Metabolism

1

Metabolism

• Metabolism = Anabolism + Catabolism • Photosynthesis requires Respiration • Respiration requires Photosynthesis • Energy Production = Energy Consumption 2

Cell Metabolism

The chemical reactions that occur in living organisms, comprising anabolism and catabolism; may be qualified to mean the chemical reactions undergone by a particular substance, or class of substances, in a living organism.

• •

General Metabolism Anabolic metabolism

: synthesizes large molecules from smaller subunits; increases biomass

Catabolic metabolism

NADH : breaks large molecules into smaller ones, usually energy extraction  ATP and 3

METABOLISM

Anabolism=

building reactions (Photosynthesis, Citric acid cycle,etc,)

Catabolism=

breaking down compounds into simpler compounds molecules or atoms. (Respiration, etc) 4

Breakdown (Catabolism) Proteins to Amino Acids, Starch to Glucose

Larger Molecules

Metabolism Smaller Molecules Energy Synthesis (Anabolism) Amino Acids to Proteins, Glucose to Starch 5

The importance of Anabolism and Catabolism

Catabolism Importance • Production of Energy for • Transport of nutrients • Biosynthesis • Other life metabolism Anabolism (biosynthesis) Importance – For Macromolecules and other cell components 6

7

•

Primary metabolism:

Primary metabolism encompasses reactions involving those compounds which are formed as a part of the normal anabolic and catabolic processes. These processes take place in most, if not all, cells of the organism.

8

Secondary metabolism: Metabolism of secondary compounds, defined simply as compounds other than primary compounds. A compound is classified as a secondary metabolite if it does not seem to directly function in the processes of growth and development. Even though secondary compounds are a normal part of the metabolism of an organism, they are often produced in specialized cells, and tend to be more complex than primary compounds.

Examples of secondary compounds include antibiotics, and plant chemical defenses such as alkaloids and steroids.

9

Plant Respiration

10

Plant Respiration

•

Respiration

is the stepwise release of energy that was captured and stored in photosynthesis.

• • So the basic overall equation for respiration is:

C 6 H 12 O 6 + 6 H 2 O + 6 0 2



6 CO 2 + 12 H 2 O + ENERGY

11

Respiration

• Overview; – Glucose to Carbon dioxide + Water +Energy – C 6 H 12 O 6 + O 2  6CO 2 + 6H 2 O + 38 ATP – Glucose is highly reduced; contains energy – Oxygen receives the electrons to form energy • 4 separate reactions – Glycolysis, Transition Reaction, Krebs Cycle, Electron Transport, Chemiosomosis • Requires Oxygen 12

Steps in Respiration

• Electron Donors – Organic Compounds (Glucose preferred) • Electron Carriers – NAD to NADH – FAD to FADH • Electron Acceptors-Terminal – O 2 to H 2 O • Phosphorylation Reactions – ADP to ATP • Chemiosmosis Reactions 13

Glycolysis- 10 steps

• Glucose is Phosphorylated to form Fructose 1,6-diphosphate • Split to form 2 Glyceraldehyde 3-phosphate • Final Products are: – 2 Pyruvic Acid (C 3 H 4 O 3 ) • Compare to original glucose - C 6 H 12 O 6 – 2 NADH – 2 ATP 14

15

Glucose ATP ADP Glucose 6-phosphate Fructose 6-phosphate ATP ADP Fructose 1,6-diphosphate Dihydroxyacetone phosphate Glyceraldehyde 3-phosphate NAD+ NADH 1,3-diphosphoglyceric acid ADP ATP 3-phosphoglyceric acid

Glycolysis

2-phosphoglyceric acid phosphoenolpyruvic acid ADP pyruvic acid ATP 16 Click here to see glycolysis animations

Transition Reaction

• Pyruvic Acid  NADH Acetyl - Co A + CO 2 + 17

Kreb ’s Cycle

Acetyl CoA  Carbon Dioxide – C 2 H 4 O 2 to CO 2 – Energy produced/Acetyl CoA (x2 for /Glucose) • 3 NADH • 1 FADH • 1 ATP • Metabolic Wheel – Fats, amino acids, etc. enter or leave – Citrate is product of first reaction • Simmons Citrate Media 18

The Krebs Cycle

Pyruvic acid (6C) NAD + CoA NADH CO 2 Acetyl CoA (2C) CoA Oxaloacetic acid (4C) NADH NAD + Malic acid (4C) H 2 O Fumaric acid (4C) FADH 2 FAD Succinic acid (4C) CoA GTP Citric acid (6C) H 2 O GDP Isocitric acid NAD + (6C) NADH CoA CO 2 alpha-Ketoglutaric acid NAD + (5C) Succinyl CoA (4C) NADH CO 2 19

Electron Transport Chain

• NADH oxidized to NAD • FAD reduced to FADH • Cytochromes shuffle electrons finally to O 2 – Cytochrome Oxidase important in G - ID • H 2 O formed and ATP • 3 ATP / 1 NADH • 2 ATP / 1 FADH 20

21

22

23

24

25

Fermentation Products from Pyruvate

• Homolactic = Lactic Acid – Yogurt, Lactobacillus • Alcohol + CO 2 • Propionic Acid • Butyric Acid • Acetic Acid • Succinic Acid • Butylene to Acetoin – basis for VP Test (Vogues-Proskauer) 26

Fermentation Products

• Alcohol and Carbon Dioxide – Yeast mostly • Lactic Acid – Humans, muscles without oxygen – Bacteria (Lactobacillus-yogurt) • Butyric Acid – Rancid butter, Clostridium-gangrene • Acetoin – Butanediol fermentation in Klebsiella • Propionic Acid – Swiss Cheese 27

Glucose Glyceraldehyde 3-phosphate

NAD+ NADH CO2

Pyruvic acid

NADH NAD+

Acetaldehyde Ethanol

Fermentation

28

Fermentation in Yeast

29

Fermentation in Muscle

30

31

32