Name: leaf pigment prep for chromatography labs
Uploaded: 2019-01-31T09:26:22.000Z
Duration: 1 min 27 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.3.2

Photosynthesis

<ul><li><a href="#" data-time="4">Plant Pigment Chromatography and Floating Leaf Discs in a Vacuum
</a></li></ul>

photosynthesis

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">Plant Pigment Chromatography and Floating Leaf Discs in a Vacuum
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">On the day before the experiment, fill a container with water.
</div></li><li data-sub-note-item="1-2"><div class="lab-step">Place the spinach leaves into the water and make sure they are submerged.
</div></li><li data-sub-note-item="1-3"><div class="lab-step">Leave the spinach leaves to soak overnight at room temperature.
</div></li><li data-sub-note-item="1-4"><div class="lab-step">Wearing gloves, prepare and measure out 18 cm x 304 cm sections of chromatography paper.
</div></li><li data-sub-note-item="1-5"><div class="lab-step">Prepare a bicarbonate solution for the second experiment by combining 0.25 g NaHCO3 with 300 mL water. Add one squirt of dish soap to the solution and mix gently.
</div></li><li data-sub-note-item="1-6"><div class="lab-step">If the solution is still sudsy, add more bicarbonate.
</div></li><li data-sub-note-item="1-7"><div class="lab-step">For the control solution, combine 300 mL water with one squirt of dish soap. Mix gently and try to avoid suds.
</div></li><li data-sub-note-item="1-8"><div class="lab-step">Just before the experiment is due to begin, select a few spinach leaves of similar smoothness and thickness without too many large veins.
</div></li><li data-sub-note-item="1-9"><div class="lab-step">Use a hole punch to create 20 uniform discs from the leaves for each student or group.
</div></li></ul></li></ol>

<div class="section-question"><h4 class="question-sect">What is photosynthesis?</h4><p>Photosynthesis is the conversion of sunlight into usable and storable energy. Autotrophs (such as plants) use carbon dioxide, water, and energy harnessed from sunlight to generate glucose and oxygen through photosynthesis, thus providing a major energy source in the food web.
</p></div><div class="section-question"><h4 class="question-sect">How do plants harness energy from the sun?</h4><p>Plants produce pigments, such as chlorophyll that allow them to absorb...

Plant Pigment Chromatography and Floating Leaf Discs in a Vacuum
ExpandOn the day before the experiment, fill a container with water.
Place the spinach ...

Education

JoVE Lab Manual

Cellular Processes

Lab Manual Sub Articles

leaf pigment prep for chromatography labs

<p class="jove_content">Leaf pigment chromatography and floating leaf disc preparation are part of a photosynthesis lab. The work begins the day before the experiment. Spinach leaves are placed in a container of water and kept fully submerged overnight at room temperature.</p>

<p class="jove_content">The setup also includes chromatography paper for the pigment test. Wearing gloves, prepare and measure 18 cm x 304 cm sections of the paper. For the leaf disc activity, make a bicarbonate solution by mixing 0.25 g NaHCO3 with 300 mL water. Add one squirt of dish soap and mix gently. If the solution stays sudsy, add more bicarbonate.</p>

<p class="jove_content">A control solution is prepared separately with 300 mL water and one squirt of dish soap. Mix this gently and avoid creating suds. Just before the lab begins, choose spinach leaves that are similar in smoothness and thickness and do not have too many large veins. Use a hole punch to make 20 uniform discs for each student or group.</p>

Leaf Pigment Prep for Chromatography Labs

leaf-pigment-prep-for-chromatography-labs

Spinach Pigments and Leaf Disc Photosynthesis

Spinach leaves contain pigments that can be separated by chromatography. In this lab, chromatography paper is used to move the pigments at different rates so their colors and positions can be compared. By measuring how far each pigment travels and calculating its retention factor, or Rf value, students can identify the pigments by matching them with literature values.<br /><br />The chromatography setup starts with a pencil line drawn 2 centimeters from one end of the paper. A spinach leaf is pressed...

Leaf pigment chromatography and floating leaf disc preparation are part of a photosynthesis lab. The work begins the day before the experiment. Spinach leaves are placed in a container of water and kept fully submerged overnight at room temperature.<br /><br />The setup also includes chromatography paper for the pigment test. Wearing gloves, prepare and measure 18 cm x 304 cm sections of the paper. For the leaf disc activity, make a bicarbonate solution by mixing 0.25 g NaHCO3 with 300 mL water. Add one...

lab manual sub articles

Prepare spinach leaves, chromatography paper, bicarbonate solution, and leaf discs for a high school photosynthesis lab on pigments and floating discs.

Leaf Pigment Prep for Chromatography Labs | JoVE K12

Pennsylvania State Academic Standards

Life Science

matter-and-energy-in-organisms-and-ecosystems

Matter and Energy in Organisms and Ecosystems

3.1.9-12.E

3.1.9-12.J

3.1.9-12.K

Louisiana Student Standards for Science

High School

Environmental Science

ecosystems-interactions-energy-and-dynamics

Ecosystems: Interactions, Energy And Dynamics

HS-LS2-4

ohios-learning-standards-and-model-curriculum

Ohio’s Learning Standards and Model Curriculum

Cells

Cellular processes

Virginia  Standards of Learning

HIgh School

BIO.2

BIO.2.e

Minnesota Academic Standards in Science

3.1.1 9L.3.1.1.2

3.2.1 9L.3.2.1.3

Next Generation Science Standards

From Molecules to Organisms: Structures and Processes

HS-LS1-5

new-york-state-science-learning-standards

New York State Science Learning Standards

HS-LS1-5.

<p>Have you ever wondered why every autumn leaves on trees change from green to shades of yellow, orange, and red? What gives leaves their bright colors in the first place? The answer lies in the plant organelles called chloroplasts which contain pigments that absorb certain wavelengths in sunlight and reflect others. One particular pigment, chlorophyll, is the most abundant in summer. It absorbs high-energy, purple, blue, and red wavelengths from sunlight, and reflects green wavelengths giving leaves their green appearance. There are other pigments in leaves, such as carotenoids, which reflect red and yellow light. In autumn the leaves stop replenishing their pigments. Since chlorophyll degrades faster than the other pigments, the colors of these carotenoids are unmasked.</p><p>The presence of different pigments in a green leaf can be demonstrated with chromatography paper, a hydrophilic polymer that separates molecules based on their solubility in a particular solvent. First, leaf extract is loaded onto the paper. When the paper is dipped into an organic hydrophobic solvent, the solvent travels along the paper due to capillary action and along the way it separates different pigments in the leaf extract. The pigments that are the most hydrophobic are carried further up the paper. Whereas hydrophilic pigments bind to cellulose which hinders their movement. After all of the pigments are sorted by their hydrophobicity, we can calculate the retention factor or Rf values. The Rf value is the ratio of the distance traveled by a pigment to the distance traveled by the solvent. Each pigment has a unique Rf value and we can easily identify pigments by comparing calculated values to standards. Photosynthesis, the process by which plants convert carbon dioxide, water and light energy into chemical energy and oxygen, is carried out primarily in the leaves of a plant, and chlorophyll plays a critical role in this process. Chloroplasts contain dozens of chlorophyll molecules, each performing a specific task and interacting in complex ways. Ultimately, light energy causes chlorophyll molecules to give up electrons which are utilized in other metabolic processes. Therefore, chlorophyll needs a continuous supply of electrons to replace the ones it loses. These replacement electrons come from splitting water molecules into protons, electrons and oxygen molecules. At high rates of photosynthesis water is split faster to replenish electrons and oxygen is generated rapidly.</p><p>This phenomenon helps us to assess the rate of photosynthesis in the lab by simply suspending leaf discs in a bicarbonate solution where bicarbonate acts as a rich source of carbon. At the beginning of the leaf disk experiment the gases are forced out of the leaf discs by applying negative pressure with a vacuum in a syringe. The leaf discs with their gases expelled become heavier and sink to the bottom of the bicarbonate solution when transferred to a beaker. When photosynthesis takes place water in the environment is split in order to replenish chlorophyll electrons. The resulting oxygen makes the discs lighter causing them to float to the surface over time. Environments that allow for higher rates of photosynthesis have discs that float faster.</p><p>In this lab you will first separate and identify pigments in spinach leaves using chromatography paper. Then you will assess the rate of photosynthesis in water and in bicarbonate solution with a leaf disk experiment.</p>

photosynthesis: light, sugars, and carbon

<p class="jove_content">Photosynthesis turns sunlight into chemical energy in the form of glucose. This process powers most life on Earth by helping autotrophs, or primary producers, make food. The glucose they make can provide quick energy or be stored as starch for later use. Consumers depend on these producers for energy.</p>

<p class="jove_content">Photosynthesis happens in many kinds of organisms. Cyanobacteria, some protists such as algae, and plants can all carry out this process. In eukaryotic cells, it takes place in the chloroplast. Chloroplasts look green because they contain chlorophyll, a pigment that absorbs light at specific wavelengths.</p>

<p class="jove_content">Plants use several pigments to capture light. Chlorophyll absorbs red and blue light and reflects green light. Other pigments, including carotenoids, anthocyanins, and betalains, absorb or reflect different wavelengths and often appear yellow to red. In autumn, when chlorophyll levels drop in temperate regions, these pigments become visible and leaves change color.</p>

<p class="jove_content">Photosynthesis has two main stages: light-dependent reactions and light-independent reactions. These stages happen in different parts of the chloroplast. The chloroplast has an outer membrane, an inner membrane, and an inner thylakoid membrane that forms disc-like folds. The space between the inner membrane and thylakoids is the stroma.</p>

<p class="jove_content">The light-dependent reactions begin in the thylakoid membrane when sunlight excites electrons in chlorophyll. Those electrons move through an electron transport chain, dropping to lower energy levels and releasing energy. The cell uses that energy to make ATP and NADPH. Water splitting, also called hydrolysis, replaces the lost electrons in chlorophyll. This process releases oxygen into the atmosphere and helps keep the flow of electrons going.</p>

<p class="jove_content">The light-independent reactions take place in the stroma. They use ATP and NADPH from the first stage to build a three-carbon sugar from carbon dioxide. That sugar can then be turned into glucose or other biomolecules. This is also called carbon fixation or carbon sequestration because carbon is pulled from the atmosphere and stored in living molecules.</p>

<p class="jove_content">Photosynthesis plays a major role in the carbon cycle. Carbon dioxide moves between reservoirs at a steady pace, but changes in that flow can upset the balance. Because carbon dioxide is a greenhouse gas, more of it in the atmosphere can raise temperatures. Much of the extra carbon dioxide comes from burning fossil fuels, which returns ancient carbon to the air very quickly.</p>

<p class="jove_content">Forests and ocean algae help lower carbon dioxide levels, so deforestation is a serious concern in a changing climate. Scientists are also studying artificial photosynthesis as a way to make carbon-neutral biofuels. Like solar panels, these methods take energy from the sun and store it as chemical energy instead of electricity. Researchers have also used photosynthetic bacteria to make simple sugars, lactic acid, biodegradable plastics, and even medically useful compounds, including substances studied for cancer diagnosis and treatment.</p>

Photosynthesis: Light, Sugars, and Carbon

Autotrophs

Almost all living organisms on Earth depend on photosynthesis, which is the process that converts sunlight energy into a simple sugar called ...

Test your understanding of Photosynthesis with this Biology assessment quiz on JoVE Lab Manual. Covers key concepts through video-based questions designed to evaluate student learning.

Photosynthesis in Biology - Assessment Quiz | JoVE Lab Manual

Separate spinach pigments by chromatography, calculate Rf values, and use floating leaf discs to compare photosynthesis in light, dark, bicarbonate, and water.

Spinach Pigments and Leaf Disc Photosynthesis | JoVE K12

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

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, ...

the-tree-of-life-bacteria-archaea-and-eukaryotes

The Tree of Life - Bacteria, Archaea, and Eukaryotes

Prokaryotes are small unicellular organisms that include the domains &#8212; Archaea and Bacteria. Bacteria include many common microorganisms, such as ...

Prokaryotic vs. Eukaryotic Cells

Prokaryotic and eukaryotic cells represent two fundamental types of cellular organization, differing significantly in structure, complexity, and function. ...

Construct explanations to compare prokaryotic and eukaryotic cells in terms of structures and degree of complexity.

LS.Bio.1.4

The DNA Helix

Deoxyribonucleic acid, or DNA, is the genetic material responsible for passing traits from generation to generation in all organisms and most viruses. DNA ...

The Central Dogma

The central dogma explains the flow of genetic information from DNA nucleotides to the amino acid sequence of proteins.
RNA is the Missing Link Between ...

What is Gene Expression?

A gene is a stretch of DNA that serves as the blueprint for functional RNAs and proteins. Since DNA is comprised&#160; of nucleotides and proteins are ...

RNA Structure

The basic structure of RNA consists of a string of ribonucleotides attached by phosphodiester bonds. Although most RNA is single-stranded, it can form ...

Types of RNA

Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse ...

Transcription

Transcription is the synthesis of RNA from a DNA sequence by RNA polymerase. It is the first step in producing a protein from a gene sequence. ...

Bacterial RNA Polymerase

Eukaryotic RNA Polymerases

General Transcription Factors

Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of ...

RNA Polymerase II Accessory Proteins

Construct an explanation to summarize how DNA and RNA direct the synthesis of proteins.

LS.Bio.1.5

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

Leaf Pigment Prep for Chromatography Labs

Learning Objectives

What is photosynthesis?

Lab Prep

Transcript

Tags

More videos by Standards