Name: cell organelles and microenvironments
Uploaded: 2025-11-18T06:54:45.000Z
Duration: 1 min 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.1.3

Eukaryotic Compartmentalization

- Ökaryot hücrelerde çeşitli iç bölmeler bulunur.
 Membrana bağlı organeller, mikro-ortamlarda çok spesifik işlevlere izin verecek şekilde hem hücre içindeki sitoplazmadan hem hücre dışındaki ortamdan korunmuş olur.
 Örneğin, hücre çekirdeğine denetimli koşullar gerekir, bu sayede içindeki genlerde kesin ayarlamalar mümkün olur.
O yüzden iki kat membran ile sarılıdır.
 Buna, çekirdek zarfı adı verilir.
 Gözenekleri sayesinde moleküllerin, örneğin MRNA'ların giriş çıkışı kontrol edilebilir.
Ayrıca, bazı proteinlere yükseltgen ortam gerekir ve bunlar sitosolden ayrı tutulmalıdır, çünkü sitosol indirgen niteliktedir.
 Böylece, ribozomlar bu proteinleri endoplazmik retikulumda üretir, burada kritik dönüşümlerden de geçebilirler.
 Hatta nihai hedeflerine doğru yol alırken, vezikül denen küçük kimyasal mikrokozmoslarda önemli ölçüde hareketlenmeleri de mümkündür.
Peroksizomlar gibi başka organeller ise kendi zararlı yan ürünlerine, sözgelimi hidrojen peroksite karşı koruma sağlamak için bazı enzimleri ele geçirirler.
 Bunlar, toksik bileşikleri su gibi zararsız moleküllere dönüştüren enzimlerdir.
 Lizozomlar da enzimleri kendilerinden ayırır, ama farklı bir nedenle.
Amaç, sitoplazmanın kaldırabileceğinden çok daha düşük pH değeri gerektiren sindirim reaksiyonlarını korumaktır.
 Mitokondrilerin de iki membranları arasında yer alan iç ortamı asitlidir.
 Bu membranlar enerji üretimine katkıda bulunmaktadır.
 Genel olarak bakıldığında ökaryotların bölümlenmesi, birbirinden ayrılmaksızın aynı anda yapılsa birbiriyle uyumsuz olacak işlemlerin pürüzsüz biçimde gerçekleştirilmesini sağlar.

Gabaldón, Toni ve Alexandros A. Pittis. "Ökaryotlarda Metabolik Alt Hücre Bölümlendirmesinin Kökeni ve Evrimi." Biochimie 119 (Aralık 2015): 262–68. [<a href="https://doi.org/10.1016/j.biochi.2015.03.021" target="__blank">Kaynak</a>]

Ökaryotik bölümlendirme

Ökaryotik hücrelerin ayırt edici özelliklerinden biri, belirli işlevleri yerine getiren —çekirdek ve mitokondri gibi— zara bağlı organelleri içermeleridir. Biyolojik zarlar yalnızca az sayıda maddeyi geçirdiğinden, bir organel etrafındaki zar, içinde kontrollü koşullara sahip bir bölme oluşturur. Bu mikro ortamlar, genellikle sitozolü çevreleyen ortamdan farklıdır ve organelin belirli işlevlerine göre uyarlanmıştır.

Örneğin, lizozomlar — molekülleri ve hücresel kalıntıları sindiren hayvan hücrelerindeki organeller— sitozolü çevreleyen ortamdan daha asidik bir ortam sağlar, çünkü onun enzimleri, reaksiyonları katalize etmek için daha düşük bir pH’a ihtiyaç duyar. Benzer şekilde pH, mitokondri içinde düzenlenir ve bu da onların enerji üretme işlevlerini yerine getirmelerine yardımcı olur.

Ek olarak, bazı proteinler düzgün katlanma ve çalışma için oksidatif bir ortama ihtiyaç duyarlar, ancak sitozol genellikle indirgeyicidir. Bu nedenle, bu proteinler, gerekli ortamı sağlayan endoplazmik retikulumda (ER) ribozomlar tarafından üretilir. Proteinler genellikle hücre içinde zara bağlı veziküller yoluyla taşınır.

Ökaryotik hücrelerin genetik materyali, çekirdek zarı adı verilen çift zarla çevrili çekirdek içinde bölümlere ayrılmıştır. Zardaki küçük gözenekler, hangi moleküllerin veya iyonların çekirdeğe girip çıkabileceğini kontrol eder. Örneğin haberci RNA (mRNA), DNA’da kodlanmış genetik talimatları proteine çevrilebilecekleri ribozomlara götürmek için bu gözenekler boyunca çekirdekten çıkar.

Organeller, tehlikeli maddeleri hapsederek ve etkisiz hale getirerek de bir hücreyi koruyabilir. Örneğin, peroksizomlar, hidrojen peroksit — hücreler için toksik olan— üreten oksidasyon reaksiyonları gerçekleştirir ama aynı zamanda onu zararsız oksijene ve suya dönüştüren enzimler de içerirler. Bu nedenle, bölümlere ayırma, ökaryotik hücrelerin aksi takdirde gerekli ortamlar veya üretilen yan ürünler açısından uyumsuz olabilecek çeşitli farklı işlevleri yerine getirmesine olanak tanır.

Ökaryotik Bölümlendirme

Ökaryotik hücrelerin ayırt edici özelliklerinden biri, çekirdek ve mitokondri gibi zara bağlı organeller içermeleridir.

Education

JoVE Core

Biyoloji

Cellular Processes

Hücresel Süreçler

Cell Structure and Function

Hücre Yapısı ve İşlevi

KEY TERMS AND CONCEPTS

TEMEL TERİMLER VE KAVRAMLAR

cell organelles and microenvironments

Eukaryotic cells use membrane-bound organelles to keep cell processes organized. The nucleus and mitochondria are two key examples. Because biological membranes are selectively permeable, they create controlled spaces inside each organelle. These small microenvironments support specialized jobs and separate them from the surrounding cytosol.

Different organelles maintain different internal conditions. In animal cells, lysosomes keep an acidic environment that helps their enzymes digest cellular debris. Mitochondria also regulate pH, which supports the synthesis of energy molecules. These conditions show how compartmentalization helps each organelle work efficiently.

Some proteins need an oxidative environment to fold and be processed correctly. The cytosol is usually reductive, so these proteins are made by ribosomes in the endoplasmic reticulum, or ER. The ER provides the needed environment, and vesicles move the proteins to their final destination. This transport system helps direct proteins to the right place in the cell.

The nucleus also depends on compartmentalization. It holds the cell’s genetic material inside a double membrane called the nuclear envelope. Small pores in the envelope control what enters and leaves the nucleus. Messenger RNA, or mRNA, exits through these pores and carries DNA instructions to ribosomes for protein synthesis. Overall, compartmentalization lets one cell carry out many functions with greater efficiency by concentrating needed materials in separate spaces.

Cell Organelles and Microenvironments

what are cells?

Cell Membrane, DNA, and Organelles

Cells are the basic units of life, from a bacterium made of one cell to a human made of trillions. Even though organisms can differ greatly, their cells share key features that support life. A cell has a plasma membrane, which is a lipid bilayer that separates the cytoplasm from the outside environment. It also contains DNA, the genetic material that carries instructions for the cell. In prokaryotic cells, DNA is found in a region called the nucleoid. In eukaryotic cells, DNA is enclosed...

cell size

Why Cell Size Is Limited

Cell size is limited by surface area and diffusion. Cells vary widely in size, both between organisms and within the same organism. Bacterial cells are usually 1 to 10 micrometers wide, and the smallest bacteria can be 0.1 micrometers in diameter. That is about a thousand times smaller than most eukaryotic cells, which are typically 10 to 100 micrometers across. A cell takes in nutrients and water through diffusion across the plasma membrane or through channels in the membrane. The membrane...

eukaryotic compartmentalization

Eukaryotic cells use membrane-bound organelles to keep cell processes organized. The nucleus and mitochondria are two key examples. Because biological membranes are selectively permeable, they create controlled spaces inside each organelle. These small microenvironments support specialized jobs and separate them from the surrounding cytosol. Different organelles maintain different internal conditions. In animal cells, lysosomes keep an acidic environment that helps their enzymes digest...

prokaryotic cells

Prokaryotic Cell Structures

Prokaryotic cells are small, single-celled organisms found in the domains Archaea and Bacteria. Bacteria include familiar species such as Salmonella and E. coli. Archaea include extremophiles, which are organisms that live in harsh environments like volcanic springs. Prokaryotic cells share several basic features with eukaryotic cells. They are surrounded by a plasma membrane, contain cytoplasm, and have ribosomes that make proteins. Their genetic material is a single, circular DNA molecule.

cytoplasm

Cytoplasm and the Cell’s Internal Framework

The cytoplasm is the cell’s internal space that holds organelles and the cytoskeleton. It is suspended in the cytosol, an aqueous fluid made of water, ions, salts, and many organic molecules. Together, these parts create the environment where key cell activities happen. The cytoplasm is also a major site for protein synthesis and folding. The water-based cytosol helps proteins fold correctly. Hydrophobic amino acid side chains tend to hide in the protein core, while hydrophilic amino acids...

endoplasmic reticulum

ER in Protein and Lipid Transport

The endoplasmic reticulum is a membrane network in eukaryotic cells. It is continuous with the outer membrane of the nucleus. This connection helps link nuclear and cytoplasmic processes and supports efficient movement inside the cell. mRNA can move from the nucleus to ribosomes, which helps protein synthesis happen efficiently. The ER is a major site for making, processing, and distributing biomolecules. The rough endoplasmic reticulum has ribosomes attached to its surface. These ribosomes...

ribosomes

How Ribosomes Build Proteins

Ribosomes build proteins by reading messenger RNA, or mRNA, and linking amino acids in the right order. Both prokaryotic and eukaryotic cells contain ribosomes. Cells that make large amounts of protein, such as secretory cells in the human pancreas, can have millions of them. Ribosomes are made of ribosomal RNA, or rRNA, and proteins. In eukaryotic cells, rRNA is transcribed from genes in the nucleolus, a part of the nucleus that specializes in making ribosomes. There, rRNA combines with...

golgi apparatus

Protein Sorting in the Golgi Apparatus

The Golgi apparatus sorts and modifies proteins after they leave the endoplasmic reticulum (ER). Properly folded and assembled proteins are packaged into vesicles, or small membrane sacs, and moved by microtubule-based motor proteins. These vesicles can fuse into vesicular tubular clusters before reaching the Golgi, which often looks like a ribbon-shaped organelle in eukaryotic cells. Vesicles enter the cis face of the Golgi, the side facing the ER. They pass through a set of pancake-shaped...

peroxisomes

Peroxisomes and Cellular Detoxification

Peroxisomes and mitochondria are two important oxygen-utilizing organelles in eukaryotic cells. Mitochondria carry out cellular respiration, which turns energy from food into ATP. Peroxisomes focus on breaking down substances such as fatty acids and other materials the cell needs to process. A peroxisome is a single membrane-bound organelle. It helps with lipid metabolism and chemical detoxification. Enzymes inside peroxisomes move hydrogen atoms from molecules to oxygen. This reaction...

microtubules

Microtubules in Cells and Cell Movement

Microtubules are cytoskeletal fibers that help cells keep their shape, move materials, and divide. They are the thickest of the three main cytoskeletal structures in eukaryotic cells, with a diameter of about 25 nm. Along with microfilaments and intermediate filaments, they form the internal support network of the cell. Microtubules are hollow tubes built from tubulin proteins. Each tubulin molecule is a heterodimer, which means it has two different parts: α-tubulin and β-tubulin. These dimers...

plant cell wall

Plant Cell Walls in Growth and Support

Plant cell walls help plant cells keep their shape, stay protected, and remain supported. As a cell matures, its wall can change based on the cell type. Parenchyma cells in leaves usually have only a thin primary cell wall. These walls are part of how different plant cells take on different jobs. Collenchyma and sclerenchyma cells are found mostly in the outer layers of stems and leaves. Collenchyma cells add strength by partially thickening the primary cell wall. Sclerenchyma cells provide...

plasmodesmata

Plasmodesmata and Plant Cell Communication

Plasmodesmata are the connections that let plant cells communicate directly. These tiny passageways link neighboring cells through the cell wall and help tissues work together in a multicellular plant. Cells in multicellular organisms must communicate to function as a unit. One way they do this is through intercellular junctions, which are contact points between adjacent cells. Fungal, plant, and animal cells all have intercellular junctions, but the types differ. In animal cells, the main...

the nucleus

Nuclear DNA and Cell Control

The nucleus is the control center of a eukaryotic cell. It is a membrane-bound organelle that contains chromosomal DNA. That DNA helps control gene expression and regulate protein production in the cell. Not all cellular DNA has the same role. The DNA in mitochondria and chloroplasts supports functions that are specific to those organelles. Inside the nucleus, DNA structure also affects how genes are regulated. Nuclear DNA is wrapped around proteins called histones. This forms chromatin, a...

the extracellular matrix

How ECM Supports Animal Tissues

The extracellular matrix (ECM) supports animal tissues by surrounding cells with structural molecules. It helps maintain tissue organization and gives tissues their specific physical properties. The ECM includes a gel-like ground substance, fibrous components, and many molecules with different jobs. A major part of the ECM is made of glycosaminoglycans, or GAGs. These polysaccharides fill much of the extracellular space and can take up a large volume for their mass. That makes the matrix...

gap junctions

Connexins and Cell-to-Cell Signaling

Gap junctions help animal cells send signals and share small materials with nearby cells. They are made of special proteins that form pores between neighboring cells and connect their cytoplasm. Through these channels, cells can exchange ions and other small molecules. These communication channels are found in many invertebrate and vertebrate species. They support important processes such as cell differentiation and development. They are also linked to human diseases, including disorders of...

tissues

Body Tissues and Their Jobs

Body tissues are groups of cells with similar structure and function. When different tissues work together, they form an organ with a specialized job. Vertebrates have four main tissue types: epithelial, connective, muscle, and nervous tissue. Epithelial tissue is made of thin sheets of cells. It covers the skin and lines internal organs and body cavities. These cells are tightly packed, so they help protect against injury, infection, and water loss. Epithelial tissue may be simple, with one...

key terms and concepts

Learn how membrane-bound organelles create controlled microenvironments in eukaryotic cells, from acidic lysosomes to the nucleus and mRNA export.

Cell Organelles and Microenvironments | 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

JoVE Core serisi, biyolojinin ana konseptlerini açıklayan 300 adet kısa ve kolay anlaşılabilir olan video dersleriyle ve günümüz laboratuvarlarında yürütülen gerçek araştırmaları gösteren 150'den fazla \"bilim insanları iş başında\" videolarıyla biyolojiye hayat vermektedir.

Pennsylvania State Academic Standards

Life Science

Structure and Function

3.1.9-12.A

ohios-learning-standards-and-model-curriculum

Ohio’s Learning Standards and Model Curriculum

Cells

Cell structure and function

Virginia  Standards of Learning

HIgh School

BIO.3

BIO.3.a

Arizona Science Standards

High School

HS+B.L1

HS+B.L1U1.4

Alabama Course of Study Science

From Molecules to Organisms: Structures and Processes

9-12.B.1.1

Florida Department of Education

SC.912.L.14

SC.912.L.14.2

SC.912.L.14.3

SC.912.L.14.5

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 ...

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 ...

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

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

Cell Organelles and Microenvironments

Description

Transcript

Tags

More videos by Standards