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

http://www.youtube.com/watch?v=EfGlznwfu9U

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 ChainTransfers ADP-ATP via carrier proteinsOccurs 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…

http://www.youtube.com/watch?v=-Gb2EzF_XqA