Overview

H2OH2O

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)(link to book)

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 CO 2. In doing so it generates a pool of chemical energy (ATP, NADH, and FADH 2 ). 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

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…

Overview

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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 FermentationWhat it producesWhere it occurs AlcoholicNAD+, Alcohol and CO2 Cytoplasm of … Yeast cells, bacteria Lactic AcidNAD+ and lactic acid Cytoplasm of … Muscle cells, bacteria

NADH is oxidized to NAD + while converting pyruvate to CO 2 and ethanol NAD  NADH NAD  GLYCOLYSIS 2 ADP  2 P ATP Glucose 2 Pyruvate released CO 2 2 Ethanol 2 2 Alcohol fermentation

NADH is oxidized to NAD + as pyruvate is reduced to lactate 2 Lactate NAD  NADH NAD  ATP 2 ADP  2 2 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 OXIDATIVE PHOSPHORYLATION (Electron Transport and Chemiosmosis) Food, such as peanuts CarbohydratesFatsProteins Sugars Glycerol Fatty acids Amino acids Amino groups GlucoseG3P Pyruvate Acetyl CoA CITRIC ACID 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