Lecture 20 - Chemical Logic of Metabolism

Question 1

What are the 2 key functions of the metabolic network?

Answer 1

1. the breakdown of food for energy + raw materials

2. production of biomolecules from raw materials

Question 2

what are the 2 distinct parts of metabolism?

Answer 2

1. catabolic pathway - breakdown of food

2. anabolic pathways - biomolecular synthesis

Question 3

what are 5 molecules involved in metabolism

Answer 3

1. metabolites
2. simple molecules
3. large molecules
4. energy currency
5. coenzymes

Question 4

what are metabolites?

Answer 4

-smaller molecules which serve as intermediates in the metabolic pathways (intermediary metabolism)

Question 5

what are simple molecules

Answer 5

-amino acids, carbs, nucleotides, fatty acids

Question 6

what are large molecules?

Answer 6

-proteins, nucleic acids, polysaccharides

Question 7

what is energy currency?

Answer 7

ATP, NADH/NADPH

Question 8

every reaction in the metabolic scheme is regulated by one or more _____

Answer 8

enzyme

Question 9

what are 5 common themes of metabolism?

Answer 9

1. maintain specific internal [ ] of ions, metabolites, enzymes
2. extract energy from external sources
3. specified by genes
4. adjusted to work with the environment
5. cells undergo constant turnover

Question 10

what are 4 regulatory controls of enzymatic activities?

Answer 10

1. expression of enzymes
2. inhibition
3. allosteric control
4. covalent modifications (kinases and phosphatases)

Question 11

what are autotrophs?

Answer 11

-synthesize its biorganic molecules entirely from inorganic sources

1. photoautotrophs - green plants
2. cheohetertrophs - most higher organisms

Question 12

what are heterotrophs?

Answer 12

-synthesize their bioorganic molecules from both inorganic and organic sources

1. photohetertrophs - certain light-harvesting bacteria
2. chemoheterotrophs - most higher organsims

Question 13

what are 4 major metabolic pathways?

Answer 13

1. carbohydrate catabolism
2. oxidative metabolism
3. carbohydrate anabolism
4. photosynthesis

Question 14

what is one of the most important reactions in metabolism

Answer 14

production of ATP

Question 15

All cells maintain _______ by pyrophosphortase

Answer 15

low [PPi]