Bellringer – April 4, 2014 1) Draw the following leaf and fill in the blanks for the 5 arrows. 2)...
-
Upload
kory-anthony -
Category
Documents
-
view
217 -
download
3
Transcript of Bellringer – April 4, 2014 1) Draw the following leaf and fill in the blanks for the 5 arrows. 2)...
Bellringer – April 4, 20141) 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 equation for photosynthesis
3
Photosynthesis:Life from Light and Air
Honors Biology
Photosynthesis
• Photo = “light”• Synthesis = “to make”• Photosynthesis = using light to make
something….• What needs to be made during
photosynthesis?
Photosynthesis is…
• When plants convert the energy of sunlight into chemical energy stored in the bonds of carbohydrates
• Examples of carbohydrates are: – Glucose– Fructose– Sucrose– Starch– Cellulose
2 Types Metabolic Pathways
• Catabolic pathways – Break down complex molecules into simpler
compounds– Release energy• Ex: Cellular Respiration
• Anabolic pathways (“add”)– Build complicated molecules from simpler ones– Sometimes called “biosynthetic pathways” – Consume energy• Ex: Building protein from amino acids
Real Life Examples…
• Exergonic (Exothermic)– Cellular Respiration– Energy (ATP) is released when glucose is
broken down• Endergonic (Endothermic) – Photosynthesis– Energy (ATP) is NEEDED (consumed) to put
together glucose from CO2, H20 and sunlight– http://flightline.highline.edu/jbetzzall/BI100/animations/energy_changes.html
What is the chemical energy needed by cells?
• ATP (Adenosine Triphosphate)• When energy is needed, ATP is broken down• ATP is renewable • Energy is released and ATP becomes ADP + P
– ADP (Adenosine Di-phosphate) + P
DRAW ME!
P
Adenosine triphosphate (ATP)
H2O
+ Free Energy given off
Inorganic phosphate + Adenosine diphosphate (ADP)
PP
P PP i
Sometimes referred to as “high energy” phosphate bonds
–ATP an “energy currency”
Example of Energy Coupling
ADP and ATP• ADP stores energy by adding phosphates– Like a rechargeable battery
• ATP releases energy by breaking bonds between phosphates
Plants are energy producers• Like animals, plants need energy to live• Unlike animals, plants don’t need to eat
food to make that energy• Plants make both food & energy– animals are consumers– plants are producers
The Process That Feeds the Biosphere
Photosynthesisthe process that converts solar
energy into chemical energyWho or What?
Plants and other autotrophsThey are producers of the
biosphere
2 Types of Autotrophs
1.Chemoautotrophs– Use chemosynthesis to make
“food” 2. Photoautotrophs– Use photosynthesis to make
“food”
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 prokaryotesThese organisms use light energy to drive the synthesis of organic molecules from carbon dioxideand (in most cases) water. They feed not onlythemselves, but the entire living world. (a) Onland, plants are the predominant producers offood. In aquatic environments, photosyntheticorganisms include (b) multicellularalgae, suchas this kelp; (c) some unicellular protists, suchas Euglena; (d) the prokaryotes clledcyanobacteria; and (e) other photosyntheticprokaryotes, such as these purple sulfurbacteria, which produce sulfur (sphericalglobules) (c, d, e: LMs).
(a) Plants
(b) Multicellular algae
(c) Unicellular protist10 m
40 m(d) Cyanobacteria
1.5 m(e) Pruple sulfur
bacteria
Figure 10.2
Autotrophs vs. Heterotrophs
HeterotrophsObtain their organic material from
other organismsThey are consumers of the
biosphere
Using light & air to grow plants
6CO2 6H2O C6H12O6 6O2sunenergy
+ ++
glucose + oxygencarbondioxide
sunenergy+ water +
(ATP)
• Photosynthesis– using sun energy to make ATP– using carbon dioxide & water to make sugar– Takes place in chloroplast– allows plants to grows– makes a waste product
• oxygen
Chloroplasts: The Sites of Photosynthesis in Plants
The leaves of plants-THEY’RE GREEN!! major sites of photosynthesis
Chloroplasts Organelle where photosynthesis
occurs Stroma
Dense fluid within chloroplast Calvin Cycle (Dark reaction) occurs here
Thylakoids Membranous sac (or “coin”) in stroma Inside space called thylakoid space Light reactions occur here
Grana (granum = singular) Stack of thylakoids (“coins”)
Lumen-inside the thylakoid
****NOTE the difference between stroma and stoma (stomata)
The Equation for Photosynthesis
Photosynthesis converts light energy to the chemical energy of food
Photosynthesis is summarized by this
Overall chemical equation
6 CO2 + 6 H2O + Light energy C6H12O6 + 6 O2
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)
The electromagnetic spectrum The entire range of
electromagnetic energy, or radiation
Gammarays X-rays UV Infrared
Micro-waves
Radiowaves
10–5 nm 10–3 nm 1 nm 103 nm 106 nm1 m
106 nm 103 m
380 450 500 550 600 650 700 750 nm
Visible light
Shorter wavelengthHigher energy
Longer wavelengthLower energy
Color we SEE = color most reflected by pigment; other colors (wavelengths) are absorbedBLACK all colors are reflected
Light
ReflectedLight
Chloroplast
Absorbedlight
Granum
Transmittedlight
28
How is Energy Absorbed by Plants?!
• Pigment molecules– PHOTONS = packets of light energy that are
absorbed by pigments to energize electrons• Chlorophyll– 2 types
1) Chlorophyll a 2) Chlorophyll b– Differ b/c they absorb different wavelengths (colors)
Primary vs. Accessory Pigments
Primary PigmentChlorophyll a (most abundant)
Accessory (Antennae) Pigments
Chlorophyll bAnthocyaninsXanthophyllsCartenoids
Why are plants green?• Whatever color wavelength is reflected is the color
that the pigment appears to be– Plants do not absorb (aka reflect) green regions of visible
spectrum are therefore GREEN! • Chlorophyll a and chlorophyll b – Absorb red and blue (best colors for PS!)– What would the worst color be…?
GREEN!
31
Carotenoids • Plant pigment• Often appear orange and yellow • Also found in green plants, too
• Can give flower petals their color!
Carotenoids
What happens to leaves in the fall?
• Days get shorter (less sunlight)• Temperature drops• Less chlorophyll is made, but is still broken
down at the same rate• Underlying red and orange pigments (which
were always there) are now seen
The Two Stages of Photosynthesis: A Preview
• The Light reactions•NEEDS LIGHT•Light Dependent Reactions
• The Calvin cycle•A.k.a- Dark Reactions or Light Independent Reactions •DOES NOT NEED LIGHT
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 (chemical energy)
The Calvin Cycle
Occurs in the stromaForms SUGAR from carbon dioxideCarbon fixation occurs (CO2
fixed carbon from C6H12O6) Uses ATP for energy and NADPH
for reducing power
An overview of photosynthesis
H2O CO2
Light
LIGHT REACTIONS
CALVINCYCLE
Chloroplast[CH2O](sugar)
NADPH
NADP
ADP+ P
O2
ATP
NADPH-Carries electrons that are needed to build molecules such as glucose.
Photosynthesis
This is the equation you are used to seeing, but this is not the whole story…
+ water + energy glucose + oxygencarbondioxide
6CO2 6H2O C6H12O6 6O2lightenergy
+ ++