Module 5: Photosynthesis

What are the 4 physiological processes in plant?

1. Photosynthesis

2. respiration

3. transpiration

4. Translocation

It means “putting together with light”. This is a biological process of plant by using sunlight to turn water and carbon dioxide into glucose and oxygen

Photosynthesis

What do you call the process by which plants, plants-like organism and algae make their energy (glucose) from sunlight

Autotrophic process

In autotrophic organisms’ energy(glucose) is stored as ___ in their body

Carbohydrates

What is the term for organisms that can’t make their own source of energy. They are also the consumers of glucose

Heterotrophic

This process is considered to be the most important biological process in plants.

Photosynthesis

What are the four things that plants need for photosynthesis?

Water, carbon dioxide, light and chlorophyll

These structures contain stacks of thylakoid.

Grana

This structures are membrane-bound sacs within chloroplast where light dependent reactions of photosynthesis occurs.

Thylakoid

__ are building blocks in plants for growing

Glucose

What are the 2 types of photosynthesis?

Anoxygenic photosynthesis and oxygenic photosynthesis

This photosynthesis captures light energy and converted to ATP, without the production of oxygen. Water is also not an electron donor.

Anoxygenic photosynthesis

This photosynthesis is most common in plants, algae and cyanobacteria. Water is an electron donor and oxygen is a by product

Provide the molecular structure of carbon dioxide use in photosynthesis

6 CO2

Provide the molecular structure of water used in photosynthesis

6 H2O

Provide the molecular structure of Oxygen as a by product of photosynthesis

6 O2

Provide the molecular structure of glucose as by product of photosynthesis

C6 H12 O6

Provide 3 significance of Photosynthesis

• Green plants with green pigments can capture and store energy for all life foms

• Light energy is converted into chemical energy

• Oxygen makes the environment livable for all aerobic organisms

This is the chief site of photosynthesis

Leaf

What are the 3 structural parts of a leaf

• Upper and lower epidermis

• Mesophyll cells

• Vascular bundles

The upper side of the mesophyll cells contains ___ which are regular shaped cells

Palisade parenchyma

The lower side of the mesophyll cells contains ____ which are irregular shaped cells

Spongy parenchyma

An opening for plant's gas exchange

Stoma or stomata

The structures where photosynthesis happens for the creation of glucose and oxygen as by products. These organelles, which contain their own DNA and are enclosed by a double membrane, give plants their green color due to the presence of the pigment chlorophyll, which captures light energy.

Chloroplasts

This theory in plants states that chloroplasts and mitochondria originated from free-living prokaryotic cells, like cyanobacteria, that were engulfed by a host cell but not digested, eventually becoming permanent organelles within the host cell.

Endosymbiotic theory

True or false

Leaves are green because they have pigments

True

What are the 2 types of photosynthetic pigments?

• Carotenoids

• Chlorophyll

What are the 2 types of pigments under carotenoids?

Carotene and xanthophyll

A photosynthetic pigment that absorb light in the regions of the spectrum not absorbed by the chlorophylls and transfer that energy to chlorophyll to be used in photosynthesis

Carotenoids

This is a principal pigment involved in photosynthesis. It absorb light (violet blue and red) and reflects green light making leaves appear green (ROY G BIV)

Chlorophyll

What is the location of chlorophyll

Between two adjacent thylakoids

This is the basic unit of chlorophyll composed of pyrrole nuclei joined carbon linkage. The center of this unit is a single magnesium atom

Porphyrin ring

What are the 2 types of chlorophyll

Chlorophyll a and chlorophyll b

This is a pigment that appears bluish-green found in autotrophic organisms except photosynthetic bacteria

Chlorophyll a

This is a pigment that appears yellowish-green.

Chlorophyll b

Light absorption in white light (ROY G BIV) is most intense in what colors?

Red and blue

Light absorption in white light (ROY G BIV) is lowest in what color/s?

Green

Called as the main pigment and the reaction center

Chlorophyll a

These are the accessory pigments and harvesting center

Chlorophyll b, xanthophyll and carotenoids

The Chlorophyll a, Chlorophyll b, xanthophyll and carotene are packed into clusters called ___?

Photosystems

What are the 2 types of photosystems

Photosystem I and Photosystem II

What is the maximum absorption of Photosystem I (PSI)? provide with unit

700 nm

What is the maximum absorption of Photosystem II (PSII)? provide with unit

680 nm

What is the function Photosystem I and Photosystem II?

To trap solar energy and convert it into chemical energy

This is a process by which there is a reduction of electron

Oxidation

This is a process by which there is a gain of electron

Reduction

What are the electron acceptor of Photosystem I

Iron and protein

What is the electron acceptor of Photosystem II

Pheophytin

What are the electron carrier of photosystem I

Plastocyanin, ferredoxin and cytochromes

What are the electron carrier of photosystem II

Heophytin, plastoquinone and cytochromes

This is a modified chlorophyll-a with 2 hydrogen place in magnesium ion

Pheophytin

How many percent is the light absorption of leaves?

83%

How many percent of light absorbed is only used in photosynthesis

4%

How many percent in the light absorbed by photosynthetic pigments is dissipated as heat?

79%

What are the 2 photochemical and biosynthetic phase of photosynthesis

Light reactions and Dark reactions

It takes place in the grana of the chloroplasts where chlorophyll is present and located on membranes

Light reaction

It takes place in the stroma of the chloroplasts and there is absence of chlorophyll

Dark reaction

__ is induced when there is a synthesis of ATP

Phosphorylation

What do you call the addition of phosphate to a phosphate group

Example: ADP + phosphate = ATP

Photophosphorylation

What are the 2 types of Photophosphorylation?

Non-cyclic photophosphorylation and cylic photophosphorylation

Determine what type of photophosphorylation:

• Both PSI AND PSII are functional

• water is the primary electron donor

• Oxygen is a by product

• NADP is the final acceptor of hydrogen and ions

• There is protolysis

• Only in green plants and algae EXCEPT photosynthetic bacteria

Non-cyclic photophosphorylation

Determine what type of photophosphorylation:

• Only PSI is functional

• electrons come from chlorophyll (700)

• No evolved oxygen as there is no photolysis of water

• PRESENT in photosynthetic bacteria and Purple sulfur bacteria

Cyclic photophosphorylation

This reaction occurs in the stoma of the chloroplasts of mesophyll cells that converts inorganic carbon to carbon whether there is an absence or presence of light.

Dark reaction

What are the end products of light reaction that are used to fixed CO2 in dark reaction. They are also called as assimilatory powers

ATP and NADPH

The carbon dioxide fixation/reduction of carbohydrates in dark reaction occurs in 3 pathways which are?

• Calvin benson cycle

• C4

• CAM

Calvin benson cycle is also known as?

Reductive pentose pathway

C4 is also known as

Hatch slack pathway

CAM is also known as?

Crussulacean acid metabolism

Determine what pathway in Dark reaction:

• Fixation and reduction of 1 molecule of CO2 into RUBP, a five carbon molecule

• RuBisCO incorporates CO2 to RUBP fixated by 3 molecule of ATP and 2 molecule of NADPH (product of light reaction)

• Final stable product is: “G3P” or Glyceride 3-Phosphate

Calvin benson cycle or Reductive pentose pathway

True or false: Glyceride 3-Phosphate is a 3 carbon sugar

True

Determine what pathway in Dark reaction:

• Carbon dioxide is fixed into 4 carbon molecule which is the oxaloacetate by PEP carboxylase enzyme

• Oxaloacetate is then converted into Malate. Malate is transported to mesophyll cells to bundle sheath cells.

• Malate is decarboxylated releasing carbon dioxide which enters the calvin cycle

C4 or Hatch slack pathway

Determine what pathway in Dark reaction:

• is a water-efficient photosynthetic process found in plants like succulents that separates carbon fixation and photosynthesis into a day/night cycle to reduce water loss in arid conditions.

• At night, stomata open to absorb CO₂, which is converted to malic acid and stored in vacuoles. During the day, stomata close, and the stored malic acid is broken down, releasing the CO₂ for photosynthesis within the same cell.

• This pathway in dark reaction is seen in orchids, pineapple and etc. Most of plants that uses this pathway closed stomates during the day and open during at night

CAM or Crussulacean acid metabolism

What are the internal factors affecting photosynthesis?

Chlorophyll, leaf age and anatomy

What are the 5 external factors affecting photosynthesis

Minerals, water, carbon dioxide, light and temperature