Making Energy

Book Ch 9 Key Terms: Pg 197, 202, 208 Ch9 Reading:

Chemical Energy Photosynthesis is the process by which plants, algae, and some bacteria use sunlight, carbon dioxide, and water to produce carbohydrates and oxygen. 6CO2 + 12H2O + Light Energy C6H12O6 + 6O2+ 6H2O Organisms that are able to perform photosynthesis, such as plants, are autotrophs. Autotrophs make organic compounds that serve as food for them and for almost all of the other organisms on Earth,

Thylakoids

Harvesting Light Energy Chlorophyll is a green pigment in chloroplasts that absorbs light energy to start photosynthesis. When light hits a thylakoid, energy is absorbed by many pigment molecules and eventually transferred to electron carriers. The first two stages of photosynthesis depend directly on light because light energy is used to make ATP and NADPH. In the final stage of photosynthesis, ATP and NADPH are used to produce energy-storing sugar molecules

Producing Sugar The reactions that fix carbon dioxide are light-independent reactions, sometimes called dark reactions. The most common method of carbon fixation is the Calvin cycle.

How do you get Energy?

Glycolysis The cells of most organisms transfer energy found in organic compounds, such as those in foods, to ATP. The primary fuel for cellular respiration is glucose. Fats can be broken down to make ATP. Proteins and nucleic acids can also be used to make ATP, but they are usually used for building important cell parts.

Glycolysis, continued In glycolysis, enzymes break down one six-carbon molecule of glucose into two three-carbon pyruvate molecules. The breaking of a sugar molecule by glycolysis results in a net gain of two ATP molecules. This process of glycolysis is anaerobic, or takes place without oxygen.

Glycolysis

Fermentation To make ATP during glycolysis, NAD+ is converted to NADH. Organisms must recycle NAD+ to continue making ATP through glycolysis. The process in which carbohydrates are broken down in the absence of oxygen is called fermentation. Fermentation enables glycolysis to continue supplying a cell with ATP in anaerobic conditions.

Fermentation, continued In lactic acid fermentation, pyruvate is converted to lactic acid. During vigorous exercise, lactic acid fermentation also occurs in the muscles of animals, including humans. During alcoholic fermentation, one enzyme removes carbon dioxide from pyruvate. A second enzyme converts the remaining compound to ethanol, recycling NAD+ in the process.

Two Types of Fermentation

Aerobic Respiration C6H12O6 + 6O2 6CO2 + 6H2O Organisms such as humans can use oxygen to produce ATP efficiently through aerobic respiration. A part of aerobic respiration is the Krebs cycle, a series of reactions that produce electron carriers. The electron carriers enter an electron transport chain, which powers ATP synthase.

Aerobic Respiration, continued Electron Transport Chain takes place in the inner membranes of mitochondria Electron carriers, transfer energy through the electron transport chain. Energy from the electrons is used to actively transport hydrogen ions out of the inner mitochondrial compartment.

Aerobic Respiration, continued Electron Transport Chain Hydrogen ions diffuse through ATP synthase, providing energy to produce several ATP molecules from ADP. At the end of the electron transport chain, the electrons combine with an oxygen atom and two hydrogen ions to form two water molecules. If oxygen is not present, the electron transport chain stops. The electron carriers are not recycled, so the Krebs cycle also stops.

Anaerobic No Oxygen Glucose- C6 2ATP 2NAD+ Glycolysis 2 Pyruvate- C3 4 ATP 2NADH Oxygen?NoYes 2 Pyruvate NADH Fermentation Ethanol or Lactic Acid NAD+ 2 Pyruvate- C3 Lose C to CO2 Krebs cycle (Citric Acid Cycle) Make 2 NADH 6NADH 2FADH2 2ATP 10 NADH 2 FADH2 34 ADP Electron Transport Chain 10 NAD+ 2FAD 34 ATP Aerobic Oxygen In, Used, Reactants Out, Made, Products In, Used, Reactants Out, Made, Products In, Used, Reactants Out, Made, Products In, Used, Reactants Out, Made, Products C stands for carbon ATP CO 2 Cellular Respiration

Net ATP Production Anaerobic- Fermination – Glycolysis= -2 ATP to initiate – Glycolysis= 4 ATP produced Total Net ATP Production 2 ATP Aerobic – Citric Acid Cycle/Kreb Cycle= 2 ATP – Electron Transport Chain= 34 ATP Total Net ATP Production 38 ATP Photosynthesis: 6CO2 + 12H2O + Light Energy C6H12O6 + 6O2+ 6H2O Aerobic: C6H12O6 + 6O2 6CO2 + 6H2O

ATP ATP is a portable form of energy “currency” inside cells. ATP is a nucleotide made up of a chain of three phosphate groups. When the bond of the third phosphate group is broken, energy is released, producing ADP.

ATP Releases Energy

all definitions will be collected on the next exam day… They will not be allowed to be used on the exam. Key Terms Pg 151, 162 – Reading assignment Pg 154 & 162 Prok Pg 155 & 163 Euk Pg Plant Euk vs animal Euk Pg Euk cellular structure Key Terms: Page 156 – Reading: Pg Key Terms Ch 8: Pg 175 and 178 Key Terms Ch 10: Pg 228 – Reading Ch 8: – Reading Ch 10: Definitions in all.

All definitions will be collected on the next exam day… They will not be allowed to be used on the exam. Key Terms Pg 77 Key Terms Pg 146 – Reading assignment Pg 74 & 75 Prok Pg 58 & 59 Euk Pg 58 & 60, 61Plant Euk vs animal Euk Pg Euk cellular structure Pg Definitions Total.