CHAPTER 7: CELLULAR RESPIRATION

CELLULAR RESPIRATION•Process where cells make ATP by breaking down glucose

CELLULAR RESPIRATION

•Process where cells make ATP by breaking down glucose

•Autotrophs and heterotrophs both undergo respiration

• Occurs in the cytoplasm and mitochondria

CELLULAR RESPIRATION

Overall equation:

C6H12O6 + 6O2 6CO2 + 6 H2O + ATP

How is this equation different from photosynthesis?

WHAT’S SO GREAT ABOUT ATP?

Every time you move a muscle, think, breathe, replicate your DNA, every time your heart beats - you use ATP to do this work!

TWO PATHWAYS EXIST FOR ACCESSING STORED ENERGY…

Aerobic Pathways take place in the presence of oxygen

TWO PATHWAYS EXIST FOR ACCESSING STORED ENERGY…

Aerobic Pathways take place in the presence of oxygen

Anaerobic Pathways take place in the absence of oxygen

Both pathways: 1) Begin with Glycolysis 2) Produce a Pyruvic Acid Intermediate 3) Differ in ATP production and final product

TWO PATHWAYS EXIST FOR ACCESSING STORED ENERGY…

Aerobic Pathways take place in the presence of oxygen

Anaerobic Pathways take place in the absence of oxygen

STEPS OF CELLULAR RESPIRATION

STEP 1: GLYCOLYSIS 6-carbon glucose molecule is broken down into two 3-carbon pyruvic acid molecules.

STEP 1: GLYCOLYSIS 6-carbon glucose molecule is broken down into two 3-carbon pyruvic acid molecules.Location: cytoplasmReactant: glucoseProducts: pyruvic acid and 2 ATPsAnaerobic: does not require oxygen

If oxygen is present then Aerobic respiration occurs

If oxygen is not available then cells continue to perform glycolysis to make 2 ATPs

MITOCHONDRIA PARTS Matrix: Fluid

Inner membrane: folded membrane inside mitochondria

Cristae: inner folds of innermembrane

Intermembrane space: space between outer and innermembrane

Krebs Cycle: • Series of reactions that

occur in mitochondrial matrix

STEP 2: KREB’S CYCLE

Krebs Cycle: • Series of reactions that

occur in mitochondrial matrix

Reactants: • Pyruvic acid (from glycolysis)

STEP 2: KREB’S CYCLE

Krebs Cycle: • Series of reactions that

occur in mitochondrial matrix

Reactants: • Pyruvic acid (from glycolysis)

Products: • 2 CO2 • 2 ATP• NADH (e- carrier)

STEP 2: KREB’S CYCLE

• The “big ATP payoff” • Location: cristae (inner membrane) of mitochondria• Reactants: NADH, O2

• Products: NAD+, H2O, 34 ATP

STEP 3: ELECTRON TRANSPORT CHAIN AND CHEMIOSMOSIS

•NADH transfers e- to the Electron transport chain

(e- move down a series of proteins)

Figure 4.22

•NADH transfers e- to the Electron transport chain

(e- move down a series of proteins)

•At the end of the chain, the electrons combine with oxygen & H+ to produce H2O.

Figure 4.22

STEP 3: ELECTRON TRANSPORT CHAIN AND CHEMIOSMOSIS Energy from the e- pulls H+ into the intermembrane space.

Figure 4.22

STEP 3: ELECTRON TRANSPORT CHAIN AND CHEMIOSMOSIS•H+ move from HIGH conc. to LOW conc.

Outer mitochondrialmembrane

Innermitochondrialmembrane

Electron transportchain proteins

NADH 26

1/2 O2 + 2H+ H2O

H+

H+ H+

H+

Cytosol

Intermembranespace

2 2

ADP + P

ATP

STEP 3: ELECTRON TRANSPORT CHAIN AND CHEMIOSMOSIS•H+ move from HIGH conc. to LOW conc.

•They diffuse through ATP synthase, generating 34 ATPs (chemiosmosis)

Outer mitochondrialmembrane

Innermitochondrialmembrane

Electron transportchain proteins

NADH 26

1/2 O2 + 2H+ H2O

H+

H+ H+

H+

Cytosol

Intermembranespace

2 2

ADP + P

ATP

2 ATP from glycolysis2 ATP from Kreb’s Cycle

2 ATP from glycolysis2 ATP from Kreb’s Cycle

34 ATP from ETC (chemiosmosis)

2 ATP from glycolysis2 ATP from Kreb’s Cycle

34 ATP from ETC (chemiosmosis)

38 ATP Made In Total

2 ATP from glycolysis2 ATP from Kreb’s Cycle

34 ATP from ETC (chemiosmosis)

38 ATP Made In Total

- 2 ATP for transporting pyruvic acid into the Mitochondria from Glycolysis

2 ATP from glycolysis2 ATP from Kreb’s Cycle

34 ATP from ETC (chemiosmosis)

38 ATP Made In Total

- 2 ATP for transporting pyruvic acid into the Mitochondria from Glycolysis

36 Net ATP Made

Aerobic Respiration is 20 times more efficient than Glycolysis alone.

ANAEROBIC VS. AEROBIC Anaerobic pathway (fermentation): Glycolysis 2 ATP

ANAEROBIC VS. AEROBIC Anaerobic pathway (fermentation): Glycolysis 2 ATP

Aerobic Pathway: Glycolysis + Kreb’s Cycle + ETC 36 ATP

MAKE AND FILL IN THIS CHART

Process Location

Reactants

Products

# of ATP Made

Glycolysis

Kreb’s Cycle

Electron Transport Chain

MOVIES: 342101, 342201 & 342301

Fact: Our bodies uses ATP at the rate of about 1 million molecules per cell per second.

There are more than 100 trillion cells in the human body. That’s about 100,000,000,000,000,000,000 ATP molecules used in your body each second!

What is the relationship between autotrophs and heterotrophs?