Presentation is loading. Please wait.

Presentation is loading. Please wait.

Chapter 23 Metabolic Pathways for Carbohydrates

Similar presentations

Presentation on theme: "Chapter 23 Metabolic Pathways for Carbohydrates"— Presentation transcript:

1 Chapter 23 Metabolic Pathways for Carbohydrates
23.1 Metabolism and Cell Structure 23.2 ATP and Energy 23.3 Important Coenzymes in Metabolic Pathways

2 Metabolism Metabolism involves:
Catabolic reactions that break down large, complex molecules to provide energy and smaller molecules. Anabolic reactions that use ATP energy to build larger molecules.

3 Stages of Metabolism Catabolic reactions are organized as stages:
In Stage 1, digestion breaks down large molecules into smaller ones that enter the bloodstream. In Stage 2, molecules in the cells are broken down to two- and three-carbon compounds. In Stage 3, compounds are oxidized in the citric acid cycle to provide energy.

4 Stages of Metabolism

5 Cell Structure Metabolic reaction occur in specific sites within cells.

6 Cell Components and Function

7 ATP and Energy In cells, energy is stored in adenosine triphosphate (ATP).

8 Hydrolysis of ATP The hydrolysis of ATP to ADP releases 7.3 kcal (31 kJ/mole). ATP ADP + Pi kcal (31 kJ/mole) The hydrolysis of ADP to AMP releases 7.3 kcal (31 kJ/mole). ADP AMP + Pi kcal (31 kJ/mole)

9 Hydrolysis of ATP to ADP and ADP to AMP

10 ATP and Muscle Contraction
Muscle fibers contains filaments of actin and myosin. When a nerve impulse increases Ca2+, the filaments slide closer together to contract muscle. The hydrolysis of ATP in muscle provides the energy for contraction. As Ca2+ and ATP decrease, the filaments return to the relaxed position.

11 ATP and Muscle Contraction

12 Coenzyme NAD+ In cells, the oxidation of compounds provides 2H as 2H+ and 2e- that reduce coenzymes. NAD+ (nicotinamide adenine dinucleotide) participates in reactions that produce a carbon-oxygen double bond (C=O). Oxidation O || CH3—CH2—OH CH3—C—H + 2H+ + 2e- Reduction NAD H+ + 2e NADH + H+

13 Structure of Coenzyme NAD+
NAD+ (nicotinamide adenine dinucleotide) contains ADP, ribose, and nicotinamide. NAD+ reduces to NADH when the nicotinamide group accepts H+ and 2e-.

14 Coenzyme FAD FAD participates in reactions that produce a carbon-carbon double bond (C=C). Oxidation —CH2—CH2— —CH=CH— + 2H+ + 2e- Reduction FAD + 2H+ + 2e FADH2

15 Structure of Coenzyme FAD
FAD (flavin adenine dinucleotide) contains ADP and riboflavin (vitamin B2). FAD reduces to FADH2 when flavin accepts 2H+ and 2e-.

16 Coenzyme A CoA activates acyl groups such as the two-carbon acetyl group for transfer. O O || || CH3—C— + HS—CoA CH3—C—S—CoA

Download ppt "Chapter 23 Metabolic Pathways for Carbohydrates"

Similar presentations

Ads by Google