Prokaryotic Cells

Question 1

Each cell (of bacterial organisms) is its own organism? T/F

Answer 1

True

Question 2

Each bacterial organism has to have enough stuff going on in the cell that it can act as its own organism? T/F

Answer 2

True

Question 3

Prokaryotes are bacterial and Archaea organisms

Answer 3

True

Question 4

Characteristics of Prokaryotes:

Answer 4

1. ) no membrane bound organelles
2. ) no membrane bound nucleus. (The area containing the DNA is called the “Nuclear Region”).
3. ) Smaller in size when compared to Eukaryotic cells. A Prokaryote is smaller than the smallest Eukaryota
4. ) consists of bacteria and Archaea

Question 5

Size of Bacterial cells:

Answer 5

Diameter= 0.2-2 µm in diameter
Length= 2-8 µm in length

Question 6

The human eye can see between:

Answer 6

300-500 microns in length

Question 7

Shapes of bacteria include:

Answer 7

Coccus= round
bacillus= rod
spirillia (spirochete)= spiral

Question 8

Hierarchy of bacteria talk

Answer 8

Gram reaction (positive/negative), Shape (coccus, bacillus, spirillia), arrangement (cluster, chain, etc.)

Question 9

Example of how to talk about bacteria:

Answer 9

Staphylococcus epidermidis= “gram positive cocci (pl) that grows in clusters”

Question 10

Why do you need to discuss the arrangement of bacteria?

Answer 10

it explains how the bacteria divides on its own divisional plane

Question 11

What is the plural of coccus?

Answer 11

Cocci

Question 12

Explain coccoid arrangements

Answer 12

Diplococcus, chains, clusters, tetrads

Question 13

What is Diplococcus?

Answer 13

Diplococcus comes in pairs. It is an arrangement term in bacteria. Cocci remain in pairs after division and it’s often seen in Neisseria spp and is a super short rod

Question 14

What does “chains” mean?

Answer 14

Chains is an arrangement of bacteria. It is end to end division and is often found in Streptococcus spp

Question 15

The term “clusters” mean:

Answer 15

Grapelike clusters. It is often found in Staphylococcus spp

Question 16

Tetrads are:

Answer 16

A bacteria arrangement that comes in groups of 4

Question 17

Staphylo means

Answer 17

Clusters

Question 18

Bacilli arrangements:

Answer 18

They mostly appear as single rods.

They are Diplobacilli (pairs),

Chains (Bacillus cereus is found in chains), and

Coccobacilli (oval shaped and look like really short rods in pairs)

Question 19

Spirilla arrangements include:

Answer 19

Vibrios -

(curved rods that kind of look like boomerangs),

Spirilla -

(helical or corkscrew shaped and rigid), and

Spirochetes -

(Helical and flexible).

Spirilla and Spirochetes look very similar but you can tell them apart by looking to see which one is rigid and which one is flexible.

Question 20

Structures outside the cell wall (MUST KNOW):

Answer 20

1. ) Glycocalyx
2. ) Flagella
3. ) Axial Filaments
4. ) Pili or fimbriae
5. ) Peptidoglycan
6. ) Plasma Membrane

Question 21

Glycocalyx

Answer 21

Includes both capsule or slime layer.

It protects pathogens from being taken up by host defenses and is very slippery!

It allows adherence to surfaces and protects from the environment (drying, chemicals, etc.)

Glycocalyx possibly may provide nutrients.

Question 22

Why is a slippery Glycocalyx beneficial to an organism?

Answer 22

because it can prevent the organism from evading the immune system.

If it’s slippery and hard to grab a hold of, then you’re immune cells aren’t going to be as effective in cleaning out that organism.

Question 23

Glycocalyx will be sticky to things it wants to be sticky to? T/F

Answer 23

True

Question 24

The most important thing about a Glycocalyx is:

Answer 24

it allows it to evade the immune system by being slippery

Question 25

A capsule is less dense than a slime layer? T/F

Answer 25

False, a slime layer is less dense than a capsule

Question 26

Flagellum (flagella pl.)

Answer 26

long, filamentous appendage. (allows organism to be motile) It is not present in all bacteria. It's primarily used for motility. (flagella rotate about the diameter of the cell, pushing it much like the propeller on a ship), Additional functions include: binding to cells and substrates.

Question 27

Most bacteria flagellum have sticky ends to them? T/F

Answer 27

True

Question 28

Structure of Flagella include:

Answer 28

Hook is the twirly part that allows the filament to move around. Filament (part that twirls and allows the bacteria to be mobile) Basal body (the anchor). Bacteria flagella is really just made of 3 parts.

Question 29

Flagellar arrangements include

Answer 29

Monotrichous- 1 filament, polar (at one end) (trichous means having hairlike projections) Lophotrichous- 2 or more filaments, polar Amphitrichous- multi filaments at each end Peritrichous- filaments distributed all around the cell (they have what's called tumbling motility)

Question 30

Axial filaments:

Answer 30

Axial filaments are unique to the spiral shaped bacteria. They analogous to a flagella that is built into the membrane (like striping on a candy cane) The rotation of these filaments causes the bacteria to rotate, resulting motion of the organism.

Question 31

Motility

Answer 31

is a huge advantage to bacteria. It allows bacteria to migrate to an area where it has the best chance of survival and replication. Movement towards or away from a stimulus is called taxis Chemotaxis is movement based on chemicals Phototaxis is movement based on light (a lot of aquatic organisms do this)

Question 32

Fimbriae

Answer 32

looks kind of like flagella. It has short, thin fibrous appendages on the outside of the cell seen with Gram (-) bacteria and some Gram (+). The thin fibrous appendages each have a sticky bit on them. If it doesn't stick to anything, it basically ends up in the toilet which won't be an organism that causes disease. Being frimbinated allows the fimbriae to stick to the gut mucosa and start an infection Adhesion to surfaces & other bacteria

Question 33

Pilus (pili pl.)

Answer 33

Sex pili (not sexual reproduction) are used for cell conjugation (transfer) Conjugation is a method of transferring DNA to another bacterial cell. DNA is usually in the form of a plasmid

Question 34

The Cell Wall Functions:

Answer 34

Separates the inside from the outside (creates a barrier) Maintains cell shape Maintains osmolarity Contributes to pathogenicity Divides bacterial cells into two groups based on the Gram stain A barrier between the inside and outside of the cell. The barrier decides what comes and goes. Active and Passive transport

Question 35

The Cell Wall Contains (listen to lecture video 3 for photos of diagrams):

Answer 35

Peptidoglycan - N-acetylglucosamine (NAG), N-acetylmuramic acid (NAM), and polypeptides. NAM is cross-linked by polypeptides The amount of chains present in the cell well, in conjunction with the amount of cross-linking determine if the cell will be gram positive or gram negative. (The test was explained in the laboratory portion)

Question 36

Active transport:

Answer 36

Requires ATP and it can go against a concentration gradient

Question 37

Passive transport:

Answer 37

No ATP required and it goes with a gradient (from high to low)

Question 38

Plasma Membrane:

Answer 38

Encloses the cell Made of phospholipid bilayer The head is polar (hydrophilic-likes water) The tail is non-polar (hydrophobic-doesn't like water) Selectively permeable Contains lots of proteins

Question 39

Osmotic Pressure:

Answer 39

Is needed to stop the flow of water across the membrane. Conditions include: Isotonic, Hypotonic, and Hypertonic

Question 40

Hypertonic:

Answer 40

the overall concentration of solutes is higher outside of the cell

Question 41

Isotonic:

Answer 41

the overall concentration of solutes equals that of the cell

Question 42

Hypotonic:

Answer 42

the overall concentration of solutes is lower outside of the cell

Question 43

Cytoplasm:

Answer 43

Is the fluid component of the cell. Is composed mostly of water but also contains: ``` Inorganic molecules Organic molecules DNA Ribosomes Inclusions ```

Question 44

Bacterial Genomic DNA

Answer 44

Chromosomes: single, circular, double stranded DNA, and accounts for 20% of a cell's volume. Plasmids: very very small, circular, extra chromosomal DNA. Doesn't contain any genes required for life on them, however; they have genes that are beneficial to bacteria. Replicate independently of the chromosome

Question 45

Plasmids:

Answer 45

Typically carry genes for: Antibiotic resistance, toxins, and tolerance to toxic metals Can be transferred from one bacteria to another: conjugation and Are highly useful in the fields of molecular biology and biotechnology

Question 46

Ribosomes:

Answer 46

Common to both prokaryotes and eukaryotes Sites of where protein synthesis occur - two subunits which contain protein and rRNA - bind to mRNA and synthesize proteins Some differences between prokayotic and eukaryotic ribosomes

Question 47

Inclusions and Granules

Answer 47

Are storage units (food isn't always available) Depending on type can store: - salts - gases - lipids - fats

Question 48

Endospores (spores):

Answer 48

Resting structures formed by some bacteria when stressed Non-reproductive and highly durable. Spores consist of a very thick wall with many additional layers underneath. Formed internal to the cell membrane. Most common spore- formers are Bacillus and Clostridium

Question 49

Fungal spores-

Answer 49

are the reproductive cells of those organisms

Question 50

Bacterial spores-

Answer 50

Have nothing to do with reproduction. They are basically a protective unit

Question 51

If a spores environment changes (in a negative way):

Answer 51

It grabs all it's important "stuff" (genetic information, DNA, ribosomes, etc.), they will form a spore casing around it (called an endospore), the cell will then fall apart and all you're left with is a "free spore". It is then almost impossible to destroy the spore. The spore is a super protective coating.

Question 52

Process of making endospores:

Answer 52

Process of making a spore is called: Sporulation or Sporogenesis Germination/Explorulation: Process from going from a spore to a vegetative state.