SB3a.
Students will be able to explain the cycling of energy through the
processes of photosynthesis and
respiration
LEQ1 : How is energy cycled through the processes of
photosynthesis and respiration?
Why do organisms need energy?• All organisms require energy to do
work– growth and development
• The original source of all energy on earth is the SUN
How is energy stored?
In living things energy is stored in a molecule of adenosine triphosphate (ATP)
WHAT IS RIBOSE???
Just a thought…
Would you want a tattoo of ATP on your arm???
What is ATP?• Energy storing molecule in organisms
Made of:•5 carbon sugar (ribose)
•Nitrogen compound (adenine)•3 Phosphates
How is energy stored in and released from ATP?
Energy is stored in chemical bonds between phosphates
Energy is released when the bond is broken and one phosphate is released
Adenosine diphosphate (ADP) is produced when the phosphate is
released
Cycling of ATP and ADP
ATP
ADP
En
erg
y re
leasedE
nerg
y
Sto
red
phosphate removed
Organisms break down carbon-based molecules to produce ATP.
• Carbohydrates are the molecules most commonly broken down to make ATP.
–not stored in large amounts
–up to 36 ATP from one glucose molecule
RECALL: MACROMOLECULES
• Fats store the most energy.
– 80 percent of the energy in your body– about 146 ATP from a triglyceride
• Proteins are least likely to be broken down to make ATP.– amino acids not usually needed for energy– about the same amount of energy as a carbohydrate
RECALL: MACROMOLECULES
• Some organisms live in places that never get sunlight.
• In chemosynthesis, chemical energy is used to build carbon-based molecules.– similar to photosynthesis– uses chemical energy
instead of light energy
RECALL: CHEMOSYNTHESIS
What are the three main uses for ATP?
1. Transports needed substances across the cell membrane
– Active Transport
2. Activating metabolic reactions– All chemical reactions in the body
3. Mechanical work – Moving muscles
Summarizer
Explain to your neighbor how energy is converted between ATP and ADP.
HINT: Make sure to use the word phosphate in your explanation.
STAY ON TASK… ONLY TALK ABOUT THIS SUMMARIZER!!!
Photosynthetic organisms are producers.
• Producers make their own source of chemical energy.
• Plants use photosynthesis and are producers.
• Photosynthesis captures energy from sunlight to make sugars.
Chlorophyll is a
molecule that absorbs
light energy.
chloroplast
leaf cell
leaf
In plants, chlorophyll isfound in organellescalled chloroplasts.
• Photosynthesis takes place in two parts of chloroplasts.– grana (thylakoids)– stroma
chloroplast
stroma
grana (thylakoids)
Each part of the chloroplast is
responsible for a specific reaction.
– take place in grana (thylakoids)– water and sunlight are needed– chlorophyll absorbs energy– energy is transferred along thylakoid membrane then to
light-independent reactions (ATP is used to drive the 2nd reaction.)
– oxygen is released
The 1st ReactionLight Dependent Reaction
– take place in stroma– needs carbon dioxide from atmosphere– use energy to build a sugar in a cycle of
chemical reactions (ATP)
This is also referred to as the CALVIN CYCLE!!!
The 2nd StepLight Independent Reaction
The equation for the overall process is:
6CO2 + 6H2O C6H12O6 + 6O2
C6H12O6
granum (stack of thylakoids)
thylakoid
sunlight
1 six-carbon sugar
6H2O
6CO2
6O2
chloroplastchloroplast1
2
43
energy
stroma (fluid outside the thylakoids)
Reactants of Photosynthesis
1. Radiant energy– Sunlight is absorbed by the chloroplasts
in the leaves of the plant
2. Carbon dioxide– Absorbed by the leaves of the plant
3. Water– Absorbed from the soil by the roots of the
plant
Products of Photosynthesis
1. Sugar (C6H12O6 = glucose)– Produced in the leaves of the plant and is
transported to the rest of the plant for chemical energy
– What is the suffix for identifying a sugar?
2. Oxygen– Is released from the leaves of the plant into
the atmosphere
Summarizer
1. Write out the equation of photosynthesis.
2. Switch papers with your neighbor and add any additional information.
Why is the release of oxygen by plants an important function?
How does it affect us?
How do animals get their energy?
Animals extract energy from the food they consume
through the process of
cellular respiration
What is Cellular Respiration?
• Process in which organisms release stored energy from food.
• Formula:
6O2 + C6H12O6 energy + 6CO2 + 6H2O
Two types of Cellular Respiration
1. Aerobic Respiration Requires Oxygen
2. Anaerobic Respiration Does NOT require Oxygen
Aerobic Respiration
• Occurs in the presence of oxygen
• Involves 3 steps: Glycolysis, Krebs Cycle, and Electron Transport Chain
• Complete breakdown of sugar
• Produces: ATP + carbon dioxide
• More efficient because it produces a greater quantity of ATP
Glycolysis
– anaerobic process (does not require oxygen)– takes place in cytoplasm– splits glucose into two three-carbon molecules– produces two ATP molecules
1st step of AEROBIC respiration
-products are transferred to the mitochondria for the 2nd step (the Kreb’s Cycle)
• The Krebs cycle transfers energy to an electron transport chain.– takes place in
mitochondrial matrix– breaks down three-carbon
molecules from glycolysis
– makes a small amount of ATP
– releases carbon dioxide– transfers energy-carrying
molecules
6H O2
6CO 2
6O 2
mitochondrionmitochondrion
matrix (area enclosedby inner membrane)
inner membrane
ATP
ATP
energy
energy from glycolysis
1
2
4
3
and
and
and
Krebs Cycle
2nd step of AEROBIC respiration
6H O2
6CO 2
6O 2
mitochondrionmitochondrion
matrix (area enclosedby inner membrane)
inner membrane
ATP
ATP
energy
energy from glycolysis
1
2
4
3
and
and
and
The electron transport chain produces a large amount of ATP.
– takes place in inner membrane
– energy transferred to electron transport chain
– oxygen enters process
– 34 ATP produced
– water released as awaste product
Electron Transport
3rd step of AEROBIC respiration
Photosynthesis vs. Respiration
• They are opposite processes
• Reactants for one process are the products for the other
• Two processes together maintain the balance of life on earth
• The equation for the overall process is:
C6H12O6 + 6O2 6CO2 + 6H2O
Anaerobic Respiration• Occurs in the absences of oxygen
– Body is deprived of enough oxygen to maintain aerobic reactions
• Involves 2 steps: Glycolysis, and Fermentation
• Incomplete breakdown of sugar
• Produces: ATP + carbon dioxide + alcohol/lactic acid
• Not as efficient as aerobic respiration (produces less ATP)
Fermentation allows the production of a small amount
of ATP without oxygen.
• Fermentation allows glycolysis to continue making ATP when oxygen is unavailable.
• Fermentation does not produce ATP.
• Lactic acid fermentation occurs in muscle cells.– glycolysis splits glucose into two pyruvate molecules– pyruvate and NADH enter fermentation– energy from NADH converts pyruvate into lactic acid– NADH is changed back into NAD+
• NAD+ is recycled to glycolysis
Fermentation and its products are important in several ways.
• Alcoholic fermentation is similar to lactic acid fermentation.– glycolysis splits glucose and the products enter fermentation
– energy from NADH is used to split pyruvate into an alcohol and carbon dioxide
– NADH is changed back into NAD+
– NAD+ is recycled to glycolysis
Alcoholic Fermentation is used in food production by yeast and microorganisms to produce:
– yogurt
– cheese
– bread
Lactic Acid Fermentation occurs in animals.
It is caused by the buildup of lactic acids in muscle cells.
-soreness
-burning
Summarizer
What is the total amount of ATP produced from one molecule of glucose during aerobic respiration?
Summarizer
How can you tell if your body is going through aerobic or anaerobic respiration when you are working out?
Summarizer:Complete the chart below on the steps of aerobic
respiration.
Use the termsGlycolysis
ETCGlucose
Carbon DioxideOxygenWater
Krebs Cycle 2 ATP
34 ATP
Complete the chart of anaerobic respiration
below: Use the Terms:
Glucose
2ATP
Fermentation
Lactic acid
Alcoholic
Glycolysis
Yeast
Microorganisms
Animals
Summarizer
Summarizer
Use the chart to answer the Essential Question:
How is energy cycled through the processes of photosynthesis and respiration?
Comparison Chart:Photosynthesis vs. Respiration
Photosynthesis Cellular Respiration
Function
Location
Reactants
Products
Chemical Equation
Summarizer