Answer: Substances that are protein based cannot cross the lipid cell membrane, but can exert their effect by binding to the proteins based receptors present on the lipid bilayer.
Explanation:
Hormones such as calcitonin , Parathyroid hormone and pituatry horomones are proteins and water soluble.They cannot cross lipid bilayer but can bind to ligand binding protein receptors.
These receptors are protein macromolecules that are specific in nature for specific hormones.
After binding to the receptors, these hormone-recpetor complexes activate second messengers and regulate the downstream effects.
Answer:
e. both vitamin c and carotenoids
Explanation:
Age-related macular degeneration is an eye related disease which causes our macula to degenerate. It leads to blurred vision which further impacts our abilities like sewing, reading and driving adversely. It can be cured by intake of vitamin C and carotenoids in appropriate amount. Cataract is another disease related to eyes which most commonly occurs in old age people. In this disease, the eye lenses appear cloudy because of the changes in the eye lens tissue. Beta carotene and vitamin C both are very helpful in restricting cataract.
Answer:
C
Explanation:
wax always melts in high temperatures
The type of control is described by the response of the operon when no regulatory protein is extant. In the case of negative regulator, the genes in the operon are distinct unless they are switched off by a repressor protein. Therefore the operon will be turned on essential (the genes will be prcise) when the repressor in inactived. In the case of positive control, the genes are distinct only when an active regulator protein, an activator, is present, Thus the operon will be turned off when the positive regulatory protein is missing or inactivated.
