CH 10: Intro Photosynthesis, Chloroplast Structure

What percentage of energy comes from the sun vs how much is captured by life processes?

90% of Earth’s energy comes from the sun and 1% of that is used for life processes

Break down photosynthesis definition

photo means light, synthesis means to put together

thus photosynthesis is the formation of molecules using light energy

How does photosynthesis feed the biosphere

photosynthesis directly or indirectly powers almost all life

because it gives energy to plants, plants give energy to animals,

Autotroph

organisms that sustain themselves without consuming other organisms

cos’ they can produce their own nutrients (organic) with CO2 and other inorganic molecules

Producers of organic molecules in the biosphere

Types of Autotrophs

Photoautotrophs

Chemoautotrophs

Heterotrophs

Cannot obtain their own nutrients so they get it from consuming other organisms or organic susbtances

they are the consumers and the decomposers of the biosphere

(ex. animals fungi, bacteria)

Types

Types of Heterotrophs

animals (consumer), fungi, bacteria (both consumer decomposer

Who are the Photoautotrophs (4)

• Plants

• Cyanobacteria

• Multicellular alga (kelp)

• Unicellular protists (euglena)

Cyanobacteria, structure, function

a photosynthetic prokaryote (photoautotroph)

has a thykaloid membranes embedded with phycobilisome proteins that taken in light

the pychobilisome have chlorophyl which allows photosynthesis

Endosymbiosis hypothesis review with pychobillosome

these proteins have the same chlorophyll of plants because prokaryote they share common ancestors (archea)

Define chroloplasts main function and structure

photosynthetic organelles found in plant and algae cells (converting light energy into chemical energy)

stroma: the fluid inside the chloroplast like cytosol (from phagocytosis)

inside the stroma is a system of membrane sacks called,

Thykaloids: compartments in the chlroroplasts which stack to form Granum

and also have interiror space called Thykaloid space

finally chloroplasts has an

inner membrane

outer membrane

Differentiate Chlrophyll from plasts and note why their important

chlrophyll is the green pigment in the chlroroplasts and it is involved in absorbing light energy

Explain leaf structure,

Define Mesophyll and their importance

Define stomata and its importance

in the leaf tissue you have mesophyll in the middle interior, this where chloroplasts are concentrated

one of its cells carry 40-50 chloroplasts

on skin of leaf tissue you have stomata attached. they are modified epithelial cells which serves as pores for CO2 and O2 to enter/leave

Write out the Photosynthesis equation

and explain it

6CO2 + 6H2O + light energy → C6H12O6+6O2

first part is the reactants (redox)

6CO2 molecules enter the leaf through stromata pores

carbon of CO2 gets reduced to form carbohydrates

6H2O (water) enter the plant through plants roots

water gets oxidized to form O

the light energy is absopred by chlorophyll

after all this is combined it forms

products:

when electrons from water are oxidized they are given to glucose

Glucose C6H12O6 and oxygen 6O2

(redox is opposite to cellular respiration)

What are 2 stages of photosynthesis

Light reaction (photo)

Calvin Cycle (synthesis)

Light reaction briefly explain, also reactant and product

Takes place in the Thylakoid space of chloroplasts, where light energy photons are absorbed and converted into into ATP and NADH

water molecules are spilt by enzymes and release oxygen (electrons)

which go to NADPH (to sugar later on)

high energy electrons are carried by NADPH to ETC where they power photophosphorylation

electrons and energy produces ATP

produces oxygen O2

and converts NADPH back NADP

reactant: H2O

product: O2, ATP, NADP

Define NADPH

an electron carrier reducing agent in photosynthesis

Calvin Cycle briefly explain, also reactant and product

Oxygen enters in the stroma

uses ATP and NADPH from light reactions to convert CO2 to sugar

reactant: O2, CO2, ATP, NADPH

product: Glucose