Unit 2 Cellular Respiration

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1 Metabolism Unit 2 Cellular Respiration Living organisms must continually to carry out the functions of life. Without energy, comes to an end. The breakdown of complex substances are the result of. The building of complex substances from simpler compounds is referred to as. The sum of all processes in a cell is called. At a fundamental level, all forms of energy can be classified as. energy is the energy possessed by, (includes thermal energy or heat, mechanical energy, electromagnetic energy, and electrical energy.) energy is. (gravitational energy, chemical energy.)

2 Laws of Thermodynamics (energy/work) 1. The First Law of Thermodynamics. Energy cannot be created or destroyed but only converted from one form into another. In most cases, organisms and into another before it can be used. (Plants capture in photosynthesis and convert it into in glucose.) Molecules possess stability because of the Some chemical bonds are. is a measure of the stability of a covalent bond. Energy is absorbed when and energy is released when.

3 Exothermic The result is a. Called an. Endothermic Energy absorbed in breaking bonds is. This is called an reaction The overall change in energy is called the The value of for endothermic reactions and for exothermic reactions. Exothermic reactions (products are more stable (less potential energy than reactants)). Endothermic reactions are.

2. The Second Law of Thermodynamics. Energy is not the only factor that determines whether a will occur Entropy (S) is a measure of the. (Think concentration of energy) Entropy.

4 2. The Second Law of Thermodynamics. Energy is not the only factor that determines whether a will occur Entropy (S) is a measure of the. (Think concentration of energy) Entropy. The universe favours an in entropy. CBC Radio - "The second law of everything" - ENTROPY Living organisms seem to of thermodynamics. Anabolic processes within cells structures. However in each and every case, the apparent order created by is accompanied by an even caused by catabolic processes.

5 All changes, either, result in an (overall disorder) of the universe. You read the section on GIBBS FREE ENERGY on pages Energy and Life Life uses 3 methods to obtain energy:, use light to produce (green plants and photosynthetic microorganisms) rely on for energy. They obtain energy from by ingesting other organisms (all animals and fungi, and most protists and bacteria). extract energy from like iron and sulfur. (archeabacteria) Since almost every living thing in a process known as to obtain energy, we will focus on the following chemical equation. Aerobic respiration is a series of about. Each step is. The previous equation represents a

6 Aerobic cellular respiration. This is known as a. The process of losing electrons is called and the process of gaining electrons is called Just remember Some redox reactions occur in which the product of is the reactant of the. A substance that was in the first reaction becomes in the next reaction. This results in the and at each step. This is the basis for. Reduction and oxidation can involve Like a loss of electrons.

7 In cellular respiration yields 2870 kj of energy per mole of glucose When glucose is burned in a test tube is given off as heat and light The living cell, have evolved methods to (about of it) by moving the in certain molecules

8 Some microorganisms don't. Some use These organisms are known as. They must live in.(clostridium tetani, Clostridium botulinum). Almost all organisms are. They require as the and cannot survive without it. Bacteria that can tolerate aerobic and anaerobic conditions are called. (Escherichia coli, Vibrio cholerae, Salmonella enteritidis 3 goals: 1. to break the of glucose. 2. to move. 3. to trap as much of the

The (aka tricarboxylic acid cycle, TCA cycle, citric acid cycle) - occurring

9 Cell Respiration - IN DEPTH Occurs in four stages, in three different places: Stage 1: occurring in the Stage 2: 1 step process occurring in the Stage 3: The (aka tricarboxylic acid cycle, TCA cycle, citric acid cycle) - occurring in the. Stage 4: (oxidative phosphorylation) - multistep process occurring in the

Before we begin, recall we are. This is done in two distinctly different mechanisms called: 1. 2.. Substrate-Level Phosphorylation - ATP is formed reaction. - A phosphate group is, forming ATP.

10 Before we begin, recall we are. This is done in two distinctly different mechanisms called: Substrate-Level Phosphorylation - ATP is formed reaction. - A phosphate group is, forming ATP kj/mol of potential energy is also transferred (living cell, closer to 50 kj/mol.) *For each this way Oxidative Phosphorylation In oxidative phosphorylation,. Involves a number of sequential, (oxygen - final electron acceptor. Involves converting, NAD+ into NADH and, FAD into FADH2, These act as mobile

11 Step 1 - Glycolysis 10 reactions, starting with, and ending with two (pyruvic acid), molecules. All the reactions in occur in the Each step is catalyzed by a. Glycolysis is an (no required).

12 The following is the energy yield for glycolysis: + produced net (immediate) (can produce more ATP) The energy efficiency of glycolysis 2 mol ATP x 31 kj/mol ATP = 62 kj total free energy in 1 mol of glucose = 2870 kj Glycolysis is thought to be the. The simplest organisms continue to use it for all their energy needs. Glycolysis yields molecule processed. sufficient for certain microorganisms, but it is not for. Nevertheless,!

13 Moving into the Mitochondria: Use pg to make your own note on a mitochondrion. Step 2: Pyruvate Oxidation The two pyruvate molecules formed in glycolysis are.

14 There are three changes to pyruvate: 1. A is removed. A (pyruvate decarboxylase).- - removed another 2 carbons (1 x 2 pyruvate)! 2. NAD+ is (from food) to NADH. Some more! 3. to the remaining acetyl portion Prepares the in the 3rd stage.

15 Overall: for energy are converted into acetyl-coa, Acetyl-CoA can be used to. It is channeled into an that synthesizes lipids as a way of storing large amounts of energy as fat. Step 3: The Krebs Cycle The Krebs cycle is, each step catalyzed by a. It is a cyclic process because, the product of, is the reactant in

16 Overall it looks like this In the end, the has been consumed. are released by the cell as waste.

17 KREBS KEYS: Krebs cycle occurs processed reacts with to produce citrate. (citric acid cycle). Citrate has. (tricarboxylic acid cycle, TCA cycle). which means another molecule in the pyruvate oxidation step can be processed (CoA is recycled). Energy is harvested in steps So far: The remaining coenzymes,, now go on to stage 4 of the process ( ) where much of their free energy will.

18 Step 4. The Electron Transport Chain and Chemiosmosis NADH and FADH2 transfer the they carry to a series of compounds, called the (ETC). The ETC works because of. Each component is more than the one before it so each is going to be reduced The electrons shuttle through the ETC (Think 4x100 relay) The electrons become ever. The released in the process is used to move from the mitochondrial into the. acts as the final in the electron transport process. The components of the ETC are (increasing electronegativity)

This results in the of electron position being converted to that forms across the inner mitochondrial membrane Much of the energy from is now stored in the NADH and FADH2 in the same

19 1. NADH givies up its. A (H+) is moved from the to the. 2. Ubiquinone shuttles. A is moved across. 3. Cytochrome c, complex. A is moved across 4. The enzyme, catalyzes the reaction to form water. This results in the of electron position being converted to that forms across the inner mitochondrial membrane Much of the energy from is now stored in the NADH and FADH2 in the same way. FADH2 transfers its to. Therefore FADH2 is used to pump only. Keep this in mind. Also, NADH from cannot pass through the to the matrix. (those from are made in the matrix) There are two shuttle systems that pass. The most common ( glycerol- phosphate shuttle), transfers the electrons from. Again this results in only moving across the inner membrane

This results in an (electric potenial difference) and a

20 Chemiosmosis and Oxidative ATP Synthesis The protons now in the create an electrochemical gradient. This results in an (electric potenial difference) and a (chemical potential) in the. The gradient creates a across the inner mitochondrial membrane similar to.

21 The protons are associated with the enzyme (ATPase). This happens because of a (PMF). As protons move through the, the free energy of the is reduced. This energy drives the and inorganic phosphate (Pi) in the matrix. This process is called because of the, although it is a misnomer today. ATP molecules are transported throughout the cell where they drive. The result is that ATP are formed per ATP molecules are formed per.

22 Energy Balance Sheet Efficiency of Aerobic Respiration

23 Controlling Aerobic Respiration Read pg and make your own note on allostaric inhibition related to cellular respiration.

24 Energy Alternatives are the first nutrients for energy. Most organisms, when necessary, also metabolize. 1. Lipid Catabolism are first digested into glycerol and fatty acids. The glycerol portion may be converted into in a process called. It may also be changed to and fed into the glycolytic pathway.

25 Fatty acids undergo. Here enzymes sequentially remove from the fatty acids. The acetyl groups are combined with molecules to form Every cleavage reaction and. Imagine a 12 C fatty acid: 2. Protein Catabolism are first digested into individual. In protein metabolism, are removed from the amino acids in a process called. This process converts the, a waste product. Other chemical reactions convert what into various components that enter the metabolic pathway at different points. Anaerobic Pathways Glycolysis allows organisms to obtain energy from nutrients in the. NAD+ however is. When NAD+ In oxidative respiration, the, allowing glycolysis to continue.

26 Another method to recycle NAD+ involves instead of the electron transport chain. This process is called. Bacteria use many types of. Eukaryotes primarily use two methods: Ethanol Fermentation In ethanol fermentation,nadh passes its This process allows NAD to be recycled and glycolysis to continue. The molecules produced satisfy the organism s energy needs, and the are released as waste products. Humans have learned to make use of this. Ethanol fermentation carried out by yeast results in pyruvate decarboxylase

27 Lactate (Lactic Acid) Fermentation During strenuous exercise,. This is when lactate fermentation begins. NADH transfers its hydrogen atoms to and allowing glycolysis to continue. is converted. The in muscle tissue causes. Some of the is oxidized in the back to The rest is broken down into. This requires. after exercise is the body s way of for the original lack of.

Respiration. Respiration. How Cells Harvest Energy. Chapter 7

Respiration. Respiration. How Cells Harvest Energy. Chapter 7 How Cells Harvest Energy Chapter 7 Respiration Organisms can be classified based on how they obtain energy: autotrophs: are able to produce their own organic molecules through photosynthesis heterotrophs: