biol 422 test 1

Who learned that bacteria can change themselves by picking things up from the environment

Frederick Griffith

What clues hinted that DNA held the genetic material of a cell

Bacteria picking up DNA caused them to change, viral DNA is what enters the infected cell

microbes definition

small living things

exceptions to the microbe definition

viruses, bacteria that can be seen with the naked eye

what size range do microbes have

2 micrometers to a few millimeters

when would you use a light microscope

When viewing bacteria or larger microbes

when would you use florescence microscopy

to view specific cells, molecules, or molecular processes

when would you use transition electron microscopy

to view internal structures of viruses or very small cellular structures

when would you use scanning electron microscopy

to view the surface structure of viruses and very small cellular structures

why do electron microscopes give a smaller resolution than light microscopes?

electrons have way smaller wavelengths, so they move more straight that light waves

prokaryotes

cells with no nucleus or membrane bound organelles and have a simpler internal structure

timeline of microbe classification

we first thought microbes were plants, then microbes were recognized as a separate kingdom, and then prokaryotes, eukaryotes, and fungi were all separated

who defined the difference between prokaryotes, eukaryotes, and fungi

Robert Whittaker

methanogens

microbes that produce methane

S-Svedburg unit

how quickly it takes for a specific particle to become sediment in a centrifuge, gives us a rough idea of protein size

16S rRNA

RNA in a ribosome that codes for ribosome creation and function

what do ribosomes have

16S rRNA and 30S proteins

both eukaryotes and prokaryotes have ___

ribosomes

who discovered how to use 16S rRNA to compare different species

Carl Woese

molecular fingerprinting process

cut DNA/RNA randomly, seperate the fragments by size via electrophesis, and sequence the short fragments with radioactive labelling

methanogens became ___

archaea

Archaea are more closely related to ____ than ____

eukaryic cells, bacteria

___% gene similarity=same species

97

Protons ___ move freely across the cell membrane

can’t

the cell membrane is made of ___

phospholipids

saturated fatty acids

have straight tails, are more rigid

unsaturated fatty acids

have bent tails, are more fluid

____ can diffuse across the cell membrane freely

small, nonpolar molecules

there are ___ phospholipids as membrane proteins

the same amount

simple transport

active transport across the membrane that is driven by the proton motive force

ABC transporter

transport that is powered by ATP

symport

simple transporter where the molecules are transported in the same directiona

antiport

simple transporter where molecules are transported in opposite directions

group translocation

chemical is modified in the transporter to make the molecule something that wants to move into the cell, usually powered by PEP

bacterial cell walls are made of __

peptidoglycan

bacteria have cell walls to ___

stop the cell from lysing when pressure is applied to the cell

peptidoglyan is made of ___

chains of sugars linked together with amino acids

cross bridges

peptides helping connect peptidoglycan strands together

gram-positive bacteria

have thick cell wall

gram-negative bacteria

have very thin cell wall and an extra cell membrane

the gram stain makes ______ bacteria ___

gram-positive, purple

the outer cell membrane binds to ___

lipopolysaccharides (LPS)

what does penecillin do

inhibits the cross-linking of peptidoglycan

autotroph

gets energy from things is in the cell

heterotroph

gets energy from things outside the cell

catabolism

breaking down things

anabolism

building things

catabolic and anabolic reactions are ___

metabolically coupled

reduced

gains electrons

oxidized

loses electrons

electron carriers

holds energy/links catabolic and anabolic reactions together

electron carrier examples

NADH/NADPH

aerobic respiration final electron acceptor

O2

aerobic respiration phosphorylation type

substrate-level and oxidative

number of ATP molecules made from aerobic respiration

38 for prokaryotes, 36 for eukaryotes

anaerobic respiration final electron acceptor

any inorganic molecule other than O2

anaerobic respiration phosphorylation type

substrate-level and oxdative

how many molecules of ATP are made from anaerobic respiration

more than 2 but less than 38

fermentation final electron acceptor

an organic molecule (usually pyruvate)

fermentation phosphorylation type

substrate-level

how many molecules of ATP are made from fermentation

2

the EMF pathway is also called ___

glycolysis

glycolysis

oxidizes glucose to pyruvate

the citric acid cycle

1 Acetyl-CoA is turned into 3 NADH and 1 ATP

Acetyl-CoA is made from ___

pyruvate

the electron transport chain first gets its electrons from ___

NADH and FADH2

electron transport chain

forms proton motive force, makes about 34 ATP for each glucose

anaerobic respiration releases less energy because the final electron acceptor is ___ electronegative

less

energy released= ___ deltaG

negative

why does fermentation happen

because it turns NADH into NAD+, letting glycolysis move as fast as possible

strict aerobes

can only do oxidative phosphorylation

faculative anaerobes

can do aerobic or anaerobic phosphorylation, uses aerobic when oxygen is available

strict anaerobes

only do fermentation

defined media

uses known concentrations of chemicals, easy to control but too complicated for complex organisms

complex media

media made from a natural environment, has all the needed nutrients but impossible to control concentrations

viable cell count

measure of alive/viable cells, done by diluting the culture and spreading it on a plate

turbidimeric growth measurement

use spectrophotomer, gives rough cell count

optical density is proportional to __

the number of cells per unit volume

growth phases

lag, exponential, stationary, decline

osmolarity

concentrations of salt/pH/etc.

what happens when cells are too cold

enzyme reactions happen too slow and the membrane becomes too stiff

what happens when cells are too hot

important proteins denature

psycrophile

likes cold

mesophile

normal temps

thermophile

decently hot temps

hyperthermophile

extra hot temps

Taq DNA polymerase is used for inducing PCR because ___

it can survive really hot temperatures

what happens when the environment has too much salt for a cell

all the water leaves the cell

what do cells do to be able to survive in salty conditions

they change the solute balance in the cell and make compatible solutes

acidophile

acidic conditions

alkaliphile

basic conditions

neutralphile

normal pH conditions

prokaryotes have an origin of plication that goes in ___

both directions

initiator proteins

recognize the origin of replication and induce DNA unwinding

sigma factor

recognizes/binds polymerase to DNA to initiate transcription

CRP

cAMP activator protein, activates lots of carbon metabolism genes

polysistronic

contains multiple protein sequences

LacY

symporter, transports lactose into cell

lacZ

beta-galactosidase, breaks down lactose

Beta-galactosidase also makes ____ sometimes as a mistake

allolactose