The gel consists of a permeable matrix, a bit like a sieve, through which molecules can travel when an electric current is passed across it. Smaller molecules migrate through the gel more quickly and therefore travel further than larger fragments that migrate more slowly and therefore will travel a shorter distance.

It is a protein which plays an important role in the immunological defense of certain bacteria against DNA viruses. It has become more well-known due to its uses in genetic engineering. Type I and Type II restriction endonucleases are multisubunit complexes that include endonucleases and methylase activities.

Which of the following is not made of protein: hair, muscle, cellulose, or enzymes? Cellulose is a carb. What are the monomers of all proteins? What is the one part of an amino acid that varies?

The tens of thousands of processes and reactions that happen within our body each day would not be possible without proteins. Hormones such as insulin are proteins. The enzymes that help to break down our foods, or trigger key processes in the body, are proteins.

This is called ketosis. Ketosis can cause side effects such as bad breath, headache, fatigue and weakness. It’s not clear what kind of possible long-term health risks a low-carb diet may pose. Restricting carbs in the long term they may result in vitamin or mineral deficiencies and gastrointestinal disturbances.

Carbohydrates are foods that get converted into glucose, or sugar, in our bodies during digestion. Glucose is a main source of fuel for our body. It is especially important for the brain, which cannot easily use other fuel sources (such as fat or protein) for energy.

The keto diet could cause low blood pressure, kidney stones, constipation, nutrient deficiencies and an increased risk of heart disease. Strict diets like keto could also cause social isolation or disordered eating. Keto is not safe for those with any conditions involving their pancreas, liver, thyroid or gallbladder.

[1] Nucleic acid molecules are separated by applying an electric field to move the negatively charged molecules through an agarose matrix. Shorter molecules move faster and migrate farther than longer ones because shorter molecules migrate more easily through the pores of the gel.

Small DNA molecules move more quickly through the gel than larger DNA molecules. The result is a series of ‘bands’, with each band containing DNA molecules of a particular size. The bands furthest from the start of the gel contain the smallest fragments of DNA.

How does the DNA rate of travel differ for small DNA fragments and large DNA fragments? Small fragments travel farther than large fragments. A high voltage rate will cause the DNA fragments to move slowly across the gel. A DNA fragment with 100 base pairs is smaller than a DNA fragment with 150 base pairs.

Shorter DNA segments find more pores that they can wiggle through, longer DNA segments need to do more squeezing and up or down moving. For this reason, shorter DNA segments move through their lane at a faster rate than longer DNA segments.

The mass of the DNA fragment depends on the length of the DNA fragment. The longer the DNA fragment ,the more atoms it contains so the more electrons it contains .

First, work out the frequency of occurrence of the restriction site as 1-in-x bases, as explained in the example for the Intermediate level calculation. Then take the size of the DNA in kb (kilobases) and multiply by 1000 to get the size in bases. Divide this by x and round to the nearest whole number.

Restriction enzymes

What two properties can be used to separate DNA fragments? Size and shape.

Like other organisms, bacteria use double-stranded DNA as their genetic material. However, bacteria organise their DNA differently to more complex organisms. Bacteria have a single circular chromosome that is located in the cytoplasm in a structure called the nucleoid.

Thus, bacterial genomes are only about 0.1% as big as the human genome, and have about 10% as many genes as we do. A comparison of those two percentages shows immediately that in bacteria the “gene density” (how many genes there are per unit length along the genome) is much higher than in humans.

Just as humans are susceptible to viruses, bacteria have their own viruses to contend with. These viruses – known as phages – attach to the surface of bacterial cells, inject their genetic material, and use the cells’ enzymes to multiply while destroying their hosts.

Bacteria are classified into five groups according to their basic shapes: spherical (cocci), rod (bacilli), spiral (spirilla), comma (vibrios) or corkscrew (spirochaetes). They can exist as single cells, in pairs, chains or clusters.