ESSENTIAL QUESTIONS: WHO USES ENERGY? WHAT IS Energy?

WHAT IS ENERGY? Energy is the ability to do work or cause a change! ATP (adenosine triphosphate) is the main energy-storing molecule used as currency in living things ATP ADPAMP Energy PiPi PiPi

Movement of cilia/flagella for locomotion. Why do living things need energy? Bioluminescence in fireflies Transmission of nerve cell impulses Maintaining warm body temperature in endotherms (warm-blooded)

Different Types of Organisms Autotrophs Make their own food Heterotrophs Obtain energy from the food they consume or absorb

ESSENTIAL INVESTIGATIVE QUESTIONS: What is cellular respiration? What is needed to carry out cellular respiration? Where does it take place? How many stages are there? What is the role of the mitochondria?

What is Cellular Respiration? A process that converts chemical (stored) energy in food molecules like glucose into energy (ATP) AUTOTROPHS & HETEROTROPHS A process used by BOTH AUTOTROPHS & HETEROTROPHS to release energy from food they have made, absorbed, or consumed.

What does Cellular Respiration Require? The process requires: Glucose Glucose – source of stored energy Mitochondria Mitochondria, a membrane-bound organelle that converts glucose into ATP. Oxygen – Oxygen – aerobic process

Where does cell respiration take place? Inside most protist, fungi, plant, and animal Inside the cell Inside the mitochondria

C 6 H 12 O 6 + 6O 2 6H 2 O + 6CO 2 + ATP GLUCOSE + OXYGEN  WATER + CARBON +ENERGY DIOXIDE The cellular respiration equation: How is this chemical reaction similar or different when compared to photosynthesis? What are the Reactants? What are the Products? REACTANTS PRODUCTS

CELLULAR RESPIRATION OCCURS in 3 STAGES Glycolysis Krebs Cycle Electron Transport Chain (ETC)

1.Glucose from the carbohydrates we eat enters the body and is broken apart and converted into 2 molecules called Pyruvic acids (Pyruvates). 2.2 ATP molecules are made along with 2 NADH molecules. 3.In the presence of Oxygen however, the Pyruvates move into the second stage called The Krebs Cycle. Stage 1: GLYCOLYSIS: (means “sugar breaking”) Takes place in the CYTOPLASM and DOES NOT REQUIRE OXYGEN.

Carbon Dioxide Water 2

STAGE 2: KREBS CYCLE (takes place in the mitochondria) 1.In the presence of oxygen (O 2 ), the 2 pyruvates from glycolysis are then transported to the matrix of the mitochondria where it interacts with an enzyme called coenzyme A (CoA) forming 2 molecules called Acetyl CoA. 2.Acetyl CoA joins together with a 4 carbon compound to make a 6 carbon compound called Citric Acid. 3.Citric Acid is broken down and releases 2 molecules of Carbon Dioxide (CO 2 ) and generates 1 ATP, 3 NADH molecules and 1 FADH 2 molecule (an electron carrier molecule).

Carbon Dioxide Water 2 2

STAGE 2: KREBS CYCLE (continued) 4.For each pyruvate, the Krebs Cycle turns twice resulting in 2 ATP molecules 6 Carbon Dioxide (CO 2 ) molecules 8 NADH molecules 2 FADH 2 molecules 5. NADH and FADH 2 move on to the third and final stage - ETC

Carbon Dioxide Water 2 2

STAGE 3: ELECTRON TRANSPORT CHAIN – ETC (also takes place in the membrane of the mitochondria) This is the stage in which MOST of ATP is made! 1.High energy electrons and Hydrogen ions from NADH and FADH 2 are used to convert ADP to ATP. 2. A total of 36 to 38 ATP molecules are made as a result of this process and 6 molecules of water are released as a by-product.

Carbon Dioxide Water total

Photosynthesis Cellular Respiration In photosynthetic organisms like some bacteria, plantlike protists (Euglena) & all plants All animals, fungi, and animal-like protists Requires CO 2 Use oxygen  aerobic respiration Occurs in the chloroplasts No oxygen  anaerobic respiration like lactic acid fermentation or alcoholic fermentation Occurs in the mitochondria Comparison of Cellular Processes

Cyclic Relationship The products of photosynthesis are the reactants for aerobic cell respiration and vice versa. CO 2 O2O2 food H2OH2O sunlight H2OH2O

Cyclic Relationship Photosynthesis sunlight 6CO 2 + 6H 2 O + sunlight  C 6 H 12 O 6 + 6O 2 Cellular Respiration ATP C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + ATP

What is Fermentation? The chemical breakdown of substances by bacteria, yeast and other microorganisms when NO oxygen (anaerobic) is present in the cells. There are 2 types of fermentation: 1. Alcoholic Fermentation 2. Lactic Acid Fermentation

Lactic Acid Fermentation Prokaryotes use this to produce CO 2 and lactic acid. These organisms are used to make cheese, yogurt, buttermilk, pickles, sour cream, sauerkraut, and kimchi. Lactic acid builds up in your muscles during vigorous exercise causing pain and a burning sensation in your muscles. Alcoholic Fermentation – Yeasts and microorganisms use this to produce CO 2 and alcohol – Causes bread dough to rise and it is used to make alcohol like beer and wine.