Answer:
Biodiversity is usually defined as the diversification of living species that exist on earth and the complexities that occurs in the ecosystem. It includes all the plants, animals, humans and micro-organisms.
The biodiversity is often affected by factors such as climate change, loss of habitat area, and occurrence of invasive species.
Three of the biological services that are provided by biodiversity are as follows-
- A large number of medicines are being made from the various plant species that exist in an ecosystem.
- It provides food, on which the organisms are dependent on it.
- It also provides materials that are used for construction purpose and used as shelter.
The phospholipid bilayer has two hydrophilic surfaces: the extracellular and the intracellular surfaces. These two layers sandwiches a major layer of lipids or fat. Because of this nature of the lipid bilayer, water-soluble or <em>hydrophilic</em> hormones cannot enter the cell membrane. They have to rely on the mechanisms of receptors.
One can find transmembrane proteins embedded across the whole length of the lipid bilayer. One of the functions of these proteins is to serve as the link for hormones such as the ones given above. When the water-soluble hormones attach to one of these receptors, the receptor will be activated and send down a signal to the intracellular environment; these signals will then travel down towards their target site and eventually activate whatever it is the hormone was made for. One example of these transmembrane proteins are <em>G-coupled proteins; </em>examples of signals that cascade down the cell are cylic AMP and cyclic GMP.
I think this is because peptide hormones are made in advance and stored in secretory vesicles while steroid hormones are synthesized on demand on precursors, thus the response of peptide hormones will be more rapid. Additionally the receptors for peptides are on the cell membrane while those for steroid hormones are located on cytoplasm or nucleus, some have receptors on the membrane also.
A scientific law is a statement that summarizes a pattern found in nature.
Hope this helps.
Answer:
A, B and C may be true
Explanation:
The three-dimensional structure (3D) of a protein, also known as tertiary structure, is critical to its function. In general, the 3D protein structure consists of alpha-helix and beta-sheets (secondary structures) associated through disordered coiled-coil regions. Genetic mutations may cause modifications in the 3D protein structure by modifying amino acids that are added to the growing polypeptide chain during the process of translation. In consequence, the relationships among amino acids (i.e., the intermolecular attractive forces that hold them together) may also be altered by these mutations. In general, mutations that generate amino acid changes at the active site of the enzyme will have a deleterious effect, thereby decreasing or inactivating protein function. However, there are situations where a mutation may be beneficial and can eventually increase the rate of reaction of a protein.
