Prokaryotic Cell Wall and Peptidoglycan Composition

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What is the function of the cell membrane?

To provide rigidity to the cell

To synthesize proteins

To enclose the cytoplasm (correct)

To store genetic material

Which part of a bacterial cell contains the chromosome in the form of looped coils?

Cytoplasm (correct)

Cell wall

Flagellum

Cell membrane

What is a distinguishing feature of archaea compared to bacteria and eukaryotic cells?

Presence of a nucleus

Lack of ribosomes

Unique membrane and envelope structures (correct)

Absence of flagella

Which characteristic is common to all cells in terms of their chemical components?

Presence of essential ions Signup and view all the answers

What is the main function of the phospholipid in the cell membrane?

Forming a selectively permeable barrier Signup and view all the answers

Which type of bacteria has a thick cell wall?

Gram-positive bacteria Signup and view all the answers

What is one characteristic of Gram-negative cell envelopes?

Have LPS as a potent activator of the immune system Signup and view all the answers

What is the function of a capsule in bacterial cells?

Protect cells from phagocytosis Signup and view all the answers

Which specialized structure is responsible for CO2 fixation in bacteria?

Carboxysomes Signup and view all the answers

What is the main component of pili in bacteria?

Pilin protein Signup and view all the answers

What is the main function of the cell wall in bacteria?

Confers shape and rigidity to the cell Signup and view all the answers

Which group of prokaryotes has a cell membrane without outer layers?

Mycoplasmas Signup and view all the answers

What is the main component of most bacterial cell walls?

Peptidoglycan Signup and view all the answers

Why are enzymes responsible for peptidoglycan biosynthesis good targets for antibiotics?

They can inhibit cell wall formation Signup and view all the answers

What is the purpose of additional envelope layers in most bacteria?

Provide structural support and protection Signup and view all the answers

What is the function of sex pili in Gram-negative enteric bacteria?

Assist in DNA exchange Signup and view all the answers

How do flagella function in chemotaxis when exposed to attractants?

Rotate counterclockwise and bundle together Signup and view all the answers

What effect do repellents have on the rotation of flagella during chemotaxis?

Cause clockwise rotation and bundling Signup and view all the answers

What happens when a bacterium undergoes a 'biased random walk' during chemotaxis?

Receptors detect attractant concentrations Signup and view all the answers

What process does bacterial cell division involve as DNA synthesis terminates?

Septation Signup and view all the answers

What is the function of the two layers of phospholipids in the cell membrane?

Structural support and selective transport Signup and view all the answers

Which process allows small uncharged molecules like O2 and CO2 to easily permeate the cell membrane?

Passive diffusion Signup and view all the answers

What type of transport mechanism do polar molecules and charged molecules require to pass through the cell membrane?

Specific protein transporters Signup and view all the answers

How do molecules move during passive transport across the cell membrane?

From an area of high concentration to an area of lower concentration Signup and view all the answers

Which type of transport across the cell membrane requires energy in the form of ATP?

Active transport Signup and view all the answers