Answer:
The presence of cholesterol in the plasma membranes of some animal cells <u>enables the membranes to stay fluid when cell temperature drops</u>.
Explanation:
Cholesterol is an essential lipid in the basic structure of cell membranes. The membranes must have a fluid structure so that the proteins integrated in them can move ''horizontally'' to interact with their ligands and with other proteins. With excess saturated fat the membranes become rigid, but only with the necessary unsaturated fat the membranes are extremely fluid, and very sensitive to changes in temperature. Cholesterol stabilizes the structure of the membranes; preventing the collapse and crystallization between lipid chains that would lead to loss of fluidity and excessive rigidity in the membrane. By decreasing the temperature; as temperatures drop, fluidity decreases, an effect that partially counteracts the presence of cholesterol.
The answer is; A
The active site of the enzyme is bound by a substrate and probably the enzyme catalyzes a hydrolysis reaction. The poison mimics the substrate and competes with the substrate for the active site of the enzyme. The poison may bind permanently to the enzyme rendering the enzyme unavailable for other substrates. This could make a particular biochemical reaction, in which the enzyme is involved, to reduce drastically hence threatening life.
The answer is <span>b. Swamps are deeper and have a larger proportion of surface water than marshes, and bogs have acidic groundwater.
Bogs, marshes, and swamps are types of wetlands. Swamps and marshes are mineral soil wetlands. Swamps are deeper and with a larger proportion of surface water than marshes. Usually, swamps develop from marshes that fill in. Bogs are organic soil wetlands. They are acid areas with acidic groundwater.</span>
Answer:
GAR and AICAR transformylase
Explanation:
Tetrahydrofolate is essential for purine and pyrimidine synthesis, its deficiency can lead to inhibition of nucleic acid such as DNA and RNA and protein synthesis, which are important for the growth and survival of both normal cells and cancer cells. N-10-formyltetrahydrofolate acts as a donor of carbon atoms to the actively growing bases. It contribution is mediated by the action of the Glycinamide Ribonucleotide (GAR) transformylase and the N-5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) transformylase.
