Chapter: 15 Microbiology Cellular Structure and Processes ⚛

The structures of cells and bacteria

unicellular

microorganism that does not have a nucleus or any other membrane-bound organelles

What do prokaryotes mean in greek

before the nut

Capsule

protective, often slimy, coating often of sugars, that helps to protect the bacterium

virulent

more likely to cause disease

Cell wall

is made of peptidoglycan which is a protein and sugar compound

cell membrane

acts by coordinating the passage of molecules into and out of the cell

Cytoplasm

serves as a medium through which molecules are transported, as well as a system to maintain conditions (like temperature and pH) that are best for the cell

Ribosomes

main site for the bacterium's protein synthesis

Nucleosome

a basic unit of chromatin

nucleoid

the region where the bacterium's DNA is located

Flagellum

the means by which the cell moves around

Taxonomy

bacteria classification

domians

a taxonomic level that is higher than a kingdom, and based on an organism's DNA

What are the three shapes of bacteria

cocci (round), spirlii (spiral), (bacilli rod shaped

Gram Stain

bacteria are subjected to a chemical stain, depends on the amount of peptidoglycan in the cell wall

Anibiotic sensitivity

preventing the peptidoglycan from forming properly

Oxygen requirement aerobes

require oxygen to carry out their day-to-day metabolic processes

anaerobes

Bacteria that grow in the absence of oxygen and are destroyed by oxygen

phylogenetic tree

traces the evoluntionary history of organisms, and indicates common ancestors

Bacteria and Archea are both ______

prokaryotes (they do not have a nucleus and lack membrane-bound organelles)

microbes

tiny, single-cell organisms which cannot be seen by the naked human eye

peptidoglycans

a molecule composed of both protein and sugar rings

extremophiles

organisms that are adapted to extreme environments

Halococcus is ...
a eukaryote.
a bacterium.
an archaea.
non-existant.

an archaea.

The Tree of Life:
has two major branches: eukarya and bacteria
has three major branches: archaea, bacteria and eukarya
has two major branches: archaea and eukarya
has two major branches: archaea and bacteria

has three major branches: archaea, bacteria and eukarya

Some bacteria:
are archaea
can form spores
are eukaryotes
are large enough on their own to be seen unaided, with the naked eye

can form spores

Archaea and bacteria:
have the same genes for flagella
are genetically different
do not share common shapes
differ in size

are genetically different

E.coli, Salmonella, and Lactobacillus are
eukaryotes
bacteria
extremophiles
archaea

bacteria

Archaea have been found to live in:
hot springs
pools with high salt content
all answer choices are correct
freezing waters

all answer choices are correct

Cocci

spherical, resembling tiny balls

bacilli

small rods, longer than they are wide

spiral

twisted in helices and resemble little cork screws

single

lives as one cell

Diplo

live in pairs

four cells forming a flat square

Sarcina (type of coccus)

cube like group of eight cocci

Strepto (type of bacilla)

form long chains

Staphylo (type of coccus)

form an irregular, grape-like cluster

Vibrio (form of spiral)

curved resembling a comma

Spirrillum(form of spiral)

shaped like helix have thick cell walls and flagella

Spirochete (form of spiral)

shaped like helix, thin flexible cell walls that lack flagella

Bacillus is a genus of bacteria that also refers to what cell shape?
Sarcina
Spherical
Vibrio
Rod

Rod

Under a microscope, which organism would appear as a chain of rod-shaped cells?
Diplobacillus
Sarcina
Streptobacillus
Vibrio

Streptobacillus

Which of these is closest to a grape like structure of bacterium?
Sarcina
Diplobacillus
Streptococcus
Staphylococcus

Staphylococcus

The three forms of spiral bacteria are _____.
vibrio, spirillum and sarcina
spirochete, bacillus and cocci
staphylococcus, streptococcus and tetrad
vibrio, spirillum and spirochete

vibrio, spirillum and spirochete

Aerobe

An organism that needs oxygen to grow

Anaerobe

an organism that doesn't need oxygen to grow

Obligate Anaerobe

Organisms that use an anaerobic metabolism to grow and are killed in the presence of oxygen

Aerotolerant Anaerobes

organisms with an anaerobic metabilism that can life in oxygen or oxygen free environments

Facultative anaerobes

Prefer to grow using aerobic metabolic processes but can switch to an anaerobic metabolism in the absence of oxygen

methanogens

A group of archaebacteria that produce methane as a by product of their metabolism.

Organisms that use an anaerobic metabolism to grow and are killed in the presence of oxygen are known as:
Aerotolerant anaerobes
Facultative anaerobes
Obligate aerobes
None of the answers are correct
Obligate anaerobes

Obligate anaerobes

Methanogens, acetogens, and staphylococcus are all examples of:
Aerobes
Fungi
Viruses
Anaerobes
Obligate aerobes

Anaerobes

Organisms with an anaerobic metabolism that can live in oxygen or oxygen-free environments are known as:
Obligate aerobes
Obligate anaerobes
None of the answers are correct
Aerotolerant anaerobes
Facultative anaerobes

Aerotolerant anaerobes

Organisms that prefer to grow using aerobic metabolic processes but can switch to an anaerobic metabolism in the absence of oxygen are known as:
None of the answers are correct
Obligate aerobes
Facultative anaerobes
Obligate anaerobes
Aerotolerant anaerobes

Facultative anaerobes

An organism that needs oxygen to grow is known as:
An obligate anaerobe
None of the answers are correct
An aerotolerant anaerobe
An aerobe
An anaerobe

An aerobe

Osmosis

the movement of water through a semipermeable membrane from areas of low solute concentration to areas of high solute concentration

Cell envelope

composed of a cell membrane and a cell wall

Cell wall

rigid, carbohydrate-containing structure that surrounds the bacterial cell

Peptidoglycan

a complex molecule composed of alternating units of N-acetylgulucosamine (NAG) and N-acetylmuramic acid (NAM) cross linked by short peptides

Gram Positive

multiple peptidoglycan layers forming very thick, rigid cell walls

Teichoic acid is only found in

gram positive bacteria

Gram negative

only one or two layers of peptidoglycan that is covered by an outer membrane

Periplasm

jelly-like layer between the outer membrane and the cell membrane

Starting from inside the cell, what is the correct order of cell envelope components in Gram-negative bacteria?
Cell membrane, periplasmic space, peptidoglycan
Outer membrane, peptidoglycan, cell membrane
Phospholipid bilayer, porins, LPS,
Cell membrane, periplasmic space, outer membrane
Cell membrane, peptidoglycan layers

Cell membrane, periplasmic space, outer membrane

Which statement is TRUE of Gram-positive bacteria?
They have a double membrane.
They are freely permeable to disinfectants.
They use teichoic acid to move ions across the cell wall.
They can release porins to poison the host.
They have a thin peptidoglycan layer.

They use teichoic acid to move ions across the cell wall.

What are the two major functions of the peptidoglycan structural layer?
To transport nutrients into the cell and synthesize porins
To prevent cell lysis and prevent water from leaving the cell
To transport ions through the wall and produce endotoxins
To separate the cell membranes and generate energy for the cell
To prevent cell lysis and allow molecules to pass through the wall

To prevent cell lysis and allow molecules to pass through the wall

What is the relationship between osmosis and the bacterial cell wall?
The cell is hypertonic and the wall prevents lysis from osmotic pressure.
The cell is hypotonic and the wall prevents water molecules from leaving.
The wall allows the cell to expand when water enters and increases the osmotic pressure.
The cell is hypotonic and the wall prevents lysis from osmotic pressure.

The cell is hypertonic and the wall prevents lysis from osmotic pressure.

Which statement about the cell wall is FALSE?
The cell wall maintains the cell shape.
Peptidoglycan is the primary component of cell walls.
All bacteria have a cell wall.
Different bacterial species can have different cell wall structures.
Cell walls allow some molecules to pass through.

All bacteria have a cell wall.

Protist

any eukaryotic organism that isn’t an animal, plant, or fungus

What do protists have in them?

A nucleus, ribosomes ( synthesize all proteins), mitochondria (turn food into energy), chloroplasts (capture sunlight turn it into sugars), Some protists contain an eyespot (detects light, so they can head towards or away from light as they desire

Alveolates

protists that have membranous tiny sacs, called alveoli

Dinoflagellates (type of alveolae)

• A type of single-celled organism belonging to the group Alveolata.

• Characterized by two flagella, one for movement and another for rotation

• Often found in marine environment

• they can glow

What is red tide

Red tide is a phenomenon caused by the rapid growth of dinoflagellates, in marine environments. These algae can produce toxins that are harmful to marine life and humans. The term "red tide" comes from the discoloration of the water, which can appear reddish or brownish due to the high concentration of these organisms.

algae

plant like protists

trypenasoma protists look like?

spindle-like structure whith flagella

Cilia

Cilia are microscopic, hair-like structures that extend from the surface of many eukaryotic cells. They play crucial roles in movement, Cilia can beat coordinated waves to propel cells or move fluids across their surface.

All protists are surrounded by a ________

cell membrane (protective layer that helps to separate the cell from it’s external environment

Protists can come together and form

algae

Which protist is responsible for making ocean water glow?

1. giant kelp

2. diatom

3. paramecium

4. dinoflagellate

1. dinoflagellate

An eyespot would help a protist find

1. food

2. bacteria

3. other protists

4. light

1. light

Protists that are able to make their own food are called:

1. kelp

2. photosynthetic

3. dinolflagellates

4. diatoms

photosynthetic

Which word best describes Protists?

1. diverse

2. plain

3. common

4. typical

diverse

Protists might use any of the following structures to move, except

1. flagella

2. false feet

3. cilia

4. feet

feet

How do Protists Reproduce

Asexually and sexually

How to protists reproduce asexually

the parent cell splits in two, copying its DNA into a second nucleus as it divides. The end result is that the parent cell is gone, and has been replaced by two 'daughter' cells.

How long can the protists cell division process take

anywhere from a few hours to a few days, depends on the organism and the conditions

How to protists reproduce sexually

gametes, are formed and merge together to create a new, genetically distinct generation.

How does Plasmodium (protists that causes malaria) reproduce

sexually using mosquitoes as vectors (or carriers), they also reproduce asexually once they are within a host.

How does slime mold reproduce?

sexually

Which of the following is true of asexual reproduction in protists?

1. It requires two separate protists to start the process

2. Gametes combine to form a new organism

3. The daughter cells are genetically identical to the parent

4. It begins with the parent absorbing another protist into itself

The daughter cells are genetically identical to the parent

Which of the following is NOT true of protists?

1. They reproduce both sexually and asexually

2. Parasitic protists might need multiple types of hosts in their life cycle

3. They can be single- or multi-celled organisms

4. They are prokaryotic

They are prokaryotic

Why would a protist go through a dormant larval stage?

1. They might go through one if resources were scarce

2. All protists go through one as a part of their life cycle

3. They would go through one only if they were a slime mold

4. There are no protists that go through a dormant stage

They might go through one if resources were scarce

How do slime molds mature?

1. They reach maturity immediately as a result of asexual reproduction

2. They go into a chrysalis and emerge later as full adults

3. They go through multiple larval stages before reaching maturity

4. They require different hosts for their larval and adult stages

They go through multiple larval stages before reaching maturity

What biological category do protists fall under?

1. None of the answers are correct

2. Fungus

3. Animal

4. Plant

None of the answers are correct

Protists are not in the _________, _________, _________ kingdoms but are in their _______ kingdom

plant, animal, or fungi, but in their own kingdom

The autotrophic protists are able to make

organic carbon-containing nutrients like glucose

Many protists are predatory and have _________

specialized structures designed to capture and aid in bringing nutrients inside their cells

trichocyst

specialized cillia that the organism projects in order to paralyze or kill prey