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