Class Rules1. Punctuality

a. The last person to come into the class later than me will teach the class for 2 minutes on a selected topic by yours truly.

b. Homework to be returned during the first Theory lesson of the week.

2. Cleanliness

3. Courtesya. If you need to speak, raise your hands.b. If someone is speaking, open your ears, and not your mouth.

4. Consistencya. You must always have your notes with you.

5. Commitmenta. If you are tasked to do something, I expect it to be done with all your

effort.

Plant NutritionPhotosynthesis

5.1 Plant Structure & Function

5.2 Photosynthesis 5.3 Leaf Adaptation & Photosynthesis

5.4 Plant Mineral Nutrition

5.1.1 General Plant Anatomy

5.1.2 Leaf Structure and Function

5.1.3 Structural Diversity in Flowering Plants

5.2.1 The Importance of Photosynthesis

5.2.2 Essential Conditions for Photosynthesis

5.2.3 Plant pigments

5.2.4 Absorption and Action Spectra

5.2.5 Photosynthesis – The Process

5.2.6 Fate of the Products of Photosynthesis

5.2.7 Factors Influencing the Rate of Photosynthesis

5.2.8 Compensation Point

5.2.9 Role of Guard Cells

5.2.10Water and Carbon Dioxide Uptake

5.4.1 Nitrates

5.4.2 Magnesium

5.3.1 Structural Adaptations

5.3.2 Sun & Shade Leaves

Plant Nutrition

Topic Overview

Learning O

bjectives

By the end of the lesso

n, you should be able to:

i)Describe the factors t

hat influence sto

matal

opening. (If time perm

its)

ii)Describe the form

ation of carbohydrates and

their subsequent st

orage.

iii)Outlin

e the intake of carbon dioxide and water

by plants for photosynthesis.

Factors that Control Stomata Opening

Factor Effect

Light• In most plants, stomata open in the presence of

light, and close in darkness.

Water supply

• Stomata open if there is sufficient water supply.• Even in bright light, when there is insufficient

supply of water or when water is lost in large amount, stomata will close.

Carbon dioxide concentration

• A low CO2 concentration in the stomatal air chamber leads to stomata opening.

• Conversely, high CO2 concentrations lead to their closing.

Abscisic Acid concentration

• In the presence of high concentrations of abscisic acid, a plant growth regulator, stomatal pores will be closed.

Fate of Photosynthetic Products

5. Proteinsexcess used as

1. Glucoseused directly as

6. Fatsforms

2. Sucrosein daylight, excess converted to

Glucose formed Reacts with Nitrates &

Mineral Salts to form 3. Starch

4. Amino Acids

used directly asAmino Acids

in darkness, converts back to

PHOTOSYNTHESIS

Fate of Photosynthetic Products

1. Glucosea. Cellular Respiration in the leafb. Cellulose Cell Wall

2. Sucrosea. For transport out of the leaf to other storage

organs

3. Starcha. For storage directly in the leaf

THE CARBOHYDRATES

C

CC

C

C

C

Fate of Photosynthetic Products

4. Amino Acidsa. For building of protoplasmb. Conversion to Proteins for storage.

5. Proteinsa. For building new protoplasm.

PROTEINS & AMINO ACIDS

Fate of Photosynthetic Products

6. FATSa. For building of protoplasm.b. For storage.c. For cellular respiration

FATS & LIPIDS

Utilizing Stored Products

Maltosediastase maltase

Sucroseconverted

to

for transport

Starch Glucose

Amino AcidsPolypeptidespepsin erepsinProteins

FatsGlycerol

Fatty Acids

Photosynthesis: Where Are We Now?

Light energy + 12 H2O + 6 CO2 C6H12O6 + 6 O2 + 6 H2Ochlorophyll

2. Fates of Photosynthetic Products

Carbohydrates Proteins Fats

3. How Mesophyll Cells Import Raw Materials into their Cytoplasm

1. How Gaseous Exchange is Controlled

Water Uptake

1) From Roots to the Xylem in the Leaves..\Transport in Plants\transpiration.swf

2) From the Xylem in the Leaves to the Mesophyll Cells

Light energy + 12 H2O + 6 CO2 C6H12O6 + 6 O2 + 6 H2Ochlorophyll

a. As photosynthesis proceeds, there is a net consumption of water in the mesophyll cells.

b. This causes the water potential in the mesophyll cells to become more negative.

c. Water from the xylem then enters the mesophyll cells by osmosis.

a. As photosynthesis proceeds, there is a net consumption of water in the mesophyll cells.

b. This causes the water potential in the mesophyll cells to become more negative.

c. Water from the xylem then enters the mesophyll cells by osmosis.

Carbon Dioxide Uptake

Light energy + 12 H2O + 6 CO2 C6H12O6 + 6 O2 + 6 H2Ochlorophyll

1 ) P h o t o s y n t h e s is lo w e r s [ C O 2] in t h e c y t o p la s m o f m e s o p h y l l c e l ls .

2 ) T h in fi lm o f m o is t u r e s u r r o u n d in g m e s o p h y l l c e l ls

n o w h a s h ig h e r c o n c e n t ra ti o n o f d is s o lv e d C O 2 t h a n

c y t o p la s m .

3 ) C O 2 d iff u s e s in t o m e s o p h y l l c e l l c y t o p la s m

d o w n c o n c e n t ra ti o n g ra d ie n t .

4 ) L o w e r s [ C O 2] in t h in fi lm o f m o is t u r e w .r.t . [ C O 2] in in t e r c e l lu la r

a ir s p a c e s .

5 ) C O 2 f r o m in t e r c e l lu la r a ir s p a c e s d iff u s e in t o t h in fi lm o f m o is t u r e .

6 ) L o w e r s [ C O 2] in in t e r c e l lu la r a i r s p a c e s w r t a t m o s p h e r ic [ C O 2] .

7 ) A t m o s p h e r ic C O 2 d iff u s e s in t o in t e r c e l lu la r a i r s p a c e s t h r o u g h

s t o m a t a .

1) Photosynthesis lowers [CO2] in the cytoplasm of mesophyll cells.

2) Thin film of moisture surrounding mesophyll cells now has higher concentration of dissolved CO2 than

cytoplasm.

3)CO2 diffuses into mesophyll cell cytoplasm down concentration gradient.

4) Lowers [CO2] in thin film of moisture w.r.t. [CO2] in intercellular air spaces.

5) CO2 from intercellular air spaces diffuse into thin film of moisture.

6) Lowers [CO2] in intercellular air spaces wrt atmospheric [CO2] .

7) Atmospheric CO2 diffuses into intercellular air spaces through stomata.

Photosynthesis

Rap

http://www.educationalrap.com/62/photosynthesis.htm

Structural Adaptation for Photosynthesis

Adaptation FunctionPetiole (leaf stalk) Holds leaf in position to absorb maximum light energy.

Thin flat lamina

Allows maximum absorption of light energy.

Allows CO2 to reach inner cells rapidly.

Enables sunlight to reach all mesophyll cells.Waxy cuticle on upper and

lower epidermis Reduces water loss through evaporation from the leaf.

Stomata present in the epidermal layers

Open in sunlight, allowing CO2 to diffuse in and oxygen to diffuse out of the leaf.

Chloroplasts, with chlorophyll, in mesophyll cells

Chlorophyll absorbs and transforms light energy to chemical energy used in the manufacture of sugars.

Presence of more chloroplast in upper palisade tissue More light energy can be absorbed near the leaf surface.

Interconnecting system of air spaces in spongy mesophyll Allows rapid diffusion of carbon dioxide into mesophyll cells.

Veins containing xylem and phloem vessels

Xylem transports water and mineral salts to mesophyll cells.

Phloem transports sugars away from the leaf.