Basic Concepts Of Cellular Metabolism And Bioenergetics

Front 1

What is metabolism?

Back 1

The overall process through which living systems acquire and utilize the free energy they need to carry out their various functions but coupling exergonic reactions of nutrient oxidation to the endergonic processes required to maintain the living state.

Front 2

Catabolism

Back 2

involved in degradation;
complex metabolites are exergonically broken down to simpler products
chemical oxidation and formation of reduced cofactors of NADH, NADPH, and FADH2

Hint 2

Convergence of Pathways

Front 3

Anabolism

Back 3

involved in biosynthesis
reduction and formation of oxidized cofactors NAD+, NADP+, and FAD
Requirement for energy input and use of ATP

Hint 3

Divergence of pathways

Front 4

What are autotrophs?

Back 4

They can synthesize all their cellular constituents from simple molecules such as H20, CO2, NH3, and H2S.
Need an energy source--usually solar energy

Front 5

What are heterotrophs?

Back 5

obtain energy through the oxidation of organic compounds (products of autotrophs); and hence are ultimately dependent on autotrophs from these substances

Front 6

What are aerobes and anaerobes?

Back 6

Two types of heterotrophs
Aerobes live in air and use molecular oxygen for metabolic reactions whereas anaerobes do no require oxygen for surviaval

Front 7

Metabolic Processes in Heterotrophic Cells

Back 7

Route A: Organic compounds from environment are absorbed into organism such as fats, carbohydrates, and amino acids

Hint 7

Route B: Special organic compounds that cannot be biosynthesized such as vitamins, essential amino acids, and fatty acids

Front 8

Stages of Metabolism

Back 8

Stage I: Cleavage of Polymeric Chain to monomeric units
Stage II: Formation of monomeric units into a common intermediate
Stage III: common intermediate enters into pathway that produces the most amount of energy

Hint 8

Common intermediate: Acetyl-CoA
used in degradative metabolism to produce CO2 and H2O by citric acid cycle, electron-transport chain, and oxidative phosphorylation

Front 9

What are metabolic pathways?

Back 9

series of consecutive enzymatic reactions that produce specific products--the reactants, intermediates, and products are referred to as metabolites.

Front 10

Glycolysis pathway

Back 10

Linear
one substrate--->product

Front 11

Biosynthesis of amino acids

Back 11

Linear

Front 12

Citric acid cycle

Back 12

subsrate reproduced, and product leaves each turn

Front 13

Fatty Acid degradation pathway

Back 13

lengthen/shortening of biomolecules

Front 14

Metabolic Pathways are irreversible

Back 14

If two metabolites are metabolically interconvertible, the pathway from the first to the second must be different from the pathway from the second to back to the first

Hint 14

Principle characteristic of metabolic pathway (#1)

Front 15

Every metabolic pathway has a first committed step

Back 15

there is generally an irreversible (exergonic) reaction that commits the intermediate it produces to continue down the pathway

Front 16

All metabolic pathways are regulated

Back 16

pathways are controlled by regulating the enzymes that catalyze their first committed step. This is the most efficient way to exert control because it prevents the unnecessary synthesis of metabolites further along the pathway when they are not required
-controlled by the concentrations of substrate, products, intermediates, and enzymes

Front 17

Pathways in eukaryotic cells occur in specific cellular locations

Back 17

the synthesis of metabolites in specific membrane bounded subcellular compartments makes their transport between these compartments a vital component of eukaryotic metabolism

Front 18

Oxidation-Reduction

Back 18

Enzyme: Oxidoreductases (dehyrogenases)

transfer of electrons

Front 19

Group Transfer

Back 19

Enzyme: Transferases

Transfer of functional group from one molecule to another or within a single molecule

Front 20

Hydrolytic Cleavage (Hydrolysis)

Back 20

Enzyme: Hydrolyases

cleavage of bonds by water (transfer of functional group to water)

Front 21

Nonhydrolytic Cleavage

Back 21

Enzyme: Lyases

Splitting a molecule by nonhydrolytic processes

Front 22

Isomerization and rearrangement

Back 22

Enzyme: Isomerases

Rearrangement of functional groups to form isomers

Front 23

Bond Formation using energy from ATP

Back 23

Enzyme: Ligase

Formation of C-C and other bonds with energy from ATP