Kumare 1

Name: Mary joy Jovellano

Date Performed: April 14, 2008

Course/Section: MLS – 2A

Date Submitted: April 17, 2008

Necessity of Light in Chlorophyll Formation (Experiment No. 19)

I – Introduction

Chlorophyll is vital for photosynthesis, which allows plants to obtain energy from light.Chlorophyll molecules are specifically arranged in and around pigment protein complexes called photosystems which are embedded in the thylakoid membranes of chloroplasts. In these complexes, chlorophyll serves two primary functions. The function of the vast majority of chlorophyll (up to several hundred per photosystem) is to absorb light and transfer that light energy by resonance energy transfer to a specific chlorophyll pair in the reaction center of the photosystems. Because of chlorophyll’s selectivity regarding the wavelength of light it absorbs, areas of a leaf containing the molecule will appear green.

II – Methods

a. Cover any part of healthy mature green leaf of any plant inside the

garden. Clip well so as not to allow sunlight to go through b. Leave this set-up for a week. After such time, pick this leaf. Pick a similar leaf but uncovered. Bring both to the laboratory. c. Uncover the leaf. What do you observe? d. Take a small portion of a leaf and boil it for a few minutes in H 2O. drain the H2O in beaker and replace it with alcohol and boil the leaf slowly until the chlorophyll has been extracted. e. Test the piece for the presence of starch by using iodine solution. Do the same with a piece of a leaf taken from another potted plant which has been left in the sunshine for at least 2 days. Note what happened.

III – Results

a. Drawing (attached)

b. Questions: 1. Why do green plants need sunlight to perform photosynthesis? Because the sunlight is the source of energy in performing photosynthesis. During photosynthesis in green plants, light energy is captured and used to convert water, carbon dioxide, and

minerals into oxygen and energy-rich organic compounds.

2. Can artificial light serve just as well as sunlight to bring about photosynthesis? No, Sunlight supplies the energy to drive photosynthesis; organisms are ultimately solar-powered.

3. Define chlorophyll. Describe chlorophyll a and b. What is its importance? a. Chlorophyll is a green pigment found in most plants, algae, and

cyanobacteria. It absorbs light most strongly in the blue and red but poorly in the green portions of the electromagnetic spectrum, hence the green color of chlorophyll-containing tissues like plant leaves.

2. What is etiolation? What practical application of etiolation is made use in the Philippines? the operation of blanching plants, by excluding the light of the sun; the condition of a blanched plant

a. Etiolation-

c. Discussion

The green pigment in leaves is chlorophyll. Chlorophyll absorbs red and blue light from the sunlight that falls on leaves. Therefore, the light

reflected by the leaves is diminished in red and blue and appears green. The molecules of chlorophyll are large (C55H70MgN4O6). They are not soluble in the aqueous solution that fills plant cells. Instead, they are attached to the membranes of disc-like structures, called chloroplasts, inside the cells. Chloroplasts are the site of photosynthesis, the process in which light energy is converted to chemical energy. In chloroplasts, the light absorbed by chlorophyll supplies the energy used by plants to transform carbon dioxide and water into oxygen and carbohydrates.

The function of the

reaction center chlorophyll is to use the energy absorbed by and transferred to it from the other chlorophyll pigments in the photosystems to undergo a charge separation, a specific redox reaction in which the chlorophyll donates an electron into a series of molecular intermediates called an electron transport chain.

IV – Conclusion

At the end of the experiment, I conclude that Chlorophyll is the molecule that absorbs sunlight and uses its energy to synthesise carbohydrates from CO2 and water. This process is known as photosynthesis and is the basis for sustaining the life processes of all plants.

V – References:

http://en.wikipedia.org/wiki/Plasmolysis http://www.bio-medicine.org/biology-definition/Plasmolysis/ http://biology.clc.uc.edu/courses/bio104/photosyn.htm

Name:　Mary Joy Jovellano 2008Course/Year: BMLS 2

Date Started: May 08, Date Submitted: May 13, 2008

Rhodophyta Exercise No. 31

I.

Introduction:

The Rhodophyta (red algae) are a distinct eukaryotic lineage characterized by the accessory photosynthetic pigments phycoerythrin, phycocyanin and allophycocyanins arranged in phycobilisomes, and the absence of flagella and centrioles (Woelkerling 1990). This is a large assemblage of between 2500 and 6000 species in about 670 largely marine genera (Woelkerling 1990) that predominate along the coastal and

continental shelf areas of tropical, temperate and cold-water regions (Lüning 1990). Red algae are ecologically significant as primary producers, providers of structural habitat for other marine organisms, and their important role in the primary establishment and maintenance of coral reefs.

II.

Methods:

A. Examine the red algae with a naked eye and with a hand lens or microscope. Sketch and label the parts.

III – Results Drawing (attached) Questions:

1. State the characteristics of Rhodophycease. •

Red algae have a number of general characteristics that in combination distinguish them from other eukaryotic groups:

•

absence of flagella and centrioles

•

floridean starch as a storage product and the storage of starch in the cytoplasm

•

phycoerythrin, phycocyanin, and allophycocyanin as accessory pigments

•

unstacked thylakoids in plastids

•

no chloroplast endoplasmic reticulum

2. What

is

erythrocyanin?

Phycoerythrin,

xanthophylls?

Carotene?

Fucoxanthin, phycocyanin? Anthocyanin? •

Erythrocyanin- bile pigment-apoprotein complexes that constitute the major light-harvesting antennae for oxygenic photosynthesis in cyanobacteria and red algae.

•

Phycoerythrin is a red protein from the light-harvesting phycobiliprotein family, present in cyanobacteria, red algae and cryptomonads.

•

Xanthophylls (originally phylloxanthins) are yellow pigments from the carotenoid group. Their molecular structure is based on carotenes; contrary to the carotenes, some hydrogen atoms are substituted by hydroxyl groups and/or some pairs of hydrogen atoms are substituted by oxygen atoms. They are found in the leaves of most plants and are synthesized within the plastids.

•

Carotene is used for several related substances having the formula C40H56. Carotene is an orange photosynthetic pigment important for photosynthesis. It is responsible for the orange colour of the carrot and many other fruits and vegetables. It contributes to photosynthesis by transmitting the light energy it absorbs to chlorophyll.

•

Fucoxanthin is a carotenoid, with formula C42H58O6. It is found as an accessory pigment in the chloroplasts of brown algae and most other heterokonts, giving them a brown or olive-green color.

•

Phycocyanin is a pigment from the light-harvesting phycobiliprotein family, along with allophycocyanin and phycoerythrin. It is an accessory pigment to chlorophyll. All phycobiliproteins are water soluble and therefore cannot exist

within the membrane like carotenoids, but aggregate forming clusters that adhere to the membrane called phycobilisomes. •

Anthocyanins are water-soluble vacuolar pigments that may appear red, purple, or blue, according to pH. The pigment belongs to a class of molecules called flavonoids, which are synthesized via the phenylpropanoid pathway. Anthocyanins are synthesized by organisms in the plant kingdom, and have been observed to occur in all tissues of higher plants, including leaves, stems, roots, flowers, and fruits. Anthoxanthins are their clear, white to yellow plant pigment counterparts.

III.

Discussion:

The Rhodophyta (red algae) are a distinct eukaryotic lineage characterized by the

accessory

photosynthetic

pigments

phycoerythrin,

phycocyanin

and

allophycocyanins arranged in phycobilisomes, and the absence of flagella and centrioles (Woelkerling 1990). This is a large assemblage of between 2500 and 6000 species in about 670 largely marine genera (Woelkerling 1990) that predominate along the coastal and continental shelf areas of tropical, temperate and cold-water regions (Lüning 1990). Red algae are ecologically significant as primary producers, providers of structural

habitat for other marine organisms, and their important role in the primary establishment and maintenance of coral reefs. Some red algae are economically important as providers of food and gels. Most Rhodophyta are multicellular organisms, although a few are unicellular or colonial. Rhodophyta are pigmented with phycoerythrin, phycocyanin and allophycocyanins. These pigments are found in phycobilisomes. Rhydophyta do not have any flagella or centrioles. Nor do they have chloroplast endoplasmic reticulum. Rhodophyta have unstacked thylakoids in plastids. Some species have pit connections between cells. In their research on cell wall composition on certain species of Rhodophyta, Youngs et. al. (1998) found that the cell walls of freshwater organism Bostrychia moritziana were highly adaptive to osmotic and ionic changes in their environment. They believe this adaptation is partially facilitated through changes in cell wall chemistry.

Red algae are red because of the presence of the pigment phycoerythrin; this pigment reflects red light and absorbs blue light. Because blue light penetrates water to a greater depth than light of longer wavelengths, these pigments allow red algae to photosynthesize and live at somewhat greater depths than most other "algae". Some rhodophytes have very little phycoerythrin, and may appear green or bluish from the chlorophyll and other pigments present in them.

Traditionally the red algae were divided into two Classes the Bangiophyceae and Florideophyceae. Alternatively a single Class, the Rhodophyceae and two Subclasses, Bangiophycidae and Florideophycidae are used. Based on ultrastructure and molecular evidence the Bangiophyceae is now accepted as a paraphyletic group, while the Florideophyceae is considered to be monophyletic based on two synapomorphic

characters - presence of a filamentous gonimoblast and tetrasporangia.

Red algae have a number of general characteristics that in combination distinguish them from other eukaryotic groups:

•

absence of flagella and centrioles

•

floridean starch as a storage product and the storage of starch in the cytoplasm

IV.

•

phycoerythrin, phycocyanin, and allophycocyanin as accessory pigments

•

unstacked thylakoids in plastids no chloroplast endoplasmic reticulum

Conclusion:

At the end of the experiment, I conclude that Rhodophyta is red algae are red because of the presence of the pigment phycoerythrin; this pigment reflects red light and absorbs

Thus, in this experiment I able to view and know the general

characteristics of the red algae that will distinguish them from other algae and other eukaryotic groups. Red algae are important builders of limestone reefs. And also I able to know that rhodophyta don’t have flagellata. Rhodophyta play an important part in the establishment and maintenance of coral reefs.

References: http://en.wikipedia.org/wiki/Rhodophyta http://tolweb.org/tree?group=Rhodophyta&contgroup=Eukaryotes http://species.wikimedia.org/wiki/Rhodophyta http://commons.wikimedia.org/wiki/Category:Rhodophyta

Family: Acanthacaca Scientific name: Pachystachysc Lutae Common name: Yellow Shrimp Plant Locality: House Garden Habitat: Terrestrial Collector: Ireneo Dordas II Identified: Dr. Adorico Aya-ay

Family: Scientific name: Common name: Locality: Habitat: Collector: Ireneo Dordas II Identified: Dr. Adorico Aya-ay