Overview

Overview

H2O

Glycolysis

FIRST step in converting the energy in food into ATP.

Occurs in ALL organisms.Occurs in the cytoplasm of cells.

Go to Activity 6B (link to book)

John Kyrk Anim

Glycolysis

Summary - In glycolysis glucose is broken down into two molecules of pyruvate. This change is accompanied by a net gain of 2 ATP molecules and 2 NADH molecules.

Although not shown 2 ATP are needed to get things started and 4

come out so in the end there is only a net gain of 2 ATP

Overview

Kreb Cycle

This cycle occurs in the mitochondrial matrix.

It turns Acetyl-CoA into CO2. In doing so it generates a pool of chemical energy (ATP, NADH, and FADH2).

Go to Activity 6C

Moving to the Mitochondria / Grooming of the pyruvate

The pyruvate must move from the cytoplasm into the mitochondria for the Kreb Cycle.

As it moves it loses carbon dioxide to form acetyl-CoA, a 2-carbon molecule.

This process creates NADH.

Kreb Cycle

Kreb Cycle

Kreb Cycle

Overview

Oxidative Phosphorylation

The pool of chemical energy created by glycolysis and the Kreb Cycle now moves to the inner mitochondrial membrane. (the squiggly line inside of a mitochondria.)

Go to Activity 6D

Oxidative Phosphorylation

Click on the picture to see it in action…

Need Content filter ATP Synthase

Most ATP production occurs by oxidative phosphorylation

Electrons from NADH and FADH2 Travel down the electron transport chain to

oxygen, which picks up H+ to form water NADH is oxidized as the first protein complex is

reduced FADH2 is oxidized while the first electron carrier

is reduced.

Energy released by the redox reactions Is used to pump H+ into the space between the

mitochondrial membranes (active transport)

Click on the picture to see it in action…

Each FADH2 produces a max of 2 ATP.Each NADH produces a max of 3 ATP.

The Final Acceptor

One oxygen atom will accept two electrons and form water with two hydrogen.

Overall VideoCH 25

ATPSynthase

Turbine

Oxidative Phosphorylationin four steps

Electron carrying molecules release e- NADH protein complex 1 FADH2 electron carrier 1

H+ ions from matrix are actively transported by pumps across the membrane into the inter membrane space.

e- are transported to Oxygen to form water

Chemiosmosis allows H+ ions to diffuse through ATP synthase in order to create ATP

Poisons

Overview

Review CR

Each molecule of glucose yields up to 38 molecules of ATP

Each NADH molecule produces 3 ATPEach FADH2 molecule produces 2 ATP

Total

10 NADH =30

2 FADH2 =4

4 ATP produced in steps 1 and 2

38

ATP Totals for Cellular Respiration

May vary depending on which carrier picks up electrons from glycolysis to the inside of the mitochondrion

38 is the maximum only

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Fermentation

Fermentation is an anaerobic alternative to cellular respiration Under anaerobic conditions (AKA in the absence of

Oxygen), many kinds of cells can use glycolysis alone to produce small amounts of ATP

Go to Activity 6E

Fermentation

Type of Fermentation What it produces Where it occurs

AlcoholicNAD+, Alcohol and

CO2Cytoplasm of …

Yeast cells, bacteria

Lactic Acid NAD+ and lactic acidCytoplasm of …

Muscle cells, bacteria

NADH is oxidized to NAD+ while converting pyruvate to CO2 and ethanol

NAD NADH NADH NAD2 2 2 2

GLYCOLYSIS

2 ADP 2 P ATP

Glucose 2 Pyruvate

releasedCO2

2 Ethanol

22

Alcohol fermentation

NADH is oxidized to NAD+ as pyruvate is reduced to lactate

2 Lactate

NAD NADH NADH NAD2 2 22

2 ATP2 ADP 22 Pyruvate

GLYCOLYSIS

P

Glucose

Lactic acid fermentation

Molecular Breakdown And Synthesis

Carbohydrates, fats, and proteins can all fuel cellular respiration when they are converted to the right molecules

Some begin with glycolysis while others the citric acid cycle

OXIDATIVEPHOSPHORYLATION

(Electron Transportand Chemiosmosis)

Food, such aspeanuts

Carbohydrates Fats Proteins

Sugars Glycerol Fatty acids Amino acids

Aminogroups

Glucose G3P Pyruvate AcetylCoA

CITRICACID

CYCLE

ATP

GLYCOLYSIS

All organisms can harvest energy from organic molecules

Plants, but not animals can also make these molecules from inorganic sources by the process of photosynthesis The fuel for respiration ultimately comes from

photosynthesis

Cellular Energy