Structure of a Bacterial Cell 1.4

Question 1

Cell Wall

Answer 1

Structure: Bacteria have a cell wall, but it’s made of a substance called peptidoglycan (not cellulose like plant cells).
Function: Provides shape, strength, and protection. Prevents the cell from bursting if it absorbs too much water (osmotic pressure).

Question 2

Cell Membrane

Answer 2

Structure: A thin, flexible layer beneath the cell wall.
Function: Controls what enters and leaves the cell (e.g., nutrients, waste, and gases), similar to the cell membrane in plant and animal cells.

Question 3

Cytoplasm

Answer 3

Structure: A jelly-like substance that fills the inside of the cell.
Function: Contains all the components of the cell and is where many chemical reactions occur.
Note: In bacteria, cytoplasm is not divided by membranes (no organelles like in plant and animal cells).

Question 4

Ribosomes

Answer 4

Structure: Small structures floating in the cytoplasm.
Function: Synthesize proteins (make proteins needed for the bacteria to survive).
Note: Bacterial ribosomes are smaller than those in plant and animal cells (70S ribosomes).

Question 5

Circular DNA

Answer 5

Structure: A single, large, circular loop of DNA, freely floating in the cytoplasm.
Function: Contains all the genetic information needed to control the cell’s activities and help it reproduce.
Note: Bacteria don’t have a nucleus—this DNA is not enclosed in a membrane.

Question 6

Plasmids

Answer 6

Structure: Small, circular pieces of extra DNA, separate from the main circular DNA.
Function: Carry additional genes, such as those for antibiotic resistance, which can be shared between bacteria.