Hi Moiz!
1. Hydrogen bonding can occur both between two molecules and within a molecule, anytime H is bonded to N/O/F it is a hydrogen bond. In biology you will usually see this between H-O or H-N
2. Saturated fatty acids are less fluid because they only have single bonds and therefore their hydrocarbon tails are straight, so they are able to pack very tightly together, making them less fluid. Conversely, with an unsaturated fatty acid there are double bonds present, which allows for kinked hydrocarbon tails. Based on that confirmation, they are harder to pack together and therefore more fluid.
3. Calmodulin: a calcium-binding protein in the cytoplasm. When calcium binds, it forms a Calcium/calmodulin complex, which is able to interact with other proteins and processes in the cell. One example of its functions is to activate calcium pumps (either into or out of the cell).
CAMS or cell adhesion molecules are proteins located on cell surfaces that help the cell in the process of adhesion to other cells or the environment. In medicine, this often comes up in the study of immunology. For example, during an immune response, selectins (a type of CAM) are activated in the blood vessels, and they allow white blood cells to adhere to them. This is one of the processes that helps facilitate the movement of cells out of the vessels and into the tissues in response to microbes or other pathogens.
Desmosomes are cells that are specialized for cell-cell adhesion. This is different from CAMS because it is more of a permanent adhesion, vs. CAMS which can be expressed when needed. They are strong adhesions and are typically found in areas of high mechanical stress such as cardiac muscle tissue and bladder tissue.
4. Yes, the ER plays a role in synthesis, folding, transport, and modification of proteins. Ribosomes in the ER use mRNA to synthesize proteins.
5. When we say that something is “statistically significant” this means that it is unlikely to have occurred by chance alone - which is why this is often what is used for a measurement of reliable data. Meaning that the results were not randomly achieved by chance, but an actual relationship between what is being measured exists.
Hope that helps!
Taylor