RESPIRATION

ENERGY- ABILITY TO DO WORK 1. What types of activities require energy? 2. How do humans obtain most of their energy? 3. How do plants obtain most of their energy?

RESPIRATION Heterotrophs (humans/animals) obtain energy through eating food! Food contains calories and glucose. Energy is released from glucose/food.

RESPIRATION EQUATION

RESPIRATION 3 step process Happens in the presence of oxygen 1) Glycolysis - cytoplasm 2) Kreb’s cycle - mitochondria 3) Electron Transport Chain- mitochondria

GLYCOLYSIS (STEP 1) (SPLITTING SUGAR) Glucose ---  pyruvate Electron carriers store energy (NAD/NADH) and transfer to other cell pathways. Takes place in cytoplasm Fast reaction No O2 needed

KREBS CYCLE (STEP 2) Aerobic (needs O2) Pyruvic acid enters mitochondrion-  CO2 NAD-  NADH Citric acid formed

KREBS CYCLE- Citric acid broken down More CO2 released NADH, ATP is released…AKA (energy!)

ELECTRON TRANSPORT (STEP 3) Electrons from Krebs cycle are taken to Electron Transport Chain Transfers ADP-  ATP via carrier proteins Occurs in mitochondrion membrane (eukaryotes) Occurs in cell membrane (prokaryotes) H20 is released as E- bond with H and O

FERMENTATION A way to release energy without O2 Anaerobic (no air/oxygen) Substitutes for Krebs and Electron Transport chain 2 types 1) Alcoholic 2) Lactic Acid Fermentation

ALCOHOLIC FERMENTATION Pyruvic acid --  ethyl alcohol Type of fermentation where alcohol and C02 are produced as waste Bread rising Yeasts

LACTIC ACID FERMENTATION Pyruvic acid + NADH --  lactic acid Produces lactic acid as a waste When your muscles run out of oxygen they begin to produce ATP by lactic acid fermentation…that is why your muscles become sore during/after activity.

TO SUMMARIZE…