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=XotF9fzo4Vo

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_xZuCPIHvk

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

mitochondrionmitochondrion

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

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

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

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.

Fermentation is used in food production.

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