Module 3 Microbial Metabolism

What is energy?

the capacity to do work

Energy currency is

Adenosine 5'-triphosphate (ATP)

3 types of cellular work

chemical, mechanical, and transport work

Ultimate source of all biological energy is _______________ ______________ through __________________________

Visible, Light, Photosynthesis

Complex molecules made by photosynthesis serve as

carbon sources for chemoheterotrophs

Major energy currency in living cell is ATP (True/False)

True

first law of thermodynamics

Energy cannot be created or destroyed. Total energy in the universe remains constant

Second Law of Thermodynamics

Physical and chemical processes proceed in such a way that the disorder of the universe increases to the maximum possible level.

What is the degree of disorder?

Entropy

How is free energy change calculated?

G = H - T * S

What does the G stand for in the equation G = H - T * S?

the change in free energy

What does the H stand for in the equation G = H - T * S?

the change in enthalpy

What does the T stand for in the equation G = H - T * S?

the temperature in degrees Kelvin (*C +273)

What does the S stand for in the equation G = H - T * S?

the change in entropy

Free energy change (G) is the amount of energy in a system that is unavailable to do work (True/False)

False (*available to do work)

What is standard energy?

the change in free energy under standard conditions of concentration ,pH, pressure, and temperature.

Negative G* indicates

exergonic reaction

Positive G* indicates

endergonic reaction

______________ ____________ removed by hydrolysis yields large -G*

Terminal Phosphate

the addition of a phosphate group to a chemical compound

Phosphorylation

generation of ATP by the transfer of a high energy phosphate to ADP

Substrate-level phosphorylation-

The synthesis of ATP coupled with electron transport

Oxidative phosphorylation-

The production of ATP in a series of redox reactions

Photophosphorylation

ATP has high phosphate group transfer potential (True/False)

True

_____________________ breakdown of ATP is frequently coupled with ______________________ synthesis reactions

Exergonic, Endergonic

Metabolic-energy-trapping processes are used to

catalyze the formation of ATP from ADP + Pi

The four inhibitors of enzymes

Competitive, Non-competitive, Allosteric, Feedback inhibition

Competitive

fills the active site and prevents the interaction of the substrate

Non-competitive

does not compete with the active site of the substrate

Allosteric

when the inhibitor binds to another site other than the substrate binding site

Feedback Inhibition

regulation by the end product of the reaction

factors influencing enzymatic activity (

temperature, pH, substrate concentration

Oxidation-reduction (redox)

a couple reaction in which one substance is oxidized and one is reduced

Electron Carriers

transfer electrons from a reductant to an acceptor with a greater, more positive reduction potential

A few electron carriers

NAD+, NADP+, Flavoproteins, Coenzymes, Cytochromes

Glycolysis

oxidation of glucose into pyruvic acid (net gain of 2 ATP and 2 NADH) Kreb cycle-oxidation of acetyl to CO2 to gain 2 ATP,6 NADH, 2 FADH2

Electron transport system

ADH and FADH2are oxidized; oxidation-reduction reactions results in the generation of ATP.

ATP total in Carbohydrate catabolism

36-38

Anaerobic respiration

fermentation (without the use of oxygen)

Aerobic respiration

requires oxygen (final acceptor)

uses a series of electron carriers to transport electrons from NADH and FADH2,in a series of redox reactions, to a terminal electron acceptor (O2)

Mitochondrial electron transport chain

extensively branched with several terminal oxidases, may be composed of different electron carriers, may be shorter than the mitochondrial electron transport chains; located in the plasma membrane

Bacterial electron transport chain

Chemiosmotive hypothesis of oxidative phosphorylation postulates that

a proton gradient is formed with the above energy

NADH is not usually oxidized by the ________________ _____________ ____________ in the absence of molecular oxygen

electron transport chain

NADH must be ______________ to replenish the supply of NAD+ for use in the catalysis of glucose

oxidized

reactions that regenerate NAD+ from NADH in the absence of O2

Fermentations

Types of Fermentations

Alcoholic(ethanol and CO2)
Lactic acid(Lactic acid~ Homolactic/Heterolactic Fermenters)
Formic acid (either mixed acids orbutanediol)

Common energy sources

Triglycerides

What is catalyzed by the beta-oxidation pathway to acetyl-CoA, NADH, and FADH2?

Fatty Acids

What may enter the Citric Acid Cycle?

Acetyl-CoA

What may enter the electron transport chain

NADH and FADH2

Amino acids are degraded by proteases to Proteins (True/False)

False (Proteins are degraded by proteases to amino acids)

The NH2 group is removed by

deamination or transamination

The resulting organic acids are converted to

pyruvate, acetyl-CoA, or a Krebs Cycle intermediate

Amino acid synthesis requires the attachment of an

amino group to a carbon skeleton

Carbon skeletons are ________________ from acetyl-CoA, TCA cycle intermediates, glycolytic intermediates, and pentose phosphate pathway intermediates

Synthesized

Replenish Citric Acid cycle intermediatesso that biosynthesis can occur. Are not limited to autotrophic organisms

Anaplerotic Reactions

use CO2 only to maintain metabolic balance and to replace Krebs cycle intermediates

Heterotrophic organisms

Purines, pyrimidines, and nucleotides important because they are used in

ATP, several cofactor, RNA, and DNA synthesis

Purine biosynthesis is very complex (True/False)

True

uses aspartic acid and carbamoyl phosphate to form the initial pyrimidine product

Pyrimidine biosynthesis

Pyrimidines and purines are joined with

pentose sugars to form nucleoside

Phosphorylation of the nucleoside forms the nucleotide (True/False)

True

very vulnerable to disruption by antimicrobial agents, including antibiotics such as beta-lactam ring containing antibiotics ; Complex 8-stage process

Peptidoglycan synthesis

What is able to weaken the cell wall and can cause lysis

Inhibition of any step in the process of peptidoglycan synthesis