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Carbon dioxide
C6H12O6
Photosynthesis
H2OCO2 O2
Water
+ 66
Lightenergy
Oxygen gasGlucose
+ 6
Photosynthesis
Chapter 8
Do you remember any of the eight characteristics of living things?
1. Living things are based on a universal genetic code (DNA)
2. Living things grow and develop3. Living things respond to their environment
(stimulus)4. Living things reproduce5. Living things maintain a stable internal
environment (homeostasis)6. Living things obtain and use material and energy
(metabolism)7. Living things are made up of CELLS8. Taken as a group, living things evolve over time
Three Subatomic Particles
Proton: (+) charged particle found inside the nucleus
Neutron: neutral particle found inside the nucleus
Electron: (-) charged particle found outside the nucleus in various energy levels
Organic Compounds
Carbohydrates
Monomer:Monosaccharide
Made up of:Carbon, Hydrogen,
Oxygen (H:O in 2:1 ratio)
Sugars – glucose, fructose, sucrose
Lipids
Monomer: Glycerol and Fatty Acids
Made up of: Carbon, Hydrogen,
Oxygen(H:O not in 2:1 ratio)
Oils, Waxes, Butter
Proteins
Monomer: Amino Acid
Made up of: Carbon, Hydrogen, Oxygen, Nitrogen
Enzymes
Nucleic Acids
Monomer: Nucleotide
1) 5 Carbon sugar, 2) phosphate group 3)nitrogenous base
Made up of: Carbon, Hydrogen,
Oxygen, Nitrogen and Phosphorus
DNA and RNA
Differences between plant and animal
Plant Animal
Cell wall Chloroplast Photosynthesis Lysosomes only in
specialized cells No centrioles
No cell wall No chloroplast No photosynthesis Lysosomes Centrioles (cell
division)
Organelle for photosynthesis – chloroplast Organelle to convert chemical energy into
energy the cell can use – mitochondria Energy currency of the cell – ATP Why are plants green? Chlorophyll
Autotrophs and Heterotrophs: Autotrophs
Organisms that manufacture their own food (Plants) Also known as producers
Heterotrophs Organisms that cannot make their own
food (Humans) Also known as consumers
Autotrophs and Photosynthesis: Autotrophs use the energy directly from sunlight
and store it in organic compounds. They convert solar energy to chemical energy
stored in carbohydrates (glucose). Photosynthesis is a series of complex reactions in which the product of one reaction is consumed in the next reaction. A series of reactions linked in this way is called a biochemical pathway.
Biochemical Pathway:
Equations: Photosynthesis: (stores energy)
6 CO2 + 6 H2O C6H12O6 + 6 O2
Cellular Respiration: (releases energy)
C6H12O6 + 6 O2 6 CO2 + 6 H2O + ATP
glucose
glucose
Photosynthesis
6CO2 + 6H2O C6H12O6 + 6O2
LIGHT
Carbon Dioxide
Water
Glucose
Oxygen
What is Light?
Light Speed, c = 2.9979 x 108 m/s
or 670.6 million mph
Which type of light carries more energy, blue or red?
• Light travels through space as waves of energy.
• Different colors have different wavelengths.
Why are plants usually green?
Electromagnetic Spectrum• Wave length and energy are inversely
proportional
• The smaller the wave length, the more energy
• Blue light is high energy
• Red light is low energy
They reflect green light
Photosynthesis Takes place in the chloroplast Thylakoids – saclike
photosynthetic membrane in the chloroplast
Grana – stacks of thylakoids
Stroma - the region outside of the thylakoid membranes
Plant (Chloroplast) Pigments Membranes of the thylakoid contain a variety
of pigments Pigments – light absorbing molecules Chlorophyll – the most abundant pigment in
plants that absorbs blue and red light. Chlorophyll a - blue-green pigment Chlorophyll b - yellow-green pigment
Accessory Pigments – absorb light in other regions of the spectrum Carotene - an orange pigment
Xanthophyll - a yellow pigment
Anthocyanin – a red pigment
Accessory Pigments Why do plants need accessory pigments?
They absorb light in other regions of the spectrum The accessory pigments are always present in
most plants but masked by the chlorophyll.
Pigments Why do leaves change color in the fall?
Answer: Shorter day lengths stop chlorophyll production, and expose accessory pigments
Chemical Energy and ATP: One of the most important compounds that cells
use to store and release energy is adenosine triphosphate (ATP).
ATP consists of adenine, a 5-carbon sugar called ribose, and three phosphate groups.
Why is ATP useful to cells?
ATP can easily release and store energy by breaking and re-forming the bonds between its phosphate groups. This characteristic of ATP makes it exceptionally useful as a basic energy source for all cells.ATP Synthase (3:21)
ADP and ATP Cells store energy by adding a phosphate group to
adenosine diphosphate (ADP) molecules Cells release energy from ATP molecules by subtracting a phosphate group
The energy of ATP is locked in the bonds between the phosphate groups. When the terminal phosphate group of the ATP molecule
is removed by hydrolysis, energy is released and adenosine diphosphate (ADP) and phosphate are formed.
ATP Synthase (3:21)
Photosynthesis (Overall)
Light
CO2H2O Chloroplast
LIGHTREACTIONS(in thylakoids)
CALVINCYCLE
(in stroma)
NADP+
ADP
+ P
ATP
NADPH
O Sugar
Electrons
Light Dark
An Overview of Photosynthesis: Because light is a form of energy, any compound
that absorbs light absorbs energy. Chlorophyll absorbs visible light especially well.
When chlorophyll absorbs light, a large fraction of the light energy is transferred to electrons. These high-energy electrons make photosynthesis work.
Photosynthesis (3:39)
Light-Dependent Reactions: Photosynthesis involves two sets of reactions.
The first set of reactions is known as the light-dependent reactions because they require the direct involvement of light and light-absorbing pigments.
Light-Dependent Reactions: The light-dependent reactions use ENERGY from
sunlight to produce energy rich compounds, like ATP and NADPH. Water is required and Oxygen is a byproduct
These reactions take place within the THYLAKOID membranes of the chloroplast.
Light-Independent Reactions (Calvin Cycle):
Plants absorb carbon dioxide from the atmosphere and complete the process of photosynthesis by producing sugars and other carbohydrates.
During light-independent reactions, ATP and NADPH molecules produced in the light-dependent reactions are used to produce high-energy sugars from carbon dioxide.
Light-Independent Reactions: No light is required to power the light-
independent reactions.
The light-independent reactions take place outside the thylakoids, in the STROMA.
An Overview of Photosynthesis:
Sunlight
H2O
O2
CO2
Sugars (C6H12O6)
Photosynthesis Overview (7:26)
_____ + _____ _____ + _____6 CO2 6 H2O 6 O2 C6H12O6
Rate of Photosynthesis: Light Intensity:
Increase rate of photosynthesis, then levels off (maximum rate of photosynthesis) Higher intensity, excites more electrons in
chlorophyll @ some intensity, all available electrons are
excited
Rate of Photosynthesis: Temperature:
Higher temperature accelerates the chemical reactions.
Peaks @ certain temperature because the enzymes become ineffective and unstable
Rate of Photosynthesis: Amount of CO2:
Increases rate of photosynthesis to a point, then levels off
Water Availability: Increases rate of photosynthesis to a point, then
levels off
Biochemical Pathway:
Structure of the Chloroplast
Chemical Energy and Food
The two equations are exact opposites!
PHOTOSYNTHESIS
___________ + _________ + ___________ →_______________ + __________6 CO2 6 H2O C6H12O6 6O2
_____________ + _________ →________ + __________ + __________
CELLULAR RESPIRATIONC6H12O6 6O2
6 CO2 6 H2O
Structure of the Mitochondria:
Cellular Respiration
Chapter 9
Comparing Photosynthesis & Cellular Respiration:
Photosynthesis Cellular Respiration
Function
Location
Reactants
Products
Produces food (chemical energy) for the plant
(glucose C6H12O6)
Produces chemical energy (ATP) for the cell
Chloroplast Mitochondria
Water (H2O), Carbon dioxide (CO2)
and sunlight
Oxygen (O2) and Glucose (C6H12O6)
Oxygen (O2) and Glucose (C6H12O6)
Water (H2O), Carbon dioxide (CO2)
and energy (ATP)
Comparing Photosynthesis & Cellular Respiration:
Which type(s) of organisms carry out photosynthesis?
Autotroph Heterotroph
Which type(s) of organisms carry out cellular respiration?
Autotroph Heterotroph
Chemical Energy and Food
Cellular respiration happens slowly and in many steps.
If all the energy was release in one step… Most would be lost as light and heat! Cellular respiration breaks down glucose
molecules and banks their energy in ATP
An Overview of Cellular Respiration:
Stages of Cellular Respiration: The three main
stages of cellular respiration are
1. Glycolysis2. Krebs cycle3. Electron transport
chain.
Oxygen and Energy: Pathways of cellular
respiration that require oxygen are called AEROBIC. The Krebs cycle and electron transport chain are both aerobic processes. Both processes take place inside the mitochondria.
Oxygen and Energy: Glycolysis and fermentation
are anaerobic processes. They do not directly require oxygen, nor do they rely on an oxygen-requiring process to run. However, glycolysis is still considered part of cellular respiration. Glycolysis takes place in the cytoplasm of a cell.
Compare Photosynthesis to Cellular Respiration
NADH
NADH FADH2
GLYCOLYSISGlucose Pyruvate CITRIC
ACID CYCLE
OXIDATIVE
PHOSPHORYLATION
(Electron Transport
and Chemiosmosis)
Substrate-level phosphorylation
Oxidative phosphorylation
Mitochondrion
and
High-energy electrons carried by
NADH
ATPATPATP
CO2 CO2
Cytoplasm
Substrate-level phosphorylation
Light
CO2H2OChloroplast
LIGHTREACTIONS(in thylakoids)
CALVINCYCLE
(in stroma)
NADP+
ADP+P
ATP
NADPH
O Sugar
Electrons
How Cells Obtain Energy (14 min)
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