Cellular metabolism

Question 1

What are the purposes of metabolic pathways?

Answer 1

• Extraction of energy
• Storage of fuels
• Synthesis of important building blocks
• Elimination of waste products

Question 2

What maintains homeostasis?

Answer 2

The flow of metabolites through the metabolic pathways, when changed, a new steady state is achieved

Question 3

When do levels of required metabolites need to be altered rapidly and how is this done?

Answer 3

During action - need to increase glycolysis
After action - need to reduce glycolysis
After successful action - increase gluconeogenesis

Question 4

What are the central pathways for energy metabolism? 7

Answer 4

Glycolysis
Citric acid cycle
Electron transport chain/oxidxative phosphorylation
Gluconeogenesis
Fatty acid synthesis
Photosynthesis
ALL PATHWAYS funnel into the citric acid cycle

Question 5

What are the cellular locations for metabolism? 8

Answer 5

Mitochondria
Golgi complex
Lysosomes
Nucleus and nucleolus
Endoplasmic reticulum
Ribosomes
Cytosol
Glycogen granules

Question 6

What must a pathway be to function and be efficient?

Answer 6

Exergonic (release energy) in the direction in which it proceeds
Pathway must be regulated to meet physiological demands
Reciprocal regulation (same molecule has opposite effects on catabolic and anabolic pathways) means futile cycle won’t occur, even though opposing cycles are in the same location

Question 7

Metabolism