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4 years ago

Describe three characteristics of cell membranes

Biology

1 answer:

Phoenix [80]4 years ago

4 0

Answer:

Explanation:

The cell membrane, also called the plasma membrane, has the following characteristics:-

It is present as the outermost layer in animal cells and lies below the cell wall in plant cells.

The cell membrane surrounds the cytoplasm of living cells, physically separating the intracellular components from the extracellular environment.

The cell membrane is semi-permeable, ie, it allows some substances to pass through it and does not allow others.

It is thin, flexible and a living membrane, which consists of a lipid bilayer with embedded proteins/

The cell membrane has large content of proteins, typically around 50% of membrane volume. These proteins are important for cell because they are responsible for various biological activities.

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Put the steps to produce spider silk protein in yeast in the correct order. 1 Purify protein. 2 Join yeast regulatory sequence a

Anuta_ua [19.1K]

<h2>The correct sequence is: 4>2>3>5>1.</h2>

Explanation:

The given question shows the sequence in which silk encoding gene from spider can be expressed in yeast in order to produce Recombinant Silk.
Originally, silk can be obtained from spider. But for the commercial production and meeting the high demand of silk it is not economical to depend on spider to produce silk as they not only take long time to produce silk them but also they have a longer life-cycle and longer generation time as a result of which the quantity of silk obtained by spider per generation is very low. Also, spiders require specialized habitat and complex nutrient for their survival.
Hence, yeast, an unicellular eukaryote, which has a shorter generation time and simple nutrient requirement for its survival, can be used for the commercial production of silk.
For this, initially a yeast gene which is constitutively expressed in yeast is selected and the coding region of this gene is removed with the help of enzymes, keeping the regulatory sequences like the promoter, enhancer, terminator, etc, intact in the 5' and 3' region of the gene.
A constitutive gene is the one which is expressed continuously at large amounts. This will result in the increased synthesis of the recombinant silk protein.
Next, the coding sequence of the gene encoding for silk protein which is obtained from the spider is joined with the help of enzymes to the regulatory gene sequences of the yeast which was obtained in the first step.
Next, this recombinant gene comprising of the yeast regulatory sequence and the coding region of the gene encoding for silk obtained from spider is inserted into the yeast cells.
Next, the yeast cells are allowed to express the silk coding gene by the process of transciption and translation utilizing the yeast specific RNA (Ribonucleic acid) polymerase (recognizes the yeast-specific promoter and enhancer in the recombinant gene) and yeast-specific ribosome, respectively.
The recombinant silk protein produced in the yeast can then be subjected to purification.

5 0

4 years ago

If you cross an AAbb individual with an aabb individual, what will the genotype ratio be in the next generation? What will be th

UkoKoshka [18]

Answer:

Genotype of offspring = Aabb

Genotype ratio will be 100 % as all the offspring will have the same genotype

Phenotypic ratio = 100% all the offspring will have the same phenotype

Explanation:

Genotype of First parent - AAbb

Genotype of Second Parent - aabb

Gamete of first parent - Ab, Ab, Ab, Ab

Gamete of second parent - ab, ab, ab, ab

All the offspring will have genotype Aabb

Phenotypic ratio = 100% all the offspring will have the same phenotype

7 0

3 years ago

What is the value of a transitional fossil? A. Transitional forms show the evolutionary steps between species. B. Transitional f

Ira Lisetskai [31]

<span>the value of a transitional fossil is : A. Transitional forms show the evolutionary steps between species
For example, take a look at human's transitional fossil. Through the fossil, we became aware about the evolution that happened within the human species and we can observe how we developed from a monkey-like organisms into a more superior organism as we are today</span>

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3 years ago

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What is relationship between light intensity and gas production?

marissa [1.9K]

The photosynthesis I guess

3 0

4 years ago

Flat, ribbon like animals are found in the ______- phylum

Brums [2.3K]

<span>Platyhelminthes phylum. This phylum is known for its flatworms, like planaria, tapeworms and flukes, that later being completely parasitic.</span>

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3 years ago