids/fats than they do in water. Therefore lipophilic hormone does not dissolve well in blood plasma which
would affect their diffusion. The carrier proteins are mainly the serum
albumins.
Through "cellular respiration" process energy is stored in the form of glucose.
<u>Answer:</u> Option A
<u>Explanation:</u>
The series of metabolic reactions and mechanism take place in organism ranging from microscopic bacteria to large organisms cells in order to transfer biochemical energy from food nutrients (stored in glucose form which is transferred) to adenosine triphosphate (ATP) and then waste product is also released, the whole process is known as "cellular respiration".
The energy required for ATP synthesis extracted from the breakdown of foods and phosphocreatine (creatine phosphate). It is stored inside muscle cells because phosphocreatine is readily available to produce ATP quickly.
Answer: a) substrate and cofactors b) covalent modification
Explanation:
Metabolic pathways involve all the chemical processes takes place in the enviornment or in an organisms.The metabolic pathways are controlled through the catalytic activities of enzymes.
The availability of enzyme is regulated by substrate and cofactors present in enzyme and enzyme activity is commonly regulated via covalent modification.
Enzymes are highly selective in nature and bind to a specific substarte only. The active site in enzyme binds with the substrate to form enzyme substrate complex. Coactors assist the enzyme activity, without cofactor enzyme can not perform its activity.
Hence enzyme availibility is regulated by substrate and cofactors regulates.
Covalent modifications regulates activity of enzyme as it involves addition and removal of chemical group to synthesis required protein. It can change the chemical properties of the site by targeting one or multiple amino acid.
Thus the correct answer is a) substrate and cofactors b) covalent modification
