Titration curves

If you have already read about buffers in Theory section, it’s time to learn a bit about titration curves. First slideshow: Second slideshow: In Singapore 2012 we have to do a titration with unknown amino acid and find what is it from the standard curve made after titration. I found a similar lab protocol with answers so study it carefully. …

Buffers

Here you will find theoretical material about buffers. According to Wikipedia, a buffer (more precisely, pH buffer or hydrogen ion buffer) is an aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa. Its pH changes very little when a small amount of strong acid or base is added to it and thus …

Principles of Gene Mapping & Practice Problems

Let’s get acquainted with gene mapping. A genetic map is simply a representation of the distribution of a set of loci within the genome. The loci included by an investigator in any one mapping project may bear no relation to each other at all, or they may be related according to any of a number of parameters including functional or …

Population genetics II

As you remember, population genetics is the study of genetic variation within populations, and involves the examination and modelling of changes in the frequencies of genes and alleles in populations over space and time. Many of the genes found within a population will be polymorphic – that is, they will occur in a number of different forms (or alleles). Mathematical …

Phylogeny

¬†Evolutionary relationships are pretty important in biology and thus constructing phylogenetic trees is becoming a part of practical exam in almost every biology olympiad. Below you will find some slideshows about UPGMA. UPGMA is a distance method and therefore needs a distance matrix. UPGMA is “ultrametric”, meaning that all the terminal nodes (i.e. the sequences/taxa) are equally distance from the …

Population genetics I

It’s just the right time to start discovering population genetics and understanding basic concepts of Hardy-Weinberg law. Population genetics attempts to describe how the frequency of the alleles which control the trait change over time. To study frequency changes, we analyze populations rather than individuals. Furthermore, because changes in gene frequencies are at the heart of evolution and speciation, population …

Molecular biology

Just found pretty useful The Beginner’s Guide to Molecular Biology HERE. The topics range from The Cell to Biotechnology to Genetics. Also below you will find a brief book Molecular Biology and Applied Genetics. Also I found a comprehensive slideshow of Cell & Molecular Biology.  

Gene interactions

A gene interaction is an interplay between multiple genes that has an impact on the expression of an organism’s phenotype. While the expression of physical traits is often described as the result of inheriting two genes, one at each allele from each parent, it is actually much more complicated. Groups of genes interact with each other, explaining why phenotypes are …