Name: interphase and cell growth
Uploaded: 2025-05-22T09:05:54.000Z
Duration: 56 s
Channel: JoVE

Nelle cellule eucariotiche, la maggior parte del ciclo cellulare è l'interfase, che è divisa in tre fasi, G1, S e G2.
 In G1, la prima fase di gap, una cellula figlia appena generata cresce di dimensioni e si prepara per la duplicazione del DNA nella fase successiva.
Ora, nella S, la fase di sintesi, le cellule duplicano il loro DNA nucleare, che rimane impacchettato come cromatina. Le cellule duplicano anche i centrosomi, la struttura organizzativa dei microtubuli che forma l'apparato del fuso mitotico.
Infine, in G2, la seconda fase di gap, le cellule continuano a crescere, moltiplicare gli organelli e le proteine necessarie per la mitosi e ricostituire le loro riserve di energia. La cellula è ora pronta per entrare nel primo stadio della mitosi.

interfase

Interphase

Il ciclo cellulare avviene nell'arco di circa 24 ore (in una tipica cellula umana) e in due fasi distinte: interfase, che comprende tre fasi del ciclo cellulare (G1, S e G2), e mitosi (M). Durante l'interfase, che occupa circa il 95% della durata del ciclo cellulare eucariotico, le cellule crescono e replicano il loro DNA in preparazione alla mitosi.

Fasi dell'interfase

Dopo ogni periodo di mitosi e citocinesi, le cellule eucariotiche entrano nell'interfase, durante la quale crescono e replicano il loro DNA in preparazione alla successiva divisione mitotica.

Durante la fase G1 (gap 1), le cellule crescono continuamente e si preparano per la replicazione del DNA. Durante questa fase, le cellule sono metabolicamente attive e copiano organelli essenziali e molecole biochimiche, come le proteine.

Nella successiva fase S (sintesi) dell'interfase, le cellule duplicano il loro DNA nucleare, che rimane confezionato nella cromatina semi-condensata. Durante la fase S, le cellule duplicano anche il centrosoma, una struttura che organizza i microtubuli che formano l'apparato del fuso mitotico. Il fuso mitotico separa i cromosomi durante la mitosi.

Nella fase G2 (gap 2), che segue la sintesi del DNA, le cellule continuano a crescere e sintetizzare proteine e organelli per prepararsi alla mitosi.

Nelle cellule umane, la fase G1 dura circa 11 ore, la fase S dura circa 8 ore e la fase G2 dura circa 4 ore. Durante G1, le cellule sono diploidi (2n, una coppia di ciascun cromosoma). Dopo la replicazione nella fase S, le cellule aumentano il loro contenuto di DNA a 4n. Le cellule rimangono 4n fino alla citocinesi, a quel punto il loro contenuto di DNA si riduce a 2n.

Interfase

Il ciclo cellulare si svolge nell'arco di circa 24 ore (in una tipica cellula umana) e in due fasi distinte: l'interfase, che comprende tre fasi del ...

Education

Didattica

JoVE Core

Anatomy and Physiology

Anatomia e Fisiologia

Unit 1

Unità 1

Essential Cellular Processes

Processi cellulari essenziali

KEY TERMS AND CONCEPTS

TERMINI E CONCETTI CHIAVE

interphase and cell growth

Interphase is the part of the cell cycle when a cell grows and prepares to divide. It is a major stage of the cell cycle, and it comes before cell division begins.

During interphase, the cell carries out its normal functions. It also copies its DNA so each new cell can receive a full set of genetic material. The cell may also build up the materials it needs for division.

Interphase is not a single step. It includes phases such as G1, S, and G2, which help the cell grow, copy DNA, and get ready for mitosis. These steps keep the cell cycle moving in an orderly way.

Interphase and Cell Growth

the central dogma

Central Dogma: DNA to Protein

The central dogma explains how genetic information flows in cells from DNA to RNA to protein. It is a core idea in molecular biology and helps show how genes influence cell function. DNA stores the instructions. During transcription, a cell copies a gene into RNA, which is a related nucleic acid. That RNA message can then be used in translation to build a protein. Proteins carry out many jobs in cells and help determine traits. The central dogma links the genetic code in DNA to the molecules...

replication in eukaryotes

Eukaryotic DNA Copying at the Replication Fork

Eukaryotic DNA copying happens at replication forks, where the two DNA strands separate and new strands are built. This process lets a cell make an exact copy of its genetic material before it divides. The transcript explains that eukaryotic replication follows the same basic steps seen in other DNA replication systems, but it takes place in cells with a nucleus. The replication machinery works on each separated strand as a template, so the new DNA matches the original sequence. This topic is...

types of rna

RNA Types in Gene Expression

RNA types play different roles in gene expression. RNA, or ribonucleic acid, helps carry and use genetic information in cells. The main types discussed here are messenger RNA, ribosomal RNA, and transfer RNA. Messenger RNA, or mRNA, carries the genetic code from DNA to the ribosome. The ribosome is the site where proteins are made. Ribosomal RNA, or rRNA, is a key part of the ribosome itself. Transfer RNA, or tRNA, brings the correct amino acids to the ribosome during protein building. These...

transcription

Transcription and RNA Synthesis

Transcription is the process of making RNA from a DNA template. It is a key step in gene expression, because cells use the DNA sequence to build an RNA copy that can carry the message forward. During transcription, RNA polymerase binds to DNA and reads one strand as the template. The enzyme links RNA nucleotides together in the correct order to form a growing RNA molecule. This copying step does not make DNA; it produces RNA. The transcript focuses on the central idea of transcription as DNA...

translation

Translation: mRNA to Protein

Translation is the step in gene expression where ribosomes use messenger RNA, or mRNA, to build a protein. The mRNA sequence carries the instructions copied from DNA. During translation, those instructions are read in order so the cell can make a specific chain of amino acids. This process depends on the ribosome and transfer RNA, or tRNA. The ribosome reads the mRNA, and tRNA brings the matching amino acids. As the chain grows, the amino acids are linked together to form a polypeptide, which...

regulation of expression at multiple steps

regulation-of-expression-at-multiple-steps

How Cells Control Gene Expression

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what is the cell cycle?

Cell Cycle Stages in Cell Growth

The cell cycle is the process that controls cell growth and division. It explains how one cell makes two new cells. This process helps cells grow and reproduce.

interphase

Interphase is the part of the cell cycle when a cell grows and prepares to divide. It is a major stage of the cell cycle, and it comes before cell division begins. During interphase, the cell carries out its normal functions. It also copies its DNA so each new cell can receive a full set of genetic material. The cell may also build up the materials it needs for division. Interphase is not a single step. It includes phases such as G1, S, and G2, which help the cell grow, copy DNA, and get...

mitosis and cytokinesis

Cell Division: Mitosis and Cytokinesis

Cell division depends on mitosis and cytokinesis. Mitosis is the stage when the cell’s nucleus divides and the copied chromosomes are separated into two sets. Cytokinesis is the step that follows and splits the cell into two daughter cells. These two processes work together to make sure each new cell receives genetic material and its own cytoplasm. Mitosis keeps the chromosome sets organized, while cytokinesis finishes the division of the whole cell. Together, they create two separate cells...

the cell cycle control system

Cell Cycle Checkpoints and Cyclin Control

The cell cycle is controlled by checkpoints that help a cell move from one phase to the next and begin mitosis. This control system uses internal regulatory molecules and outside signals to send stop or advance instructions. It makes sure each step is finished before the cell moves forward. Cyclins and cyclin-dependent kinases, or Cdks, are the main regulators of the cell cycle. They act during the G1, G2, and M phases. These regulators work at specific checkpoints to keep cell division...

molecular factors affecting cell division

molecular-factors-affecting-cell-division

Cell Cycle Regulators That Control Division

Cell division is controlled by outside signals and by internal cell cycle regulators. Nearby cell death can encourage division, and human growth hormone (hGH) can also promote it. In contrast, too little hGH or crowded cells can slow or stop division. Inside the cell, regulator molecules help each stage finish correctly before the next stage begins. Some regulators act directly on the cycle, while others affect the activity or production of other regulatory proteins. These molecules can either...

what is meiosis?

Meiosis and the Formation of Gametes

Meiosis is the cell division process that forms gametes, or sex cells. It reduces the chromosome number so offspring can inherit the correct amount of genetic material. This process includes two successive divisions. First, one cell divides, and then the resulting cells divide again. These steps separate the genetic material in a controlled way. Meiosis helps explain how sexual reproduction passes traits from one generation to the next. It is a key topic in high school biology because it...

overview of cell signaling

Cell Signaling Pathways and Responses

Cell signaling pathways and responses help cells communicate and react to changes. Cells send signals to one another, and those signals can trigger a specific response in the target cell. A signal usually begins when a signaling molecule reaches a cell with the right receptor, which is a protein that receives the message. The receptor helps the cell recognize the signal and start the communication process. Inside the cell, the message can move through a signaling pathway. This pathway passes...

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g protein-coupled receptors

G Protein-coupled Receptor Signaling

G protein-coupled receptors are a major class of cell-surface receptors. They help cells detect signals outside the cell and pass that information inward. These receptors are important in many kinds of cell communication. When a signal binds to a G protein-coupled receptor, the receptor changes shape. That change activates a G protein inside the cell. The activated G protein can then start a signaling pathway. This signaling system includes the receptor, the G protein, and the downstream...

cellular differentiation

From Stem Cell to Specialized Cells

Cellular differentiation turns unspecialized cells into specialized cells with specific jobs. This process helps a complex organism, such as a human, develop from a single fertilized egg into a body with many cell types. Nerve cells, muscle cells, and epithelial cells are examples of the final cell types that appear during development. A zygote is the first cell after fertilization. It is a totipotent stem cell, which means it has very high differentiation potential and can form all cell types...

key terms and concepts

Learn how interphase supports cell growth, DNA copying, and preparation for mitosis. A clear high school explanation of this key cell cycle stage.

Interphase and Cell Growth | JoVE K12

anatomy and physiology

JoVE Core Anatomy and Physiology showcases the anatomical and physiological details of the human body in comprehensive, clear, and engaging video animations. This collection of lessons focuses on the structures, components, functions, and requirements of the human body. It is complemented by scientist-in-action videos that demonstrate the application of this knowledge in real-world medical and research settings.

Interphase and Cell Growth

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