Photosynthesis and the light independent reaction

UNIT 3 AOS 2

Photosynthesis definition

Process in which plants use radiant energy of sunlight trapped by chlorophyll to build carbohydrates from carbon dioxide and water

Why can plants photosynthesize

Due to the presence of chloroplast

Where is chemically potential energy stored?

In the glucose

What’s the photosynthesis equation (in words)?

Carbon dioxide + water + sunlight - Glucose + Oxygen

What’s the photosynthesis equation (in their abbreviations)?

6CO2 + 6H2O - C6H12O6 + 6O2

What are the 4 main components in chloroplast?

• Chlorophyll

• Thylakoid

• Thylakoids

• Stroma

What’s chlorophyll do?

Pigment that absorbs light

What’s thylakoid do?

A disk-like structure where chlorophyll is found

What’s thylakoids do?

Arranged in stacks called grane which are connected to one another by lamella

What’s stroma do?

The clear fluid found inside the chloroplast

What’s the light dependent phase formula

Water + NADP + ADP + Pi + sunlight - Oxygen + Hydrogen (NADPH) + ATP

Where does the light dependent reaction occur?

On the surface of the thylakoid

What happens to the light energy absorbed by he chlorophyll

The energy splits water molecules into oxygen and hydrogen and produces a little ATP

What happens to the hydrogen and electrons after the water molecule is split?

The hydrogen and electrons are picked up by a special carrier molecules called NADP to become NADPH

What is the light independent reaction also known as?

The Calvin cycle or Carbon fixation

Does the light independent reaction require light?

No

What happens during the Calvin cycle

The NADPH that carries the hydrogens produced during the light dependent phase and ATP are used to start a series of reactions that fix carbon to produce glucose

Why do autotrophs convert radiant energy into glucose?

As radiant energy isn’t useful as it can’t directly be used or stored while glucose and other sugars can be stored and used by the plant

What’s the main purpose of photosynthesis?

To convert captured radiant energy into concentrated chemical energy of organic sugar molecules

What’s the inputs of photosynthesis?

Water and carbon dioxide

What’s the output of photosynthesis?

Glucose and oxygen

Light-dependent stage definition

First stage of photosynthesis where light energy is trapped by chlorophyll

Light-independent stage definition

The second stage of photosynthesis where glucose is formed

Chloroplast definition

Chlorophyll-containing organelle that’s the site of photosynthesis

Chlorophyll definition

Green pigment that traps the radiant energy of sunlight

What are the unloaded coenzymes in photosynthesis?

NADP+ and ADP-Pi

What are the loaded coenzymes in photosynthesis?

NADPH and ATP

What are the inputs in the light-dependent stage?

• Sunlight energy

• Water

• NADP+

• ADP +Pi

What are the outputs of the light-dependent stage?

• Oxygen

• ATP

• NADPH

Calvin Cycle definition

A cycle of reactions occurring in the stroma of the chloroplasts in the light independent stage of photosynthesis

What does the Calvin cycle involve?

It’s the stage where inorganic CO2 molecules are made into energy-rich reduced organic molecules like glucose

RubisCO defintion

An important enzyme involved in the carbon fixation process

Carbon fixation definition

The process where atmospheric CO2 is added into organic molecules like sugar

What’s the main enzyme in C3 plants

RubisCO

What’s the inputs of the light-independent stage?

• NADPH

• ATP

• CO2

What’s the outputs of the light-independent stage?

• NADP+

• ADP

• Glucose

How are both the light-dependent and light-independent stages connected?

The loaded coenzymes are the output for the light-dependent stage and the unloaded coenzymes are the output for the light-independent stage. These coenzymes are recycled