Metabolic Pathways & Energy Production Chapter 18 DE Chemistry – King William High School Metabolic Pathways & Energy Production Chapter 18

Metabolism Chemical reactions and substances that provide energy for cell growth 2 types: 1. catabolic reaction – complex molecules are broken down and release energy 2. anabolic reaction – use energy to build large molecules from smaller molecules

Catabolic reactions Stage 1: Digestion polysaccharides  monosaccharides fats  glycerol & fatty acids proteins  amino acids **products go into bloodstream for transport to cells Stage 2: digestion product 2 & 3 carbon cmpds **pyruvate & acetyl-CoA

Catabolic reactions Stage 3: *acetyl-CoA is oxidized in the citric acid cycle *production of energy in mitochondria * products of citric acid cycle (NADH & FADH2) are transferred to electron transport to make ATP (as long as there is enough oxygen in the cells)

3 Stages of Catabolism

Animal cell

ATP & Energy ATP (Adenosine triphosphate) is released as energy from the oxidation of food

ATP Hydrolysis

ADP hydrolysis ADP + H2O  AMP + Pi + 34 kJ Catabolic reactions are energy producing ADP + Pi + 34 kJ  ATP + H2O Anabolic reactions are energy requiring (stored ATP hydrolyzes to produce energy)

Digestion of carbohydrates

Digestion of fats

Digestion of proteins

NAD+ Nicotinamide adenine dinucleotide Oxidizing agent Accepts electrons to become NADH Reacts with alcohols to produce aldehydes and NADH

NAD+

FAD Flavin adenine dinucleotide Contains ADP Used in the citric acid cycle

Coenzyme A Prepares small acyl groups for reactions with enzymes

Glycolysis

Glycolysis Anaerobic (no oxygen involved) Glucose  2 pyruvate Occurs in cytoplasm Nets 2 ATP & 2 NADH

Overall reaction for glycolysis

Pyruvate Aerobic conditions – pyruvate is converted to acetyl-coenzyme A Anaerobic conditions – pyruvate is converted to lactate

Citric acid cycle

Citric acid cycle products 2 carbon dioxides 3 NADH & 3H+ 1 FADH2 1 GTP (1 ATP) 1 CoA

Electron Transport

Oxidative Phosp Proton pump – H+ (protons) concentration goes up, pH goes down…makes an electrochemical gradient Protons must move through ATP synthase in order to get back into the matrix When protons move through ATP synthase…energy is generated (ADP  ATP)

ATP Production

Oxidation of fatty acids Produces lots of energy Occurs in the mitochondria Produces acetyl-CoA # of Cs determines how much energy is produced

ATP energy from amino acids About 10% of our energy

Whoomp here it is…