Microbiology Chapter 3 Quiz & Flashcards on Bacteria

Questions and Answers

Which two of the following are differences between spirochetes and spirilla? (Select all that apply)

Spirochetes have a unique internal flagella arrangement. (correct)

Spirochetes are more flexible, spiral shaped structures. (correct)

Spirochetes have one or more flagella at one or both ends.

Spirilla are more rigid spiral shaped structures. (correct)

What is a reasonable hypothesis for the highly convoluted cell membrane of E. fishelsoni?

To deal with surface area to volume ratio problems of being large.

In most bacterial cells, the cell ______ is the structural 'sugar bound with protein' layer surrounding the cell.

wall

Which three of the following cellular activities are associated with the bacterial plasma membrane? (Select all that apply)

Photosynthesis Signup and view all the answers

Which metric unit is best used to describe the thickness of a plasma membrane?

Nanometer (nm) Signup and view all the answers

The amphipathic character of phospholipids found in plasma membranes implies that ______.

the lipid is asymmetric Signup and view all the answers

Proteins that extend through a membrane must have _______.

hydrophobic regions with the membrane and hydrophilic regions interacting with the membrane surface Signup and view all the answers

Regions of the plasma membrane that contain several types of lipids in addition to phospholipids are termed _____.

microdomains Signup and view all the answers

Cell membranes are a heterogeneous mixture of complex compounds floating in a 'sea' of lipids.

True Signup and view all the answers

Which transport mechanisms rely only on concentration gradients to provide the 'force' to move materials across the plasma membrane?

Facilitated diffusion Signup and view all the answers

Which transport mechanisms rely on concentration gradients of one substance to power the translocation of a different substance across a membrane?

Secondary transport Signup and view all the answers

If a cell is placed into a slightly hostile environment, which transport mechanisms would probably work the fastest?

Passive diffusion because it is unaffected by the hostile conditions Signup and view all the answers

A carrier protein that transports solute molecules by facilitated diffusion has _ configuration(s) because _.

two; it needs to bind solute outside the cell and then release it in the cytoplasm Signup and view all the answers

Why do bacteria often have multiple transport systems for certain solutes?

It can take up nutrients under multiple environmental conditions Signup and view all the answers

Which transport mechanisms use ATP-binding cassette transporters?

Primary active transport Signup and view all the answers

Active transport and facilitated diffusion are similar because they both ____.

use proteins to move materials across a membrane Signup and view all the answers

Transport of molecules across the membrane using an additional solute is termed _____.

secondary active transport Signup and view all the answers

During secondary active transport, when ions move opposite to the movement of a substance, this is termed ____.

antiport Signup and view all the answers

When bacteria use different transport systems for the same substance, which three properties do the systems differ in? (Select all that apply)

Their affinity for the solute Signup and view all the answers

One distinguishing characteristic of group translocation is ______.

the molecules transported are chemically modified Signup and view all the answers

The transfer of phosphate from phosphoenol pyruvate (PEP) to an incoming molecule is an example of a(n) ____.

phosphorelay system Signup and view all the answers

Almost all microbes require ______ as a component of cytochromes and many enzymes.

iron Signup and view all the answers

Many bacteria secrete ______ to capture iron and allow it to be translocated into the cell.

siderophores Signup and view all the answers

In the PTS group translocation mechanism, glucose is transported into the cell and modified by ______.

the addition of a phosphate Signup and view all the answers

Study Notes

Differences Between Spirochetes and Spirilla

Spirochetes are flexible and spiral-shaped, while spirilla are rigid and spiral-shaped.
Unique internal flagella arrangement characterizes spirochetes; spirilla have flagella at one or both ends.

E. fishelsoni and Cell Membrane Structure

E. fishelsoni is one of the largest bacteria known.
Highly convoluted cell membrane helps address surface area to volume ratio issues.

Bacterial Cell Wall

The bacterial cell wall is a structural layer composed of sugar bound with protein, located external to the plasma membrane.

Key functions of the bacterial plasma membrane include:
- Importing and exporting proteins
- Cellular respiration
- Photosynthesis

Measurement of Plasma Membrane Thickness

Nanometer (nm) is the appropriate metric unit for describing plasma membrane thickness.

Amphipathic Nature of Phospholipids

The amphipathic character of phospholipids indicates their asymmetry.

Membrane-Extending Proteins

Proteins that penetrate membranes must possess hydrophobic regions interacting with the bilayer and hydrophilic regions interacting with the surrounding environment.

Microdomains in Plasma Membranes

Plasma membrane regions containing various lipid types aside from phospholipids are known as microdomains.

Characteristics of Cell Membranes

Cell membranes are described as heterogeneous mixtures of complex compounds dispersed in a lipid "sea."

Transport Mechanisms: Facilitated Diffusion

Facilitated diffusion utilizes concentration gradients to move materials across the plasma membrane.

Secondary Transport Mechanisms

Secondary transport uses the concentration gradient of one substance to drive the movement of another substance across the membrane.

Passive Diffusion in Hostile Environments

In slightly hostile environments, passive diffusion operates fastest, unaffected by adverse conditions.

Carrier Protein Configurations in Facilitated Diffusion

Carrier proteins involved in facilitated diffusion have two configurations to bind solute outside the cell and release it within.

Advantages of Multiple Transport Systems in Bacteria

Bacteria with multiple transport systems for certain solutes can utilize available nutrients across varying environmental conditions.

ATP-Binding Cassette Transporters

Primary active transport mechanisms employ ATP-binding cassette transporters for energy.

Active Transport vs. Facilitated Diffusion

Both active transport and facilitated diffusion utilize proteins to transport materials across membranes.

Definition of Secondary Active Transport

Secondary active transport involves the movement of molecules across a membrane using an additional solute.

Antiport in Secondary Active Transport

Antiport describes the action when ions move in the opposite direction of another substance during secondary active transport.

Variability in Bacterial Transport Systems

Bacterial transport systems for the same substance may differ in energy source, affinity for the solute, and regulatory mechanisms.

Group Translocation Characteristic

A distinguishing feature of group translocation is the chemical modification of transported molecules.

Phosphorelay System

The transfer of phosphate from phosphoenol pyruvate to an incoming molecule exemplifies a phosphorelay system.

Iron as a Microbial Component

Almost all microbes require iron for cytochromes and many enzymes.

Role of Siderophores in Iron Capture

Many bacteria secrete siderophores to capture iron, facilitating its translocation into the cell.

PTS Group Translocation Mechanism

Glucose is transported into the cell in the PTS mechanism and is modified through the addition of a phosphate.

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Test your knowledge with these flashcards from Microbiology Chapter 3. Dive into the differences between spirochetes and spirilla and learn about unique bacterial characteristics. Perfect for reinforcing key concepts in microbiology.

Microbiology Chapter 3 Flashcards