Microbiology

Chap 8,9,11,12

Metabolism

Change; all chemical reactions and physical workings of cell

Anabolism

(Biosynthesis) synthesis of cell molecules and structures; building and bond - making process that forms macromolecules and requires energy

Catabolism

Breaks bonds of larger molecules into smaller ones; releases energy

Types of energy reactions

Exergonic and endergonic

Exergonic

Reactions release energy and stored in high energy phosphate bonds

Endergonic

Reactions require energy

Where does energy come from

Light and chemical bonds

When is energy stoved

ATP

What do cells require

Constant input and expenditure of usable energy

What drives cell transactions

Chemical energy

Classifications of organisms by energy and carbon source

Chemotrophs and phototrophs

Chemotrophs

Chemocetotrophs and chemoheterotrophs

Chemoautotroph'S

Energy source is chemical, carbon source is inorganic, examples are hydrogen, sulfur, and iron

Chemoheterotrophs

Energy source is chemical, carbon source is organic, examples are all animals, most fungi, and Protozoa

Phototrophs

Photoautotrophs and photoheterotrophs

Photoautotrophs

Energy source is light, carbon source is inorganic, examples are all plants, algae, and Cyanobacteria

Photoheterotrophs

Energy source is light, carbon source is organic, examples are green and purple nonsulfur bacteria

Metabolic pathways

Can be catabolic or anabolic, each reaction is catalyzed by its own enzyme

Pathway types

Linear, branched, cyclic

Enzymes

Proteins that accelerate rate of reaction without being changed themselves, lower activation energy, provide a way to control or regulate biochemical reactions, enzymes won't occur unless enzyme that catalyzes reaction is present and active

Sucrose

Glucose and fructose

What are biochemical reactions controlled by

Changes in enzyme activity

Changes in amount of enzyme or substrate

More enzyme and or more substrate equals more product

Change in temp, ph, or salt

Affects enzyme structure

Availability of necessary cofactors

Some enzymes don't work without a non-protein cofactor

Effect of inhibitors

Molecules that bind enzymes and reduce their activity

Ph

Enzyme structure depends on ph, it affects charge of r groups

Temperature

Reactions occur more rapidly as temperature rises, as long as enzyme is active

Substrate

Reactions occur more rapidly as substrate rises, saturation occurs when substrate is high enough

Enzyme Denaturation

Enzymes are polypeptides that retain their ability to function only when folded properly, precise 3D structure

What causes protein to unfold

Change in temp, ph, or salt concentration can disrupt amino acid R group interactions

What is it called when proteins unfold

Denatured; interactions are disulfide bridges, ionic bonds, and hydrophobic interactions

cofactors

inorganic ions (Fe2+)

Coenzymes

organic molecules, dietary vitamins

apoenzyme

becomes active by binding of coenzyme or cofactor to enzyme

holoenzyme

formed when associated cofactor or coenzyme binds to enzymes active state

inhibitors bind enzymes in two ways

competitive and allosteric

competitive inhibition

binding to active site

allosteric inhibition

binding elsewhere, changing shape

how do inhibitors bind

reversibly or irreversibly

feedback inhibition

end-products of metabolic pathways are important reversible enzyme inhibitors

feedback inhibition

inhibit first enzyme in pathway, turning pathway off

low inhibitor

pathway ON

high inhibitor

pathway OFF

ATP

adenosine triphosphate (ATP)

what is atp

source of useable energy of ALL cells

what is food energy converted to

atp

what exactly is atp

breaking bond of third phosphate releases ideal amount of energy (bond is easily broken)

how is atp produced

glycolysis followed by either fermentation (Low atp yield) or respiration (high atp yield)

Glycolysis

catabolic pathway where sugars are broken down to two 3-carbon molecules of pyruvic acid (or pyruvate)

how many atp come from glycolysis

2 atp per glucose; also transfers high energy electrons to NAD+ to yield 2 NADH

OIL/RIG

? idk it says to remember this

how is energy in food molecules captured

as high energy electrons by electron carriers (cofactors) such as NADH and FADH2

Reduction

when a molecule receives/gains electrons (e- are usually transfered as part of hydrogen atom)

oxidation

a molecule that loses electrons (loses H+)

fermentation

atp production begins and ends with glycolysis in organisms that ferment

what is recycled during fermentation

NAD+ so that glycolysis can continue

why does glycolysis need NAD+

to pick up high energy electrons from glucose splitting

how is NADH oxidized to NAD+

reducing pyruvate to lactic acid (For example)

what does fermentation result in

reduction of pyruvate to form lactic acid

fermentation process

lactic acid gains electrons (RIG) generated from glycolysis carried by NADH; NADH is oxidized (OIL) to form NAD+; NAD+ is replenished and glycolysis continues

what are used to regenerate NAD+ from NADH

organic molecules

when did fermentation evolve

long before aerobic respiration when little oxygen was present in the atomosphere

respiration

energy in pyruvate and NADH are used to produce more ATP

krebs cycle

breaks down pyruvate to 3 CO2, energy captured as electrons by NADH and FADH2

electron transport

electrons from NADH and FADH2 are used to produce a H+ gradient

chemiosmosis

H+ gradient used to make atp

Krebs Cycle

cyclical metabolic pathway catalyzed by enzymes in the matrix of mitochondria or cytoplasm of bacteria; pyruvate is converted to Acetyl-CoA which enters the cycle; generates 2 ATP; generates a lot of NADH/FADH2; energy stored in pyruvate is converted to NADH/FADH2

what is pyruvate converted to in krebs cycle

Acetyl-CoA

how many atp come from kreb cycle

2 atp

what is more importantly generated by the krebs cycle

a lot of NADH and FADH2

what are NADH and FADH2

high energy electron carriers

what is energy stored in pyruvate converted to

NADH and FADH2

how many nadh and fadh2 does krebs produce

6 NADH and 2 FADH2

how many nadh does pyruvate converted to Acetyl-Coa make

2 NADH

how many NADH does glycolysis produce

2 NADH

where do bacteria complete electron transport chain

in the cell

oxidation does what

loses electrons

reduction does what

gains electrons

why use fermentation

some bacteria live in anoxic environments and can not use oxygen; they never evolved the ability to respire

aerobic respiration

Pseudomonas aeruginosa; final electron acceptor is O2; max yield of atp molecules is 38

anaerobic respiration

paracoccus denitrificans; final e- acceptor are NO3-, SO4-2, FE+3; max yield of atp molecules is 5-36

fermentation

candida albicans; final e- acceptor is organics (pyruvate); max yield of atp molecules is 2

what else can be used to produce atp energy

lipids and proteins

proteases

different amino acids enter krebs cycle or glycolysis at various stages

lipases

fatty acids are broken down to acetyl groups and fed in krebs cycle

autotrophic processes

carbon dioxide plus water with suns energy and chlorophyll produce sugars and oxygen

autotrophs

make their own food and can produce organic molecules from CO2 (an inorganic carbon source)

heterotrophs

require an organic source of carbon

what come from autotrophs

organic molecules, directly or indirectly

source of energy for autotrophic processes

light or chemical

light source for autotrophic processes

photoautotrophs that carry out photosynthesis

chemical source for autotrophic processes

chemoautotrophs that use various molecules as a source of high energy electrons

what phases does photosynthesis have

light and dark

what do atp and NADH provide in the dark reactions

energy to fuel production of sugars

electrons (from H2O) energized by sunlight

fuel synthesis of atp through electron transport and chemiosmosis; reduce NADH to NADPH

dark reactions of photosynthesis

involves anabolic pathway which is Calvin-Benson cycle

Calvin-Benson

endergonic reactions are fueled by atp and nadph from “light” reactions; process of carbon fixation (converting CO2 to organic compounds); sugars can be used as energy or to build other organic molecules

carbon fixation

converting CO2 to organic compounds

how do bacteria divide

binary fission