Question

What are the barriers that need to be broken down to extract DNA out of a plant cell?

Answer 1

Deoxyribonucleic acid (DNA) can be considered the hereditary "code of life" because it possesses the information that determines an organism's traits and is transmitted from one generation to the next. DNA can be compared to a recipe or a list of instructions about how to create and maintain a specific living thing. The DNA in an individual's cells contains unique genetic instructions about how to make and operate that individual. 

DNA can be removed from organisms through a common and useful scientific procedure called DNA extraction. In order to understand this process, it is useful first to identify the basic structures that hold DNA molecules within living things.

Cells

DNA is located inside the cells of all species. However, different organisms are made up of different types of cells. Members of the Animal, Plant, Protist (algae, amoebas, paramecia, etc.), and Fungi (mushrooms, yeasts, molds, etc.) kingdoms are comprised of eukaryotic cells. This means that these cells have a true nucleus, a membrane bound organelle within which the DNA is contained. The nucleus of eukaryotic cells is the "control center" that directs all cellular activities. Members of the kingdom Monera (bacteria and cyanobacteria) are comprised of prokaryotic cells that do not have nuclei. In these cells, DNA exists as a long loop coiled loosely within the cytoplasm of the cell. 
The nucleus of eukaryotic cells is surrounded by a nuclear membrane (also called a nuclear envelope) and the entire cell is bound by a cell membrane (also called a plasma membrane). These barriers are both made up of two layers of fatty, oily compounds called lipids. The most abundant types of membrane lipids are phospholipids. These molecules have hydrophilic ("water-loving") heads linked by a phosphate group to two hydrophobic ("water-hating") tails. The formation and stability of cell membranes is based on the orientation of phospholipid molecules in an aqueous (watery) environment. In such surroundings, phospholipids form a barrier of two rows with their hydrophobic tails facing each other (away from water) and their hydrophilic heads pointed outward (in contact with the aqueous environment). This two-layered structure is known as a phospholipid bilayer Protein and carbohydrate molecules are also imbedded within the phospholipid bilayer of cell membranes to transport particular molecules into and out of the 
cell, and to conduct cellular messages. (see Figure below).



All eukaryotic cells have a nuclear membrane that encircles the nucleus, as well as a cell membrane that encases the entire cell. However, plant cells (and some bacterial, fungal, and protist cells) have an additional barrier surrounding the cell membrane called a cell wall. Animal cells do not have cell walls. Plant cell walls are made of cellulose, which is a sturdy polysaccharide material comprised of glucose units. Cellulose gives plants their rigidity and provides a tough barrier that enables plant cells to hold a great deal of fluid without bursting.