Answer:
b. the composition of R groups varies among the 20 amino acids in proteins, which can be either polar or charged.
Explanation:
As proteins consist of numerous amino acids connected together, their connections occur uniformly across all amino acids because one segment remains identical among them all.
The remainder of each amino acid, known as the R group, differs across the various types, defining their unique characteristics and contributing to their chemical properties.
A muscle cramp happens when a muscle contracts involuntarily and suddenly. Various factors can cause this, such as insufficient minerals like calcium or poor blood flow.
By straightening and vigorously massaging an athlete's leg, the muscle relaxes and returns to its normal position.
In a lake, oxygenic phototrophs generate new organic materials and oxygen. If the primary production rates are overly high, the resulting surplus of organic matter can deplete oxygen levels in the bottom water due to respiration, leading to anoxic conditions, which then promotes anaerobic processes such as anaerobic respiration and fermentation. Organic matter that remains unconsumed in the surface layers sinks and is broken down by anaerobic organisms.
Carbon dioxide is produced during cement production as a result of burning fossil fuels.
