d bc (a b c and d) r the same to make a tidepool
Testosterone is an example of a steroid. Its physiological functions include:
1. Determines the the gender of a developing embryo.
2. Development of reproductive organs and the prostrate gland in males.
3. Responsible for secondary sexual characteristics in males such as deeper pitch, increased muscle bulk, hair on the upper lip.
4. Regulates normal sperm development.
Another steroid is cholesterol. Physiological functions include:
1. Helps maintain the structure of cells and vessels improving overall health and function in the body.
2. Precursor to important sex hormones such as testosterone and estrogen.
3. Used as an insulator around nerves and is absolutely essential for brain function.
4. Precursor to Vitamin D, which supports a healthy immune and nervous system
The temperature is the independent variable. The independent variable is the variable that the researcher can control. And the dependent variable will change because of the change of independent variable. In this question, the student controls the temperature(independent variable) to see wether the gender(dependent variable) will change due to the temperature.
Answer:
For both actin and microtubule polymerization, nucleotide hydrolysis is important for decreasing the binding strength between subunits on filaments.
Explanation:
Cytoskeletal filaments are common to eucaryotic cells and are impotartant to the spatial organization of cells. Intermediate filaments provide mechanical strength and resistance to shear stress. Microtubules determine the positions of membrane-enclosed organelles and direct intracellular transport. Actin filaments determine the shape of the cell's surface and are necessary for whole-cell locomotion. A large number of accessory proteins are present that link the filaments to other cell components, as well as to each other. Accessory proteins are essential for the assembly of the cytoskeletal filaments in particular locations, and it includes the motor proteins that either move organelles along the filaments or move the filaments themselves.
Actin filaments and microtubules are assembled with expenditure of energy i.e the ATP/GTP tightly bound to actin/tubulin is irreversibly hydrolyzed to ADP/GTP during the assembly process, and liberation of Pi in the medium occurs subsequent to the incorporation of subunits in the polymer. Pi release acts as a switch, causing the destabilization of protein-protein interactions in the polymer, therefore regulating the dynamics of these fibres. The progress is made in four areas: the chemistry of the NTPase reaction; the structure of the intermediates in nucleotide hydrolysis and the nature of the conformational switch; the regulation of parameters involved in dynamic instability of microtubules; and the possible involvement of nucleotide hydrolysis in the macroscopic organization of these polymers in highly concentrated solutions, compared with the simple case of a equilibrium polymers.
