cellular respiration how do cells use food to make energy (atp)? chapter 9
TRANSCRIPT
Cellular RespirationHow do cells use food to
make energy (ATP)?Chapter 9
Batteries of Life Adenosine Triphosphate – ATP Adenosine Diphosphate – ADP
Adenine Ribose 3 Phosphate groups
ATP
Cellular Respiration
The process that releases energy by breaking down food molecules in the presence of oxygen
C6H12O6 + 6O2 -> 6H2O + 6CO2 + Energy
Main Types of Energy-Releasing Pathways
Aerobic pathways
Evolved laterRequire oxygenStart with glycolysis in cytoplasmCompleted in mitochondria
Anaerobic pathways
Evolved firstDon’t require oxygenStart with glycolysis in cytoplasmCompleted in cytoplasm
3 Steps - When Oxygen is Present
Glycolysis Krebs Cycle (Citric Acid cycle) Electron Transport Chain (Oxidative
Phosphorylation)
GlucoseGlycolysis
Cytoplasm
Pyruvic acid
Electrons carried in NADH
Krebs Cycle
Electrons carried in
NADH and FADH2 Electron
Transport Chain
Mitochondrion
Cellular Respiration: An Overview
Mitochondrion
Glucose
To the electron transport chain
Glycolysis
2 Pyruvic acid
Glycolysis
Glucose broken into 2 molecules of Pyruvic Acid
Oxygen not required 2 ATP are used and 4 ATP and 2
NADH are produced Occurs for a short time because
NAD+ are used up
Krebs Cycle
When O2 is present, pyruvic acid from glycolysis produces CO2, ATP, NADH and FADH2.
1 molecule of Glucose produces 2 turns of the cycle
Citric Acid Production
The Krebs Cycle
Mitochondrion
Electron Transport Chain
NADH and FADH2 made in glyoclysis and the Krebs Cycle are used to make ATP
Oxygen accepts low energy electrons and H+ to form water.
ATP produced when H+ diffuses across the membrane
Electron Transport Chain
Electron TransportHydrogen Ion Movement
ATP Production
ATP synthase
Channel
Inner Membrane
Matrix
Intermembrane Space
Mitochondrion
What does 1 molecule of glucose produce?
36-38 ATP
How do we measure energy?
calorie- the amount of energy needed to raise the temp of 1 g of water 1 degree celsius.
IMPORTANT NOTE FOR YOUR LIFE
Food is labeled ___Calories/serving Capital letter means Kilocalories =
1000 calories. Package tells you how much energy the
food can give you!
What happens when O2 isn’t available?
Fermentation 2 Types occurs after glycolysis anaerobic - without oxygen
Alcohol Fermentation Lactic Acid Fermentation
Alcohol Fermentation
Baking
Yeasts during this process release carbon dioxide which causes bread to rise
Glucose Pyruvic acidLactic acid
Lactic Acid Fermentation
The Burn
Large muscles that run out of oxygen quickly build up lactic acid which causes a painful burning sensation.
This occurs in animal cells
Quick Energy - Anaerobic
4 seconds of ATP in the cell 5 seconds - 90 seconds - Lactic Acid
Fermentation Oxygen debt and Heavy Breathing Anaerobic training builds up
glycogen in the muscles and develops lactic acid tolerance
Priscah Jeptoo: winner for women 2:25:24
Geoffrey Mutai: winner for men: 2:08:07
NYC Marathon 2013
Long-Term Energy - Aerobic
Cellular Respiration after 90 seconds
Glycogen (Carbs) during the first 15-20 minutes
Fats after 20 minutes Aerobic activity increases the size
and number of mitochondria and increase oxygen delivery by improving the heart and lungs
Where does a runner get energy for a 5K race?
1st- any available ATP 2nd- glycolysis and lactic acid
fermentation 3rd- cellular respiration
Break down sugars When out of sugars, break down fats
4th- sometimes revert back to glycolysis and lactic acid fermentation if their body is not fit enough for the distance/terrain.
Where does your body “look” for energy?
1. Carbs (Glucose for CR) When out of carbs…
2. Fats When out of fats…
3. Proteins When out of proteins…you are dead.
Creatine
Creatine Phosphate donates a phosphate to ADP to make more ATP
Prolongs the 4 seconds before lactic acid fermentation
Allows for more repetitions and more intense workouts
If abused could lead to kidney and liver problems