Name: prokaryote chromosomes and plasmids
Uploaded: 2025-08-06T09:37:52.000Z
Duration: 46 s
Channel: JoVE

K12 Standards

north-carolina-k-12-science-standard-course-of-study

North Carolina K-12 Science Standard Course of Study

9-12

Biology

from-molecules-to-organisms-structures-and-processes

From Molecules to Organisms- Structures and Processes

LS.Bio.2.1

Genomic DNA in Prokaryotes

כמו אורגניזמים מורכבים יותר, פרוקריוטים משתמשים ב-DNA כפול תילים כחומר הגנטי שלהם. עם זאת, חד תאיים אלו הם אורגניזמים מאורגנים ומאחסנים DNA אחרת. לתא הפרוקריוט אין גרעין קרום אמיתי.במקום השטח של הציטופלסמה, הנוקלאיד, מאחסנים את כל הגנום שלהם בלולאה אחת. וכרומוזום כפול תקועים. DNA כאן הוא פצע חזק, מפותל מאוד, לאחסון יעיל.בנוסף לגנום המלא, מולקולות DNA כפולות תקועים קטן יותר, פלסמידים, קיימים בציטופלסמה. הם משתכפלים באופן עצמאי מהתא והוא יכול להכיל גנים המעניקים הישרדות תאים כמו התנגדות אנטיביוטית אם נחשף לאנטיביוטיקה כמו אמפיצילין.

מילאן, אלוורו סן. "אבולוציה של עמידות לאנטיביוטיקה בתיווך פלסמיד בהקשר הקליני". מגמות במיקרוביולוגיה 26, מס' 12 (1 בדצמבר 2018): 978–85. <a href="https://doi.org/10.1016/j.tim.2018.06.007" target="__blank">https://doi.org/10.1016/j.tim.2018.06.007</a>.

dna גנומי בפרוקריוטים

<div style="direction:rtl">הגנום של רוב האורגניזמים הפרוקריוטים מורכב מ-DNA דו-גדילי המאורגן לכרומוזום עגול אחד באזור ציטופלזמה הנקרא נוקלואיד. הכרומוזום כרוך בחוזקה, או מפותל, לאחסון יעיל. פרוקריוטים מכילים גם חלקים עגולים אחרים של DNA הנקראים פלסמידים. פלסמידים אלה קטנים יותר מהכרומוזום ולעיתים נושאים גנים המקנים פונקציות אדפטיביות, כגון עמידות לאנטיביוטיקה. <h4>מגוון גנומי בחיידקים</h4> למרות שהגנומים החיידקיים קטנים בהרבה מהגנומים האוקריוטיים, הם משתנים במידה ניכרת בגודלם ובתוכן הגנים. אחד הגנומים הקטנים ביותר של חיידקים הידועים הוא זה של Mycoplasma genitalium, פתוגן המועבר במגע מיני הגורם לזיהומים בדרכי השתן ודרכי המין בבני אדם. גנום M. genitalium הוא באורך 580,076 זוגות בסיסים ומורכב מ-559 (476 מקודדים ו-83 לא מקודדים). בקצה השני של הספקטרום נמצא זן מסוים של Sorangium cellulosum, חיידק שוכן באדמה. הגנום S. cellulosum הוא עצום עבור חיידק והוא באורך 14,782,125 זוגות בסיסים, המקודד ל-11,599 גנים. <h4>חיידקים יכולים לקבל עמידות לאנטיביוטיקה מפלסמידים</h4> לפני גילוי האנטיביוטיקה, פציעות קלות עלולות היו להפוך לקטלניות עקב חוסר היכולת לעצור זיהומים חיידקיים פשוטים. גילוי הפניצילין ב-1928 הוביל את עידן האנטיביוטיקה, המאופיין במהפכה בטיפולים הרפואיים ובעלייה בתוחלת החיים. עם זאת, שימוש יתר באנטיביוטיקה בבני אדם ובבעלי חיים חקלאיים גרם לחיידקים מסוימים לפתח עמידות לאנטיביוטיקה, מה שהפך אותם לפחות יעילים או לא יעילים. גנים של עמידות לאנטיביוטיקה יכולים להינשא על פלסמידים, וזה בעייתי מכיוון שחיידקים רבים יכולים להחליף פלסמידים עם מינים קרובים רחוקים באמצעות תהליך הנקרא צימוד חיידקים. עמידות לאנטיביוטיקה יכולה, אם כן, להתפשט במהירות דרך אוכלוסיות חיידקים, מה שמדגיש את הצורך הדחוף בפיתוח אנטיביוטיקה חדשה.</div>

DNA גנומי בפרוקריוטים

הגנום של רוב האורגניזמים הפרוקריוטים מורכב מדנ"א דו-גדילי המאורגן בכרומוזום מעגלי אחד באזור של ציטופלסמה הנקרא ...

Education

JoVE Core

ביולוגיה

Cellular Processes

תהליכים תאיים

Cell Cycle and Division

מחזור התא והחלוקה

KEY TERMS AND CONCEPTS

מונחים ומושגים מרכזיים

prokaryote chromosomes and plasmids

Most prokaryotes store their DNA in one circular chromosome inside the nucleoid, a region of cytoplasm. This chromosome is double-stranded and tightly wound, or supercoiled, so it fits efficiently inside the cell. Prokaryotes also carry smaller circular DNA pieces called plasmids.

Plasmids often carry genes that give bacteria helpful traits. One important example is antibiotic resistance. Bacteria can gain these plasmids and the traits they carry, which can help them adapt to changing conditions.

Bacterial genomes can differ a lot in size and gene content. Mycoplasma genitalium has one of the smallest known bacterial genomes. It is 580,076 base pairs long and contains 559 genes, including 476 coding genes and 83 noncoding genes.

At the other extreme, a strain of Sorangium cellulosum has a much larger genome for a bacterium. Its genome is 14,782,125 base pairs long and encodes 11,599 genes. These examples show how much prokaryotic genomes can vary.

Plasmids also matter because they can spread antibiotic resistance. Before antibiotics were discovered, even minor injuries could become deadly bacterial infections. Penicillin, discovered in 1928, helped start the antibiotic era and greatly improved medical treatment and life expectancy.

Overuse of antibiotics in people and agricultural animals has helped some bacteria evolve resistance. Resistance genes can move on plasmids, and many bacteria can exchange plasmids with distantly related species through bacterial conjugation. This can spread resistance quickly through bacterial populations and shows why new antibiotics are still needed.

Prokaryote Chromosomes and Plasmids

what is the cell cycle?

Cell Cycle Checkpoints and Cancer

The cell cycle is the set of steps a eukaryotic cell follows as it grows and divides. In somatic cells, it has two main stages: interphase and the mitotic phase. During interphase, the cell grows, carries out its basic metabolic functions, copies its DNA, and gets ready for mitotic cell division. After interphase, the cell enters mitosis and cytokinesis. Mitosis divides the nuclear material, and cytokinesis divides the cytoplasm. These steps produce two daughter cells that are identical to the...

genomic dna in prokaryotes

Most prokaryotes store their DNA in one circular chromosome inside the nucleoid, a region of cytoplasm. This chromosome is double-stranded and tightly wound, or supercoiled, so it fits efficiently inside the cell. Prokaryotes also carry smaller circular DNA pieces called plasmids. Plasmids often carry genes that give bacteria helpful traits. One important example is antibiotic resistance. Bacteria can gain these plasmids and the traits they carry, which can help them adapt to changing...

binary fission

How Cells Split by Binary Fission

Binary fission is a common way that bacteria and archaea reproduce. In this process, one parent cell divides into two parts. Each new cell can then grow to the size of the original parent cell. This is an asexual form of reproduction, so the cells produced are genetically identical. Binary fission can happen very fast. In the time it takes one bacterial cell to divide, the number of cells in the culture doubles. That time is called the doubling time. Escherichia coli cells often divide every...

genomic dna in eukaryotes

How Eukaryotic DNA Fits Inside the Nucleus

Eukaryotic DNA fits inside the nucleus by packing into a highly compact form. Eukaryotes have large genomes compared with prokaryotes, so their DNA must be tightly organized to fit inside one cell. The process starts when DNA wraps around proteins called histones. These DNA-histone units form nucleosomes, which are connected by linker DNA. The nucleosomes then coil into chromatin fibers, and additional fibrous proteins compact the chromatin even more. This packed material is called chromatin,...

interphase

Interphase in the Cell Growth Cycle

Interphase is the stage of the cell cycle when a eukaryotic cell grows and copies its DNA before mitosis. In a typical human cell, the full cell cycle takes about 24 hours, and interphase makes up about 95 percent of that time. It is followed by mitosis, also called M, when the cell divides. After mitosis and cytokinesis, cells enter the G1 phase, or gap 1. During G1, cells grow continuously and prepare for DNA replication. They are metabolically active and copy essential organelles and...

mitosis and cytokinesis

Cell Cycle Stages in Mitosis

Cell cycle stages in mitosis show how a eukaryotic cell copies its DNA and then divides into two daughter cells. The cycle is controlled by regulatory systems and by outside signals that affect cell growth and division. In typical human cells, the full cycle takes about 24 hours and includes two major phases. The first is DNA replication during the S phase of interphase. The second is the mitotic, or M, phase, which includes mitosis and cytokinesis. G1 and G2 are the gap stages between these...

positive regulator molecules

Cyclins and CDKs in the Cell Cycle

Cyclins and CDKs help control the cell cycle, the process that produces daughter cells. Cells use internal checkpoints to make sure their size, energy reserves, and DNA are ready before they move forward. At these checkpoints, positive regulators help the cell continue, while negative regulators slow or stop it. The main positive regulators are cyclins and cyclin-dependent kinases, or CDKs. These proteins are found in eukaryotes, from yeast to humans. Cyclins are grouped by the stage they help...

negative regulator molecules

Cell Cycle Stop Signals: p53, p21, and Rb

Cell cycle stop signals help control when a cell can move forward through division. Negative regulators pause or end the cell cycle until the cell meets the right conditions. Three well-studied negative regulators are p53, p21, and retinoblastoma protein, or Rb. Their roles became clear after faulty versions were found in cancer cells that kept replicating uncontrollably. These proteins act mostly at the G1 checkpoint, which comes early in the cell cycle. P53 has a strong effect on whether a...

cancer

Cancer Treatment, Personalization, and Cell Growth

Cancer develops when mutations affect genes that control cell division. Those changes can remove the normal brakes on growth and lead to uncontrolled cell proliferation. Modern science and medicine have improved how cancer is understood and treated, and some patients can now be cured. There is still no single cure for cancer because cancer is not one disease. It is a large group of many diseases. Even when two people have the same mutation in an oncogene or a tumor suppressor gene, their...

key terms and concepts

Learn how prokaryotes package DNA in a circular chromosome and plasmids, and how plasmids can spread antibiotic resistance between bacteria.

Prokaryote Chromosomes and Plasmids | JoVE K12

JoVE Core series brings biology to life through over 300 concise and easy-to-understand animated video lessons that explain key concepts in biology, plus more than 150 scientist-in-action videos that show actual research experiments conducted in today’s laboratories.

biology

Pennsylvania State Academic Standards

Life Science

Inheritance and Variation of Traits

3.1.9-12.Q

Structure and Function

3.1.9-12.A

Louisiana Student Standards for Science

High School

Life Sciences

From Molecules To Organisms: Structures And Processes

HS-LS1-1

ohios-learning-standards-and-model-curriculum

Ohio’s Learning Standards and Model Curriculum

Heredity

Cellular genetics

Virginia  Standards of Learning

HIgh School

BIO.3

BIO.3.c

Arizona Science Standards

HS+B.L3

HS+B.L3U1.11

Alabama Course of Study Science

From Molecules to Organisms: Structures and Processes

9-12.B.1.2.a

Next Generation Science Standards

HS-LS1-4

Texas Essential Knowledge and Skills

BIO.5

BIO.5.B

south-carolina-college-and-career-ready-science-standards

South Carolina College and Career Ready Science Standards

B-LS1-1.

new-york-state-science-learning-standards

New York State Science Learning Standards

HS-LS1-4.

myJoVE Corporation

Compounds Essential to Human Function

The human body is composed of cells that are fundamentally made up of several different molecules. These molecules are essential to carry out all ...

Macromolecules

Biomolecules
Organisms contain a wide variety of organic molecules with numerous functions which depend on the chemical structures and properties of these ...

Solution Preparation
ExpandCAUTION: It is important to always use care when handling reagents. For example, iodine will stain clothes and skin so wear ...

Identifying Macromolecules with Indicator Solutions
ExpandHYPOTHESES: In this activity, the experimental hypothesis might be that the addition of an ...

pH Regulation in Cells

pH plays a critical role in maintaining normal cellular activities. It helps maintain the structure and function of various proteins, dictates the charge ...

Chemistry of the Cell

Overview of Functional Groups

Functional groups are a group of atoms with characteristic properties, which when linked to the carbon skeleton of a molecule, alter the properties of ...

Introduction to Carbohydrates

Carbohydrates, proteins, and fats are the primary macronutrients in the human diet. However, carbohydrates are the most favored source of energy in the ...

Carbohydrate Metabolism

Sugars as Energy Storage Molecules

What are Lipids?

lipid-derived-compounds-in-the-human-body

Lipid-derived Compounds in the Human Body

Fats and lipids are crucial components in the human body. Some lipid-derived compounds, such as fat-soluble vitamins, eicosanoids, lipoproteins, and ...

Fats as Energy Storage Molecules

What are Proteins?

Protein Organization

Globular Proteins

In organisms, proteins are the most abundant macromolecules. They act as the building blocks of life and play various crucial roles in the body. Proteins ...

Fibrous Proteins

Fibrous proteins are either long and narrow proteins or assemble to form long and thin structures. They contain repetitive units and usually consist of ...

Protein Denaturation

The function of proteins depends on their native three-dimensional structure, which is dictated by the amino acid sequence of the specific protein. ...

Role of Proteins in the Human Body

Proteins are the building block of life. They are also&#160; the most abundant macromolecules with as many diverse roles in the body. They are part of ...

Nucleic Acids and Nucleotides

Nucleic acids are the most important macromolecules for the continuity of life. They carry the cell&#39;s genetic blueprint and have instructions for its ...

Nucleic Acid Structure

The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group ...

ATP Energy Storage and Release

ATP and Macromolecule Synthesis

Biological macromolecules are organic compounds, predominantly composed of carbon atoms. The carbon atoms are covalently bonded with hydrogen, oxygen, ...

Construct an explanation to illustrate relationships between structure and function of major macromolecules essential for life.

LS.Bio.1.1

Introduction to Enzymes

The use of enzymes by humans dates to 7000 BCE. Humans first used enzymes to ferment sugars and produce alcohol without knowing that this was an ...

Enzymes and Activation Energy

The activation energy (or free energy of activation), abbreviated as Ea, is the small amount of energy input necessary for all chemical reactions to ...

Introduction to Enzyme Kinetics

Enzyme kinetics studies the rates of biochemical reactions. Scientists monitor the reaction rates for a particular enzymatic reaction at various substrate ...

Turnover Number and Catalytic Efficiency

The turnover number of an enzyme is the maximum number of substrate molecules it can transform per unit time. Turnover numbers for most enzymes range from ...

Catalytically Perfect Enzymes

The theory of catalytically perfect enzymes was first proposed by W.J. Albery and J. R. Knowles in 1976. These enzymes catalyze biochemical reactions at ...

introduction-to-mechanisms-of-enzyme-catalysis

Introduction to Mechanisms of Enzyme Catalysis

For many years, scientists thought that enzyme-substrate binding took place in a simple &#34;lock-and-key&#34; fashion. This model stated that the enzyme ...

Ligand Binding and Linkage

Cooperative Allosteric Transitions

Ribozymes

Carry out investigations to illustrate how enzymes act as catalysts for biochemical reactions and how environmental factors affect enzyme activity.

LS.Bio.1.2

What are Cells?

Cells are the smallest and basic units of life, whether it is a single cell that forms the entire organism, e.g., in a bacterium or trillions of them, ...

Cell Size

Cell sizes vary widely among and within organisms. Bacterial cells range between 1-10 micrometers (&#x3BC;m)and are considerably smaller than most ...

Eukaryotic Compartmentalization

One of the distinguishing features of eukaryotic cells is that they contain membrane-bound organelles, such as the nucleus and mitochondria, that carry ...

Prokaryotic Cells

Prokaryotes are small unicellular organisms that include the domains&#x2014;Archaea and Bacteria. Bacteria include many common organisms, such as ...

Cytoplasm

The cytoplasm consists of organelles and a framework of protein scaffolds called the cytoskeleton suspended in an aqueous solution, the cytosol. The ...

The Nucleus

The nucleus is a membrane-bound organelle that acts as a control center in a eukaryotic cell. It contains chromosomal DNA, which controls gene expression ...

Endoplasmic Reticulum

Endoplasmic ReticulumThe endoplasmic reticulum (ER) is an extensive network of membranous sacs and tubules in eukaryotic cells, continuous with the outer ...

Ribosomes

Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells that ...

Golgi Apparatus

As they leave the Endoplasmic Reticulum (ER), properly folded and assembled proteins are selectively packaged into vesicles. These vesicles are ...

Lysosomes

Lysosomes are membrane-enclosed spherical sacs derived from the Golgi apparatus. The most important function of the lysosome is degrading macromolecules ...

Peroxisomes

Peroxisomes and mitochondria are two important oxygen-utilizing organelles in eukaryotic cells. Mitochondria carry out cellular respiration&#x2014;the ...

Introduction to the Cytoskeleton

Overview of the Cytoskeleton
The cytoskeleton is a network of protein filaments present within the cell, having three distinct filaments ...

Introduction to Actin

Actin is a highly conserved cytoskeletal protein found abundantly in eukaryotic cells. It constitutes 10% weight of the total cellular protein in muscle ...

Cell Structure

Background
Cells represent the most basic biological units of all organisms, whether it be simple, single-celled organisms like bacteria, or large, ...

overview-of-myosin-structure-and-function

Overview of Myosin Structure and Function

Myosins are a family of molecular motor proteins, first identified in the skeletal muscles, where they are responsible for muscle contraction. Along with ...

Visualizing Onion and Cheek Cells
ExpandImmediately before the experiment, wash and peel onion bulbs for the class.
Remove the entire brown outer skin and ...

Microtubules

Microtubules are the thickest cytoskeletal filaments with a diameter of 25 nm. In prokaryotic organisms, microtubules are commonly found in locomotory ...

The Structure of Intermediate Filaments

The intermediate filaments are one of three widely studied cytoskeletal filaments. They are so named as their diameter (10 nm) is in between that of ...

Types of Intermediate Filaments

The intermediate filaments are an essential component of the cytoskeleton. Presently six types of intermediate filament have been identified. Type I and ...

Gap Junctions

Multicellular organisms employ a variety of ways for cells to communicate with each other. Gap junctions are specialized proteins that form pores between ...

The Extracellular Matrix

In order to maintain tissue organization, many animal cells are surrounded by structural molecules that make up the extracellular matrix (ECM). Together, ...

Tissues

Cells with similar structure and function are grouped into tissues. A group of tissues with a specialized function is called an organ. There are four main ...

Plant Cell Wall

The plant cell wall gives plant cells shape, support, and protection. As a cell matures, its cell wall specializes according to the cell type. For ...

Plasmodesmata

The organs in a multicellular organism&#x2019;s body are made up of tissues formed by cells. To work together cohesively, cells must communicate. One way ...

Use models to explain how the structure of organelles determines its function and supports overall cell processes.

LS.Bio.1.3

Analyze how the relationship between structure and function supports life processes within organisms.

Prokaryote Chromosomes and Plasmids

Description

Transcript

Tags

More videos by Standards