Overview Of Metabolism

Front 1

What is anabolism?

Back 1

metabolic building of complex molecules

requires energy input

Front 2

What is catabolism?

Back 2

metabolic breakdown of complex molecules to make energy

Front 3

What is metabolism?

Back 3

the breakdown of complex molecules in order to make other molecules necessary for the cell

Front 4

Name some inorganic molecules in metabolism

Back 4

CO2, O2, H2O, ions (Na+, Cl-)

Front 5

What is an autotroph?

Back 5

a cell that uses inorganic molecules or light to create energy

Front 6

What is a heterotroph?

Back 6

a cell that requires organic molecules for energy

Front 7

What is a linear metabolic pathway?

Back 7

the most common pathway for the metabolism where a complex process is broken down into small discrete steps where each step is on a one way path to the final product

Front 8

What is a closed loop pathway?

Back 8

A circular metabolic pathway where the final product can re-enter the pathway as the starting product again

These are rare and an example is the citric acid cycle

Front 9

What is a spiral pathway?

Back 9

The same enzymes are used over and over again to create progressively larger end products

An example of this is fatty acid synthesis

Front 10

What is metabolic flux?

Back 10

the movement of substrates through a metabolic pathway that leads to an end product

Front 11

What is the steady state of metabolic flux?

Back 11

The use of LeChatlier's Principle to drive a reaction forward leading to a constant concentration of substrates in a cell

Front 12

What is feedback inhibition?

Back 12

The inhibition of an irreversible step of a metabolic pathway by the end product of that pathway

Front 13

What is feedforward activation?

Back 13

the activation of an enzyme later in a pathway by the metabolic intermediate (substrate) of an earlier step in the pathway

Front 14

How are enzymes regulated through phosphorylation?

Back 14

activation of a signal transduction pathway activates a protein kinase that then phosphorylates a protein in a metabolic pathway.

This can inhibit or activate the protein depending on the pathway.

This leads to signal amplification because the protein kinase can phosphoylate many substrate proteins.

Front 15

How does a cell store energy?

Back 15

In "energy carriers" with high energy bonds

These molecules release energy upon breakdown

Ex: ATP, GTP, phosphoenolpyruvate

Front 16

Why is anabolic metabolism carried out in multiple steps?

Back 16

The end product is a complex molecule and requires a great deal of energy to create, so the cell has to build it in dicrete steps

Front 17

Why is catabolic metabolism carried out in multiple steps?

Back 17

The cell wants to harness as much energy as possible through the breakdown of the molecule, so breaking it down in several steps allows multiple points for capturing energy in an energy carrying molecule

Front 18

How does the cell store energy from biological oxidation reactions?

Back 18

In coenzymes, such as NADH or FADH, which can then participate in other enzymatic reactions or electron transport.

Front 19

What is a near-equilibrium reaction?

Back 19

A reversible reaction where the enzyme can participate in both the forward and reverse reaction

These enzymes are often involved in multiple metabolic pathways. (Efficiency!!!)

Front 20

What is an irreversible reaction?

Back 20

A "one-way street" in a metabolic pathway where the cell must use a different enzyme to reverse the process.

These reactions almost always involve the use of energy.

These reactions are the most common place for cellular regulation of metabolic pathways. (not wasting energy)

Front 21

Which metabolic pathways occur in the cytosol?

Back 21

glycolyis, gluconeogenesis, and the pentose phosphate pathway

Front 22

Which metabolic pathways occur in the mitochondria?

Back 22

the citric acid cycle, oxidative phosphorylation (electron transport)