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What separates DNA from the rest of the cell? In prokaryotes, the DNA (chromosome) is in contact with the cellular cytoplasm and is not in a housed membrane-bound nucleus. In eukaryotes, however, the DNA takes the form of compact chromosomes separated from the rest of the cell by a nuclear membrane (also called a nuclear envelope).
What separates cells from other cells? The cell membrane, also called the plasma membrane, is found in all cells and separates the interior of the cell from the outside environment.
What separates the DNA from the cytoplasm? The nuclear envelope is a double membrane of the nucleus that encloses the genetic material. It separates the contents of the nucleus from the cytoplasm.
How does DNA divide? The initiation of DNA replication occurs in two steps. First, a so-called initiator protein unwinds a short stretch of the DNA double helix. Then, a protein known as helicase attaches to and breaks apart the hydrogen bonds between the bases on the DNA strands, thereby pulling apart the two strands.
The cytoplasm is the gel-like fluid inside the cell. It is the medium for chemical reaction. It provides a platform upon which other organelles can operate within the cell. All of the functions for cell expansion, growth and replication are carried out in the cytoplasm of a cell.
A Golgi body, also known as a Golgi apparatus, is a cell organelle that helps process and package proteins and lipid molecules, especially proteins destined to be exported from the cell. Named after its discoverer, Camillo Golgi, the Golgi body appears as a series of stacked membranes.
The nuclear envelope is a double membrane of the nucleus that encloses the genetic material. It separates the contents of the nucleus from the cytoplasm. These nuclear pores help to regulate the exchange of materials (such as RNA and proteins) between the nucleus and the cytoplasm.
Interphase is the longest part of the cell cycle. This is when the cell grows and copies its DNA before moving into mitosis. During mitosis, chromosomes will align, separate, and move into new daughter cells. The prefix inter- means between, so interphase takes place between one mitotic (M) phase and the next.
The Mitotic Phase and the G0 Phase. During the multistep mitotic phase, the cell nucleus divides, and the cell components split into two identical daughter cells.
Helicase breaks the hydrogen bonds holding the complementary bases of DNA together (The complementary bases of DNA: A with T, C with G). 3. While separating the two single strands of DNA, a ‘Y’ shape is formed which is called a replication fork.
In the eukaryotic cell cycle, chromosome duplication occurs during “S phase” (the phase of DNA synthesis) and chromosome segregation occurs during “M phase” (the mitosis phase).
After replication, there will be two double-stranded DNAs; each will have one parental DNA strand and one newly synthesized DNA strand. Because the original double-stranded DNA is not conserved but one parental strand is found in each new duplex DNA, replication is said to be semiconservative.
A lysosome is a membrane-bound cell organelle that contains digestive enzymes. They break down excess or worn-out cell parts. They may be used to destroy invading viruses and bacteria. If the cell is damaged beyond repair, lysosomes can help it to self-destruct in a process called programmed cell death, or apoptosis.
A ribosome is a cellular particle made of RNA and protein that serves as the site for protein synthesis in the cell. The ribosome reads the sequence of the messenger RNA (mRNA) and, using the genetic code, translates the sequence of RNA bases into a sequence of amino acids.
In particular, organelles called chloroplasts allow plants to capture the energy of the Sun in energy-rich molecules; cell walls allow plants to have rigid structures as varied as wood trunks and supple leaves; and vacuoles allow plant cells to change size.
The nucleolus is the most conspicuous domain in the eukaryotic cell nucleus, whose main function is ribosomal RNA (rRNA) synthesis and ribosome biogenesis.
The nucleolus is an organelle in the nucleus that plays a key role in the transcription and processing of ribosomal RNA (rRNA). While many studies have highlighted the viscoelastic material state of the nucleolus, how the material properties of the nucleolus affect its function in rRNA biogenesis is not understood.
The Golgi processes proteins made by the endoplasmic reticulum (ER) before sending them out to the cell. Proteins enter the Golgi on the side facing the ER (cis side), and exit on the opposite side of the stack, facing the plasma membrane of the cell (trans side).
The nucleus is where most of the genetic material (genes, DNA) is housed. It is enclosed by a two-layered nuclear membrane that is perforated by pores that regulate the passage of molecules and particles. Within the nucleus is the nucleolus that makes the ribosomes.
The Nucleus & Its Structures
Eukaryotic cells have a true nucleus, which means the cell’s DNA is surrounded by a membrane. Therefore, the nucleus houses the cell’s DNA and directs the synthesis of proteins and ribosomes, the cellular organelles responsible for protein synthesis.
The nucleus is an organelle found in eukaryotic cells. Inside its fully enclosed nuclear membrane, it contains the majority of the cell’s genetic material. This material is organized as DNA molecules, along with a variety of proteins, to form chromosomes.
During telophase, the chromosomes arrive at the cell poles, the mitotic spindle disassembles, and the vesicles that contain fragments of the original nuclear membrane assemble around the two sets of chromosomes. This dephosphorylation results in the formation of a new nuclear membrane around each group of chromosomes.
During this phase, the DNA is uncoiled and called chromatin.
These phases are prophase, prometaphase, metaphase, anaphase, and telophase.
The two strands of the double helix have separated, or ¨unzipped¨, allowing two replication forks to form. As each new strand forms, new bases are added following the rules of base pairing. The result is two DNA molecules identical to each other and to the original molecule.