It can be a compound or a single element. An element is a pure substance that cannot be separated into simpler substances by chemical or physical means. There are about 117 elements, but carbon, hydrogen, nitrogen and oxygen are only a few that make up the largest portion of Earth.
hopefully that helps

5 0

3 years ago

In contracting skeletal muscle, a sudden elevation of cytosolic Ca2 concentration will result in: Inactivation of phosphorylase

skad [1K]

Answer:

ACTIVATION OF PHOSPHORYLASE KINASE AND ALLOSTERICALLY ACTIVATION OF PHOSPHORYLASE KINASE B

Explanation:

In a contracting skeletal muscle, there is a rapid need of ATP by the muscle cell. The energy need is obtained by the degradation of glycogen into glucose which then enters glycolysis. Muscle contraction causes muscle depolarization in which there is the rapid influx of calcium ions from the sarcoplasmic reticulum into the sacroplasm of the myocytes. This in turn causes the binding of calcium ion with calmodulin which thenb activates phosphorylase kinase from which it allosterically activate the b form of the enzyme needed for the conversion of glycogen to glucose. The other options do not occur as a result of increase in cytolic calcium concentration.

4 0

3 years ago

You need 270 ml of a 65% alcohol solution. on hand, you have a 90% alcohol mixture. how much of the 90% alcohol mixture and pure

olganol [36]

You must add 75 mL water to 195 mL 90 % alcohol to make 270 mL of 65 % alcohol.

Step 1. Calculate the volume of 90 % alcohol needed

You can use the dilution formula

V1×C1 = V2×C2

where

V1 and V2 are the volumes of the two solutions

C1 and C2 are the concentrations

You can solve the above formula to get

V2 = V1 × C1/C2

V1 = 270 mL; C1 = 65 %

V2 = ?; _____C2 = 90 %

∴V2 = 270 mL × (65 %/90 %) = 195 mL

You need 195 mL of 90 % alcohol to make 270 mL of 65 % RA

Step 2. Calculate the amount of water to add.

Volume of water = 270 mL – 195 mL = 75 mL

8 0

3 years ago