1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
tia_tia [17]
2 years ago
15

PLEASEEE HELP!! Ill mark brainlist

Biology
1 answer:
zalisa [80]2 years ago
4 0

Electrophoresis is a technique commonly used in the lab to separate charged molecules, like DNA, according to size.

Gel electrophoresis is a technique commonly used in laboratories to separate charged molecules like DNA?, RNA? and proteins? according to their size.

Charged molecules move through a gel when an electric current is passed across it.

An electric current is applied across the gel so that one end of the gel has a positive charge and the other end has a negative charge.

The movement of charged molecules is called migration. Molecules migrate towards the opposite charge. A molecule with a negative charge will therefore be pulled towards the positive end (opposites attract!).

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. As a result the molecules are separated by size.

Gel electrophoresis and DNA

Electrophoresis enables you to distinguish DNA fragments of different lengths.

DNA is negatively charged, therefore, when an electric current is applied to the gel, DNA will migrate towards the positively charged electrode.

Shorter strands of DNA move more quickly through the gel than longer strands resulting in the fragments being arranged in order of size.

The use of dyes, fluorescent? tags or radioactive? labels enables the DNA on the gel to be seen after they have been separated. They will appear as bands on the gel.

A DNA marker with fragments of known lengths is usually run through the gel at the same time as the samples.

By comparing the bands of the DNA samples with those from the DNA marker, you can work out the approximate length of the DNA fragments in the samples.

How is gel electrophoresis carried out?

Preparing the gel

Agarose gels? are typically used to visualise fragments of DNA. The concentration of agarose used to make the gel depends on the size of the DNA fragments you are working with.

The higher the agarose concentration, the denser the matrix and vice versa. Smaller fragments of DNA are separated on higher concentrations of agarose whilst larger molecules require a lower concentration of agarose.

To make a gel, agarose powder is mixed with an electrophoresis buffer and heated to a high temperature until all of the agarose powder has melted.

The molten gel is then poured into a gel casting tray and a “comb” is placed at one end to make wells for the sample to be pipetted into.

Once the gel has cooled and solidified (it will now be opaque rather than clear) the comb is removed.

Many people now use pre-made gels.

The gel is then placed into an electrophoresis tank and electrophoresis buffer is poured into the tank until the surface of the gel is covered. The buffer conducts the electric current. The type of buffer used depends on the approximate size of the DNA fragments in the sample.

Preparing the DNA for electrophoresis

A dye is added to the sample of DNA prior to electrophoresis to increase the viscosity of the sample which will prevent it from floating out of the wells and so that the migration of the sample through the gel can be seen.

A DNA marker (also known as a size standard or a DNA ladder) is loaded into the first well of the gel. The fragments in the marker are of a known length so can be used to help approximate the size of the fragments in the samples.

The prepared DNA samples are then pipetted into the remaining wells of the gel.

When this is done the lid is placed on the electrophoresis tank making sure that the orientation of the gel and positive and negative electrodes is correct (we want the DNA to migrate across the gel to the positive end).

Separating the fragments

The electrical current is then turned on so that the negatively charged DNA moves through the gel towards the positive side of the gel.

Shorter lengths of DNA move faster than longer lengths so move further in the time the current is run.

The distance the DNA has migrated in the gel can be judged visually by monitoring the migration of the loading buffer dye.

The electrical current is left on long enough to ensure that the DNA fragments move far enough across the gel to separate them, but not so long that they run off the end of the gel.

Illustration of DNA electrophoresis equipment used to separate DNA fragments by size. A gel sits within a tank of buffer. The DNA samples are placed in wells at one end of the gel and an electrical current passed across the gel. The negatively-charged DNA moves towards the postive electrode. Image credit: Genome Research Limited

tank.

You might be interested in
collagen is a protein found in connective tissue in animals and lysozyme is a protein that breaks down bacterial cell walls. Aft
Stells [14]
<h2>The Protein Structure</h2>

Explanation:

  • Protein structure is the three dimensional game plan of particles in an amino corrosive chain atom.
  • Proteins are polymers explicitly polypeptides framed from groupings of amino acids, the monomers of the polymer.By show, a chain under 30 amino acids is regularly distinguished as a peptide, rather than of a protein.  
  • All proteins have primary, auxiliary and tertiary structures yet quaternary structures possibly emerge when a protein is comprised of at least two polypeptide chains.
  • The collapsing of proteins is additionally determined and fortified by the arrangement of numerous bonds between various pieces of the chain.
  • Connective tissues for the most part have barely any cells and extensive extracellular filaments including collagen and elastin.
  • Collagen is the absolute most  abundant protein in the creature body and establishes roughly 25–35% of the entire body content.
6 0
3 years ago
This is a homogeneous, generally clear jelly-like material that fills cells.
Rama09 [41]
Its is c<span>ytoplasm to that answer</span>
7 0
3 years ago
The difference in concentration between solutions on either side of a cell membrane is?
SpyIntel [72]

The difference in concentration between solutions on either side of a cell membrane is a concentration gradient.

In the field of biology, a concentration gradient can be described as a difference in the concentration of molecules inside and outside of a cell. It is due to concentration gradient that molecules move into and out of a cell through the cell membrane.

Some molecules move from an area of higher concentration gradient to an area of lower concentration along the concentration gradient. Diffusion is an example of such a process.

On the other hand, some molecules move from an area of lower concentration to an area of higher concentration against the concentration gradient. Active transport is an example of such a process.

To learn more about concentration gradient, click here:

brainly.com/question/13814995

#SPJ4

7 0
1 year ago
A) Chromosome B) DNA nucleotide C) Codon D) Gene
Gre4nikov [31]
The answer os C
C D B A
4 0
3 years ago
Read 2 more answers
Learning objective: 12.08.05 describe the initiation and propagation of depolarization and repolarization.
denis-greek [22]
Depolarization is initiated when there is an influx of sodium inside the cell as opposed to repolarization, where potassium exits the cell (occurring after Na+ gates close). Remember that for every 3 Na+ in, there is 2 K+ out. This imbalance helps to stabilize the membrane.
7 0
3 years ago
Other questions:
  • Which gland helped Elisa to lift the branch?
    15·2 answers
  • The classifications system changed from seven to get. This happened because
    11·1 answer
  • How can fertilizer use be detrimental to the environment?
    6·2 answers
  • What is the advantage of crossing-over?
    15·1 answer
  • When a muscle lengthens as it contracts, the movement is referred to as an eccentric contraction.
    7·1 answer
  • 2. How many substances are there in the unlabeled mixture? What were they?
    6·1 answer
  • According to United States predictions, what will be the total population of the world by 2100?
    7·1 answer
  • Which of the following is an example of organic matter?
    10·1 answer
  • Are all nerve cells are connected to the brain?
    15·2 answers
  • What type of mutation occurred?
    12·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!