Microbiology Introduction 13th ed. Tortora, Funke and Case

Microbiology Introduction 13th ed. Tortora, Funke and
Case

Prokaryote - (correct Answer) - A unicellular organism that lacks a nucleus and membrane bound
organelles with singularly arranged chromosomes. Their DNA is not associated with histones and
generally lack organelles such as nuclei, mitochondria and chloroplasts.



Cell walls usually contain peptidoglycan

Divide by binary fission

Eukaryotes - (correct Answer) - Cells that contain nuclei

DNA is found in cll's nucleus, and DNA is consistently associated with chromosomal proteins called
histones and with nonhistones.

They have mitochondria, endoplasmic reticulum, Golgi complex, lysosomes, and and sometimes
chloroplasts.

Their cell walls are chemically simple.

Cell division usually involves mitosits in which chromosomes replicate and and identialc set is distrubited
into each of two nuclei. Division of the cytoplasm and other organelles occur so that the two cells
produced are identical to each other.

Prokaryotic cell structure - (correct Answer) - 3 basic shapes

Bacillus - Rod-shaped

Coccus - Spherical

Spirillum - Helical-shaped



Most bacteria range from .2t 2.0um in diameter and 2 to 8um in length.

monomophric : one shape all the time

pleomorphic : can have many shapes not jsut one.



Glycocalyx: bacteria secrete this on thier surface composed of polysaccaride, polypeptid, or both. It
varies widely from species to species. If it's organized and firmly attached it's called a capsule. If it's not,
then it's called a slimy layer.

What are the structural differences between gram + and gram -cell walls? - (correct Answer) - Gram +

,peptidoglycan (cell wall) is thick vs thin in gram -

What is the structure of peptidoglycan? - (correct Answer) - Peptidoglycan consists of two types of
monosaccharides (N-acetyl glucosamine and N-acetyl muramic acid) that alternate with each other and
are linked by beta-1,4-glycosidic linkages. In addition, one of the monosaccharides has a chain of amino
acids that allows side-by-side chains to peptide bond.

aerobic respiration - (correct Answer) - Respiration that requires oxygen produces more energy than
anaerobic respiration

glucose + Oxygen ---> CO2 + H20

Final electron acceptor is Oxygen

Anaerobic respiration - (correct Answer) - creates less energy than aerobic respiration, doesn't use
oxygen

inorganic compound as final electron acceptor

creates Lactic Acid which is toxic and must be broken down which is why we still breathe hard AFTER
exercise and also makes muscles sore

Common in microbes (can live without oxygen)

glycolysis, krebs cycle, electron transport chain - (correct Answer) - 3 stages of cellular respiration

glycolysis products - (correct Answer) - 2 ATP, 2 NADH, 2 pyruvate

Krebs cycle - (correct Answer) - second stage of cellular respiration, in which pyruvic acid is broken down
into carbon dioxide in a series of energy-extracting reactions, where 2 ATP are released and NAD+ is
reduced (e- released) => NADH, FAD+reduced (e- released) => FADH

substrate phospholation occurs in Krebs cycle

Electron Transport Chain (ETC) - (correct Answer) - series of electron carrier proteins that shuttle high-
energy electrons during ATP-generating reactions, results in 34 ATP, H+ released outside membrane
acted on by enzyme then pumped back into organelle by Chemiosis. Oxidation with H+ produced H2O,
O2 is the final accepter e-. 3ADP + 3 Phosphate Group => 3 ATP

Oxidative Phospholation occurs here.

Catabolic - (correct Answer) - A process in which large molecules are broken down

Think "cut" abolic energy is released

Anabolic - (correct Answer) - A process in which large molecules are built from small molecules

Think "Ana" addition

Metabolism - (correct Answer) - the combination of chemical reactions through which an organism
builds up or breaks down materials

, Gram + bacteria - (correct Answer) - Several layers of peptidoglycan. Very thick and rigid. Contains
teichoic acid.

Stains Purple/Blue due to alcohol trapping in large crystal violet iodine as the alcohol shrinks the cells so
the dye can't escape

Gram - bacteria - (correct Answer) - -envelope absorbs safranin and appears pink-red



-contain smaller amount of peptidoglycan (having think layer of it)



-contains lipopolysaccharides (triggers immune system response in humans)

peptidoglycan structure - (correct Answer) - meshlike polymer of identical subunits forming long strands

hydrophilic, hydrophobic make it ideal for creating cell wall

bacterial cell wall - (correct Answer) - composed of peptidoglycan

Bacterial Structure - (correct Answer) - -most bacteria have a rigid layer outside their plasma membrane
called the *cell wall*

--mainly made of *peptidoglycan*

--comes in 2 forms: *gram-positive* (thick with many peptidoglycan layers) & *gram-negative* (thin with
small amount of peptidoglycan with an outer membrane of lipopolysaccharide (LPS))



-other structures on outer surface of bacteria include

--*flagella*: for movement - bacteria don't have cilia, they are motile bc of flagella

--*fimbrae*: hairlike structures for attachment to surfaces

--*pilli/sex pilus*: for exchange of DNA

--*glycocalyx*: sugar-containing layer that protects the bacteria or attaches it to surfaces



-internal structures include

--*single c'some*: circular and free floating within cell

--no membrane bound organelles

--*plasmids*: small circular piece of DNA that replicates independently of the c'some

--some have very tough survival structures called *endospores* (Bacillus and Clostridium)