Mr. Wagner How Organisms Obtain Energy

Vocabulary: Metabolism Photosynthesis Cellular Respiration Adenosine Triphosphate (ATP) Anabolic Catabolic

All living organisms use energy to carry out all biological processes. Like the city that never sleeps, cells never sleep!

Transformation of energy Your cells are constantly working, breaking down molecules, transporting substances across membranes, growing, & dying. This all requires ENERGY  the ability to do work

Thermodynamics  the study of the flow & transformation of Energy in the universe

Autotrophs & heterotrophs All organisms need energy. Most energy comes from the Sun. Autotrophs make their own food. Heterotrophs need to eat food to obtain energy.

Metabolism All of the chemical reactions that occur within a cell.

Metabolic pathway  series of chemical reactions in which the product of 1 reaction is the substrate for the next reaction (a substrate binds to an enzyme to help speed up chemical reactions)

2 types of metabolic pathways: 1) Catabolic  release E by breaking down large molecules into smaller ones

2) Anabolic  use the E released by catabolic to take small particles & put them together to make bigger ones

Photosynthesis is the anabolic pathway that takes light energy from the Sun & converts it to chemical energy for use by the cell.

Autotrophs: light + CO 2 + H 2 O = glucose & oxygen The energy stored in the glucose can now be used by other organisms when they eat it as food.

Cellular respiration is catabolic pathway in which organic molecules are broken down to release E for use by the cell. Oxygen is used to break down organic molecules, resulting in the production of CO 2 & H 2 O

Cyclical! One pathway’s products are other pathway’s reactants.

ATP: The Unit of Cellular Energy Energy comes in diff. forms: light E, mechanical E, thermal E, & chemical E. In organisms, chemcial energy can be stored & then converted into another form of energy when needed. Like when your muscles contract!

Adenosine triphosphate (ATP)  the most important biological molecule that provides chemical E

ATP structure Most abundant energy-carrier molecule in cells. ATP is made of an adenine base, a ribose sugar, & 3 phosphate groups.

ATP Function It releases energy when the bond between the 2 nd & 3 rd phosphate group is broken forming a molecule called adenosine diphosphate (ADP) & a free phosphate group.

Review Section 1

Answer the following question: What are the two metabolic pathways? Catabolic & Anabolic

Answer the following question: What is the first law of thermodynamics? Law of Conservation

Answer the following question: Chemical reactions in a cell are referred to as the cells ____________. Metabolism

Answer the following question: Where does all the energy for organisms come from? The Sun

Answer the following question: What does ATP stand for? Adenosine Triphosphate

Answer the following question: What are the three molecules that make up an ATP molecule? An adenine molecule A ribose sugar 3 phosphates (phosphate group)

Answer the following question: What are two examples of a catabolic pathway? Cellular Respiration & Diet Pills

Answer the following question: What are heterotrophs? Organisms that rely on others to obtain energy

Answer the following question: What is a metabolic pathway? Where the reactants make a product, and the product is used in another chemical reaction. A+B  CC+D  EE+F  G

Answer the following question: Where is the bond broken to release energy in an ATP molecule? Between the 2 nd & 3 rd phosphate group.

Answer the following question: What is the 2 nd law of thermodynamics? Entropy Increases

Answer the following question: What are autotrophs? Organisms that make their own energy.

Answer the following question: What is entropy? Heat

Chapter 8 Section 1 Practice Problems YOU MUST WRITE OUT THE QUESTION & COMPLETELY ANSWER TO RECEIVE FULL CREDIT! 1. Recall the basic components of ATP. 2. Paraphrase the first law of thermodynamics. 3. Contrast catabolic pathways and anabolic pathways. 4. Examine how nearly all energy for life comes directly or indirectly from the Sun, given that heterotrophs get their energy from the food that they eat. 5. Classify the synthesis of a protein from amino acids as anabolic or catabolic. Explain.