#denaturing

The three parts of the experiment have led to good results that we can use to validate our hypothesis. The results clearly show that as enzyme concentration increases to rate of reaction also increases. This is because. For Part 2 of the experiment we also gained excellent results. The results gained concur with the prediction made and further validate the hypothesis. The greatest rate of…

Denaturing DNA DNA can be made single stranded by:

heating to 80 degrees +

adding a strong alkali 

Once single stranded (ss) DNA will hybridise (join) with other complementary ss DNA or RNA.

e.g RNA probe AAAGCTTGCCCA will find and hybridise with TTTCGAACGGGT

Restriction enzymes Bacteria have DNA which cleave (cut up) DNA of the virus so it can't take over, protecting its own DNA.

Type II restriction enzymes cut DNA within a specific sequence of bases called a recognition sequence which hydrolizes the phosphodiester bonds.

If the enzymes cut zigzag or diagonally through DNA it will produce 'sticky ends', if the enzymes cut straight through it will produce 'blunt ends'.

Gel Electrophoresis The gel can be used to separate DNA fragments of different sizes 

Smaller fragments move further

fragments move towards either positive/negative end

Transformation Plasmids are self-replicating, circles of DNA, which occur naturally in bacteria cells. 

Please. Don't hate mascarpone cheese just because Giada de Laurentiis insists on saying "MOSS-CAR-PONE-AY" in that torturously put-upon Italian way.

Mascarpone cheese, like Giada, is Italian in its origin. It comes from the area southwest of Milan, where it was first made around the late 16th or early 17th Centuries.

Making mascarpone starts with cow's milk crème fraiche, which is sort of a French style of sour cream. Unlike American sour cream, crème fraiche is much milder in flavour and isn't as "sour." It also has a higher fat content (the French really know what's important) and isn't as thick. It's made by adding bacterial culture (like the kinds found in yogurt or buttermilk) to heavy cream and letting them do their thing.

The crème fraiche is then denatured using our old friend tartaric acid. Denaturing is a chemical process that involves breaking down the structures of proteins (and nucleic acids, but in the case of mascarpone we're talking about proteins).

Protein molecules are basically long strings, like strands of pearls. Each pearl is an amino acid, and the specific order of those amino acids is called the protein's "primary structure." Parts of the string will then fold around themselves to create different localized shapes, like zig-zags and spirals; these parts are called the protein's "secondary structure." The various secondary structures then fold on themselves again to bring the whole protein into its final shape, called the "tertiary structure."

When you denature a protein, you break down its tertiary and secondary structures, essentially unfolding it back to a string. Depending on the protein, this can have many different effects, but usually in the case of food it involves making things less soluble in water (less liquid) and more solid. For example, when you cook an egg the heat is denaturing the proteins, which you can see as the white going from clear and liquidy to opaque and solid.

So you can see how the tartaric acid, by denaturing the proteins in the milk, would make the crème fraiche less liquid and more solid like a cheese. Because mascarpone is a "young" cheese, it isn't aged or pressed to remove the whey (the liquid part of cheese; remember Little Miss Muffet, with her tuffet and curds and whey?). When it's done, mascarpone is a triple-cream cheese (meaning it has a fat content of 75%) that should have a milky white colour and is easily spreadable at room temperature.

If you're a fan of cheesecake, I'd suggest giving mascarpone a whirl. It definitely takes it to the next level over good ol' Philadelphia.