What is cellular movement

Question

I tried googling it but none of the websites have it in layman's terms. I have no background what so ever in Biology save for 8th grade bio, and I wasn't too good at that either.

So here's the basic question: How does cellular movement function in the cell and give an example. Also indicate and explain how ATP is used in cellular movement. Someone lend me a hand here please

Answer 1

Cellular movement is movement of the cell as a whole unit, right?

Single-celled organisms move around using three major methods:

- little hair-like structures called cilia (eg: paramecium http://www.infovisual.info/02/004_en.htm...

- bigger and longer structures called flagella (sperm-tail)

- pseudopodia (sticking out parts of the cell by building and breaking down the cell skeleton of fibers - how amoeba move http://www.fotosearch.com/ATB719/vml132/...

Cilia and flagella are composed of microtubules, which are one of three fibers that make up the cell microskeleton. There are microtubules (structure and locomotion), microfilaments (locomotion), and intermediate filaments (structure).

The microtubules in cilia and flagella are associated with locomotory (movement) proteins, called dynein. When ATP is present, the dyneins can move from one microtubule to another, which either pulls parts of microtubules together or pushes them apart, bending the whole long structure. And you know how if you push the door at the hinge, the outside edge of the door moves a lot further than the part you're pushing? The end of the flagellum or the cilium moves a lot further than the inner part, and you can see it really well in the whip-like movement of a sperm's tail.

Here's a link with more information about how cilia and flagella move:

http://cellbio.utmb.edu/cellbio/cilia.ht...

But basically, ATP lets the dynein move around, and that moves the microtubules, which moves the entire structure. Sperm would probably be the best example.

As for amoebas, ATP activates two other locomotor proteins (the equivalents of dynein) called actin and myosin. You may remember these from learning about muscle movement in humans - it's the same proteins. They group together at the tip of a pseudopodium (the sticky-out "limb" of an amoeba) and cause the cytoplasm (liquid inside the cell) two flow towards them, which pushes the pseudopodium out further.

Answer 2

It depends on whether "cellular movement" means movement of the cell or movement of molecules within the cell.  Unfortunately I can't tell as the phrasing is vague, but you should be able to tell based on your study topic.

I'm going to assume you mean movement of the cell.  If it's movement of molecules within the cell, google "active transport" and your question will be easily answered.

Examples of cellular movement are external movement such as cilia and flagella (think of the stereotypical "hairy" cells in cartoons - the hairs are cilia) which allow cells to move around.  Then there's internal movement, such as contraction of muscle cells.

ATP provides the energy necessary for this movement. Hydrolysis of ATP into ADP or AMP (ATP has three P's, ADP has two, and AMP has one... each P you take off releases energy) provides chemical energy that the cell converts into kinetic energy/movement.

I doubt I can explain this without making it too complicated, but I did some hunting and found you an excellent tutorial that provides the layman's explanation that you wanted.  See the link below.  Hope this helps!