Components of Prokaryotic cell

Question 1

How many components does a prokaryotic cell have?

Answer 1

13

Question 2

What does the cell envelope consist of?

Answer 2

GLYCOCALYX
CELL WALL
PLASMA MEMBRANE

Question 3

What differs in different GLYCOCALYX?

Answer 3

It differs in composition and thickness in different bacteria:-
1] SLIME LAYER - A loose sheath
2] CAPSULE - Thick and Tough

Question 4

Where is the cell wall present?

Answer 4

All prokaryotes have a cell wall surrounding the cell membrane.
EXCEPTION : Mycoplasma

Among eukaryotes , all plant cells have a cell wall but not animal cells.

Question 5

What is the role of the cell wall?

Answer 5

1] It determines the shape of the cell

2] Provides a strong structural support to prevent the bacterium from collapsing or bursting

Question 6

What is the cell wall made up in plant cells?

Answer 6

GLUCOSE
a strong, fibrous carbohydrate

Question 7

What is the cell wall made up in prokaryotic cells?

Answer 7

PEPTIDOGLYCAN
A unique polymer made up of sugars and amino acids

Question 8

What is the nature of the cell wall?

Answer 8

Freely permeable

Question 9

What is the nature of the plasma membrane ?

Answer 9

Selectively permeable

Question 10

What is the role of the cell membrane?

Answer 10

1] Interacts with the outside world
2} Controls what goes in and out of the cell

Question 11

What is the cell membrane made up of in prokaryotic cells?

Answer 11

PHOSPHOLIPIDS AND PROTEINS
-amphipathic molecules, meaning they have both hydrophilic (water-attracting) and hydrophobic (water-repelling) regions, which allows them to spontaneously arrange into a bilayer structure in aqueous environments.

Question 12

Which layer of the plasma membrane is hydrophobic?

Answer 12

Phospholipid bilayer (interior)

Question 13

If the phospholipid bilayer is hydrophobic , how does water enter the cell?

Answer 13

Carrier proteins / specialized protein channels called aquaporins

Question 14

Is the middle lamella present in prokaryotic cells?

Answer 14

NO

Question 15

What is mesosome?

Answer 15

• A special membranous structure
• formed by the extensions or infoldings of the plasma membrane into the cytoplasm of the cell,

Question 16

Mesosome extensions are in the form of …….

Answer 16

VESICLES
TUBULES
LAMELLAE

Question 17

What do mesosomes help in?

Answer 17

C - cell wall formation
D - DNA replication and
distribution to daughter
cells
I - increase the surface area of
the plasma membrane and
enzymatic content
R - Respiration
S - Secretion

Question 18

What are Chromatophores ?

Answer 18

Chromatophores are membranous extensions into the cytoplasm which contain pigments.

Question 19

What do you mean by Flagella?

Answer 19

The thin filamentous extensions from the cell wall of motile bacterial cells is called flagella.

Question 20

Bacterial flagellum is composed of how many parts and what are they?

Answer 20

Bacterial flagellum is composed of parts ;-
1] FILAMENT
2] HOOK
3] BASAL BODY

Question 21

What is the longest part of the flagella?

Answer 21

FILAMENT which extends from the cell surface to the outside

Question 22

Name two surface structures of Bacteria which do not play a role in motility .

Answer 22

PILLI and FIMBRIAE

Question 23

What are Pilli?

Answer 23

• elongated tubular structures
• made up of a special protein
• help in conjugation

Question 24

What are Fimbriae?

Answer 24

-small bristle like fibres
- sprouting out of the cell
- in some bacteria they are know to attach the bacteria to rocks in streams and also to the host tissues.

Question 25

What are the two sub-units of Ribosomes in prokaryotic cells?

Answer 25

50 S and 30 S - which when present together form 70 S Ribosomes..

Question 26

What are the two sub-units of Ribosomes in eukaryotic cells?

Answer 26

60 S and 40 S - which when present together form 80 S Ribosomes...

Question 27

What are the site of protein synthesis?

Answer 27

Ribosomes

Question 28

Define polyribosomes or polysome.

Answer 28

Several ribosomes may attach to a single mRNA and form a chain which is called polyribosomes or polysome.

Question 29

What is the role of the ribosomes of a polysome?

Answer 29

They translate the mRNA into Proteins.

Question 30

What is mRNA?

Answer 30

-messenger ribonucleic acid -mRNA is a single-stranded RNA molecule that carries the genetic code from DNA to Ribosomes.

Question 31

IN 30S RIbosomes, S stands for?

Answer 31

Svedberg's unit

Question 32

What is R-strain?

Answer 32

Rough (R) Strain: The R strain lacks the polysaccharide capsule, resulting in a rough appearance. This lack of a capsule makes the R strain non-virulent.

Question 33

What do we mean by virulent?

Answer 33

capable of causing disease

Question 34

What is S strain?

Answer 34

Smooth (S) Strain: The S strain has a smooth, shiny appearance due to a polysaccharide capsule. This capsule is a protective outer layer that helps the bacteria evade the host's immune system, making it virulent

Question 35

Polysaccharide capsule?

Answer 35

a protective outer layer, or shell, found in many bacteria. It's primarily made of long chains of repeating sugar molecules (polysaccharides).

Question 36

What happens if the S strain of bacteria is heated?

Answer 36

it becomes heat-killed, meaning the bacteria cells are no longer alive. Thus, it becomes non-virulent

Question 37

What happens if the heated S strain is taken up to the R strain?

Answer 37

**live R strain ----> virulent S strain**The DNA from the heat-killed S strain can survive the heating process and be taken up by live R strain bacteria, transforming them into virulent S strain bacteria. This transformation allows the R strain to produce a smooth polysaccharide capsule, which protects it from the host's immune system and allows it to cause disease

Question 38

What does a Broad Spectrum antibiotic do?

Answer 38

It kills or inhibits both Gram positive [ thick cell wall ] and Gram negative [ thin cell wall ] bacteria.

Question 39

What are inclusion bodies?

Answer 39

Reserve material in prokaryotic cells are stored in the cytoplasm in the form of inclusion bodies.

Question 40

Characteristics of inclusion bodies:-

Answer 40

- not bound by any membrane system - lie free in the cytoplasm

Question 41

Examples of inclusion bodies.

Answer 41

Phosphate granules Cyanophycean granules glycogen granules

Question 42

Where are gas vacuoles found?

Answer 42

Blue green and purple bacteria green photosynthetic bacteria