Post on 02-Jan-2016
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Energy Release
• When bonds are broken, __________ is released for use by the cell
energy
Sucrose: A disaccharideGlucose Fructose
Monosaccharides
ATP
Energy Storage
Glucose: A Monosaccharide Fructose: A Monosaccharide
• When bonds are made, energy (E) is stored
Sucrose: A dissaccharide
Carbohydrates
1. Carbohydrates are:– an important energy (E) source– Cellular structures
2. Carbon, Hydrogen and Oxygen in a ratio of 1:2:1
3. General Formula (CH2O)nCH2O
Water = hydrateCarbon hydrate
Types of Carbohydrates
Monosaccharides (simple sugars) – Contain 3-7 Carbons each
• Examples: Glucose, Galactose, FructoseGlucose
Types of Carbohydrates, cont…
Disaccharides (two sugars)• Examples: Sucrose, Maltose, Lactose
– Maltose = Glucose + Glucose– Lactose = Glucose + Galactose
Sucrose
Glucose Fructose
Types of Carbohydrates, cont…
Polysaccharides (many sugars)• Examples: Starch, Glycogen, CelluloseStarch Cellulose
Chloroplast Starch
Glycogen
Liver Cell
Plant Cells
Plant Cells
Cellulose
Check for Understanding…I’m a carbohydrate polymer made of 4 monomers. What are my monomers called?
Monosaccharides, of course!
How is energy released?
• When bonds are made by dehydration synthesis, energy is stored within the bonds of the compound.
Sucrose: A disaccharideGlucose Fructose
Monosaccharides
ATP
OH HO
How is energy released?
• When bonds are broken by hydrolysis, __________ is released from the bondsenergy
Sucrose: A disaccharideGlucose Fructose
Monosaccharides
ATP
What are some examples of common energy storing
compounds?
1. ATP (Most important usable energy for the cell.)
2. NADPH
3. FADH2
4. NADH
How is ATP made?
• ATP is made from the precursor AMP (Adenosine Mono-phosphate)
• If a phophate and energy is added to AMP, ADP is created.
• Furthermore, if another phosphate is added to ADP, ATP is created.
How are NADPH, FADH2, and NADH made?
• NADP+ + H+ + electrons NADPH• FAD+ + 2H+ + electrons FADH2
• NAD+ + H+ + electrons NADH• Notice that high energy electrons and
hydrogen ions (H+) are needed to create NADPH, FADH2 and NADH.
1. Mesophyll
1. Mesophyll
A layer of cells that contain & are responsible for most of the plant’s photosynthesis
chloroplasts
Page 2
2. Stomata
Openings in plant leaves that allow for to occur
(CO2) passes in and (O2) passes out.
CO2
O2
gas exchange
Carbon Dioxide Oxygen
Page 2
Mesophyll Cell
3. Chloroplast
The site of Photosynthesis
Double-membrane bound organelle
5. Inner membrane
4. Outer membrane
Page 2
Pathway of Photosynthesis
On your own, balance this equation:
CO2 + H2O + (Light) C6H12O6 + O2
Reactants must equal Products
16 66
Carbon
Hydrogen
Oxygen
Carbon
Hydrogen
Oxygen
6
12
6
12
18 18
Page 4
Photosynthesis: The Light Reaction
• are chemical factories powered by the sun.
• Their thylakoids transform light energy into the energy of
and .
Page 5
Chloroplasts
NADPH ATP
Why are leaves green?Substances that absorb light are called
Page 5
Chlorophyll a
Chlorophyll b
Carotenoids
Chlorophyll absorbs and light, reflecting
pigments
red blue green
Fluorescence of ChlorophyllE
nerg
y of
ele
ctro
n
Photon
Chlorophyll molecule
e-
Heat
Fluorescence
Ground state
High energy state
Photosystems: Harvest LightPhoton
Transfer of Energy Antenna pigment molecules
Reaction Center Chlorophyll
Primary Electron AcceptorElectron Transfer (high energy state)
Light ReactionE
nerg
y of
Ele
ctro
ns
Primary Acceptor
2 e-
H2O
1) photons
2H+ + O2
2e-
Photosystem II Photosystem I
2) Spliiting of water releases O2
gas and refills 2e- to the chlorophill pigment
Electron Transport Chain (ETC)
3) Electrons “fall” in energy, moving through a protein complex called the ETC, and ATP is created from this energy
ATP
2e-
4) photons
Primary Acceptor 2e-
ETCNADP+ + H+
NADPH making enzyme
NADPH
5)
Mechanical analogy for the light reactions
1. Photon excites an electron in Photosystem II
2. ATP is produced during this stage (ETC)
3. The electron moves on to Photosystem I
4. An electron is excited by another photon
5. NADPH is produced
ATP Synthetase
• An enzyme embedded in the
Thylakoid membrane
thylakoid membrane
• Creates ATP from the electron’s energy in the ETC
Dark Reaction:An Overview
• The General Formula for Photosynthesis is:
6CO2 + 6H2O + (Light ) C6H12O6 +6O2
• Which of these reactants has not been accounted for so far?
ATP & NADPH energy are used to convert
CO2 into glucoseNADPH
ATP
CO2
Sugar!
This is done in a three-phase cycle…
ATP and NADPH energy is used
This energy rearranges atoms of PGA
PGA changes into PGAL, a different 3-carbon sugar
PGAL
Phase 2: Makes PGAL, a 3-Carbon sugar