Answer:
not see clearly yrr.........
First, he should measure how long it takes for the liquid to become clear if X and Y are mixed together. Then, he should measure how long it takes if he also adds substance A to X and Y. He will find out if substance A is a catalyst. hope this helps :)
Answer:
Primary active transport directly uses a source of chemical energy (e.g., ATP) to move molecules across a membrane against their gradient.
Answer:
The polarity of membrane phospholipids
Explanation:
The inner core of membranes is made of nonpolar tails of phospholipids which in turn makes the membranes impermeable for polar, large and charged substances since these substances cannot cross the non-polar inner core. The saturated hydrocarbon tails pack tightly and make membrane less permeable while cholesterol affects the membrane permeability by interacting with non-polar tails.
Higher temperatures make the membrane more fluid and more permeable while at lower temperatures, membranes are more rigid due to tight packing of hydrocarbon tails and less permeable. The polar heads of phospholipids make the inner and outer surface of the membrane. Therefore, the polarity of phospholipids does not affect the membrane permeability.
