Bacteria

Question 1

What is a prokaryote?

Answer 1

The simplest and small organisms made of a single cell (smaller than eukaryotic cells). They have no membrane bound organelles or nucleus. They have circular DNA, however they’re not protected by a nucleus (floating in the cytoplasm).
Kingdoms: archaea and bacteria

Question 2

What is a eukaryote?

Answer 2

Larger and more complex organism. Can be made of a single cell or made of many cells. They contain a nucleus with linear DNA inside and have membrane bound organelles.
Kimgdoms: protists, fungi, plants, animals

Question 3

What is microbiology

Answer 3

Study of small organisms that are so small that they can only be seen with a microscope

Question 4

What are the two major type of microorganisms

Answer 4

Bacteria and viruses

Question 5

How long have bacteria been around

Answer 5

Earliest fossils of prokaryotes from 3.4-3.5 billion years ago

Question 6

How have bacteria evolved

Answer 6

They’ve been around of a long time and developed gradually into a wide variety of different types. They have been able to adapt to a wide variety of different environments

Question 7

How many cells are bacteria made of and how if this different from plants, humans, and animals

Answer 7

They’re just made of one cell (they’re unicellular) and they’re different cause humans, plants and animals and trillions of cells

Question 8

Are bacterial cells smaller than human cells?

Answer 8

Ye.. 2um thingy

Question 9

Bacteria are unicellular prokaryotic cells meaning that they lack a nucleus and membrane bound organelles. Instead what part of the soul performs many of the functions that organelles in eukaryotes do?

Answer 9

The plasma/cell membrane

Question 10

Parts of bacteria: fimbriae

Answer 10

Short, thin bristles that help the bacteria to attach to host cells (ex. Animal cells) or inanimate objects to help the bacteria obtain nutrition

Question 11

Parts of bacteria: pili

Answer 11

Pili or longer, thicker and fewer number compared to Fimbriae. They are used to allow the bacteria to attach to other bacteria during conjugation for DNA to transfer. Due to their function, they can also be called sex pili. Bacteria usually have 1 pilus or 2 pili

Question 12

Parts of bacteria: flagellum

Answer 12

Helps bacteria move and sense their environment. The flagella act like tiny propellers by rotating and moving the cell in response to chemical stimuli

Question 13

Parts of bacteria: nucleoid

Answer 13

The nucleoid exists In a large, long, circular molecule called a bacterial chromosome. The nucleoid Is all bunched up forming an irregularly shaped structure that contains the bacteria’s DNA.

Question 14

Parts of bacteria: plasmid

Answer 14

In addition to the chromosome, bacterial often contains plasmids which are small, circular DNA molecules. Bacteria can pick up new plasmids from other bacterial cells [during conjugation] or from the environment. Bacteria can also lose plasmids, for example when a bacterium divides into two, one of the daughter cells might miss out on getting a plasmid.

Question 15

Parts of bacteria: ribosomes

Answer 15

Structures that make proteins in the bacteria

Question 16

 Parts of bacteria: cytoplasm

Answer 16

A gel-like substance where the ribosomes, plasmids and nucleoid are located and held in place.

Question 17

Bacterial cell structures: Capsule

Answer 17

It’s the outer layer of the bacterium. It enhances the ability of bacterial pathogens to cause disease since it can provide protection from phagocytosis (engulfment by white blood cells known as phagocytes). Capsules can also help in attachment to surfaces since it’s made out of a stick material

Question 18

Bacterial cell structures: Cell (or plasma) membrane and cell wall

Answer 18

They help control the movement of nutrients and wastes that go into and out of the cell. The cell wall is made of peptidoglycan and is located under the capsule. Cell membrane is located under the cell wall. *capsule>wall>membrane

Question 19

Why is the cell wall the most important bacterial structure (4 reasons)?

Answer 19

-protects bacteria from burning due to osmosis
-helps give bacteria it’s shape
-controls entry of molecules in the cell
-thickness of cell wall helps scientists identify the different types of bacteria

Question 20

Bacterial cell structures: endospores

Answer 20

When living conditions become unfavorable, the bacteria form a protective, dormant structure, called an endospore, which is a thick wall surrounding the bacterial DNA as well as a small amount of cytoplasm. What is the endospore forms, the rest of the cell may die.

Question 21

What are probiotic bacteria

Answer 21

Most bacteria are probiotic and they are good for your health. Ex. We have a bacteria that live in our digestive system (like our stomach and intestines) which helped prevent harmful germs.

Question 22

What are pathogenic bacteria

Answer 22

Bacteria that cause diseases are called pathogenic bacteria. They are a variety of different diseases that exist that are caused by pathogenic bacteria.

Question 23

What are examples of pathogenic bacteria (4)

Answer 23

-Lyme disease (bitten by tick)
-salmonella (contaminated food/water)
-strep throat (streptococci transmitted cough/sneeze)
-Pneumonia (affects lungs from air breathed)

Question 24

What certain foods can be made from bacteria (4)

Answer 24

-converting alcohol to vinegar
-sauerkraut (finely cut cabbage that’s been fermented)
-dairy products
Sourdough bread

Question 25

What are some benefits of bacteria

Answer 25

-act as decomposers (break down plants and animals) -used to creat antibiotics -used to clean up environmental disasters like oil spills -preparing skins for making leather -Food preservation -Fuel production -insecticides

Question 26

What are the two ways bacteria are classified

Answer 26

1) by the thickness of their cell wall 2) by their shape

Question 27

How would u identify a gram positive bacteria (how would it look under the microscope)

Answer 27

Thick cell wall made of peptidoglycan and appears a purple/blue colour because they retain a stain called crystal violet

Question 28

How would u identify a gram negative bacteria (how would it look under the microscope)

Answer 28

Thin cell wall of peptidoglycan. They appear pinkish red colour when they are dyed because they lose the crystal violet stain when treated with alcohol or acetone since this causes them to lose crystal violet colour and become colorless. Once they are colourless and subjected to a second stand called saffron, that’s red in colour, the bacteria will appear to be pink or red colour since they retain that stain.

Question 29

Explain 4 steps of gram staining

Answer 29

0) Bacteria are colourless prior to staining 1) Bacteria are stained with crystal violet and appear blue/purple under the microscope 2) Bacteria Receive an iodine treatment to help speed up the decolorizing step. The cells are still purple/blue in colour at this point 3) Bacteria are subjected to alcohol or acetone as a decolorizing treatment. Those with a thin cell wall of peptidoglycan will not be able to keep the crystal violet stain and will now be colourless. Those with a thick cell wall of peptidoglycan will stay purple/blue since they keep the crystal stain. 4) Bacteria are subjected to a counterstain called safranin. If the bacteria are gram-negative with a f thin cell wall, they are Colourless and will therefore be able to pick up the pink red colour. if the bacteria is gram positive they are still blue/purple and their thick cell wall will not allow them to pick up the safranin’s pink/red colour.

Question 30

What is the abbreviation used for the order of gram staining ?

Answer 30

Come in and stain Crystal violet Iodine Alcohol Safranin

Question 31

What are the 5 main shapes of bacterial cells

Answer 31

-cocci (circles) -bacilli (pili) -spirilla (many flagellum) -vibrios (flagellum) -spirochaetes (worm)