Cellular RespirationCHAPTER 9

INTRO

• Fast and slow twitch muscles

What kind of runner are you?

• SLOW-TWITCH

• LONG DISTANCE RUNNING

• for repeated long contractions

• FAST-TWITCH

• SPRINTING or WEIGHT LIFTING

• Contract more quickly and powerfully

What makes these muscle fibers so different?

• SLOW TWITCH

• breaks down glucose to get ATP AEROBICALLY (using oxygen)

• FAST TWITCH

• breaks down glucose to get ATP ANAEROBICALLY(not using oxygen)

SLOW-TWITCH MUSCLES

• 1. Thin fibers• 2. have many

mitochondria• Many

myoglobin (lots of hemoglobin in muscle fibers)

FAST-TWITCH MUSCLES

• Thicker fibers

• Fewer mitochondria

• Less myoglobin

• (white meat)

• Chickens use their legs (red meat) for walking and standing for large periods of time,

• while their wings (white meat) are used for brief bursts of activity

Video of Fast and Slow-Twitch Muscles

• Teachers' Domain: The Powerhouse of the Cell

Big Question for Chapter 9

• How do our cells obtain O2

for cellular respiration and dispose of CO2?

• Respiratory System

Respiratory System

• Air intake

Nose

1. mouth

2. Larynx (Voice Box)

• Sound production

• Protection of trachea

Houses epiglottis

3. Vocal chords

• Flaps that vibrate as air goes past them.

• larynx video

4. Trachea

Windpipe

20 rings of

cartilage

5. Right Lung-shorter, broader, larger than left lung

• CT Scan

• X-ray Exchange air rich in CO2

with air rich in O2

6. Bronchioles

• Small branches of airways in lungs

Note Blood Vessel and Bronchiole and Alveoli Closeness

7. Alveoli

• Grape-like clusters of air sacs that exchange with blood vessels carbon dioxide and oxygen

How the Lungs Work - What

Happens When You Breathe Video -

About.com

8. Bronchi

• Large air tubes branch from trachea to lungs

9. Esophagus

• Tube that connects pharynx with stomach

• Glands in it produce mucus to help food slide down

10. Epiglottis

• Flap to control food from going to lungs Swallowing Animation

11. Pharynx

• Throat

• Propels food when swallowing into esophagus

12. Left Lung

• See collapse of left lung

• Smaller due to being on the same side as the heart

Diaphragm

• Muscle at base of lungs to move air in and out of lungs

• How do our bodies burn glucose for energy?

• One gram of glucose when burned in the presence of oxygen releases 3811 calories of heat energy.

calorie

• Amount of energy needed to raise the temperature of one gram of water one degree Celsius.

Calorie

• Calorie = 1000 calories

• = 1 kilocalorie

Calories on food labels are actually

kilocalories

• How does the amount of energy released in glycolysis compare to burning one gram of glucose?

• Small amount (around 3.5% the amount from burning)

• So….. 3811 X 3.5% =• 133.4 calories

Cellular Respiration

• 1. Glycolysis

• 2. Krebs cycle

• 3. ETC and chemiosmosis

Cellular Respiration

• C6H12O6 + 6O2 --> 6CO2 + 6H2O + ~38 ATP

• Glucose + oxygen --> carbon+ water +energy• dioxide

 

In the mitochondrion

Glycolysis Animation: How Glycolysis Works

glucose

Pyruvic acid

Starts with 2 ATP

Makes 4 ATP

Nets: 2 ATP

NAD+

• An electron carrier• Nicotinamide adenine

dinucleotide• Accepts electrons (H+)

to form NADH

e-

e-

Electron Carrier

• A.k.a. “hydrogen carrier”

• Electron taxi cab NADH

(full)

NAD+(empty)

e-

NAD+ NADHe- carrier

Glycolysis is Anaerobic

• Without oxygen

oxygen

Only catch...

• NAD+ is used up in glycolysis

• So a cell needs a way to regenerate it (to keep glycolysis going)

How does NADH regenerate back to NAD+?

• The process of fermentation.

• It loses the electrons of NADH to form NAD+ again.

• Remember the yeast lab?

Sing or Simulate

• Glucose, Glucose SONG

• See Teacher Tube

END OF GLYCOLYSIS

• How much of the energy in glucose is still unused?

• 90% Doesn’t seem very efficient, does it?

Now What, Pyruvic Acid?

• Fermentation

• Anaerobic – no oxygen

• In cytoplasm

• Krebs Cycle

• Aerobic –needs oxygen

• In mitochondria

Fermentation

sauerkraut

cheese

bread

wine

OK, if you are yeast...

• Making

2 ATP from glycolysis is enough

Yeast Acting on Pyruvic Acid

• Ethanol is released as a waste product O

o

o

o

NAD+

CO2

Alcoholic Fermentation

• Pyruvic acid + NADH alcohol + CO2 + NAD+

Lactic Acid in Bacteria

• Used in dairy industry to make cheese and yogurt

Lactic Acid Fermentation

• Pyruvic acid + NADH lactic acid + NAD+

Why must oxygen be kept out of the wine and beer vats?

• If oxygen is present, the pyruvic acid will make CO2 and water.

• If oxygen is not present, yeast and bacteria will make ethanol and CO2.

CONTRAST

• ANAEROBIC

• Does not use oxygen

• In the cytoplasm

EX: Glycolysis

Fermentation

• AEROBIC

• Uses oxygen

• In the mitochondrion

• EX: Krebs cycle

ETC and chemiosmosis

#3 CONTRAST

• Respiration• Really mean

breathing• Means of getting

oxygen into body and carbon dioxide out

• Cellular Respiration

• energy-releasing pathway within the cell (mitochondrion)

#4 Pyruvic Acid (Pyruvate)

In order to further break down pyruvic acid we need

oxygen.

2 2 34

Cytoplasm

CO2 CO2

#5 Mitochondrion

• Organelle that can use oxygen for cellular respiration.

“Grooming” Pyruvic Acid Haircut and Conditioning

“HAIRCUT”

As NADH is reduced to NAD+

pyruvic acid is oxidized (carbon atom removed as CO2)

“CONDITIONING”

Coenzyme A (from B vitamin) joins the 2-c fragment

MAKES-Acetyl Coenzyme

A or CoA

#6

#7

Cut, Groom and Krebs Cycle Animation

• krebstca

• animation

Ready to GO

• The Acetyl-CoA is now ready to enter the Krebs cycle

Hans Krebs (1900-1981)Yeah, he got a Nobel Prize, too

#4- #8 Krebs Cycle

• Also known as “citric acid cycle”

#9

Cellular Respiration

• Respiration animation

• Cellular respiration

CONTRAST

• AEROBIC

• Does use oxygen

Glycolysis

Fermentation

• ANAEROBIC

• Does not oxygen

• In the mitochondrion

• Krebs cycle

• ETC and chemiosmosis

ATP Synthase

• VCAC: Cellular Processes: ATP Synthase: The Movie (Cool)

Where does it all come from?

•1 NADH = 3 ATP

•1 FADH2 = 2 ATP

ChemiosmosisPowers Most of ATP Produced

• Glycolysis -2 ATP

• Krebs Cycle - 2 ATP

• Chemiosmosis/ ETC - 34 ATP

• TOTAL 38 ATP from one glucose molecule

ETC

• Electron Transport Chain

• VCAC: Cellular Processes: Electron Transport Chain

• Or krebstca

Where is the ETC located?

• Inner membrane of the mitochondrion

What gets made via the ETC?

• 1. electrons + H+ + Oxygen = water

• 2. H+ ions go across the inner membrane and build up in the inner membrane space

• H+ ions go through ATP synthase to generate ATP

e-e- e-

ATP ADP + P

e-

ATP SYNTHASE

• H+ ions move through this enzyme to generate energy for P to join ADP to make ADP

Chemiosmosis and ETC

• H+ ions can only pass through a special port ATP synthase (see knobs on cristae)

ETC Animation

• Krebstca (clear, nice animation)

• Electron transport system (very simple)

• VCAC: Cellular Processes: Electron Transport Chain click on THE MOVIE)

• ETC (nice from McGraw Hill)

ATP GRAND TOTALS

• Glycolysis produces 2 ATP• Krebs cycle produces 2 ATP• ETC and chemiosmosis produces 34 ATP

GRAND TOTAL 38 ATP from one glucose molecule

CONTRAST CHART

• Photosynthesis• Makes sugars for

food energy• Chloroplast• React: CO2 and H2O• Prod: C6H12O6 and O2

• EQUATION:

6 CO2 and 6 H2O

6 O2 + C6H12O6

• Cellular Respiration• Energy released

• Mitochondrion• C6H12O6 and O2

• CO2 and H2O• EQUATION:• 6 O2 + C6H12O6 6

CO2 and 6 H2O