The major enzyme that metabolizes caffeine is: о CYP1A2 0 CYP2B6 о CYP3A4 0 CYP2A6 0 CYP2C9

Signaling by tyrosine kinase receptors is generally associated with all of the following except: A) receptor dimerization B) growth factor responses C) heterotrimeric G proteins D) cross phosphorylation E) generating protein binding sites due to phosphorylation

Leghemoglobin is a globin protein found in the roots of Legume plants inoculated with Nitrogen fixing bacteria. Leghemoglobin has a binding affinity for oxygen 20 times greater than myoglobin. What function might Leghemoglobin have in the roots of the plant for Nitrogen fixing bacteria? (Hint: The enzyme that catalyzes Nitrogen fixation can also bind O2 , which is not ideal for the enzyme)

Researchers isolated a yeast phosphofructokinase (PFK) mutant in which a serine at the fructose-2,6-bisphosphate binding site was replaced with an aspartate residue. The amino acid substitution completely abolished the binding of fructose-2,6-bisphosphate to PFK. There was a dramatic decline in glucose consumption and ethanol production in the mutant compared to control yeast. Why can't the mutant PFK bind with fructose-2,6-bisphosphate?

While endocytosis and exocytosis refer to the direction in which a vesicle moves into and out of a cell respectively, it is important to think about what is being moved with and within the vesicles. To demonstrate how this process is utilized in human cells we will focus on the human body's insulin response. The purpose of the insulin response is to create a pathway for glucose entry into cells by releasing glucose transporters into the membrane. Cell Type #1- insulin producers: In humans, pancreatic B-cells create steroid insulin that can be packaged into vesicles starting at the ER. These vesicles are prepared for exocytosis so that the insulin can be released from the pancreatic B - cells and get into the bloodstream when signaled to do so. When glucose is present in the blood stream these cells will release the pre-packed insulin into the blood stream. Cell Type #2- insulin responders: Other cells do not produce insulin but instead respond when they have received the insulin signal…

For each of the following statements regarding protein import into mitochondria, indicate whether it is likely to be true or false. [Select] into the mitochondria matrix. [Select] [Select] being translated [Select] unfolded state. The signal sequence is always retained after proteins are imported Chaperon proteins are needed for protein import into mitochondria ✓ Imported proteins cross the mitochondrial membrane while it is still Proteins imported into mitochondria cross the membrane in

All of the following are true about the cytochrome P450 system except: 13 A) This system contains Phase II biotransforming enzymes B) The highest concentration of P450 enzymes is in the liver endoplasmic reticulum All P450 enzymes are heme containing proteins P450 enzymes play a key role in the detoxification of xenobiotics

The seed of the castor bean (Ricinus communis) contains large amounts of ricin, a deadly poison for animals, including humans. One of the two subunits of this toxin is a lectin that binds terminal N-acetylgalactosamine residues on glycoproteins on the surface of eukaryotic cells, allowing the other subunit to enter the cell and kill it by preventing proteins from being made. Select the possible antidotes that could prevent or reverse ricin-mediated entry of the toxin. a high concentration of N-acetylgalactosamine an oligosaccharide with the same structure as that recognized by ricin a compound that prevents synthesis of extracellular glycoproteins a compound that activates enzymes that break down glycogen into glucose an enzyme that degrades lipopolysaccharides

In human cells, where does fatty acid elongation (that is, beyond the C16:0 normally produced by fatty acid synthase) occur?   a)On the outer (cytosolic) face of the outer mitochondrial membrane b)On the outer (cytosolic) face of the endoplasmic reticulum membrane c)Free in the cytosol d)In the mitochondrial matrix

The Amoeba, the paramecium, and the euglena ( These are unicellular Protozoans) produce electrical impulses that travel along their cell membrane. This is possible because they are specialized to use properties exhibited by all cells. These properties include ... A) Separation of the fluid environments inside and outside the cell B) Active transport of Na+ out of and K+ into the cell. C) Portal proteins that allow diffusion of Na+ and K+ back in to the cell D) Maintaining unequal Na+ and K+ concentrations on the two sides of the membrane. E) All of these are true Explain why