Why does glucose need to be broken down to get into the cell membrane??

Question

explain thoroughly what happens or please give me the site to find it . because i've been lookin all over and cant find anything. | the question more thoroughly stated : what would happen if ATP wasn't there and a BIG glucose went straight into the cell without getting broken down first??

okay forget i ever said that. i just need the answer to the first question .

Answer 1

What do you mean by Big glucose? Glucose is a molecule C6H12O6 and doesn't change size. It is actively transported by Glucose transporter proteins on the cell membrane. It can't get into the cell without ATP active endocytosis.

Answer 2

Polymerized glucose, like starch or glycogen, cannot cross the cell membrane because there are no transporters that can ferrry these macromolecules across. Once hydrolyzed into monomeric glucose, transporters can move the glucose across the membrane into the cytoplasm.

Glucose movement through glucose transporters is by facilitated diffusion and so does not require ATP.

http://en.wikipedia.org/wiki/Glucose_transporter

Answer 3

Oxygen is the necassary gas (oxydative phosphorylation) to change glucose into an energy that can be used by the cell (adenosine triphosphate or ATP) which happens in the cristae of the mitochondria In addition to supplying cellular energy, mitochondria are involved in a range of other processes, such as signaling, cellular differentiation, cell death, as well as the control of the cell cycle and cell growth

Answer 4

glucose needs to be broken down to get into the cell membrane because only a certain sized membrane can get through into the cell and for those that are too big they go through a swpecial way

Answer 5

Glucose enters a cell by facilitated diffusion. No ATP is needed. Glucose is metabolized to CO2 by aerobic respiration to generate ATP.

Answer 6

well if there were no ATP you couldnt break down the glucose you need to break the glucose down because if you were to use it all at once you would waste energy. so it gets broken down so that it can be used for a greater length of time rather than all at once. it would be like if an engine were to just blow all its gasoline at once youd get a big boom but you dont need that much energy. instead it does it little by little to use the gas more efficently