Which of the following exert their cell signaling ability by directly phosphorylating other proteins? multiple answers    A. RAS   B. Epidermal Growth factor   C. HER2   D. SRC   E. Estrogen Receptor

Metabolic syndrome is a clustering of various conditions including high blood pressure, high blood sugar, excess body fat, high serum triglycerides, and low high-density lipoproteins. Scientists studying metabolic syndrome cultured fibroblast cells from a metabolic syndrome patient and a healthy volunteer and challenged the cells to 100 nM insulin. Ten minutes after the stimulus was applied, they used a protein immunoblot to measure the amount of phosphorylated insulin receptor in the cultures.   Use the passage to answer the question. Insulin, in addition to regulating blood glucose, also promotes satiety. Ghrelin, on the other hand, is a peptide hormone that promotes hunger. Which statement BEST predicts the effect of ghrelin release on the insulin receptor?   A. It increases insulin receptor expression.   B. It decreases insulin receptor expression.   C. It increases insulin receptor phosphorylation.   D. It decreases insulin receptor phosphorylation.

In the RAD signaling pathway the EGF ligand binds the EGF receptor, this initiated a phosphorylation cascade that results in cell proliferation. Which of the following statements is correct: a. RAS protein is the sognal b. EGF ligand is the signal c. cell proliferation is the signal d. EGF receptor is the signal e. none of the above

Which of the following statements are correct about the drug Gleevec (select all that apply)?   A. Only inhibits activity of transit amplifying cells   B. Gleevec is a natural product that was identified in a rare plant   C. Negative side effects of drug are inhibition of PDGF and KIT   D. Mutations in ABL gene cause resistance to Gleevec     E. Inhibits the phosphorylation activity of tyrosine kinase

Which of the following enzymes does NOT catalyzes the formation a second messenger? A. PI3K B. Protein kinase C C. Phospholipase C D. Guanylyl cyclase   Which of the following statements is correct? A. Lipolysis is inhibited by epinephrine and glucagon B. Phosphorylation of triacylglycerol lipase inhibits its activity C. Activation of protein kinase A inhibits lipolysis D. Fatty acids are activated in mitochondria before undergoing b-oxidation E. Lipolysis is stimulated by cAMP F. None of the above

Which of the following would be considered second messengers of a signaling pathway?   Select one: a. A kinase enzyme b. A scaffolding protein holding three kinases c. Adenyl cyclase d. All answers are examples of second messengers e. A sugar like inositol f. Ligand gated channel

Interacellular receptors bind  a. Hydrophilic molecules  B. Cell membrane receptors  c. Second messengers such as Camp  d. Protein hormones  e. Small signals that can diffuse through the cell membrane

Cancer cells may be more susceptible than normal cells to mitotic catastrophe in response to chemotherapeutic drugs because of which of the following (select all that apply)?   A. They express unique receptors for those drugs on their surface   B. They may be resistant to apoptosis   C. Cancer cells have more efficient DNA repair mechanism than normal cells.   D. Only cancer cells are actively dividing   E. They may lack key G2/M checkpoint controls

Which of the following statements about our defenses to protect DNA are correct (select all that apply)? A. Genetic differences in GST enzymes may affect risk of cancer B. Reactive Oxygens species that damage DNA are removed by catalase C. On average, humans are exposed to more naturally occurring plant pesticides compared to man made pesticides. D. Cancer cells upregulate concentration of Glutathione S-Transferase (GST) to remove electrophilic compounds E. High levels of melanin are correlated with increased risk of skin cancer