Polypeptide chains undergo some modifications before they become fully functional. Some of these modifications include: proteolytic cleavage, lipidation and glycosylation. Proteolytic cleavage refers to the removal of some amino acids from a polypeptide chain by proteases in order for the protein to become active. An example of a substance that is modified through this process is insulin.
ATP energy is required to carry out the removal of waste
The correct answer is option I) Steroid hormones are lipid soluble and easily cross the phospholipid bilayer.
The steroid hormones are made up of steroid molecules, the steroid molecules are hydrophobic and lipid soluble. This property makes help the steroid molecule to cross the phospholipid bilayer membrane easily. The steroid molecule has a direct influence on the genome transcription, they act by binding with the DNA as a transcriptional factor.
False
Not always, some proteins are used in a variety. <span>Protein channels are needed to transport substances because it accelerates the transport process. Very few substances enter or leave cells without being attached to a transport protein. Different types of substances require different types of proteins to transport them. Protein channels transport water or ions downwards and ATP-powered pumps transport molecules or ions upwards. ATP generates energy to transport the molecules upwards. </span>
