Cellular Respiration
Chapter 9 in the textbook
Overall Equation for Cellular Respiration:
Oxidation: Glucose loses electrons (and hydrogens)
Reduction: Oxygen gains electrons (and h
The equation for cellular respiration is catabolic.
• Catabolic Reactions: ____________________________________________________
_____________________________________________________________________
– Catabolic reactions are exergonic: ____________________________________
• Anabolic reaction: ______________________________________________________
_____________________________________________________________________
– Photosynthesis is an anabolic reaction.
Cellular Respiration is an oxidation/reduction reaction
• Oxidation: ____________________________________________________________
• Reduction: ___________________________________________________________
• In cellular respiration glucose is oxidized and oxygen is reduced
• Hydrogen is a source of electrons
Chemical Energy and Food
Heterotrophic organisms get glucose from the food they consume.
• Calorie: ______________________________________________________________
– 1 Calorie = _______________________________________________________
________________________________________________________________
– 1 calorie = _______________________________________________________
________________________________________________________________
– 1 Calorie = _________________________
– Unit for measuring energy in food = Calorie
Carbohydrates, lipids and proteins can all be broken down to release energy.
• 1 Gram of Carbohydrates = ____ Calories
– The bodies primary source of energy
– Only a small amount of carbohydrates can be stored in the body.
– Glycogen: _______________________________________________________
– Amylase: ________________________________________________________
________________________________________________________________
• 1 Gram of Lipids = ___ Calories
– The bodies secondary source of energy
– Carbohydrates can be converted to
lipids for storage.
– The body can store an unlimited
amount of lipids.
• 1 Gram of Proteins = ___ Calories
– Lipids and Proteins are broken down
with processes other than cellular
respiration.
– Proteins in food are broken down into amino acids which are used as building
material.
– The body can break down proteins into energy as a last resort.
An Overview of Cellular Respiration
Cellular respiration occurs at the mitochondria:
Parts of the Mitochondria
– Outer Membrane: _____________________
_____________________________________
_____________________________________
– Inner Membrane: _____________________
____________________________________
– Cristae: ________________________
_______________________________
– Inner membrane is about 5 times
larger than the outer membrane
(increases surface area and rate of
respiration)
– The inner membrane must be folded to fit inside
– Intermembrane Space: ______________________________________________
___________________________________________________________________
– Matrix: ____________________________________________________________
– Contains proteins, cytosol, and mitochondrial DNA.
Three steps of cellular respiration
– Cellular respiration happens slowly and in many steps.
– If all the energy was released in one step . . . Most would be lost as light and heat.
1. _______________ 2. ________________ 3. __________________
Step 1: Glycolysis
• Location: ________________________________
________________________________________
• Purpose: ________________________________
________________________________________
– To begin glycolysis the cell needs to invest two
ATP
– How much energy is produced by glycolysis?
____________________________________
__
(NADH is similar to NADPH in
photosynthesis)
Step 2: Krebs Cycle
• Location:
_______________________________
– Pyruvic acid from glycolysis enters the
mitochondria.
• Purpose: ______________________________
______________________________________
• Every turn of the Krebs Cycle produces:
Step 3: Electron Transport Chain
• Location: _______________________________________________________________
• Purpose: ________________________________________________________________
– NADH and FADH2 were produced during glycolysis and the Kred’s cycle.
– NADH → ________
– FADH2 → ________
• The Process
1. NADH and FADH2 give high energy elections to protein pumps in the inner
mitochondria membrane.
2. Energy from the electrons is used to pump H+ ions from to matrix to the
intermembrane space.
3. There is now a higher concentration of H+ in the intermembrane space compared to
the matrix.
4. Chemiosmosis: ________________________________________________________
_____________________________________________________________________
5. ATP Synthase:
_____________________________________________
____________
_____________________________________________
________________________
Cell Respiration Summary
• The totals:
– 1 glucose = ________
• Importance of Oxygen:
– _____________________________________________________________________
_____________________
– _____________________________________________________________________
_____________________
Fermentation
Fermentation: ______________________________________________________________
• Anaerobic: ______________________________________________________________
• Cell Respiration is an aerobic process (it requires) oxygen.
– Glycolysis occurs with or without oxygen.
– Krebs Cycle and Electron Transport Chain do not occur in the absence of oxygen.
Fermentation
• Location: _______________________________________________________________
• Purpose: _______________________________________________________________
– During fermentation all of the ATP is produced during glycolysis.
– ____________ would not be able to occur if there was no _______
• There are two different types of fermentation:
1. Alcoholic Fermentation
2. Lactic Acid Fermentation
Lactic Acid Fermentation
• Why do your muscles feel sore during periods of intense exercise?
________________________________________________________________________
________________________________________________________________________
• Bacteria use lactic acid fermentation to make several foods: ______________________
________________________________________________________________________
Alcoholic Fermentation
Occurs in yeast cells
• Why is yeast added to bread recipes?
____________________________________________________________________
_____________________________________________________________________
• Alcoholic drinks such as wine usually have a maximum alcohol concentration of 12%
Why does fermentation stop at this point?
_____________________________________________________________________
_____________________________________________________________________
Comparing Respiration and Fermentation
Advantages
Fermentation
Cellular
Respiration
Disadvantages
Efficiency