<span>I believe the answer is: D. proteins
The main functions of these proteins is to allow specific substance to pass through the membrane of the cells which needed for the energy formation for cells'functions.It created through the combination of more than 20 amino acids with different functions.</span><span />
When cells communicate by the signaling process, one cell produces a signaling molecule that must be received by the signal receptor on or in the responding cell. Signaling molecules are often called ligands, a general term for molecules that bind specifically to other molecules (such as receptors).
The hormones are sent as chemical signals
Answer: Respiration in Animals.
Explanation:
This is a body systems which involves the intake of oxygen, and the release of carbon dioxide ,(breathing),for the breakdown of digested food substances for example (glucose), to generate energy.
Most organisms make s use of oxygen for survival they are aerobes, while some organisms thrived in absence of Oxygen; these are anaerobes.The
DNA makes up genes. Transcription: The info stored in the gene's DNA is transcribed to RNA in the cell nucleus. The type of RNA that contains the info for making a protein is called messenger RNA, also known as mRNA. It carries out the information from the DNA, out of the nucleus, and into the cytoplasm. Translation: This happens in the cytoplasm. It is where the mRNA interacts with the ribosome, which "reads" the sequence of mRNA bases. Three bases make a <em>codon</em>, which usually codes for one particular amino acid, which is building blocks of proteins. Then, another type of RNA called transfer RNA, aka tRNA, assembles the protein by folding. This continues until the ribosome reaches a stop codon.