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Biology-Related Homework Help Cell Biology Topic started by: Sayshell on Nov 2, 2012



Title: Couple of questions PLZ HELP!
Post by: Sayshell on Nov 2, 2012
If the answer is long just tell me the name of the topic and I will research it.

1) How do cells of the same type form different shapes? For example a nose

2) Why doesn't ATP hydrolyze the second its made? Doesn't it travel through the cytoplasm which is filled with water?

3) Do non-replicating cells such as nerve cells mutate without external factors such as radiation?

Post Merge: 11 years ago

anyone?


Title: Re: Couple of questions PLZ HELP!
Post by: manbearpig on Nov 3, 2012
1. Try searching morphogenesis.

2. ?

3. Mutations are accidental changes in a genomic sequence of DNA: the DNA sequence of a cell's genome or the DNA or RNA sequence in some viruses. These random sequences can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic chemicals, as well as errors that occur during meiosis or DNA replication.They can also be induced by the organism itself, by cellular processes such as hypermutation.


Title: Re: Couple of questions PLZ HELP!
Post by: bob12345123 on Nov 3, 2012
2) Why doesn't ATP hydrolyze the second its made? Doesn't it travel through the cytoplasm which is filled with water?

It is stable in water. Hydrolysis of ATP happens at a very low rate (at least on biological time scales). However, there are literally hundreds of enzymes that are ATPases, and these have specialized active sites to increase the rate of hydrolysis, often by many orders of magnitude.



Title: Re: Couple of questions PLZ HELP!
Post by: bob12345123 on Nov 3, 2012
1) How do cells of the same type form different shapes? For example a nose

That is an extensive embryology question. I believe neural crest cells lead to nose formation

3) Do non-replicating cells such as nerve cells mutate without external factors such as radiation?

They can, but it is much less likely. Mutations that lead to cancer usually involve many "hits" to the cell's genome, and these hits are not likely to happen in one cell. The first hit happens, then the cell produces a thousand more of itself, then one of those gets another hit, etc.