Which molecule forms the bulk of a cell membrane? which is the best definition of diffusion? which substance is commonly found in a cell membrane? what is the process whereby molecules in vesicles are exported out of a cell? in a eukaryotic cell, where is most of the dna located?

1. which molecule forms the bulk of a cell membrane?

phospholipid 
In terms of structure, a cell membrane (or plasma membrane) consists mainly of a phospholipid bilayer (with associated proteins embedded in it).

 

2. which is the best definition of diffusion?

Diffusion is the bulk movement of particles from a region of higher concentration to a region of lower concentration 

 

3. which substance is commonly found in a cell membrane?

proteins 
Proteins are enzymes which help transport things through the membrane. 

 

4. what is the process whereby molecules in vesicles are exported out of a cell?

exocytosis 

Actually there are 2 types of bulk transport and these are: exocytosis and endocytosis, and both require the spending of energy (ATP). In exocytosis, resources are excreted out of the cell via secretory vesicles.

 

5. In a eukaryotic cell, where is most of the DNA located?

inside the nucleus 

The nucleus is the main center of our cells. This contains our chromosomes and genetic information essential for the reproduction of life.

The salt in the sea water dehydrated the sailor because her body could not take in the amount to salt in the sea water

A  reaction  in which  energy  is  released  to the surroundings is called an exothermic  reaction. in this type of  reaction  the enthalpy, or stored  chemical energy, is lower for the products than the reactants. when ammonium nitrate is dissolved in water,  energyis  absorbed  and the water cools.