UNIT 4- CELLS AND ENERGY
ATP, PHOTOSYNTHESIS AND CELLULAR
RESPIRATION
WHAT MAKES THESE CELLS SO IMPORTANT TO MANY OTHER
ORGANISMS????????? These diatoms are single
celled algae that use the process of photosynthesis to store chemical energy in sugars. Animals eat photosynthetic organisms such as plants and algae to get this chemical energy. They also produce oxygen that is required to release much of the chemical energy in sugars.
READ THE CAPTION ABOVE OR ON THE POWERPOINT. WHAT THREE THINGS MENTIONED ARE CRITICAL TO YOUR LIFE?
Energy Sugar Oxygen
WHAT IS ANOTHER NAME FOR CARBON FIXATION?
Photosynthesis
WHY DOES CARBON NEED TO BE FIXED? Organisms can’t live off of carbon
dioxide. We would die. Therefore photosynthetic plants / organisms turn the CO2 into organic compounds like carbohydrates. The plants process the CO2 and give us glucose!!!!!
WHAT TYPES OF CARBON BASED MOLECULES OR ORGANIC MOLECULES ARE NECESSARY FOR ALL LIFE TO EXIST ON EARTH?
Proteins Carbohydrates Lipids Nucleic Acids
HOW DOES A WHALE USE THE ORGANIC MOLECULES IT GETS FROM FEEDING ON DIATOMS?
Breaks them down for materials and energy needed to maintain life.
ENERGY…………• Energy for living things comes from food.
Originally, the energy in food comes from the sun.
WHO ARE THESE PEOPLE??????????? Organisms that use light and energy
from the sun to make their own food are called autotrophs or producers. For example, plants and algae.
Organisms that rely on other for food are called heterotrophs or consumers. For example, you, fish, whales, bears, etc….
AUTOTROPHS
HETEROTROPHS
CHEMOSYNTHESIS Some animals don’t need sunlight &
photosynthesis as a source of energy. Chemosynthesis- process by which
organisms use chemical energy to make their food.
Example- Deep Ocean Hydrothermal Vents. https://www.youtube.com/watch?v=X
otF9fzo4Vo
HOW DOES THE FOOD GO FROM OUR MOUTHS TO GIVING OUR BODY ENERGY?
ATP- Adenosine triphosphate Main energy currency ATP- molecule that transfers energy from
the breakdown of food molecules to cell processes.
Cells use ATP for building molecules and moving materials through active transport.
ATP is made up of the sugar ribose, adenine, and three phosphates.
file:///D:/data/nsmedia/visualconcepts/60028.htm
HOW DOES ATP WORK EXACTLY????? Step 1- The energy carried by ATP is released when
a phosphate group is removed from the molecule. The third bond is unstable and is easily broken.
Step 2- Reaction takes place and the energy is released for cell functions, meaning the third phosphate fell off.
Step 3- ATP (high energy) then becomes ADP (lower energy molecule) because it just lost a phosphate.
Step 4-The molecules get broken down and energy gets added.
Step 5- Phosphate is added and it’s back to ATP!
phosphate removed
WHY IS THIS IMPORTANT? The foods that you eat don’t contain ATP. The food needs to be digested and
broken down Everything that you eat has a different
calorie amount (measures of energy) therefore different foods produce different amounts of ATP.
The number of ATP produced depends on what you eat- Carbohydrate, protein, or lipid.
CARBOHYDRATES Carbohydrates are not stored in large
amounts in your body because they are the most commonly broken down molecule.
The breakdown of glucose yields 36 ATP.
Carbohydrates DO NOT provide the body with the most ATP. Lipids do!
LIPIDS Store the most energy, about 80% of
the energy in your body. When they are broken down they yield
the most ATP, 146 ATP
PROTEINS Store about the same amount of
energy as carbohydrates, but they are less likely to be broken down to make ATP.
The amino acids that cells can break down to make ATP are needed and used to build new proteins.
FUN VIDEO https://www.youtube.com/watch?v=V_x
ZuCPIHvk
PHOTOSYNTHESIS Defined as the process that captures energy from sunlight to make sugars that store chemical energy.
Location- Chloroplast of plant cells. Chlorophyll- the molecule in the
chloroplast that absorbs the energy from the sunlight. Two main types chlorophyll a and b that absorb mostly red and blue light. Other pigments absorb the green.
Green color in plants comes from the reflection of light’s green wavelengths by chlorophyll.
Chloroplast
Leaf Cell
Leaf
Fall Foliage
CHLOROPLAST Two main parts are:
Grana- stacks of coined shaped membranes.
Thylakoid- Inside the grana and they are the little disks. They contain chlorophyll and other light absorbing pigments.
Stroma- Fluid that surrounds the grana inside the chloroplast.
Calvin
Cycle
LIGHT DEPENDENT REACTIONS Rely / dependent on energy from the
sun. Take place within and across the
thylakoid membrane. Water and sunlight are needed here.
LIGHT INDEPENDENT REACTIONS Uses the energy transferred from the light
dependent reactions to make sugars. Reactions occur in the stroma Carbon dioxide is absorbed and used at this
stage. Calvin Cycle- metabolic pathway found in the
stroma of the chloroplast in which carbon enters in the form of CO2 and leaves in the form of sugar.
ATP is produced as a final step and the enzyme ATP synthase is responsible for making ATP by adding phosphate groups to ADP.
THE WHOLE PROCESS………. Step 1- Chlorophyll absorbs energy from
sunlight. Energy is transferred along the thylakoid membrane, water molecules are broken down, and oxygen is released.
Step 2- Energy carried along the thylakoid is transferred to molecules that carry energy, like ATP
Step 3- CO2 is added and larger molecules are built.
Step 4- A molecule of simple sugar (glucose) is formed.
EQUATION FOR PHOTOSYNTHESIS
Carbon
Dioxide
Water Glucose
Oxygen
http://www.youtube.com/watch?v=lDwUVpOEoE4
QUESTIONS TO REVIEW 1. Where do light- dependent reactions
occur? 2. Where do the light independent
reactions occur? 3. What two reactants are shown
entering the chloroplast? 4. What two products are shown
leaving the chloroplast? 5. What does the Calvin Cycle produce?
ANSWERS 1. thylakoid membrane 2. Stroma 3. water and carbon dioxide 4. oxygen and sugar 5. sugar- converts CO2 into sugar
– Makes sugars– takes place in
stroma– needs carbon
dioxide from atmosphere
– use energy to build a sugar in a cycle of chemical reactions
Light Dependent Reactions
Light Independent Reactions
– Requires sunlight– take place in
thylakoids– water and sunlight
are needed– chlorophyll absorbs
energy– energy is transferred
along thylakoid membrane then to light-independent reactions
– oxygen is released
STAGE 1 IN DETAIL Photosystems->Molecules that capture
and transfer energy in the thylakoid.
LIGHT DEPENDENT REACTIONS
Sugars are not made yet Main function: capture and transfer energy Water molecules are broken down into
hydrogen ions, electrons, and oxygen gas. Oxygen is a waste product and sugars are not made at this point.
Energy is transferred to electrons. Electrons are used for energy during
photosynthesis not for the cells general energy needs.
LIGHT DEPENDENT CONT. Like a special ticket at an amusement park
that can only be used for a specific rollercoaster.
Energy-> electrons->ATP and NADPH (transferred to the later stages)
Arrows represent energy and enzymes! NADP= coenzyme that can accept hydrogen
and acts as an enzyme
http://www.biology-online.org/dictionary/Nicotinamide_adenine_dinucleotide_phosphate
LETS PUT IT ALL TOGETHER Step 1-> Energy is absorbed from
sunlight Step 2-> Water molecules breakdown,
electrons enter, and oxygen is released as waste.
Step 3-> Hydrogen ions are transported across the thylakoid membrane
Step 4-> Chlorophyll absorbs energy from sunlight
Step 5-> NADPH is produced when electrons are added to NADP+
STEPS 6 AND 7!!! Step 6-> Hydrogen ions diffuse through
a protein channel Step 7-> ADP is changed into ATP when
hydrogen ions flow through ATP synthase (enzyme).
CALVIN CYCLE Does not need sunlight Produces sugars Energy sources are ATP and NADPH Energy that is needed for a series of
chemical reaction is called the Calvin Cycle, named after a scientists- Melvin Calvin.
STEPS 1. CO2 is added to the 5 carbons that are
already there making a 6 carbon sugar 2. ATP and NADPH is used from LDR to split the
six carbons into 2 groups of 3. 3. Three carbon molecules exit. After they both
exit they bond together to form glucose. 4. Three carbon molecules are recycled and
changed back to five carbon molecules by energy from ATP.
LIGHT INDEPENDENT / CALVIN CYCLE- INSERT INTO NOTES
Occur in the stroma A molecule of glucose is
formed as it stores some of the energy captured from sunlight.
carbon dioxide molecules enter the Calvin cycle
energy is added and carbon molecules are rearranged
a high-energy three-carbon molecule leaves the cycle
CALVIN CYCLE CONT. A molecule of
glucose is formed as it stores some of the energy captured from sunlight
Two three-carbon molecules bond to form a sugar
Remaining molecules stay in the cycle
VIDEOS http://highered.mcgraw-hill.com/
sites/0072437316/student_view0/chapter10/animations.html#
http://dendro.cnre.vt.edu/forestbiology/photosynthesis.swf
CELLULAR RESPIRATION!! Releases chemical energy from
sugars and other carbon based molecules to make ATP when oxygen is present.
BY THE TIME YOU REACH 16 YOU HAVE TAKEN ABOUT 200 MILLION BREATHS
Breathe in oxygen and the oxygen releases energy in sugars and other carbon based molecules ATP
Animals use cellular respiration
Plants use photosynthesis Breakdown food-> ATP Aerobic-> Need Oxygen Anaerobic= no oxygen Takes place in the
Mitochondria
After you eat and the food is broken down into glucose then the glucose needs to get broken down by glycolysis (2-3 carbon chains, ATP), which takes place in the cytoplasm and is anaerobic.
GLYCOLYSIS- DRAW INTO NOTES
2 STAGES Stage 1= Krebs Cycle Stage 2= Electron Transport
KREBS CYCLE Produces
molecules that carry energy to the second part.
Occurs in the matrix of mitochondria
6H O2
6CO 2
6O 2
mitochondrion
matrix (area enclosedby inner membrane)
inner membrane
ATP
ATP
energy
energy from glycolysis
1
2
4
3
and
and
and
STEP 1 2- 3 carbons
from glycolysis through pyruvate enter the cells matrix
Pyruvate is broken down before the Krebs cycle. carbon dioxide
released NADH produced coenzyme A (CoA)
bonds to two-carbon molecule
STEP 2 Energy carrying molecules
transfer energy through the matrix.
STAGE 3 Energy is transferred to the
chain of proteins (electron transport chain)
STAGE 4 Large # ATP is made. Heat and H2O are released as waste products.
END RESULT 38 ATP molecules are made from 1
glucose molecule-> 2 glycolysis and 34/36 come from cellular respiration.
PRODUCT CREATED IN THE BODY VIA METABOLISM AND IS THE END PRODUCT OF GLYCOLYSIS
Pyruvate-> enzyme that speeds up the phosphates
WHAT ENZYME IS DIRECTLY ASSOCIATED WITH THE KREBS CYCLE?
Pyruvate and coenzyme a
WHAT GETS FORMED?
Citric acid
Photosynthesis Cellular Respiration
Location Chloroplast Mitochondria
Reactants CO2 and H2O C6H12O6 and O2
Products C6H12O6 and O2 CO2 and H2O
Electron Transport Chain
Proteins within the thylakoid membrane
Proteins within the inner mitochondrial membrane
Cycle of chemical reaction
Calvin cycle in the stroma of chloroplasts builds sugar molecules.
Krebs cycle in matrix of mitochondria breaks down carbon based molecules.
• Fermentation allows glycolysis to continue making ATP when oxygen is
unavailable.Fermentation is an anaerobic process.occurs when oxygen is not available for
cellular respirationdoes 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+
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
Fermentation is used in food production.
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