Download Cellular Energy PPT

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
Energy Stored
Energy released
ADP
phosphate removed
RECALL: MACROMOLECULES
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: CHEMOSYNTHESIS
• 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
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.
STAY ON TASK… ONLY TALK ABOUT
THIS SUMMARIZER!!!
HINT: Make sure to use the word phosphate
in your explanation.
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
In plants, chlorophyll is
found in organelles
called chloroplasts.
leaf
• Photosynthesis takes place in two parts of
chloroplasts.
– grana (thylakoids)
– stroma
Each part of the
chloroplast is
responsible for a
specific
reaction.
grana (thylakoids)
chloroplast
stroma
The 1st Reaction
Light Dependent 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 2nd Step
Light Independent 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 equation for the overall process is:
6CO2 + 6H2O  C6H12O6 + 6O2
granum (stack of thylakoids)
1
chloroplast
6H2O
6O2
2
thylakoid
energy
stroma (fluid outside the thylakoids)
6CO2
1 six-carbon sugar
C6H12O6
3
4
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
1st step of AEROBIC respiration
Glycolysis
–
–
–
–
anaerobic process (does not require oxygen)
takes place in cytoplasm
splits glucose into two three-carbon molecules
produces two ATP molecules
-products are transferred to the mitochondria for the 2nd step (the Kreb’s
Cycle)
2nd step of AEROBIC respiration
• 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
Krebs Cycle
1
mitochondrion
ATP
matrix (area enclosed
and
by inner membrane) 6CO
2
energy
2
3
energy from
glycolysis
and
6O2
inner membrane
ATP
and
6H2 O
4
3rd step of AEROBIC respiration
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 a
waste product
1
mitochondrion
matrix (area enclosed
by inner membrane)
ATP
and
6CO2
energy
Electron Transport
3
energy from
glycolysis
and
6O2
2
inner membrane
ATP
and
6H2 O
4
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.
• NAD+ is recycled to glycolysis
• 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+
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 terms
Glycolysis
ETC
Glucose
Carbon Dioxide
Oxygen
Water
Krebs Cycle
2 ATP
34 ATP
Complete the chart of
anaerobic respiration
below:
Summarizer
Use the Terms:
Glucose
2ATP
Fermentation
Lactic acid
Alcoholic
Glycolysis
Yeast
Microorganisms
Animals
Summarizer
Use the chart to answer the Essential
Question:
How is energy cycled through the processes
of photosynthesis and respiration?
Summarizer
Comparison Chart:
Photosynthesis vs. Respiration
Photosynthesis
Function
Location
Reactants
Products
Chemical
Equation
Cellular
Respiration