Chapter 19: BioLab

Most bacteria are ___, and many are ___. Pathogenic bacteria cause ___

harmless, beneficial, disease

Bacteria can be helpful to the environment and medicine by:

1. Producing ___
2. Helps clean ___ through ___
3. Produces ___ in medicine
4. Makes atmospheric ___ usable by plants.
5. Helps human ___
6. Food ___

1. Oxygen

2. pollutants, bioremediation

3. antibiotics

4. nitrogen

5. digestion

6. production

Infections transmitted from animals to humans are called ___ infections.

zoonotic

Bacteria are ___, meaning they lack a membrane-bound ___ and ___. Most are also ___

prokaryotic, unicellular

Prokaryotes differ from eukaryotes by having no ___, no ___-___ organelles, and a generally smaller ___ size.

nucleus, membrane-bound, cell

Photoautotroph bacteria: use ___ for energy and ___ as their carbon source to build cell parts

Sunlight, CO2

Photoheterotroph: use ___ for energy and ___ molecules, such as ___, as their carbon source to build cell parts

Sunlight, organic, sugar

Chemoautotroph bacteria: Use ___ chemicals and ___ as their carbon source to build cell parts

inorganic, CO2

Chemoheterotrophs: Uses ___ molecules, such as ___, for energy and as their carbon source to build cell parts.

organic, sugars

Some bacteria are obligate aerobes, meaning they ___ ___ for survival

require oxygen

Some bacteria are obligate anaerobes, meaning ___ can harm them.

oxygen

Some bacteria are facultative anaerobes, meaning they can survive ___ or ___ ___

with, without oxygen

Bacteria in domain archaea are called ___

extremophiles

Halophiles live in ___ conditions

salty

Thermophiles live in ___ temperatures (60-90C)

hot

Hyperthermophiles live in ___ temperatures (exceeding ___C)

hotter, 100

Psychrophiles live in ___ conditions, such as the Antarctic

cold

Acidophiles live in ___ conditions

acidic

Alkaliphiles live in ___ conditions

basic

Gram-positive cells have a ___ peptidoglycan cell wall, whereas Gram-negative cells have a ___ one.

thicker, thinner

Prokaryotes reproduce through ___ ___, which can lead to ___ ___ in pathogenic bacteria.

binary fission, antibiotic resistance

Not all archaea live in extreme environments. Some are called ___, which live in moderate conditions.

mesophiles

Methanogens produce ___ in ___ environments, such as ___ and some animals’ ___ tracts.

methane, anaerobic, swamps, digestive

Cyanobacteria produce ___ through ___

oxygen, photosynthesis

Proteobacteria are a ___ group with beneficial and ___ members

diverse, pathogenic

Spirochetes are ___-___ and move in a ___ motion

spiral-shaped, corkscrew

Chlamydias ___ and ___ inside host cells; includes human ___

lives, reproduces, pathogens

Gram-positive bacteria include pathogens but also actinomycetes, which some are used to make ___

antibiotics

Bacteria have three main shapes:

1. ___, known as rod-shaped
2. ___, known as spiral-shaped
3. ___, known as spheres

1. Bacilli

2. Spirilli

3. Cocci

Cell wall maintains ___; helps prevent the cell from ___

shape, bursting

Flagella helps in ___

movement

Pili have two different functions:

1. Fimbriae helps it to ___ to surfaces

2. Sex pili help transfer ___during bacterial conjugation

attach, DNA

Plasma membrane controls what ___ and ___ the cell

enters, leaves

Endospore: Helps bacteria ___ ___ conditions

survive unfavorable

Ribosomes make ___

proteins

Nucleoid contains the bacterial ___

chromosome

Plasmids are additional small ___ molecules which may carry genes to help ___ resistance

DNA, antibiotic

Bacterial cell walls contain ___, and archaeal cell walls contain ___ and ___.

peptidoglycans, polysaccharides and proteins

Gram-positive bacteria have thick ___ and appear ___. Gram-negatives have a thin ___ and appears ___.

peptidoglycan, purple, peptidoglycan, pink

What is the stain order?

Crystal violet, iodine, alcohol, safranin

Crystal violet is the ___ stain, makes both ___

primary, purple

Iodine helps ___ the crystal violet

trap

Alcohol removes ___ from Gram-___ cells.

purple, negative

Safranin makes Gram-negative cells ___

pink

Too ___ alcohol makes Gram-positive appear negative whereas too ___ alcohol makes gram-negative appear positive

much, little

Pathogenic species are disease-causing. Pathogenic species that infect humans are called ___ ___

human pathogens

The vast majority of bacteria are harmless, and they can be helpful by producing ___, play a role in ___ production, and can help human ___ and produce ___

O2, food, digestion, antibiotics

Methanogens produce methane from CO2 and H2 found in anaerobic environments. Based on this information, what is their nutritional mode and their oxygen requirement?

Chemoautotroph and a obligate anaerobe

Bacillus anthracis causes anthrax. What shape would you guess it has?

Bacilli (rod shape)

Staphycoccus pyogenes causes strep. What shape would you guess it has?

Coccus (spherical)

Leptospira interrogans causes leptospirosis. What shape would you guess it has?

Spirilli (spiral)

Cyanobacteria are considered Gram ___. Their role in the biosphere is to perform ___ and produce ___, making them photoautotrophs.

negative, photosynthesis, oxygen

Cell wall composition of Archaea, bacteria, fungi, and plants?

Archaea: polysaccharides and proteins
Bacteria: peptidoglycans
Fungi: Chitin
Plants: Cellulose

Using an oil immersion objective, what is the total magnification?

1000x

Clostridium tetani is an endospore-producing bacteria that causes ___. It is commonly found in ___, and the endospores may enter the body through ___

tetanus, soil, wounds

Gram positive: Because of their thick peptidoglycan walls, the retain the ___-___ complex and appear ___.

crystal-violet

Gram-negative: Because of their thin peptidoglycan walls, the purple stain is lost during the ___ treatment and absorbs the ___, which makes them appear ___

alcohol, safranin, pink

Thiomargia namibienis: 750 millimicrons in diameter that occur in anaerobic, hydrogen sulfide-rich ocean floor sediments. What is the extremophile type and oxygen requirement?

Halophile, facultative anaerobe

What is the organism, what is the cell shape, and is it colonial?

Oscillatoria, discoid, and it is colonial