Lab Exam Info

up

condenser should ALWAYS be in the ___ position

iris diaphragm

part of the microscope that allows you to control the width of the beam of light

open

position the iris diaphragm ___ if u want to see colors

close

position the iris diaphragm ___ if u want to see contrast

form

the terms circular, irregular, filamentous, wrinkled and punctiform can be used to describe a colony’s ___

elevation

the words flat, raised, convex, pulvinate, and umbonate can be used to describe a colony’s ___

margin

the words entire, undulate, lobate, and erose can be used to describe a colony’s ___

texture

the words brittle, butyrous, membraneous, and viscid can be used to describe a colony’s ___

surface quality

the words opaque, translucent, dull, glossy, and shiny can be used to describe a colony’s ___

titre

basic stain

stain that sticks to the outer surface of a bacterial cell; positively charged stain

acidic cell

stain that is repelled from the outer surface of the cell so it leaves a negative stain; negatively charged stain

positive

only gram ____ make true endospores

mannitol fermenters

mannitol salt agar is differential bcuz _____ turn the agar bright yellow

high

mannitol salt agar is selective bcuz it can only grow microbes that can tolerate ___ salt concentrations

beta

blood agar: a ___ bacteria has total destruction of red blood cells which makes a complete zone of clearing around the colony

gamma

blood agar: a ___ bacteria has no hemolysis which means the colony grows as normal

alpha

blood agar: a ___ bacteria has incomplete destruction of red blood cells which makes the colony look slightly green

macconkey agar

which agar is specifically designed to grow enteric bacteria

• bacteria that grows in intestines

positive

macconkey agar is incredibly selective so no gram ___ bacteria can grow

• crystal violet and bile salts contribute to this

lactose fermenters

macconkey turns ____ pink-purple bcuz its a differential

growth factor

1. amino acids

2. purines and pyrimidines

3. vitamins

amylase

if a bacteria on a starch plate has a zone of clearing after being flooded with iodine it means the bacteria has the enzyme ___, and it breaks down starch into sugar

urea tube

___ turns bright pink if it produces urease