He is incorrect because a catalyst is a substance that speeds up a chemical reaction so if there is no reaction to begin with a catalyst will not due anything.
Answer: a. capillary action.
Water is a taken up by the plants from the roots, which needs to be transferred to all the parts of the plants to conduct cellular metabolic processes like photosynthesis and respiration. The properties of water molecules are responsible for conduction of water from the root to the stem and other higher parts. The cohesion is the property of water which water molecules are combined with each other due to sharing of bonds at the atomic level. The adhesion is the property of water which allows water molecules to attach with other substances or substrate. Adhesion will cause the attachment of water molecules to the wall of the vessel (xylem) of the plant. Capillary action occurs when the adhesive force is greater than the cohesive force between water molecules. The supply will be upward and force of gravity will also be applicable on this. Capillary action mimics the transfer of water from a tube or pipe. In this way water is drawn upward from the roots through plant tissues to the leaves by capillary action.
The contamination cleanup strategy called bioremediation—using naturally occurring or genetically modified microbes to clean up our messes—is gaining steam, as scientists devise new ways to use bugs against mercury, oil spills, radioactive waste and more.
Answer:
This protein consists of 8 subunits of equal size linked by disulfide bonds
Explanation:
The sodium dodecyl sulfate-polyacrylamide gel (SDS-PAGE) is a technique widely used in molecular biology laboratories to separate proteins with molecular weights between 5 and 250 kDa. SDS is an anionic detergent used to denature proteins before electrophoresis. SDS can denature proteins by altering non-covalent bonds such as hydrogen, hydrophobic and ionic interactions, but they cannot cleave disulfide bonds. In this case, reducing agents (e.g., β-mercaptoethanol or dithiothreitol) have been used to cleave disulfide bonds.