Plant Pigment Chromatography and Photosynthesis

Warm up (11-17-14)

• Explain what you know about plants.• Try to be specific and use scientific terms if

possible.

Outline

• Objectives• Plant Background Info

Objectives

• To gain background information about plants and how they colonized land

Where did ‘plants’ come from?

• Land plants evolved from green algae– Charophyceans

• Evidence to support the relationship between algae and plants– Plants: multicellular, eukaryotic, photosynthetic

autotrophs– Algae: certain types of green algae, brown, and

red algae are also multicellular, eukaryotic, photosynthetic autotrophs

Where did plants come from?

• Both plants and green algae (also dinoflagellates, and brown algae) have cell walls made of cellulose

• Both plants and green algae (also a few dinoflagellates, and euglenids) have chloroplasts with chlorophylls a and b

Evidence for plant relationship

• 4 characteristics that plants share with charophyceans1. Rose-shaped complexes for cellulose synthesis

1. Rosette cellulose-synthesizing complexes (charyphyceans)

2. Peroxisome enzymes: minimize loss of organic products as a result of photorespiration

3. Structure of flagellated sperm4. Formation of a phragmoplast: alignment of

cytoskeletal elements and Golgi-derived vesicles across the midline of the dividing cell during cell division

Adaptations to Survive on Land

• Charophycean algae inhabit shallow areas that may dry out

• Natural selection favors the algae that can survive without the water during those periods of drying

How are plants different from algae?

• Embryophytes: plants with embryos– This is the plant kingdom under the traditional scheme

for dividing the kingdoms• Five traits that are different between

charophyceans and plants1. Apical meristems2. Alternation of generations3. Walled spores produced in sporangia4. Multicellular gametangia5. Multicellular dependent embryos

gametangia

Apical Meristems

• Responsible for plant growth• Localized regions of cell division at the tips of

shoots and roots• Cells produced here differentiate into various

tissues• Shoot (produce leaves) and root (produce

roots) apical meristems

Alternation of Generations

• Sporophyte and gametophyte– Cells of the gametophyte are haploid• Produced by mitosis of haploid gametes (eggs and

sperm) that fuse during fertilization, forming diploid zygotes• Mitotic division of the zygote produces the multicellular

sporophyte (spore-producing generation, diploid)• Meiosis in a mature sporophyte creates haploid spores

(reproductive cells)

How are Land Plants Grouped?

• Based on the presence of vascular tissue• Plants with this tissue are called vascular

plants• Plants without this tissue are called

nonvascular plants (liverworts, hornworts, and mosses)– bryophytes

How are Land Plants Grouped?

• Vascular plants form a clade– Specified into smaller clades1. Seedless Vascular plants

1. Lycophytes (club mosses and relatives)2. Pterophytes (ferns and relatives)

2. Seeded Vascular plants1. Gymnosperms(seeds not enclosed in chambers)2. Angiosperms (flowering plants, seeds develop in

ovaries which mature into fruits)

Terrestrial Adaptations of Seed Plants

• Common seed plant attributes: reduced gametophytes, heterospory, ovules, and pollen

• Advantage of reduced gametophytes– Gametophytes of seed plants are mostly

microscopic– Allows for development of spores contained in the

sporangia of the parental sporophyte• Protects the female gametophyte

Evolutionary Advantage of Seeds

• Sperm fertilizes an egg of a seed plant, zygote grows into a sporophyte embryo

• Whole ovule develops into a seed, contains an embryo, food supply, surrounded by a protective coat

Evolutionary Advantage of Seeds

• Seed is multicellular structure that is more resistant than spores

• Seeds can be dormant for days, months, or years

• Germinates under favorable conditions• They can be carried to distant locations by

wind or animals

Warm up (11-18-14)

• What is the difference between a sporophyte and a gametophyte?

• What do you think the difference is between a gymnosperm and an angiosperm?

Outline

• Objectives• Plant Notes

Objectives

• To gain background information about plants and how they colonized land

Gymnosperms

• “naked seeds” – not enclosed in ovaries• Typically on cones• Cone-bearing plants – conifers– Pines, firs, and redwoods

• 4 phyla: Cycadophyta, Ginkophyta, Gnetophyta, and Coniferophyta

• Pollination for most is wind-directed

Phylum Cycadophyta

• Cycads• Large cones, palmlike leaves (true palm

species are angiosperms)

Phylum Ginkophyta

• Ginkgo biloba is only species of this phylum• Fanlike leaves• Fleshy seeds smell rancid as they decay

Phylum Gnetophyta

• Some are tropical, some in deserts• Grouped based on molecular data

Phylum Coniferophyta

• Largest of the gymnosperm phyla• 600 species• Evergreens – retain leaves throughout the

year• Winter – photosynthesis still occurs with sun

Life Cycle of a Pine

Angiosperms

• Have flowers and fruits• Flower– Specialized for sexual reproduction– Insects or other species can transfer pollen from

one flower to the female sex organs on another flower for most

– Some have wind-directed pollination• Dense populations• Why would this be more advantageous?

Flowers

Flowers• Sepal

– Usually green, enclose the flower before it opens (rosebud)• Petals

– Brightly colored, aid in attracting pollinators– Wind-pollinated flowers (what do you think their colors are?)

• Stamens– Microsporophylls, produce microspores that give rise to pollen grains that

contain male gametophytes– Consists of filament (stalk) and anther (terminal sac where pollen is produced)

• Carpels– Megasporophylls, make megaspores, female gametophytes– Stigma – sticky, receives the pollen– Single carpel or group of fused carpels is called a pistil

Flowers

• Sepals and petals are sterile floral organs– Not directly involved in reproduction

Fruits• Consists of a mature ovary• May include other flower parts• Wall of the ovary becomes the pericarp (thickened

wall of the fruit) with hormonal changes after pollination

Fruits

• When mature, can be fleshy or dry• Dry fruits: beans, nuts, grains• How are seeds dispersed?– People, wind, animals, water– What about edible fruits? How are those seeds

dispersed?

Angiosperm Life Cycle

Vascular Plants

• Review of Transport:– Active and passive– Transport proteins– Proton pumps

• Plasma membrane, uses energy from ATP to pump hydrogen ions out of the cell

• Causes proton gradient and a differential charge on opposite sides of the membrane causing membrane potential

• Plants use the stored energy of membrane potential and proton gradients to help with transport of materials

Water Potential

• Pressure and solute concentration– Solute potential is sometimes called osmotic potential –

solutes affect the direction of osmosis– Solute potential of pure water is 0, solute potential of a

solution is always negative– Pressure potential – physical pressure on a solution, can

be positive or negative relative to atmospheric pressure– If external solution has lower(more negative) water

potential, water will leave the cell and the cell’s protoplast will plasmolyze – shrink or pull away from its wall• Flaccid cell: limp cell• Walled cell that has greater solute concentration than its

surroundings is turgid – very firm

Water Transport

• Water is moved across the membranes of plant cells by water potential

• Water transport across biological membranes is too quick and specific for diffusion to be the only explanation– Water crosses vacuolar and plasma membranes

through aquaporins – transport proteins– These channels don’t affect water potential gradient

or direction of water flow… they only affect the rate at which water diffuses down its water potential gradient

Transport in Plants

• Compartmental structure of plant cells1. Protoplast is surrounded by cell wall 2. Plasma membrane is directly involved with

movement of molecules3. Vacuole – large organelle can occupy up to

90% or more of protoplast’s volume• Vacuolar membrane (tonoplast) – regulates

molecular traffic between cytosol and vacuolar contents

Transport in Plants

• Most plants, cytosol and cell wall are continuous from cell to cell

• Connected by plasmodesmata

• Symplast: cytoplasmic continuum• Apoplast: continuum of cell walls plus

extracellular spaces

Warm up (11-19-14)

• Explain some of the evolutionary advantages to seed-bearing plants.– Why is the seed an evolutionary advantage?

• Why are the flower and fruit further evolutionary advantages?

Outline

• Objectives• Plant Transport Experiment• Plant Background Notes• Plant Transport Video

Objectives

• To gain background information about the structure of plant cells and plants to determine how nutrients are transported through the plants.

Celery Transport

• You will need 2 stalks of celery• Take 1 stalk of celery, cut off the bottom end (2 cm or so) • Place in beaker full of colored water (you can choose what

color you want)• Set the beaker off to the side.• In your composition notebooks

– Take notes on what you notice about the structure of the 2nd stalk of celery.

– You may cut up this stalk of celery and examine the structure– You may draw diagrams and pictures to help describe what you are

seeing– Pay careful attention to the leaves of the celery as well

Flower Dissection

• See if you can identify the parts of your flower.• You may need to use your notes• You can cut open the side of the reproductive

organs and get a more detailed view of the flower

Flower Dissection

Plant Structure to Determine How Transport Occurs

• https://www.youtube.com/watch?v=xGCnuXxbZGk

Water Potential

• Pressure and solute concentration– Solute potential is sometimes called osmotic potential –

solutes affect the direction of osmosis– Solute potential of pure water is 0, solute potential of a

solution is always negative– Pressure potential – physical pressure on a solution, can

be positive or negative relative to atmospheric pressure– If external solution has lower(more negative) water

potential, water will leave the cell and the cell’s protoplast will plasmolyze – shrink or pull away from its wall• Flaccid cell: limp cell• Walled cell that has greater solute concentration than its

surroundings is turgid – very firm

Water Transport

• Water is moved across the membranes of plant cells by water potential

• Water transport across biological membranes is too quick and specific for diffusion to be the only explanation– Water crosses vacuolar and plasma membranes

through aquaporins – transport proteins– These channels don’t affect water potential gradient

or direction of water flow… they only affect the rate at which water diffuses down its water potential gradient

Warm up (11-20-14)

• How does plant structure help determine its function?

– Think of things like gymnosperms and angiosperms, seeded plants versus non-seeded plants

Outline

• Objectives• Plant Notes

Objectives

• To gain background information about the structure of plant cells and plants to determine how nutrients are transported through the plants.

Transport in Plants

• Compartmental structure of plant cells1. Protoplast is surrounded by cell wall 2. Plasma membrane is directly involved with

movement of molecules3. Vacuole – large organelle can occupy up to 90% or

more of protoplast’s volume1. Not shared with neighboring cells

• Vacuolar membrane (tonoplast) – regulates molecular traffic between cytosol and vacuolar contents

Transport in Plants

• Most plants, cytosol and cell wall are continuous from cell to cell

• Connected by plasmodesmata• Symplast: cytoplasmic continuum• Apoplast: continuum of cell walls plus

extracellular spaces

Routes of Short Distance Transport

1. Transmembrane Route: requires repeated crossings of plasma membranes as the solutes exit one cell and enter the next

2. Symplast Route: requires only one crossing of the membrane, after entering one cell, solutes can move via plasmodesmata

3. Apoplast Route: without entering the protoplast, solutes can move through the continuum of cell walls

Bulk Flow – Long Distance Transport

• Diffusion takes too long• Bulk Flow: movement of a fluid driven by pressure– Move through the tracheids and vessels of the xylem

and through the sieve tubes of the phloem– Ex. In phloem… loading sugar causes high positive

pressure at one end of a sieve tube, forcing sap to the opposite end of the tube

– Ex. In xylem… tension(neg. pressure) drives long distance pressure• Transpiration: evaporation of water from a leaf helps reduce

pressure in the leaf xylem

Leaf Structure

• Upper Epidermis: contains stomata (allow CO2 exchange between surrounding air and photosynthetic cells inside the leaf, loss of water), guard cells (regulate opening and closing of stomata)

• Mesophyll: contains parenchyma cells specialized for photosynthesis, – Palisade Mesophyll: elongated parenchyma cells, upper part of

leaf– Spongy Mesophyll: loosely arranged parenchyma cells, contains

air spaces for Co2 and oxygen to flow through, larger spaces around stomata

• Lower Epidermis: similar structure to the upper epidermis

Photosynthesis

• https://www.youtube.com/watch?v=joZ1EsA5_NY

• Take notes on this video!!!

• https://www.youtube.com/watch?v=joZ1EsA5_NY

Photosynthesis

Photosynthesis

Photosynthesis

• Conversion of light energy to chemical energy stored in sugar and organic molecules

• Autotrophs: self-feeder, producers• Heterotrophs: other-feeder, consumers• Leaves are the major sites of photosynthesis• 6CO2 + 12 H2O + Light energy => C6H12O6 +

6O2 + 6H2O

Why are Plants Green?

• Chloroplasts: contain chlorophyll (green pigment that gives the plants their color)– Found in mesophyll tissue– Double membrane structure– Stroma: fluid within the chloroplast– Thylakoids: interconnected membranous sacs within

the stroma, chlorophyll is in the thylakoid membranes• Thylakoid space: interior of the thylakoids

– Grana: stacks of thylakoids

Photosynthesis

• Chloroplasts split water into hydrogen and oxygen– Allows plants to “give off” gases into the atmosphere

• Redox Process– Redox reactions– Reverse electron flow than from cellular respiration

• Water is split, electrons transferred with hydrogen ions from water to carbon dioxide, reducing it to sugar

• Electrons increased in potential while moving from water to sugar – processes requires energy (light)

ReDox Reactions

• Oxidation and Reduction Reactions• Talking about electrons…• OIL RIG– Oxidation is lost– Reduction is gained

Light Dependent Reactions

• Thylakoid• Conversion of light energy to chemical energy• Light absorbed by chlorophyll transfers electrons and hydrogen

from water to electron acceptor called NADP+ (temporary storage for electrons)

• Use solar power to reduce NADP+ to NADPH by adding electrons and H+

• Generate ATP using chemiosmosis– Photophosphorylation – chemiosmosis to add phosphate to ADP = ATP

• Photosystem I and Photosystem II– Produce energy that will be used to produce sugar

Sunlight and the Electromagnetic Spectrum

Electromagnetic Spectrum

• Wavelength: distance between crests of 2 consecutive waves– 380nm – 750 nm visible light – detectible to the human eye

• Photons: discrete particles, not tangible objects but behave like so, fixed amount of energy

• Pigments: substances that absorb visible light, specific to wavelengths– Spectrophotometer: measures ability of pigment to absorb

specific wavelengths– Absorption spectrum: pigment’s light absorption versus

wavelength– Action spectrum: profiles relative effectiveness of different

wavelengths of radiation in driving photosynthesis

Pigments in Chloroplasts

1. Chlorophyll a : absorbs violet-blue and red light– Blue-green

2. Chlorophyll b : almost identical to a but structurally different which causes different absorption spectra– Yellow-green

3. Carotenoids: hydrocarbons, absorb blue-green and violet light– Photoprotection: absorb and dissipate excessive light energy

that might damage chlorophyll or interact with oxygen causing oxidative molecules

– Phytochemicals: antioxidant powers

Excitation of Chlorophyll in the Photosystems

• Within the thylakoid membranes are photosystems (reaction center surrounded by light-harvesting complexes)

• Light harvesting complex: contains the pigment molecules bound to specific proteins

• Reaction center: protein complex contains 2 special chlorophyll a molecules and a primary electron acceptor

Dark Reactions / Calvin Cycle

• Calvin Cycle – Stroma

• Reduce carbohydrates1. Carbon Fixation: incorporate carbon into organic

compounds existing in chloroplast2. Reduce Carbon Dioxide: all electrons, reducing power

is provided by NADPH3. Convert Co2 to Carbohydrate – need energy ATP**Has to run through 6 times to make 1 molecule of glucose

Warm up (11-21-14)

• Explain the importance of plant pigments.• What are some inferences you can make as to

what would happen if plants didn’t have those pigments?

Outline

• Objectives• Photosynthesis Notes• Photosynthesis video

Objectives

• To gain background information about the structure of plant cells and plants to determine how nutrients are transported through the plants.

Warm up (11-24-14)

• Explain to your neighbor!• What are some things that you are still

confused about regarding photosynthesis or cellular transport in plants?

Outline

• Determine more background information about photosynthesis and cellular transport within plants.

Objectives

• Gain background knowledge on photosynthesis and cellular transport within plants

Warm up (11-25-14)

• Explain to your neighbor!• Explain what you have learned so far about

transport in plants.

• Explain what you have learned so far about photosynthesis.

Outline

• Objectives• Quiz: plant cell transport and photosynthesis

Objectives

• Demonstrate knowledge of Photosynthesis by taking the photosynthesis and plant transport test

Photosynthesis Quiz

• This one is just for practice, you may talk with one another to figure out the answers.

• http://www.biologycorner.com/quiz/qz_photosynthesis.html

• This one is for real… You need to work by yourself, alternate computers and come up with your own answers. I want to see what you know.

• http://highered.mheducation.com/sites/0073031208/student_view0/chapter10/multiple_choice.html

Extra Info on Plants

• http://education-portal.com/academy/topic/ap-biology-plant-biology.html

Warm up (12-1-14)

• What is the purpose of the plant pigment and chromatography lab?

• In your lab notebooks, write a hypothesis for each of the parts

Outline

• Objectives• Plant pigment and chromatography lab prep• Plant pigment and chromatography lab

Objectives

• To prepare for the plant pigment and chromatography lab by reviewing information about the plant pigments

• To conduct the plant pigment and chromatography lab to gain insight as to what the purpose of plant pigments are.

Plant Pigments and Chromatography

Lab Walk Through

• http://www.phschool.com/science/biology_place/labbench/

Warm up (12-2-14)

• What are some ways that you think this lab can be improved?

• In other words, what are some areas that you are finding difficult to complete? How would you provide suggestions and hints to future scientists to make this lab easier for them to complete?

Outline

• Objectives• Plant pigment and chromatography lab

Objectives

• To conduct the plant pigment and chromatography lab to gain insight as to what the purpose of plant pigments are.

Warm up (12-3-14)

• What are some errors in experimental design that you are finding yourself committing throughout the completion of this lab?– Are you seeing any strange results that you might

not logically expect to see? How might you explain those results?

Outline

• Objectives• Plant pigment and chromatography lab

Objectives

• To conduct the plant pigment and chromatography lab to gain insight as to what the purpose of plant pigments are.

Warm up (12-4-14)

• How might the results of this lab be different if we used a leaf that was just about to fall off of the tree in autumn after it had changed colors?

Outline

• Objectives• Plant pigment and chromatography lab

Objectives

• To conduct the plant pigment and chromatography lab to gain insight as to what the purpose of plant pigments are.

Warm up (12-5-14)

• Why do you think leaves change color in the autumn?

• Are the leaves really dying when this happens?

• What is happening within the leaf that causes it to change color and no longer be green?

Outline

• Objectives• Plant pigment and chromatography lab

Objectives

• To conduct the plant pigment and chromatography lab to gain insight as to what the purpose of plant pigments are.

Warm up (12-8-14)

• Explain what has been happening in the photosynthesis lab so far. Explain what those results mean.

Outline

• Objectives• Photosynthesis lab

Objectives

• To conduct the plant pigment and chromatography lab to gain insight as to what the purpose of plant pigments are.

• To determine the rate of photosynthesis for spinach leaves and to apply that information to the rates of photosynthesis for other types of plants.

Warm up (12-9-14)

– Why does the rate of photosynthesis matter? What can that tell us about the plant?

– Do you think all plants photosynthesize at the same rate?

– Give some examples of plants that might photosynthesize at different rates and why this might be helpful for a plant.

Outline

• Objectives• Transpiration lab prep

Objectives

• To prepare for the transpiration lab and set up the lab.

• Be able to have a basic understanding of the process of transpiration and relate that process to the structure of a plant.

Transpiration

• Watch the following video to gain background information regarding Transpiration

• https://www.youtube.com/watch?v=U4rzLhz4HHk

• Read through the following web page and take notes on Transpiration!

• http://water.me.vccs.edu/courses/SCT112/lecture3b.htm

Warm up (12-10-14)

– What is the purpose of the transpiration lab?– What does transpiration tell you about a plant?– What can transpiration rates tell you about the

environments that a plant lives in?

Outline

• Objectives• Transpiration lab

Objectives

• To conduct the transpiration lab and to determine how transpiration is an advantage to some plants and a disadvantage to other plants

Warm up (12-11-14)

– What are some of your results from the transpiration lab?

– What are some ways that the transpiration lab might be changed or extended in order to provide more descriptive results of all plants?

Outline

• Objectives• Transpiration lab• Transpiration lab analysis

Objectives

• To conduct the transpiration lab and to determine how transpiration is an advantage to some plants and a disadvantage to other plants

• To analyze the results from the transpiration lab to determine what transpiration can tell us about a plant and its environment.

Lab Walk Through

• http://www.phschool.com/science/biology_place/labbench/

Transpiration

• Watch the following video to gain background information regarding Transpiration

• https://www.youtube.com/watch?v=U4rzLhz4HHk

• Read through the following web page and take notes on Transpiration!

• http://water.me.vccs.edu/courses/SCT112/lecture3b.htm

Warm up (12-12-14)

– Give some reasons why transpiration rates might be lower in desert plants.

– How would lower transpiration rates be an evolutionary advantage to desert plants?

Outline

• Objectives• Transpiration lab• Experimentation

Objectives

• To conduct the transpiration lab and to determine how transpiration is an advantage to some plants and a disadvantage to other plants

• To determine the best way to test for transpiration in plants by adjusting experiments to allow for better pressure readings.

Warm up (12-15-14)

• Explain how you think different respiration rates might relate to the rates of photosynthesis.

• Do you think they are similar? If so, why do you think they are similar and what does this mean?

• If not, why do you think so and what does that mean?

• Why might this be an advantage or a disadvantage?

Outline

• Objectives• Transpiration lab• Transpiration lab analysis

Objectives

• To conduct the transpiration lab and to determine how transpiration is an advantage to some plants and a disadvantage to other plants

• To analyze the results from the transpiration lab to determine what transpiration can tell us about a plant and its environment.

Warm up (12-16-14)

• What are some things that you are still confused about regarding photosynthesis, gymnosperms and angiosperms, and transpiration

Outline

• Objectives• Transpiration lab• Transpiration lab analysis

Objectives

• To conduct the transpiration lab and to determine how transpiration is an advantage to some plants and a disadvantage to other plants

• To analyze the results from the transpiration lab to determine what transpiration can tell us about a plant and its environment.

Warm up (12-17-14)

• Write down everything you remember about this unit.

• Think of photosynthesis, transpiration, gymnosperms, angiosperms, and chromatography

Outline

• Objectives• Transpiration lab analysis

Objectives

• To analyze the results from the transpiration lab to determine what transpiration can tell us about a plant and its environment.

• To review information from transpiration and photosynthesis in order to prepare for the semester test