Search found 23 matches

by Chemhalp
Sat Jan 24, 2009 6:19 pm
Forum: Evolution
Topic: The Hardy-Weinburg equation describes a situation...
Replies: 3
Views: 3758

Re: The Hardy-Weinburg equation describes a situation...

I have had a think about it and I could only decide that H-W equilibrium wouldn't take place if the conditions for HW were incorrect A small population size which would cause genetic drift right? That covers two of the principals right? large pop size and no gene flow... If the alleles in the popula...
by Chemhalp
Sat Jan 24, 2009 5:15 pm
Forum: Evolution
Topic: The Hardy-Weinburg equation describes a situation...
Replies: 3
Views: 3758

The Hardy-Weinburg equation describes a situation...

The Hardy-Weinburg equation describes a situation where there is no change in allele frequencies. Describe four scenarios where Hardy-Weinberg no longer applies. My exam is on monday and I have misplaced my lecture notes pertaining to this subject, I've search all over the net but can't find four sc...
by Chemhalp
Sat Aug 02, 2008 3:40 pm
Forum: Cell Biology
Topic: Glycolysis + Glycogen
Replies: 10
Views: 14903

So if the body was hypoglycemic, the glycogen can be converted back to G6P and then converted to Glucose anyway?

Stupid essay question trying to trick me
by Chemhalp
Sat Aug 02, 2008 2:01 pm
Forum: Cell Biology
Topic: Glycolysis + Glycogen
Replies: 10
Views: 14903

Glycolysis + Glycogen

Explain the difference in atp yield when glycogen rather than glucose is used as the starting point glycolysis In outlining the process of glycolysis explain the difference in atp yield when glycogen rather than glucose is used as the starting point : Please give me a full essay answer, or notations...
by Chemhalp
Sat Apr 26, 2008 10:11 pm
Forum: Molecular Biology
Topic: Exponential Growth and Decay
Replies: 11
Views: 7433

or...

75 is the number of colonies and not the number of cells so you have to divide the number of colonies by the dilution factor which was 10^-6 and then x 100 to get the number of cells in 10ml. I got 7.5x10^9.

Then ln(7.5x10^9/270) /ln2 = 24.7
so the number of divisions is 24

maybe?
by Chemhalp
Sat Apr 26, 2008 12:10 am
Forum: Molecular Biology
Topic: Exponential Growth and Decay
Replies: 11
Views: 7433

log(x^n) = nlog(x).

right right?

or log(27.7777778) / log(2) = 4.79585928

Right?

I can't tell if i've done question 1 right at all :(
by Chemhalp
Thu Apr 24, 2008 11:25 pm
Forum: Molecular Biology
Topic: Exponential Growth and Decay
Replies: 11
Views: 7433

ah yeah, exponential growth not decay

Cheers,

So its 75/2.7 = 2^n, right

2^n = 27.7777778

How do I go on from there?
by Chemhalp
Thu Apr 24, 2008 9:49 pm
Forum: Molecular Biology
Topic: Exponential Growth and Decay
Replies: 11
Views: 7433

Re: Exponential Growth and Decay

Ok just had a look at question 1 again... 270 cells in 10ml then 100 microlitres taken So... 10000/100 = 100 so 270/100 = 2.7 So... starting with 27 and ending with 75 is what I have right? original stuff * (1/2)^n = stuff left as you said above So... 2.7 * 0.5^(n) = 75 75/2.7 = 0.5^(n) But that giv...
by Chemhalp
Thu Apr 24, 2008 4:03 pm
Forum: Molecular Biology
Topic: Exponential Growth and Decay
Replies: 11
Views: 7433

Yeah it makes sense, it should be around an 8th (0.125) anyway so I guess its right.

Can I use the formula you gave for all of the questions?
by Chemhalp
Wed Apr 23, 2008 7:58 pm
Forum: Molecular Biology
Topic: Exponential Growth and Decay
Replies: 11
Views: 7433

Re: Exponential Growth and Decay

So for question three,

42 days / 13 day half life = 3.23
ergo
0.5^3.23 = 0.106579361, which is fraction of the sample after the 6 weeks?
by Chemhalp
Wed Apr 23, 2008 6:11 pm
Forum: Molecular Biology
Topic: Exponential Growth and Decay
Replies: 11
Views: 7433

Exponential Growth and Decay

So I have been given a couple of questions from my tutor however I have no idea where to start, I'm not asking for the answers just a push in the right direction. 1) 270 Vibrio cholerae cells were inoculated into 10 ml of a liquid culture and incubated for 9 hours. At the end of this time the cells ...
by Chemhalp
Thu Jan 17, 2008 12:52 pm
Forum: Molecular Biology
Topic: Absorbance - Spectrophotometer
Replies: 11
Views: 13159

With the same extinction coefficient from which one? I'll just do the working out (or try to) 1ml tryptophan stock with 19ml water is a 20 fold change, so you divide the observed absorbance by the extinction coefficient and multiply by 20? or (Observed absorbance/Extinction Coefficient)*20 and the s...