Download Photosynthesis - Ms Kim`s Biology Class

Bellringer – 9/23/14
1) Draw the following leaf and fill in the blanks
for the 5 arrows.
2) In what organelle
does photosynthesis
take place?
3) Try and write the
FULL and BALANCED
equation for
photosynthesis
Photosynthesis:
Life from Light and Air
AQUAPONICS
All organisms need energy
• Like animals, plants need energy to live
• Unlike animals, plants don’t need to eat
food to make that energy
• Plants make their own energy
– animals are consumers
– plants are producers
Autotrophs vs.
Heterotrophs
 Autotroph
 Obtain their organic material from
inorganic sources
 They are producers of the biosphere
 Heterotrophs
 Obtain their organic material from
other organisms
 They are consumers of the biosphere
The Process That Feeds
the Biosphere
 Photosynthesis
 the process that converts solar
energy into chemical energy
 What organisms?
Plants and other autotrophs
Plants form the base of most
food chains
2 Types of Autotrophs
 Plants, some bacteria and algae are
photoautotrophs
 Use energy of sun to make organic molecules from
H2O and CO2
 Some worms and bacteria are chemoautotrophs
 Use energy from chemicals to make organic
molecules
 Photosynthesis
 Occurs in plants, algae, certain
other protists, some prokaryotes
They feed not only themselves, but the entire
living world. (a) On land, plants are the
predominant producers of food. In aquatic
environments, photosynthetic organisms
include (b) multicellular algae, such as this
kelp; (c) some unicellular protists, such as
Euglena; (d) the prokaryotes called
cyanobacteria; and (e) other photosynthetic
prokaryotes, such as these purple sulfur
bacteria, which produce sulfur (spherical
globules)
(a) Plants
10 m
(c) Unicellular
protist
Figure 10.2
1.5 m
(e) Purple sulfur
bacteria
(b) Multicellular
algae
40 m
(d) Cyanobacteria
The Equation for
Photosynthesis
 When plants convert the energy of
sunlight into chemical energy stored in
the bonds of carbohydrates
 Photosynthesis is summarized by this
Overall chemical equation
6 CO2 + 6 H2O + Light energy  C6H12O6 + 6 O2
Using light & air to grow
plants
– using sun energy to make glucose
– Then use glucose to generate ATP
– using carbon dioxide from air & water from roots to make
sugar
– Takes place in chloroplast
– allows plants to grows and do work
– makes a waste product
• oxygen
(ATP)
carbon
sun
+ water + energy  glucose + oxygen
dioxide
6CO2
+ 6H2O + sun
 C6H12O6
energy
+ 6O2
Chloroplasts: The Sites of
Photosynthesis in Plants
 The leaves of plants-THEY’RE GREEN!!
 major sites of photosynthesis, also occurs in
stems.
Chloroplasts
 Stroma
 Dense fluid within chloroplast
 Dark reaction occurs here
 Thylakoids
 Membranous sac (or “coin”) in stroma
 Light reactions occur here
 Grana (granum = singular)
 Stack of thylakoids (“coins”)
The Nature of Sunlight
 Light
 a form of electromagnetic energy,
which travels in waves and particles
(called photons)
 Wavelength
 distance between crests of waves
 Determines type of electromagnetic
energy (wavelength & energy are
inversely proportionate)
  wavelength,  energy
 The Electromagnetic Spectrum
 The entire range of electromagnetic energy,
or radiation
 Visible light is only a small part of the
spectrum
10–5 nm
10–3 nm
Gamma
rays
X-rays
UV
1m
106 nm
106 nm
103 nm
1 nm
Microwaves
Infrared
103 m
Radio
waves
Visible light
380
450
500
Shorter wavelength
Higher energy
550
600
650
700
750 nm
Longer wavelength
Lower energy
Color we SEE = color most reflected by
pigment; other colors (wavelengths) are
absorbed
 BLACK  all colors are reflected
How do the light reactions
capture solar energy?
 Photosynthetic Pigments
 molecules that absorb visible light
 different pigments absorb different
wavelengths of light
 Many different pigments used in light
reactions of photosynthesis
Primary vs. Accessory
Pigments
 Primary Pigment
 Chlorophyll a (most abundant)
 Accessory (Antennae)
Pigments
 Chlorophyll b
 Anthocyanins
 Xanthophylls
 Caratenoids
Photosynthetic pigments
• Primary pigment = chlorophyll a
– takes direct part in light reactions
• Accessory pigments
• protect chlorophyll a from UV light
damage
• absorb light at wavelengths that are not
absorbed by chlorophyll a
• Transfer energy to chlorophyll a  help
broaden the absorption spectrum for
photosynthesis (act as “antennae”)
The Two Stages of
Photosynthesis: A Preview
• The Light reactions
• NEEDS LIGHT
• Occurs in Thylakoids
• The Calvin cycle
• DOES NOT NEED LIGHT
• A.K.A- Dark Reactions
• Occurs in Stroma
The Light Reactions
 Occur in the grana (& thylakoids)
 Convert solar energy to chemical
energy
 Chlorophyll absorbs solar energy
 Splits water
 release O2 (a by-product)
 produce ATP and NADPH (chemical
energy)
The Calvin Cycle
 Occurs in the stroma (gel of
chloroplast)
Forms SUGAR (glucose) from
carbon dioxide
Carbon fixation occurs (CO2
organic carbon)
Uses ATP for energy and NADPH
to carry electrons
What do plants do with
the glucose?
• Use it!
– They can use cellular respiration to break
glucose down and make ATP (cellular
energy)
• Store it!
– They can string together lots of glucose
molecules to form starches (stored energy)
or cellulose (strong fibers that support cell
walls)
An overview of photosynthesis
H2O
CO2
Light
NADP 
ADP
LIGHT
REACTIONS
+ P
CALVIN
CYCLE
ATP
NADPH
Chloroplast
O2
[CH2O]
(sugar)
Basics of Photosynthesis
2 Phases
Light reactions happen in
the thylakoid
Inputs to
Light
Reaction?
Outputs of
Light
Reaction?
Dark reactions happen
in the stroma
Inputs to
Dark
Reaction?
Outputs of
Dark
Reaction?
Photosynthesis
carbon + water + energy  glucose + oxygen
dioxide
6CO2 + 6H2O + light
 C6H12O6 + 6O2
energy
This is the equation you are used to seeing,
but this is not the whole story…