Search found 778 matches

by biohazard
Mon Nov 12, 2007 1:31 pm
Forum: Microbiology
Topic: fungal disease vs bacterial disease
Replies: 4
Views: 57739

Fungal diseases are difficult to treat mainly because they are eukaryotic organisms just like us humans, and therefore have less differences for drugs to target without harming the human body as well. Most antibiotics target e.g. the peptidoglycan layer in the bacterial (a prokaryote) cell wall, whi...
by biohazard
Mon Nov 12, 2007 1:11 pm
Forum: Microbiology
Topic: deep mycosis
Replies: 1
Views: 3442

Probably the most profound group of people affected by systemic fungal infections is those who are in a state of immunosuppression: this can be due to some persistent primary infection (often AIDS, but can be others as well), ongoing chemotherapy or other immunosuppressive treatment. Furthermore, ce...
by biohazard
Tue Oct 30, 2007 9:48 am
Forum: Molecular Biology
Topic: dsRNA
Replies: 8
Views: 4045

In addition to the high error rate of RNA synthesis, I think one profound aspect is the great stability of DNA. For various reasons, (such as the DNA helix itself, ans well as proteins that assist DNA packaging) DNA is much more stable than RNA in just about all cases I can think of - be that heat, ...
by biohazard
Mon Oct 22, 2007 10:50 am
Forum: Cell Biology
Topic: viruses
Replies: 10
Views: 7392

Agreed.

I sort of meant that the lipid membrane is "borrowed" from the cell when the virus exits, even though it often is crucial for the proper functioning of the virus. Then again, one could probably say that everything in a virus is borrowed (or stolen) from the host cell anyway...
by biohazard
Sun Oct 21, 2007 5:20 pm
Forum: Cell Biology
Topic: viruses
Replies: 10
Views: 7392

Uhuh... define what you mean with chemical substances? Viruses can contain a lot of different stuff, including macromolecules such as DNA or RNA, as well as proteins in their capsule or as enzymes inside the capsule. Furthermore, several viruses have lipid envelopes, which they have acquired when bu...
by biohazard
Wed Oct 17, 2007 8:11 am
Forum: Molecular Biology
Topic: What gas is liberated from hydrogen peroxide?
Replies: 11
Views: 7397

Jammerz wrote:Catalase breaks down hydrogen peroxide, doesn't it?


Yes.
by biohazard
Wed Oct 17, 2007 6:55 am
Forum: Evolution
Topic: mammary gland of male in mammals
Replies: 18
Views: 31546

Actually, if we go nitpicking here, mammary glands aren't completely inoperative in males, one could say that they are rather "dormant" - with proper hormonal treatment, certain men can even lactate. And like someone earlier said, men can also have breast cancer, which pretty much indicate...
by biohazard
Sun Sep 30, 2007 1:26 pm
Forum: Microbiology
Topic: blood agar hemolysis by gram negative bacteria?
Replies: 3
Views: 14709

Firstly, I presume you are talking about beta hemolytic bacteria here - although my reply will cover a bit of the alpha type too. Secondly, no, you cannot assume there aren't hemolytic gram negative bacteria, even though the references are scarce If memory serves me right, Pseudomonas aeruginosa is ...
by biohazard
Sun Sep 30, 2007 1:03 pm
Forum: Cell Biology
Topic: Cells and pH
Replies: 5
Views: 17971

Well, few quick answers: 1. Do you mean the pH inside or outside the cells? Although the answer is partially the same in both: cellular metabolism affects the cytoplasmic pH, and as a result also the pH of the surrounding medium. The growth environment naturally affects as well. Blood cells, for exa...
by biohazard
Sun Sep 30, 2007 12:39 pm
Forum: Cell Biology
Topic: Cells - Slow Freeze & Fast Thaw
Replies: 8
Views: 12771

During freezing, water forms ice crystals that damage the cell membrane. Hence mammalian and other sensitive cells usually die no matter how you freeze them, unless you put some additives to the freezing medium - such as DMSO. The optimal rate of freezing is around 1 degree of Celsius per minute, if...