Green Book 7

Cellular EnergyCellular Energy

Created by Created by Wesley R. McCammonWesley R. McCammon

Pisgah High School

I. Cellular Energy

All Living cells use energy– Energy is released when chemical bonds are

broken.– When chemical bonds in foods are broken

cells obtain energy.

I. Cellular Energy

The main form of energy is adenosine triphosphate or ATP.– Living things use ATP to store and release

energy.– ATP has 3 parts

• Adenine – an amino acid

• Ribose – a sugar moleucle

• Three phosphate groups

I. Cellular Energy

I. Cellular Energy– ADP only has 2 phosphate groups (adenosine

diphosphate)– AMP has only 1 phosphate group (adenosine

monophosphate)– When a phosphate group is added energy is

store. When a phosphate group is removed energy is released.

– ATP (energy rich) ADP + energy– ADP + Pi ATP (energy rich)– ATP is NOT good for long term energy

storage

I. Cellular Energy

ATP Cycle

ATP/ADP Cycle

II. Aerobic and Anaerobic Cellular Respiration

Cellular respiration is a series of reactions that break down food for energy in the presence of oxygen.

There are three parts of aerobic cellular respiration: Glycolysis, the Kreb’s cycle, and the Electron Transport Chain.

Structure of the Mitochondrion

II. Aerobic and Anaerobic Cellular Respiration

Glycolysis– Glycolysis is the first stage of cellular

respiration.• Glycolysis occurs in the cytoplasm

• Glucose is broken down into the following end products

– 2 ATP

– 2 Pyruvic acids

– 2 NADH

II. Aerobic and Anaerobic Cellular Respiration

Glycolysis (con’t)– Pyruvic acid is used in the next stage of

cellular respiration; NADH is used in the last stage of cellular respiration.

– NADH is a carrier molecule used to transport hydrogen ions and electrons to the Electron transport chain.

– ALL organisms on the planet do Glycolysis. Glycolysis occurs without the presence of oxygen.

II. Aerobic and Anaerobic Cellular Respiration If oxygen is present, the next step is the Kreb’s

cycle which takes place in the inner spaces of the mitochondria.– Pyruvic acid enters the Krebs cycle. It proceeds

through the cycle and returns back to the starting point.

– The end products of the Kreb’s cycle are 1 ATP, 1FADH2, and 3 NADH. However, there are 2 pyruvic acids (from glycolysis) therefore the cycle runs TWICE so the true end products for molecule of glucose is 2 ATP, 2 FADH2, and 6 NADH.

– FADH2 is a also a carrier molecule.

II. Aerobic and Anaerobic Cellular Respiration

The last stage of cellular respiration is the Electron Transport Chain.– The NADH and FADH2 are used

– This causes a concentration gradient to form along the inner mitochondria membrane.

– ATP synthase is the enzyme/protein channel that the H+ ions pass through to form ATP.

– The end product of Cellular respiration is 36 ATP

II. Aerobic and Anaerobic Cellular Respiration

The overall summary equation for cellular respiration is:

C6H12O6 + 6O2 6CO2 + 6 H20 +ATP

Glucose + oxygen carbon +water+energy

dioxide

II. Aerobic and Anaerobic Cellular Respiration

Anaerobic Respiration– After glycolysis, if there is no oxygen present,

some cells can perform anaerobic respiration. (ana=no; aerobic=air)

II. Aerobic and Anaerobic Cellular Respiration

All the reactions take place in the cytoplasm.– Only 2 ATP are made from glycolysis and no

more.– Lactic acid fermination

• Pyruvic acid is converted into lactic acid.• Muscle cells do this when they run out of oxygen.

Results in muscle soreness because the lactic acid is poisonous.

II. Aerobic and Anaerobic Cellular Respiration

– Alcoholic fermentation• Pyruvic acid is converted into alcohol and carbon

dioxide.

• Makes bread wise

• Responsible for beer and wine production

III. Photosynthesis The sun is the primary source of energy for

most all ecosystems. All organisms on the planet can be divided

into either autotrophs (organisms like plants that make their own food by converting sunlight energy into carbohydrates) or heterotrophs (organisms like animals that get their energy from consuming foods.)

III. Photosynthesis

Photosynthesis is the process by which autotrophs use sunlight to change water and carbon dioxide into simple sugar and oxygen.

III. Photosynthesis

The overall summary equation for photosynthesis is:

6CO2 + 6 H20 +ATP C6H12O6 + 6O2

carbon+water+energy Glucose+oxygen

dioxide

III. Photosynthesis

The reactions of photosynthesis are divided into the light dependent reactions and the light independent reactions.

Structure of the Chloroplast

III. Photosynthesis The Light Dependent Reactions (AKA The

photosystems)– Can only occur in the presence of light– Chlorophyll is the green pigment found in

plants.– Chlorophyll absorbes light and the energy

goes through a series of reactions that convert ADP to ATP

– 2 Water molecules are split to form 4H+ (hydrogen ions) and the O2 (oxygen gas)

– The oxygen gas given off by plants com from the plant splitting of water.

– NADPH is also produced during the dependent reactions

III. Photosynthesis

Light Independent Reactions (AKA The Calvin Cycle or the Dark reactions)– Light is not needed– CO2 gas is taken in and used during the

Calvin cycle.– CO2 and hydrogen ions (from NAHPD)

combine to form simple sugars.– Simple sugars combine to form complex carbs

like starch and cellulose.

III. Photosynthesis

C3 plants use the process described above. C4 plants (tropical plants) store extra

carbon dioxide in 4 carbon compounds for when times it too hot for the stomata to open (stomata – leaf pores).

CAM plants (succulents) store extra carbon dioxide in Crassulacian acid for the day time when it’s too hot to open a stomata.

IV. Cellular Respiration vs. Photosynthesis

The 2 processes are basically the reverse of each other.

Photosynthesis is a building process and cellular respiration is a tearing down process.

IV. Cellular Respiration vs. Photosynthesis

 Cellular Respiration Photosynthesis

Takes place in- All cells Cells with chlorophyll

Occurs when- All of the time In the presence of light

What goes in- Carbohydrates and oxygen

Carbon dioxide and water

What comes out- Carbon dioxide and water

Carbohydrates and oxygen

Energy source- Chemical bonds Light

Result- Energy is stored as ATP Energy is stored as carbohydrates

Processes -Glycolysis-Krebs Cycle-Electron Transport Chain

-Light Dependent Reactions-Light Independent Reactions