The replisome is coded for by essential genes passed between bacteria. Without these proteins, a bacterial cell cannot form more cells. "-some" stands for a collection of proteins that function together, and "repli-" for replication. The TATA box is a DNA sequence involved in the indication of the start of a gene, chromosomes are collected strands of genetic material, the spliceosome removes introns from pre-mRNA, but this, along with all post translational modification, only occurs in eukaryotes. The cytosome is the part of the cell that is specialized for phagocytosis.

The Michaelis-Menten constant  is temperature and pH dependent. It is the substrate concentration at which the rate is half of . Noncompetitive inhibitors alter the shape of an enzyme, slowing down the reaction rate without affecting _. Competitive inhibitor bind to enzyme active sites, increasing the _.

Helothermine is a peptide toxin that inhibits calcium channels in the cerebellar granule cells. The cerebellum is the part of the brain that controls voluntary muscle movements such as those in the limbs, and the toxin must be inhibiting very specifically to cause those two symptoms and not total paralysis or other problems.

Proteins serve all of these functions and many more. Most enzymes are proteins, which help to catalyze spontaneous reactions. Ribozymes can also serve this function but are instead made out of RNA. Proteins can act as transcriptional regulators which can turn on or off gene transcription. Structural proteins, such as actin, can help to maintain the shape of a cell. Other small proteins, such as insulin, can act as hormones which can diffuse throughout the body relaying important messages. 

Enzymes are capable of many things but they are not able to help facilitate non-spontaneous reactions. An enzyme can however help spontaneous reactions occur much faster. Enzymes help catalyze reactions by orienting substrates in the necessary positions for reaction. Without enzymes, substrates would have to bump into each other with the exact necessary orientation and energy, which is very rare. Enzymes are capable of lowering the activation energy of a reaction but have no effect on the overall free energy change of a reaction; recall the distinction between kinetics and thermodynamics.

Enzymes can be inhibited by end products of an enzymatic pathway. This is illustrated in the case of ATP acting as an inhibitor of enzymes found within the pathway for ATP production. This prevents the overabundance of a certain end-product. Competitive inhibitors do not lower an enzymes . Maximal velocity can still be achieved in the presence of a competitive inhibitor, but it requires a higher concentration of substrate to do so. Non-competitive inhibitors can lower an enzymes . This is because non-competitive inhibitors bind to sites other than the active site, known as allosteric binding sites.

Enzymes are not consumed or used up during a reaction, rather they simply increase the rate of reaction by making it "easier" for the reaction to occur, i.e. lowering the activation energy. Equilibrium is not altered by the presence of an enzyme. There are examples of catalytic RNA molecules (ribosomes) and therefore biological catalysts are not always proteins. 

The definition of allosteric enzyme regulation is that a cofactor or molecule binds and interacts with a site on the enzyme other than the active site. This often changes something about the shape of the enzyme which changes something about its interaction with its substrate, thus modulating how active the enzyme is.

Cofactors are not always metal ions, nor are enzymes limited to interactions with a single cofactor. Cofactors can be metal ions, but they can also be organic molecules, and an enzyme may be able to bind and be altered by many of them. The other two statements are true. 

The key here is knowing that metabotropic receptors are NOT ion channels. They exert their effects through downstream signaling cascades. Ions cannot travel through a metabotropic receptor.

All other answers are potential outcomes of activating an mGluR.