1. All living organisms need energy
CELLULAR RESPIRATION
All living organisms need energy

2. Cellular Respiration Harvesting Chemical Energy
ATP

3. INTRODUCTION TO CELLULAR RESPIRATION
Introduction: All living organisms need energy
Respiration: the life process by which organisms convert the chemical energy stored in food to a form of energy more easily utilized by the cell
Process of Cell Respiration: a biochemical process used by cells to release energy from organic molecules (food) such as glucose
~this energy is stored in the molecule ATP
~ ATP = adenosine triphosphate or A~P~P~P
~ the process is controlled by enzymes

4. Harvesting energy stored in food
Cellular respiration
breaking down food to produce ATP
in mitochondria
using oxygen
“aerobic” respiration
usually digesting glucose
but could be other sugars, fats, or proteins
ATP
food O2
Movement of hydrogen atoms from glucose to water
glucose + oxygen  energy + carbon + water
dioxide
C6H12O6
6O2
ATP
6CO2
6H2O  +

5. What do we need to make energy?
The “Furnace” for making energy
mitochondria
Fuel
food: carbohydrates, fats, proteins
Helpers
oxygen
enzymes
Product
ATP
Waste products
carbon dioxide
then used by plants
water
Make ATP! Make ATP! All I do all day… And no one even notices!
food
ATP
enzymes
CO2
H2O O2

6. Mitochondria are everywhere!!
animal cells
plant cells

7. Using ATP to do work? Can’t store ATP
too unstable
only used in cell that produces it
only short term energy storage
carbohydrates & fats are long term energy storage
Adenosine TriPhosphate
work
Adenosine DiPhosphate
ADP
A working muscle recycles over 10 million ATPs per second
Whoa! Pass me the glucose & oxygen!

8. { { { ATP A Body’s Energy Budget make energy eat food synthesis1
make energy
• energy needed even at rest
• activity
• temperature control {
ATP
eat food
• growth
• reproduction
• repair { 2
synthesis
(building)
• glycogen (animal starch)
• fat { 3
storage

9. Aerobic Cellular Respiration
Aerobic = with oxygen
Occurs in the mitochondria
The use of oxygen releases more energy per glucose molecule than anaerobic = without oxygen
Uses oxygen but releases carbon dioxide and water
SUMMARY EQUATION:

10. Breathing and cellular respiration are closely related
CO2
Lungs
CO2
Bloodstream
Muscle cells carrying out O2
CELLULAR RESPIRATION
Sugar + O2  ATP + CO2 + H2O

11. Oxidation-Reduction Reactions Redox for short
Oxidation= loss of electrons (or H+)
Reduction= gain of electrons (or H+)
OIL RIG:
Oil = Oxidation is loss
Rig = Reduction is gain
~chemical reaction which involve a partial or complete transfer of electrons form one reactant to another
~ a coupled reaction
Cell Respiration is a redox process that transfers hydrogen form sugar to oxygen
oxidation
C6H12O6 + 6O2 -- 6CO2 + 6H2O + ATP( energy)
reduction

12. Hydrogen carriers such as NAD+ shuttle electrons in redox reactions
Enzymes remove electrons from glucose molecules and transfer them to a coenzyme / electron carriers[ NADH & FADH2]

13. Redox reactions release energy when electrons “fall” from a hydrogen carrier to highly electronegative oxygen
NADH ( & FADH2) delivers electrons to a series of electron carriers in an electron transport chain
As electrons move from carrier to carrier, their energy is released in small quantities
Energy released and now available for making ATP
ELECTRON CARRIERS of the electron transport chain

14. STAGES OF CELLULAR RESPIRATION
Respiration occurs in three main stages
High-energy electrons carried by NADH
ELECTRON TRANSPORT CHAIN
GLYCOLYSIS
KREBS CYCLE
Cytoplasmic fluid
Mitochondrion

15. 1. Glycolysis: [Glyco=sweet, sugar lysis = to split]
~process in which one molecule of glucose is broken in half, producing 2 molecules of pyruvic acid, a 3-carbon compound
~ takes place in cytoplasm
~ makes 2 ATP {part of anaerobic respiration too]
~NO OXYGEN NEEDED
~ 2 molecules of NADH are formed
Pyruvic acid
Glucose

16. 2. Krebs Cycle
Each pyruvic acid molecule is broken down to form CO2 and a two-carbon acetyl group, which enters the Krebs cycle [Transition phase]
The Krebs cycle completes the oxidation of organic fuel, generating many NADH and FADH2 molecules
2 turns per glucose molecule
Occurs in mitochondria
Produces 2 ATP
6 NADH & 2 FADH2
Acetyl CoA
CO2
KREBS CYCLE

17. 3. Electron Transport Chain
In the electron transport chain, the carrier molecules NADH and FADH2 give up electrons that pass through a series of reactions. Oxygen is the final electron acceptor forming water.
This sets up a H+ (proton) gradient
Allow the protons to flow through ATP synthase which synthesizes ATP (ADP + Pi = ATP)
Produces 32 ATP
Occurs in the inner mitochondrial membrane
the electron transport chain adds 32 ATP molecules

19. What if oxygen is missing?
No oxygen available = can’t complete aerobic respiration
Anaerobic respiration
also known as fermentation
alcohol fermentation
lactic acid fermentation
no oxygen or no mitochondria (bacteria)
can only make very little ATP
large animals cannot survive
yeast
bacteria

20. Fermentation is an anaerobic alternative to aerobic respiration
Process operates by means of chemical reactions catalyzed by enzymes in cytoplasm of cell
Primary mode of energy production for some bacteria and fungi (yeast)
use glycolysis alone to produce small amounts of ATP
Important in production of foods such as cheese, buttermilk, yogurt, alcohol, (wine/beer) and bread
2 types:
1. alcohol &
2. lactic acid

21. Anaerobic Respiration
Fermentation
alcohol fermentation
yeast
glucose  ATP + CO2+ alcohol
make beer, wine, bread
lactic acid fermentation
bacteria, animals
glucose  ATP + lactic acid
bacteria make yogurt
animals feel muscle fatigue
Tastes good… but not enough energy for me!

22. Alcoholic Fermentation
glucose -> pyruvic acid-> 2 ethyl alcohol + 2 CO2
2ATP
GLYCOLYSIS FERMENTATION

23. Lactic Acid Fermentation
Glucose->pyruvic acid -> 2 lactic acid 2ATP GLYCOLYSIS FERMENTATION ~ used to make cheese and yogurt ~ in humans during strenuous exercise not enough oxygen from blood “oxygen debt” ~ lactic acid accumulates in muscle; leads to fatigue and pain Will be converted back to pyruvic acid in liver Both types a of fermentation are considered inefficient , only produce 2ATP from glycolysis

24. Cells use many kinds of organic molecules as fuel for cellular respiration
Polysaccharides
Fats
Proteins
Sugars
Cellular respiration

25. Comparing Cellular Respiration & Photosynthesis
Cell Respiration
Photosynthesis