Unit 3 Microbiology

Monomoer of protein

amino acid

Monomer of carbohydrates

monosaccharides

Monomer of lipids

glyucerol and fatty acids

Monomer of nucleic acids

nucleotides

Catoblism produces ____ to transport electrons

NADH

Phototrophs obtain energy by

trapping light during light reaction of photosynthesis

Chemoautotrophs derive energy from

the oxidation of organic and inorganic electron donors

What is used by most autotrophs to fix CO2

Calvin-Benson Cycle

Where does the CB Cycle occur in eukaryotes

in strome of chloroplasts

3 Phases of CB Cycle

1. Carboxylation

2. Reduction

3. Regeneration

How many ATPS and NADPHs are used during the incorporation of one CO2?

3 and 2

The carboxylation phase of the CB cycle changes ________ to _____

ribulose 1,5-bisphosphate; 3-phosphoglycerate

The conversion of ribulose 1,5-bisphosphate —> 3-phosphoglycerate uses what enzyme?

Ribulose 1,5-bisphosphate carboxylase/oxygenase

The reduction phase of the CBC changes ______ to ______

3-phosphoglycerate; glycerate-3-phosphate

What is added in the reduction phase of CBC?

ATP and NADPH

What is added in the regeneration phase of CBC?

ATP

The regeneration phase of CBC changes _____ to _________

glycerate-3-phosphate —> ribulose 1,5-bisphosphate

What runs in the reverse direction of the oxidative TCA cycle?

Reductive TCA cycle

Gluconeogenesis

the synthesis of glucose-6-phosphate from noncarbohydrate precursors

Starch synthesis

ATP + glucose 1-P —> ADP-glucose + PPi

Glgycogen synthesis

(glucose)n + ADP-glucose —> (glucose)N+1 + ADP

Cross links in peptidoglycan synthesis are formed by

transpeptidation

Bactoprenol is connected to

NAM pentapeptide by 2 phosphates

Inhibition of peptidoglycan synthesis can

weaken cell wall and lead to lysis

____ is a major component of proteins, nucleic acids, coenzymes and other cell constituents

nitrogen

2 mechanisms ammonia can be incorporated into carbon skeletons

1. reductive amination

2. glutamine synthase

Once incorporated, nitrogen can be transferred to other carbon skeletons by

transaminases

Assimilatory nitrate reduction of NO3 to NH3 is used by bacteria to

reduce nitrate to ammonia and incorporate it into an organic form

Nitrate reduction to nitrite is catalyzed by

nitrate reductase

Reduction of nitrate to ammonia is catalyzed by

nitrite reductase

Sulfur is used for

Synthesis of amino acids and coenzyme A

Sulfur synthesizes which amino acids?

Cysteine and methionine

Assimilatory sulfate reduction

SO₂-4 —> SO₃ 2- —> H₂ S —> synthesize cysteine

Cysteine is made by

combinidng hydrogen sulfide with serine

Assimilatory sulfate reduction involves sulfate activaton through formation of _______, followed by _____

phosphoadenosine 5—phosposulfate; reduciton of sulfate

A single precursor metabolite can give rise to

several amino acids

The carbon skeletons of precursor metabolites used for 2 purposes

Biomass and extracting energy from carbon-carbon bonds

Replenishment of the intermediates of TCA cycle is provided by

anaplerotic reactions

Purine

2 nitrogenous rings

Purine examples

Adenine and guanine

Pyrimidines

1 nitrogenous ring

Pyrimidine examples

uracil, cytosine, and thymine

Phosphorous containing molecules

nucleic acids, proteins, phospholipids and ATP

ATP is synthesized by various ways such as

photophoshorylation, oxidative phosphorylation and substrate-level phosphorylation I

Inorganic phosphorus is released from organic phosphates by

phosphatases

Lipids contain

fatty acids

Fatty acids

long chain of hydrocarbon

Fatty Acid Synthesis comes from

Acetyl-CoA and malonyl-CoA

The enzyme the catalyzes fatty acid synthesis is

fatty acid synthase

THe protein involved in fatty acid synthesis is

acyl carrier protein

Triacylglycerol and phospholipids are made from

fatty acids and glycerol phosphate

what is the intermediate in triacylglycerol and phospholipid synthesis?

Phosphatidic acid

Sterols are in

eukaryotic plasma membranes

Isoprenes are in

archaeal membranes

Isoprense made from

two sterol pathway intermediates

Lipopolysaccharides are made of a

Lipid A-core branch and O-antigen branch

LPS combines

lipid and carbohydrate

Heteretrophs

Use organic molecules as their carbon source

Autotrophs

use Co2 as sole or principal carbon source

phototrophs

obtain energy from light

Chemotrophs

obtain energy from oxidation of chemical compounds

lithotrophs

use reduced inorganic substances as an electron source

organotrophs

extract electrons from reduced organic substances

three major products of catabolic reactions

1. ATP

2. Electron Carriers (Reducing Power)

3. Precursor metabolites

What are examples of the final electron acceptors in anaerobic respiration?

Nitrate, sulfate, CO2

Fermentation

A process that uses an endogenous electron acceptor, not an ETC, and produces various products

Four main Stages of glucose catabolism

1. Glycolysis

2. Brdige Reaction

3. Krebs Cycle

4. ETC

Function of glycolysis

converts glucose into pyruvate and generates ATP and NADH

What is the bridge reaction?

Converts pyruvate into acetyl-CoA

What is the main function of the Krebs cycle?

Extracts electrons from acetyl-coA and transfers them to NAD+ and FAD

What does the ETC do?

Uses electrons to generate ATP via oxidative phosphorylation

Net yield of EMP?

2 ATP / glucose

Unique features of EDP?

Found in Pseudomonas and replaces 6-Carbon phase of EMP

What is the function of the PPP?

Generates NADPH and ribose-5-phosphate for biosynthesis

Two other names for the TCA

Citric Acid Cycle and Krebs Cycle

How many turnsm of the TCA cycle are required to fully oxidize 1 molecule of glucose?

2

What are the products of 1 Acetyl-CoA entering the TCA Cycle?

2CO2, 3NADH, 1FADH2 and 1 GTP

How many ATP molecules are directly synthesized from glucose oxidation to CO2?

Four

Where does most ATP production occur?

ETC

What are the 3 hydrogen pumps in the mitochondrial ETC?

Complex I, III and IV

What is the chemiosmotic hypothesis?

Proton movement across membrane generates a PMF that drives ATP synthesis

Maximum theoretical ATP yield in eukaryotic aerobic respiration?

32 ATP

Common terminal electron acceptors in anaerobic respiratoin?

Nitrate, Sulfate, Co2, Metals and organic molecules

How does ATP yield in anaerobic respiration compare to aerobic?

It’s lower

Why does fermentation occur?

No available ETC to take electrons from NADH

How is ATP produced in fermentatoin?

By substrate-level phosphorylation

How are carbohydrates catabolized?

Broken down into monomers that enter gylcolytic pathways

How are lipids catabolized?

Triglycerides are hydrolyzed into glycerol and fatty acids. Fatty acids broken down by beta-oxidatoin

How are proteins catabolized?

Hydrolyzed into amino acids by proteases than deaminated to enter metabolic pathways

What do chemolithotrophs oxidize for electrons?

Inorganic molecules

What is nitrification?

Oxidation of ammonia to nitrate by nitrifiying bacteria

Primary electron acceptor in chemolithotrophy

oxygen

What are the 2 stages of photosynthesis?

1. Light reactions

2. dark reactoins

What do light reactions produce?

ATP and NADPH

What is the function of dark reactions?

Use ATP and NADPH to fix CO2 into organic molecules

What is the difference between oxygenic and anoxygenic photosynthesis?

Oxygenic produces oxygen, anoxygenic doesnt

Bacteriorhodopsin

Protein used by microbes for light-driven proton pumping without an ETC

Characteristics of Anoxygenic Photosynthesis

• cyclic

• PS 1

• ATP

Characteristics of oxygenic photosynthesis

• noncyclic

• PS 1 and 2

• ATP , NADPH and O2

Whart are the 2 types of heterotrophs?

saprophytics and parasitic