Cell membranes regulate the passage of materials into and out of cells. They are partially permeable, allowing some substances like oxygen, carbon dioxide, water and salts to pass through via diffusion or osmosis. Larger molecules require transport proteins and may move through active transport which requires energy. The movement of water into and out of cells depends on the solution's tonicity - whether it has a higher, lower or equal concentration of solutes compared to the cell.
The document summarizes different types of cell transport mechanisms. Passive transport includes diffusion, which is the movement of substances from high to low concentration areas without energy usage. Facilitated diffusion utilizes membrane protein channels to transport molecules. Osmosis is a type of facilitated diffusion where water moves through membrane channels from high to low concentration areas. Active transport moves substances against concentration gradients and requires energy in the form of transport proteins. Endocytosis transports larger particles into cells through membrane invagination, while exocytosis releases materials from cells.
This document discusses various organelles found in plant and animal cells including the Golgi apparatus, lysosomes, mitochondria, plastids, vacuoles, and differences between plant and animal cells. The Golgi apparatus packages and transports proteins, lysosomes contain digestive enzymes, mitochondria generate energy, plastids aid photosynthesis in plants, and vacuoles provide storage. It also covers cell division and the process of mitosis and meiosis.
Cell is the fundamental unit of life. It is the structural and functional unit that forms the basic unit of all living organisms. There are two main types of cells - prokaryotic and eukaryotic. Prokaryotic cells like bacteria are simpler with no organelles while eukaryotic cells like plant and animal cells are more complex with membrane-bound organelles. The cell consists of a plasma membrane, cytoplasm and nucleus. Within the cytoplasm are various organelles that perform specific functions like mitochondria, chloroplasts and lysosomes.
The document discusses various methods of cell transport, including passive transport mechanisms like diffusion and facilitated diffusion, the active transport mechanism of osmosis, and other active transport processes. It also describes endocytosis and exocytosis for bulk transport of larger particles and molecules into and out of cells.
1. Passive transport mechanisms like diffusion, osmosis, and facilitated diffusion allow substances to move across cell membranes down their concentration gradients without expending energy.
2. Active transport requires cells to use energy to move substances against their concentration gradients or from areas of lower to higher concentration.
3. The document discusses different types of passive transport mechanisms like diffusion, osmosis, and facilitated diffusion. It also introduces the concept of active transport and how it differs from passive transport by requiring cells to expend energy.
This document discusses different types of cell transport mechanisms, including passive transport through diffusion and facilitated diffusion, as well as active transport. It explains that passive transport involves the movement of materials across membranes without using energy, such as diffusion of substances from high to low concentration areas. Active transport requires energy and moves materials against a concentration gradient using protein pumps and channels. It also describes osmosis as a type of facilitated diffusion and how osmotic pressure impacts cells. Bulk transport of larger particles uses endocytosis to bring materials into cells and exocytosis to expel them.
Robert Hooke discovered cells in 1665 when examining a slice of cork under his microscope. He saw that cork had a honeycomb-like structure consisting of many small compartments, which were later termed cells. All organisms are made of cells, with some being single-celled and others multicellular. Cells have a plasma membrane, nucleus, cytoplasm, and various organelles that allow them to carry out functions necessary for life. The basic components and structures of cells were described.
1. Robert Hooke first observed cells in 1665 when examining a thin slice of cork under a microscope. He saw that the cork resembled a honeycomb structure made up of many small compartments, which he called cells.
2. The cell theory, developed by Schleiden and Schwann in 1838-1839, states that all living things are composed of cells, and the cell is the basic unit of life.
3. Cells can be unicellular, with a single cell constituting the whole organism, or multicellular, with many cells grouped together to form organisms like plants and animals.
The document summarizes different types of cell transport mechanisms. Passive transport includes diffusion, which is the movement of substances from high to low concentration areas without energy usage. Facilitated diffusion utilizes membrane protein channels to transport molecules. Osmosis is a type of facilitated diffusion where water moves through membrane channels from high to low concentration areas. Active transport moves substances against concentration gradients and requires energy in the form of transport proteins. Endocytosis transports larger particles into cells through membrane invagination, while exocytosis releases materials from cells.
This document discusses various organelles found in plant and animal cells including the Golgi apparatus, lysosomes, mitochondria, plastids, vacuoles, and differences between plant and animal cells. The Golgi apparatus packages and transports proteins, lysosomes contain digestive enzymes, mitochondria generate energy, plastids aid photosynthesis in plants, and vacuoles provide storage. It also covers cell division and the process of mitosis and meiosis.
Cell is the fundamental unit of life. It is the structural and functional unit that forms the basic unit of all living organisms. There are two main types of cells - prokaryotic and eukaryotic. Prokaryotic cells like bacteria are simpler with no organelles while eukaryotic cells like plant and animal cells are more complex with membrane-bound organelles. The cell consists of a plasma membrane, cytoplasm and nucleus. Within the cytoplasm are various organelles that perform specific functions like mitochondria, chloroplasts and lysosomes.
The document discusses various methods of cell transport, including passive transport mechanisms like diffusion and facilitated diffusion, the active transport mechanism of osmosis, and other active transport processes. It also describes endocytosis and exocytosis for bulk transport of larger particles and molecules into and out of cells.
1. Passive transport mechanisms like diffusion, osmosis, and facilitated diffusion allow substances to move across cell membranes down their concentration gradients without expending energy.
2. Active transport requires cells to use energy to move substances against their concentration gradients or from areas of lower to higher concentration.
3. The document discusses different types of passive transport mechanisms like diffusion, osmosis, and facilitated diffusion. It also introduces the concept of active transport and how it differs from passive transport by requiring cells to expend energy.
This document discusses different types of cell transport mechanisms, including passive transport through diffusion and facilitated diffusion, as well as active transport. It explains that passive transport involves the movement of materials across membranes without using energy, such as diffusion of substances from high to low concentration areas. Active transport requires energy and moves materials against a concentration gradient using protein pumps and channels. It also describes osmosis as a type of facilitated diffusion and how osmotic pressure impacts cells. Bulk transport of larger particles uses endocytosis to bring materials into cells and exocytosis to expel them.
Robert Hooke discovered cells in 1665 when examining a slice of cork under his microscope. He saw that cork had a honeycomb-like structure consisting of many small compartments, which were later termed cells. All organisms are made of cells, with some being single-celled and others multicellular. Cells have a plasma membrane, nucleus, cytoplasm, and various organelles that allow them to carry out functions necessary for life. The basic components and structures of cells were described.
1. Robert Hooke first observed cells in 1665 when examining a thin slice of cork under a microscope. He saw that the cork resembled a honeycomb structure made up of many small compartments, which he called cells.
2. The cell theory, developed by Schleiden and Schwann in 1838-1839, states that all living things are composed of cells, and the cell is the basic unit of life.
3. Cells can be unicellular, with a single cell constituting the whole organism, or multicellular, with many cells grouped together to form organisms like plants and animals.
Robert Hooke first observed cells in 1665 using a primitive microscope. The cell theory proposed by Schleiden and Schwann states that all living things are made of cells, cells are the basic unit of structure and function, and new cells are produced from existing cells. Organisms can be either unicellular, consisting of a single cell, or multicellular, consisting of many cells. The basic features of cells include a plasma membrane that regulates what enters and exits the cell, cytoplasm within the membrane, and a nucleus containing DNA.
The word cell is derived from the Latin word “cellula” which means “a little room”
It was the British botanist Robert Hooke who, in 1664, while examining a slice of bottle cork under a microscope, found its structure resembling the box-like living quarters of the monks in a monastery, and coined the word “cells”
1. Robert Hooke first observed cells in 1665 while examining a thin slice of cork under a microscope. He saw that the cork resembled a honeycomb consisting of many little compartments, which he called cells.
2. All living things are made up of cells, which are the basic structural and functional units of life. Cells may exist as individual unicellular organisms or as groups of cells forming multicellular organisms.
3. The key components of cells are the plasma membrane, nucleus, and cytoplasm. The plasma membrane separates the cell from its external environment, and regulates what moves in and out of the cell. The nucleus houses the cell's genetic material.
The document discusses the key components and functions of the cell. It begins by explaining that the cell is the basic unit of life and was first discovered by Robert Hooke in 1665. It then provides details about the main parts of animal and plant cells, including their shapes, structures, and distinguishing characteristics. The remainder of the document delves into the important organelles found within animal cells, such as the cell membrane, cytoplasm, nucleus, endoplasmic reticulum, Golgi apparatus, lysosomes, mitochondria, and vacuoles. It provides a brief description of the structure and role of each organelle.
This document provides an overview of cells. It begins by defining cells as the fundamental unit of life, and notes that organisms can be unicellular or multicellular. It then lists different types of cells like plant cells, animal cells, prokaryotic cells, and eukaryotic cells. The key differences between plant and animal cells are outlined, such as plant cells having cell walls and chloroplasts while animal cells do not. Prokaryotic cells are described as unicellular and lacking organelles like nuclei, while eukaryotic cells form multicellular organisms and have membrane-bound nuclei.
Cell is the fundamental unit of life. It is the structural and functional unit that forms the basic unit of all living organisms. There are two main types of cells - prokaryotic and eukaryotic. Prokaryotic cells like bacteria are simpler with no organelles while eukaryotic cells like plant and animal cells are more complex with membrane-bound organelles. The cell consists of a plasma membrane, cytoplasm and nucleus. Within the cytoplasm are various organelles that perform specific functions to keep the cell alive.
The document provides information about cell structure and organization. It defines cells as the basic structural and functional units of living things. It then describes the structures and functions of key animal cell organelles like the cell membrane, cytoplasm, nucleus, mitochondria, vacuoles, ribosomes, endoplasmic reticulum, and Golgi apparatus. It also compares the structures of typical animal and plant cells, noting additional structures like the cell wall and chloroplasts in plant cells. Finally, it discusses how cells are organized into tissues, organs, and organ systems to carry out specific body functions.
Life originated from inorganic matter but interaction of these inorganic matter lead to the formation of organic molecules which makes up the life sustaining entity called cell. In this chapter we will study about cell, how it is discovered, cell theory, parts of cell and their functions.
The key discoveries in cell biology were made with the invention and improvement of microscopes. Robert Hooke first observed cells in 1665 using a primitive microscope. Antonie van Leeuwenhoek later discovered free living cells in pond water using an improved microscope. It was established that cells are the basic unit of all living things through the work of Schleiden, Schwann, and Virchow, who proposed the cell theory in the 1800s.
Cells were first discovered by Robert Hooke in 1665 using a microscope. He observed thin slices of cork that resembled a honeycomb structure consisting of boxes or compartments, which he termed "cells". A cell is the smallest unit capable of performing life functions and is made of organelles that each have a specialized purpose. Important organelles include the nucleus that contains DNA, mitochondria that generate energy, the endoplasmic reticulum and Golgi apparatus that synthesize proteins and lipids, and plastids in plant cells that perform photosynthesis.
- A cell is the basic unit of structure and function in organisms, and all organisms are unicellular or multicellular.
- Key structures of the animal cell include the cell membrane, nucleus, cytoplasm, mitochondria, ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, and centrioles. The cell membrane regulates what enters and exits the cell, the nucleus houses genetic material, and mitochondria generate energy.
- Plant cells also contain a cell wall, chloroplasts, and a central vacuole. The cell wall provides structure and support, chloroplasts facilitate photosynthesis, and the vacuole stores water and nutrients.
Robert Hooke first observed plant cells in the 1600s when examining a sliver of cork under a microscope. He coined the term "cell" to describe the structures he saw that resembled an "empty boxes". Cells are the basic units of all organisms. There are two main types of cells - plant cells and animal cells. Plant cells have a cell wall made of cellulose which provides structure and support. Animal cells do not have a cell wall. Both plant and animal cells contain cytoplasm and organelles like the nucleus, mitochondria, and chloroplasts that carry out essential functions. The document provides details on the structures and differences between plant and animal cells.
- Cells are the fundamental unit of life and all organisms are made up of one or more cells.
- Robert Hooke first observed cells in 1665 while examining a slice of cork under a microscope.
- The cell theory established that cells are the basic unit of structure and function in living things.
The document discusses various types of passive transport mechanisms including diffusion, osmosis, and facilitated diffusion. Diffusion is the net movement of molecules from an area of higher concentration to lower concentration. Osmosis specifically refers to the diffusion of water molecules across a semi-permeable membrane according to the water concentration gradient. Facilitated diffusion uses carrier proteins to assist with the movement of molecules that cannot freely diffuse through the cell membrane. Ion channels also use protein channels to regulate the passage of ions across the membrane.
NCERT Solutions | Class IX | Science (Biology) | Chapter 5 | The Fundamental ...Biswarup Majumder
NCERT Solutions for Class 9 Biology is available in PDF format which you can download easily. Here is the most accurate and detailed Biology NCERT solutions for Class 9th CBSE textbook for free of cost.
I hope this document is helpful to you. Please share the document with your friends if you think this will benefit them. Get ready for the next solution. Thanks.
The document discusses the key components and structures of plant and animal cells. It begins by explaining how Robert Hooke first observed cells in cork in 1665 under a microscope. It then describes the basic components of cells, including the cell membrane, cytoplasm, organelles like the nucleus, mitochondria, chloroplasts, and vacuoles. The functions of these various organelles are outlined. The document concludes with an overview comparing the main differences between typical plant and animal cells.
The document discusses cells as the fundamental unit of life. It covers that cells are made up of molecules of life including carbohydrates, proteins, fats, and DNA/RNA. Cells have a cell membrane that separates the interior from the outside environment and regulates what passes through. Within eukaryotic cells are membrane-bound organelles that perform functions like mitochondria producing energy and chloroplasts performing photosynthesis. The document also discusses protein synthesis within cells.
In this presentation, the presenter has described the basics of Cell Biology. The features of a cell, types of cells, functions, components of cells etc. This will be very handy for class 7-9th standard students.
The Fundamental Unit Of Life Class 9th By ADHWEAT GUPTAAdhweat Gupta
The document discusses the basic unit of life - the cell. It describes that cells can be either prokaryotic or eukaryotic. The key components of a typical cell are the cell membrane, cell wall, cytoplasm and nucleus. The nucleus contains the cell's genetic material in the form of chromosomes and controls cell activities. The discovery of cells is also summarized, noting that Robert Hooke first observed cells in 1665 and Leeuwenhoek later studied living cells under a microscope.
1. Specialized transport systems are necessary in multicellular organisms to transport materials over long distances as cells may be too widely separated for diffusion and osmosis alone.
2. In plants, the xylem transports water and dissolved minerals from the roots to the shoots, while the phloem transports photosynthates from source to sink tissues.
3. The xylem contains tracheids and vessels that transport materials passively. Their lignified walls and tapered shape allows for an uninterrupted flow. The phloem contains sieve tubes that transport organic compounds with help from companion cells.
The document discusses the major parts of the cell involved in transporting materials. The plasma membrane, made of a phospholipid bilayer with ion channels and aquaporins, controls what enters and exits the cell. Transport occurs through passive diffusion of substances through the membrane or active transport using protein pumps and transporters that require energy. The two main types of transport are passive transport, which moves substances down their concentration gradient, and active transport, which moves substances against their concentration gradient using energy.
Robert Hooke first observed cells in 1665 using a primitive microscope. The cell theory proposed by Schleiden and Schwann states that all living things are made of cells, cells are the basic unit of structure and function, and new cells are produced from existing cells. Organisms can be either unicellular, consisting of a single cell, or multicellular, consisting of many cells. The basic features of cells include a plasma membrane that regulates what enters and exits the cell, cytoplasm within the membrane, and a nucleus containing DNA.
The word cell is derived from the Latin word “cellula” which means “a little room”
It was the British botanist Robert Hooke who, in 1664, while examining a slice of bottle cork under a microscope, found its structure resembling the box-like living quarters of the monks in a monastery, and coined the word “cells”
1. Robert Hooke first observed cells in 1665 while examining a thin slice of cork under a microscope. He saw that the cork resembled a honeycomb consisting of many little compartments, which he called cells.
2. All living things are made up of cells, which are the basic structural and functional units of life. Cells may exist as individual unicellular organisms or as groups of cells forming multicellular organisms.
3. The key components of cells are the plasma membrane, nucleus, and cytoplasm. The plasma membrane separates the cell from its external environment, and regulates what moves in and out of the cell. The nucleus houses the cell's genetic material.
The document discusses the key components and functions of the cell. It begins by explaining that the cell is the basic unit of life and was first discovered by Robert Hooke in 1665. It then provides details about the main parts of animal and plant cells, including their shapes, structures, and distinguishing characteristics. The remainder of the document delves into the important organelles found within animal cells, such as the cell membrane, cytoplasm, nucleus, endoplasmic reticulum, Golgi apparatus, lysosomes, mitochondria, and vacuoles. It provides a brief description of the structure and role of each organelle.
This document provides an overview of cells. It begins by defining cells as the fundamental unit of life, and notes that organisms can be unicellular or multicellular. It then lists different types of cells like plant cells, animal cells, prokaryotic cells, and eukaryotic cells. The key differences between plant and animal cells are outlined, such as plant cells having cell walls and chloroplasts while animal cells do not. Prokaryotic cells are described as unicellular and lacking organelles like nuclei, while eukaryotic cells form multicellular organisms and have membrane-bound nuclei.
Cell is the fundamental unit of life. It is the structural and functional unit that forms the basic unit of all living organisms. There are two main types of cells - prokaryotic and eukaryotic. Prokaryotic cells like bacteria are simpler with no organelles while eukaryotic cells like plant and animal cells are more complex with membrane-bound organelles. The cell consists of a plasma membrane, cytoplasm and nucleus. Within the cytoplasm are various organelles that perform specific functions to keep the cell alive.
The document provides information about cell structure and organization. It defines cells as the basic structural and functional units of living things. It then describes the structures and functions of key animal cell organelles like the cell membrane, cytoplasm, nucleus, mitochondria, vacuoles, ribosomes, endoplasmic reticulum, and Golgi apparatus. It also compares the structures of typical animal and plant cells, noting additional structures like the cell wall and chloroplasts in plant cells. Finally, it discusses how cells are organized into tissues, organs, and organ systems to carry out specific body functions.
Life originated from inorganic matter but interaction of these inorganic matter lead to the formation of organic molecules which makes up the life sustaining entity called cell. In this chapter we will study about cell, how it is discovered, cell theory, parts of cell and their functions.
The key discoveries in cell biology were made with the invention and improvement of microscopes. Robert Hooke first observed cells in 1665 using a primitive microscope. Antonie van Leeuwenhoek later discovered free living cells in pond water using an improved microscope. It was established that cells are the basic unit of all living things through the work of Schleiden, Schwann, and Virchow, who proposed the cell theory in the 1800s.
Cells were first discovered by Robert Hooke in 1665 using a microscope. He observed thin slices of cork that resembled a honeycomb structure consisting of boxes or compartments, which he termed "cells". A cell is the smallest unit capable of performing life functions and is made of organelles that each have a specialized purpose. Important organelles include the nucleus that contains DNA, mitochondria that generate energy, the endoplasmic reticulum and Golgi apparatus that synthesize proteins and lipids, and plastids in plant cells that perform photosynthesis.
- A cell is the basic unit of structure and function in organisms, and all organisms are unicellular or multicellular.
- Key structures of the animal cell include the cell membrane, nucleus, cytoplasm, mitochondria, ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, and centrioles. The cell membrane regulates what enters and exits the cell, the nucleus houses genetic material, and mitochondria generate energy.
- Plant cells also contain a cell wall, chloroplasts, and a central vacuole. The cell wall provides structure and support, chloroplasts facilitate photosynthesis, and the vacuole stores water and nutrients.
Robert Hooke first observed plant cells in the 1600s when examining a sliver of cork under a microscope. He coined the term "cell" to describe the structures he saw that resembled an "empty boxes". Cells are the basic units of all organisms. There are two main types of cells - plant cells and animal cells. Plant cells have a cell wall made of cellulose which provides structure and support. Animal cells do not have a cell wall. Both plant and animal cells contain cytoplasm and organelles like the nucleus, mitochondria, and chloroplasts that carry out essential functions. The document provides details on the structures and differences between plant and animal cells.
- Cells are the fundamental unit of life and all organisms are made up of one or more cells.
- Robert Hooke first observed cells in 1665 while examining a slice of cork under a microscope.
- The cell theory established that cells are the basic unit of structure and function in living things.
The document discusses various types of passive transport mechanisms including diffusion, osmosis, and facilitated diffusion. Diffusion is the net movement of molecules from an area of higher concentration to lower concentration. Osmosis specifically refers to the diffusion of water molecules across a semi-permeable membrane according to the water concentration gradient. Facilitated diffusion uses carrier proteins to assist with the movement of molecules that cannot freely diffuse through the cell membrane. Ion channels also use protein channels to regulate the passage of ions across the membrane.
NCERT Solutions | Class IX | Science (Biology) | Chapter 5 | The Fundamental ...Biswarup Majumder
NCERT Solutions for Class 9 Biology is available in PDF format which you can download easily. Here is the most accurate and detailed Biology NCERT solutions for Class 9th CBSE textbook for free of cost.
I hope this document is helpful to you. Please share the document with your friends if you think this will benefit them. Get ready for the next solution. Thanks.
The document discusses the key components and structures of plant and animal cells. It begins by explaining how Robert Hooke first observed cells in cork in 1665 under a microscope. It then describes the basic components of cells, including the cell membrane, cytoplasm, organelles like the nucleus, mitochondria, chloroplasts, and vacuoles. The functions of these various organelles are outlined. The document concludes with an overview comparing the main differences between typical plant and animal cells.
The document discusses cells as the fundamental unit of life. It covers that cells are made up of molecules of life including carbohydrates, proteins, fats, and DNA/RNA. Cells have a cell membrane that separates the interior from the outside environment and regulates what passes through. Within eukaryotic cells are membrane-bound organelles that perform functions like mitochondria producing energy and chloroplasts performing photosynthesis. The document also discusses protein synthesis within cells.
In this presentation, the presenter has described the basics of Cell Biology. The features of a cell, types of cells, functions, components of cells etc. This will be very handy for class 7-9th standard students.
The Fundamental Unit Of Life Class 9th By ADHWEAT GUPTAAdhweat Gupta
The document discusses the basic unit of life - the cell. It describes that cells can be either prokaryotic or eukaryotic. The key components of a typical cell are the cell membrane, cell wall, cytoplasm and nucleus. The nucleus contains the cell's genetic material in the form of chromosomes and controls cell activities. The discovery of cells is also summarized, noting that Robert Hooke first observed cells in 1665 and Leeuwenhoek later studied living cells under a microscope.
1. Specialized transport systems are necessary in multicellular organisms to transport materials over long distances as cells may be too widely separated for diffusion and osmosis alone.
2. In plants, the xylem transports water and dissolved minerals from the roots to the shoots, while the phloem transports photosynthates from source to sink tissues.
3. The xylem contains tracheids and vessels that transport materials passively. Their lignified walls and tapered shape allows for an uninterrupted flow. The phloem contains sieve tubes that transport organic compounds with help from companion cells.
The document discusses the major parts of the cell involved in transporting materials. The plasma membrane, made of a phospholipid bilayer with ion channels and aquaporins, controls what enters and exits the cell. Transport occurs through passive diffusion of substances through the membrane or active transport using protein pumps and transporters that require energy. The two main types of transport are passive transport, which moves substances down their concentration gradient, and active transport, which moves substances against their concentration gradient using energy.
This document discusses the importance of discovery sessions with clients to understand their needs and wants for a project even if they are unclear. It recommends engaging clients through interactive activities like stakeholder interviews, user shadowing, heuristic evaluations and affinity mapping to gather requirements. Affinity mapping involves organizing features onto cards and grouping them into "towers" by similarity. Screen mapping defines the site structure through primary, secondary and tertiary navigation pages. Understanding requirements through discovery saves time and money by ensuring the right features are designed and developed to meet the client's needs.
This document discusses the importance of information architecture for websites. It explains that websites are non-linear and contain vast amounts of varied information. Information architecture is important to ensure websites are goal-oriented and guide readers effectively. The document provides tips for developing the voice of a website, organizing content, prioritizing visual layouts, and giving readers opportunities to explore further while maintaining a consistent voice.
The document discusses the structure and functions of the cell membrane. It covers the transport of materials into and out of cells through both active transport, which requires energy, and passive transport, which does not require energy. Different types of cellular transport, including active transport like endocytosis and exocytosis and passive transport through diffusion and osmosis, are examined.
The document discusses the major parts of the cell involved in transporting materials. The plasma membrane, made of a phospholipid bilayer with ion channels and aquaporins, controls what enters and exits the cell. Transport occurs through passive diffusion of substances through the membrane or active transport using protein pumps and transporters that require energy. The two main types of transport are passive transport, which moves substances down their concentration gradient, and active transport, which moves substances against their concentration gradient using energy.
Este documento presenta un taller de sensibilización al cambio de 5 horas de duración dirigido a integrantes de la organización Jovenes Contigo A.C. El objetivo del taller es fortalecer la receptividad al cambio, las relaciones humanas y la comunicación para lograr una mayor integración en grupos de trabajo de manera asertiva. El taller abordará temas como herramientas de cambio, identidad, cambio de paradigmas en diferentes niveles, y procesos de transformación y aprendizaje para enfrentar mejor los cambios.
The cell membrane and cell wall function to regulate what passes in and out of cells. The cell membrane is a lipid bilayer with proteins that acts as a selective barrier through passive diffusion and active transport. The cell wall provides additional support and protection for plant, fungi and bacteria cells. Osmosis allows for diffusion of water across the cell membrane to equalize concentrations. Cystic fibrosis is caused by a mutation impairing proper ion transport across cell membranes, resulting in thick mucus buildup.
The document discusses the fundamental components and structure of cells. It explains that cells contain organelles like the plasma membrane, nucleus, and cytoplasm. The plasma membrane is selectively permeable and allows movement of substances in and out of the cell through diffusion and osmosis. Osmosis is the movement of water across the plasma membrane from high to low concentration areas until equilibrium is reached. Solutions can be hypotonic, isotonic, or hypertonic depending on their concentration of water compared to the cell. Plant cells also contain a cell wall that provides structure and allows the cell to withstand changes in water concentration without bursting.
The document describes the structure and functions of the cell membrane. It discusses the fluid mosaic model which describes the cell membrane as a fluid bilayer of phospholipids with embedded proteins. The membrane acts as a semipermeable barrier that regulates what passes in and out of the cell through diffusion, osmosis, active and passive transport. It also discusses endocytosis and exocytosis which allow cells to take in and expel larger molecules and particles.
This document summarizes different types of membrane transport in cells, including passive transport through diffusion and osmosis, as well as active transport that requires energy. It describes how diffusion moves molecules from high to low concentration down a gradient, and osmosis moves water across membranes. Active transport uses protein pumps to move molecules against their concentration gradient by consuming ATP. The roles of exocytosis and endocytosis in moving larger molecules in and out of cells is also outlined. Directed evolution in the lab can be used to accelerate the natural process of evolving new enzymes through genetic mutation and selection.
This document discusses different types of cell transport mechanisms, including passive transport (diffusion and facilitated diffusion) and active transport. Passive transport involves the diffusion of substances across the cell membrane down their concentration gradient without cellular energy expenditure. Active transport requires cellular energy and transports substances against their concentration gradient using transmembrane protein pumps and channels. Osmosis, a type of facilitated diffusion, allows for the diffusion of water across the cell membrane through water channel proteins. The document provides examples and diagrams to explain these transport mechanisms.
This document discusses the structure and function of cell membranes. It explains that cell membranes are made up of a phospholipid bilayer with integral and peripheral proteins. The phospholipid bilayer forms a selectively permeable barrier that controls what enters and exits the cell. Temperature can affect cell membrane structure by impacting the fluidity of the phospholipid bilayer and increasing membrane permeability. This allows cellular contents like pigments to leak out of organelles, as demonstrated when heating beetroot slices causes their red pigment to diffuse into surrounding water.
The document discusses various mechanisms of transport through cell membranes, including:
1) Diffusion and facilitated diffusion, which are passive processes where molecules move from areas of high concentration to low concentration through the phospholipid bilayer or protein channels.
2) Osmosis, which is the passive diffusion of water across a partially permeable membrane from an area of high water concentration to low water concentration.
3) Active transport, which requires energy and uses transport proteins to move molecules against a concentration gradient into or out of cells.
10/1/13 10:29 AMBIO156 - Lab 4
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Lab 4 Cell Structure, Osmosis, and Diffusion
Introduction: Connecting Your Learning
The basic building block of life is the cell. Each cell contains several structures, some
of which are common to both eukaryotic and prokaryotic cells and some that are
unique to specific cell types. This lab will discuss cell structures and how materials
are moved in and out of the cell. Specifically, the principles of diffusion and osmosis
will be demonstrated by performing a scientific investigation that studies the effect of
salt concentration on potato cells.
Focusing Your Learning
Background Information
In 1662, Robert Hooke investigated the properties of cork when he discovered cells.
He named them after small rooms in a monastery because they reminded him of
them. Years later, in 1837, Schleiden and Schwann were attributed with developing
the cell theory. While their original theory was modified, the fundamental ideas be-
hind the theory held true. Three general postulates are included in the cell theory: 1)
All organisms are composed of cells. 2) The cell is the unit of life. 3) All cells arise
from pre-existing cells.
Because a cell is the basic building block of living things, it is important to become
familiar with its characteristics. Several structures comprise a cell. Many of these
structures are visible with the use of a standard compound microscope. Below are
pictures of idealized plant and animal cells, illustrating the important structures.
The cell membrane encloses all cells and is responsible for separating the internal en-
vironment from the extracellular space (the space between cells). Because other struc-
tures within the cell are also surrounded by a membrane, the outer membrane is of-
ten called the plasma membrane.
10/1/13 10:29 AMBIO156 - Lab 4
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The cell membrane is semi-permeable, allowing cer-
tain molecules to enter into the cell freely, while oth-
ers are prohibited from entering the cell. It is com-
posed of phospholipids, which have a head consist-
ing of a phosphate group and a tail of two fatty acid
chains. The phosphate group is attracted to water
(hydrophilic) while the fatty acid chains are repulsed by water (hydrophobic). When
in water, the properties of the phospholipids cause them to form two layers: The hy-
drophobic tails face the inside of the double layer (away from the water), and the hy-
drophilic heads face out (toward the water). Because two layers are formed, the mem-
brane is made up of a phospholipid bilayer, as seen in the image.
The cell wall surrounds the cell membrane in plant cells, bacteria, and some fungi. In
plant cells, the cell wall is composed of cellulose. In bacteria, the wal.
The plasma membrane and material transportIan Anderson
The plasma membrane maintains the internal environment of cells through selective permeability. It is composed of a phospholipid bilayer with embedded and attached proteins. Molecules move across the membrane via diffusion, facilitated diffusion, osmosis, active transport, and endocytosis/exocytosis. These processes allow for the exchange of materials while maintaining different internal and external compositions.
The document discusses cell membrane structure and function. It describes the cell membrane as a semi-permeable barrier made of lipids and proteins that surrounds the cell cytoplasm. The membrane regulates what enters and exits the cell and helps maintain its shape. Substances can pass through the membrane through diffusion, osmosis, facilitated transport, active transport, endocytosis, and exocytosis. The membrane plays a key role in cellular processes and transport.
1. Plant cells contain different types of tissues and cells, including dermal cells, parenchyma cells, collenchyma cells, sclerenchyma cells, xylem tracheary elements, and sieve tube elements.
2. The cell wall is made of cellulose microfibrils as well as other polymers like hemicellulose, pectins, and lignins. It also contains catalytic proteins.
3. The nucleus contains DNA organized into chromosomes, and directs transcription and translation. It is surrounded by a nuclear envelope containing pores.
The document discusses several key topics in human physiology:
1) It describes homeostasis as the maintenance of nearly constant internal conditions in the body. Various organ systems like the respiratory, gastrointestinal, and musculoskeletal systems help maintain homeostasis.
2) It discusses the structure and functions of cells, including their membranous structures, organelles, water and ion content, and proteins.
3) It examines the locomotion of cells through ameboid movement and ciliary movement, describing the mechanisms by which these types of cell movement occur.
The document discusses the cell, which is considered the fundamental unit of life. It describes key discoveries in cell biology from Hooke's observation of cells in 1665 to the formulation of the cell theory in 1838. The cell theory states that all living things are made up of cells, cells are the basic functional units of life, and new cells develop from existing cells. The document then discusses various types of cell structures, including the cell membrane, nucleus, organelles, and differences between unicellular and multicellular organisms. It provides details on cell transport mechanisms like diffusion and osmosis.
The Fundamental Unit Of Life Class - 9NehaRohtagi1
This PowerPoint Presentation will help the students of Class - 9 to understand that How a Cell Divides and the Organization Of Nucleas and so on. This Slide Presentation will clear your doubts and help you to score good marks in the examinations.
The plasma membrane is a thin, flexible barrier that surrounds cells and controls what moves in and out. It is made of phospholipids arranged in a bilayer. The membrane regulates passage through selective permeability and transport mechanisms like diffusion. It contains proteins for communication and maintains cell shape. When in different solutions, water movement changes cell volume and shape depending on solution concentration.
The document discusses the structure and function of cells. It describes the key components of cells including the plasma membrane, nucleus, cytoplasm, and organelles. The plasma membrane surrounds the cell and regulates what enters and exits. The nucleus contains DNA and controls the cell's functions. The cytoplasm contains organelles that carry out specialized functions. Transport across the plasma membrane, including diffusion, osmosis, active transport and endocytosis/exocytosis are also summarized.
The cell membrane surrounds the cytoplasm of the cell and separates its contents from the external environment. It is a semi-permeable bilayer that regulates what enters and exits the cell through membrane proteins. The nucleus contains the cell's DNA and controls its metabolism and reproduction. Mitochondria have a double membrane and produce energy for the cell in the form of ATP through aerobic respiration. Ribosomes are sites of protein synthesis and consist of large and small subunits that can float freely in the cell or attach to the endoplasmic reticulum.
The plasma membrane acts as a selectively permeable barrier that regulates what enters and exits the cell. It has a fluid mosaic structure consisting of a phospholipid bilayer with embedded proteins. This structure allows small hydrophobic molecules to pass through the membrane freely via diffusion, while hydrophilic molecules require transport proteins like channels and carriers. Transport proteins help move molecules across the membrane through active or passive transport.
This document discusses different types of transport mechanisms in cells, including passive transport mechanisms like diffusion, osmosis, facilitated diffusion, and diffusion through ion channels. It also discusses active transport mechanisms like the sodium-potassium pump, endocytosis, and exocytosis, which require energy. Specific examples are given about how paramecia and plants deal with osmosis due to their cell structures and environments.
Similar to Transport of materials through cell membranes (20)
1. Transport of materials through Cell Membranes
Cell biology Tagged cells, experiment, membrane, osmosis, permeable, transport February 20,
2011
Image Source
All living organisms consist of cells and all cells are surrounded by a membrane. One of the
major functions of the membrane is to regulate the passage of materials into and out of the cell.
These materials include dissolved gases, sugars, salts and water. Cell membranes are partially-
permeable which means that some substances can easily pass through them whereas others can
not. Most materials move by simple diffusion from high concentration on one side of the
membrane to a lower concentration on the other. Substances which will not move by passive
diffusion require energy and are actively transported.
Water is the most abundant and one of the most important substances in cells. The diffusion of
water across a partially-permeable membrane is called osmosis. An egg is a large cell containing
mainly water, proteins and salts for the possible benefit of the growing embryo. It is surrounded
by a shell, and inside that, a membrane. It provides an excellent model to assist the
understanding of the structure and function of membranes. Our experiment will use hen’s eggs,
with the shell removed by dissolving the calcium carbonate in acetis acid (vinegar). We will then
record the mass of each egg and place them in different concentrations of saline soution (distilled
water, 1%, 5%, 10% and 20%). After several hours we will remove the eggs and weigh each to
record the mass gained or lost in the solution.Download the practical investigation
here: investigating-osmosis-in-chickens-eggs-ss-28
Graph your results to show which eggs gained and lost mass due to the movement of water
through the membrane. Did you get any unexpected results? What may have caused any
irregularities?
Create a table listing the different forms of transport through cell membranes (passive diffusion,
facilitated diffusion, active transport) and describe how each of these methods worked and what
materials may be transported using each of these methods.
2. The Cell Membrane | Back to Top
The cell membrane functions as a semi-permeable barrier, allowing a very few
molecules across it while fencing the majority of organically produced chemicals
inside the cell. Electron microscopic examinations of cell membranes have led to the
development of the lipid bilayer model (also referred to as the fluid-mosaic model).
The most common molecule in the model is the phospholipid, which has a polar
(hydrophilic) head and two nonpolar (hydrophobic) tails. These phospholipids are
aligned tail to tail so the nonpolar areas form a hydrophobic region between the
hydrophilic heads on the inner and outer surfaces of the membrane. This layering is
termed a bilayer since an electron microscopic technique known as freeze-fracturing
is able to split the bilayer.
Diagram of a phospholipid bilayer. Image from Purves et al., Life: The Science of Biology,
4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman
(www.whfreeman.com), used with permission.
Phospholipids and glycolipids are important structural components of cell membranes.
Phospholipids are modified so that a phosphate group (PO4
-
) replaces one of the three
fatty acids normally found on a lipid. The addition of this group makes a polar "head"
and two nonpolar "tails".
3. Structure of a phospholipid, space-filling model (left) and chain model (right). Image
from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates
(www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
4. Diagram of a cell membrane. Image from Purves et al., Life: The Science of Biology, 4th
Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com),
used with permission.
Cell Membranes from Opposing Neurons (TEM x436,740). This image is copyright
Dennis Kunkel at www.DennisKunkel.com, used with permission.
Cholesterol is another important component of cell membranes embedded in the
hydrophobic areas of the inner (tail-tail) region. Most bacterial cell membranes do not
contain cholesterol.
Proteins are suspended in the inner layer, although the more hydrophilic areas of these
proteins "stick out" into the cells interior as well as the outside of the cell. These
integral proteins are sometimes known as gateway proteins. Proteins also function in
cellular recognition, as binding sites for substances to be brought into the cell, through
channels that will allow materials into the cell via a passive transport mechanism, and
as gates that open and close to facilitate active transport of large molecules.
The outer surface of the membrane will tend to be rich in glycolipids, which have
their hydrophobic tails embedded in the hydrophobic region of the membrane and
their heads exposed outside the cell. These, along with carbohydrates attached to the
integral proteins, are thought to function in the recognition of self. Multicellular
5. organisms may have some mechanism to allow recognition of those cells that belong
to the organism and those that are foreign. Many, but not all, animals have an immune
system that serves this sentry function. When a cell does not display the chemical
markers that say "Made in Mike", an immune system response may be triggered. This
is the basis for immunity, allergies, and autoimmune diseases. Organ transplant
recipients must have this response suppressed so the new organ will not be attacked
by the immune system, which would cause rejection of the new organ. Allergies are in
a sense an over reaction by the immune system. Autoimmune diseases, such as
rheumatoid arthritis and systemic lupus erythmatosis, happen when for an as yet
unknown reason, the immune system begins to attack certain cells and tissues in the
body.
Cells and Diffusion | Back to Top
Water, carbon dioxide, and oxygen are among the few simple molecules that can cross
the cell membrane by diffusion (or a type of diffusion known as osmosis ). Diffusion
is one principle method of movement of substances within cells, as well as the method
for essential small molecules to cross the cell membrane. Gas exchange in gills and
lungs operates by this process. Carbon dioxide is produced by all cells as a result of
cellular metabolic processes. Since the source is inside the cell, the concentration
gradient is constantly being replenished/re-elevated, thus the net flow of CO2 is out of
the cell. Metabolic processes in animals and plants usually require oxygen, which is in
lower concentration inside the cell, thus the net flow of oxygen is into the cell.
Osmosis is the diffusion of water across a semi-permeable (or differentially permeable
or selectively permeable) membrane. The cell membrane, along with such things as
dialysis tubing and cellulose acetate sausage casing, is such a membrane. The
presence of a solute decreases the water potential of a substance. Thus there is more
water per unit of volume in a glass of fresh-water than there is in an equivalent
volume of sea-water. In a cell, which has so many organelles and other large
molecules, the water flow is generally into the cell.
Animated image/movie illustrating osmosis (water is the red dots) and the selective
permeability of a membrane (blue dashed line). Image from the Internet. Click on image to
view movie.
Hypertonic solutions are those in which more solute (and hence lower water potential)
is present. Hypotonic solutions are those with less solute (again read as higher water
potential). Isotonic solutions have equal (iso-) concentrations of substances. Water
potentials are thus equal, although there will still be equal amounts of water
movement in and out of the cell, the net flow is zero.
6. Water relations and cell shape in blood cells. Image from Purves et al., Life: The Science
of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman
(www.whfreeman.com), used with permission.
Water relations in a plant cell. Image from Purves et al., Life: The Science of Biology, 4th
Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com),
used with permission.
7. One of the major functions of blood in animals is the maintain an isotonic internal
environment. This eliminates the problems associated with water loss or excess water
gain in or out of cells. Again we return to homeostasis. Paramecium and other single-
celled freshwater organisms have difficulty since they are usually hypertonic relative
to their outside environment. Thus water will tend to flow across the cell membrane,
swelling the cell and eventually bursting it. Not good for any cell! The contractile
vacuole is the Paramecium's response to this problem. The pumping of water out of
the cell by this method requires energy since the water is moving against the
concentration gradient. Since ciliates (and many freshwater protozoans) are
hypotonic, removal of water crossing the cell membrane by osmosis is a significant
problem. One commonly employed mechanism is a contractile vacuole. Water is
collected into the central ring of the vacuole and actively transported from the cell.
The functioning of a contractile vacuole in Paramecium. Image from Purves et al., Life:
The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH
Freeman (www.whfreeman.com), used with permission.
Active and Passive Transport | Back to Top
Passive transport requires no energy from the cell. Examples include the diffusion of
oxygen and carbon dioxide, osmosis of water, and facilitated diffusion.
8. Types of passive transport. Image from Purves et al., Life: The Science of Biology, 4th
Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com),
used with permission.
Active transport requires the cell to spend energy, usually in the form of ATP.
Examples include transport of large molecules (non-lipid soluble) and the sodium-
potassium pump.
9. Types of active transport. Image from Purves et al., Life: The Science of Biology, 4th
Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com),
used with permission.
Carrier-assisted Transport | Back to Top
The transport proteins integrated into the cell membrane are often highly selective
about the chemicals they allow to cross. Some of these proteins can move materials
across the membrane only when assisted by the concentration gradient, a type of
carrier-assisted transport known as facilitated diffusion. Both diffusion and facilitated
diffusion are driven by the potential energy differences of a concentration gradient.
Glucose enters most cells by facilitated diffusion. There seem to be a limiting number
of glucose-transporting proteins. The rapid breakdown of glucose in the cell (a
process known as glycolysis) maintains the concentration gradient. When the external
concentration of glucose increases, however, the glucose transport does not exceed a
certain rate, suggesting the limitation on transport.
In the case of active transport, the proteins are having to move against the
concentration gradient. For example the sodium-potassium pump in nerve cells. Na+
is
maintained at low concentrations inside the cell and K+
is at higher concentrations.
The reverse is the case on the outside of the cell. When a nerve message is
propagated, the ions pass across the membrane, thus sending the message. After the
message has passed, the ions must be actively transported back to their "starting
positions" across the membrane. This is analogous to setting up 100 dominoes and
then tipping over the first one. To reset them you must pick each one up, again at an
energy cost. Up to one-third of the ATP used by a resting animal is used to reset the
Na-K pump.
Types of transport molecules | Back to Top
Uniport transports one solute at a time. Symport transports the solute and a
cotransported solute at the same time in the same direction. Antiport transports the
solute in (or out) and the co-transported solute the opposite direction. One goes in the
other goes out or vice-versa.
Vesicle-mediated transport | Back to Top
Vesicles and vacuoles that fuse with the cell membrane may be utilized to release or
transport chemicals out of the cell or to allow them to enter a cell. Exocytosis is the
term applied when transport is out of the cell.
10. This GIF animation is from http://www.stanford.edu/group/Urchin/GIFS/exocyt.gif. Note the
vesicle on the left, and how it fuses with the cell membrane on the right, expelling the vesicle's
contents to the outside of the cell.
Endocytosis is the case when a molecule causes the cell membrane to bulge inward,
forming a vesicle. Phagocytosis is the type of endocytosis where an entire cell is
engulfed. Pinocytosis is when the external fluid is engulfed. Receptor-mediated
endocytosis occurs when the material to be transported binds to certain specific
molecules in the membrane. Examples include the transport of insulin and cholesterol
into animal cells.
Endocytosis and exocytosis. Image from Purves et al., Life: The Science of Biology, 4th
Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com),
used with permission.
Learning Objectives | Back to Top
11. Materials are exchanged between the cytoplasm and external cell environment across the
plasma membrane by several different processes, some require energy, some do not..
Describe the general structure of a phospholipid molecule and what makes it suitable as a
major component of cell membranes.
Explain the behavior of a great number of phospholipid molecules in water.
Describe the most recent version of the fluid mosaic model of membrane structure.
Molecules moving to regions where they are less concentrated are moving down their
concentration gradient.
Random movement of like molecules or ions down a concentration gradient is called
simple diffusion.
When salt is dissolved in water, which is the solute and which is the solvent?
Explain osmosis in terms of a differentially permeable membrane.
Define tonicity and be able to use the terms isotonic, hypertonic, and hypotonic.
When water moves into a plant cell by osmosis, the internal turgor pressure developed
pushes on the wall. What does this do to your understanding of a neglected houseplant?
Terms | Back to Top
Active transport ATP diffusion endocytosis exocytosis
fluid-mosaic model glycolipids glycolysis homeostasis hydrophilic
hydrophobic hypertonic hypotonic immune system isotonic
osmosis passive transport phagocytosis phosphate group phospholipid
sodium-potassium pump vacuoles vesicles