CH 3 Mastering Micro

An important characteristic of antibacterial drugs is their selective toxicity. If antibacterial drugs were not selectively toxic, then they would kill or interfere with the hosts' cells as well as bacterial cells. Examining cellular differences between bacterial (prokaryotic) cells and host (eukaryotic) cells suggests strategies to achieve selective toxicity. We can capitalize on these differences and take advantage of them in the design of antibacterial drugs

-interfering with translation at 70s ribosomes -inhibition of peptidoglycan synthesis -inhibition of fimbriae synthesis

Why is ATP necessary for active transport?

ATP provides energy to transfer material against its concentration gradient.

Which type of active transport protein uses one protein to pump two different molecules?

Antiport and Symport

Which molecule shown in the animation, the square or the circle, is moving against its concentration gradient?

Both

Hydrophobic molecules move across a membrane -Through integral transport proteins. -By passive transport directly across the membrane. -By active transport directly across the membrane.

By passive transport directly across the membrane.

How does water enter and exit a cell?

By simple diffusion or by use of an integral transport protein

Sequence the path of a solute from the external environment to the cytoplasm of a prokaryotic cell.

Capsule, Cell Wall, Plasma Membrane

The immune response of a host against an invading bacterium is often triggered by surface components on the bacterium that are recognized as "non-self" or "foreign" by the host. These non-self components, often protein or polysaccharide in nature, are referred to as antigens. The host responds to these antigens by making antibodies that will react with invading bacteria and mark them or tag them for destruction by phagocytes.

Flagella Cell Wall Capsule Fimbraie

Which of the following is part of the endomembrane system?

Golgi Apparatus

What is a hallmark of passive transport across cell membranes?

It occurs along an electrochemical gradient, and may involve the use of transport proteins

Which of the following statements regarding active transport is false? -It powers the diffusion of water across the cell membrane. -It requires the use of a transport protein. -It requires ATP.

It powers the diffusion of water across the cell membrane.

A strain of Streptococcus pneumoniae is no longer able to synthesize its capsular polysaccharide. What is a likely outcome?

It will be readily phagocytized upon entering the host

A strain of Neisseria gonorrhoeae has been genetically altered and can no longer produce fimbriae. What is a likely outcome?

It will be unable to adhere to host tissue and establish infection

Which of the following types of bacterial cells would have flagella located at only one end of the cell?

Lophotrichous and monotrichous

Which of the following organelles breaks down worn-out organelles?

Lysosomes

Which of the following types of bacterial cells would have only a single flagellum?

Monotrichous

Where is the genetic information of the cell stored?

Nucleus

Which of the following would not move freely across the cytoplasmic membrane -Positively charged hydrogen ions -Dissolved oxygenSmall alcohols -Dissolved carbon dioxide

Positively charged hydrogen ions

Procaryote vs Eucaryote

Procaryote -Circular chromosome -Not enclosed within a nuclear envelope -Peptidoglycan-containing cell wall -70s ribosomes -Flagella that rotate, composed of flagellin Eukaryote -Linear chromosomes enclosed within a nuclear envelope -80s ribosomes -Flagella that wave, composed of microtubules -Cellulose or chitin-containing cell wall -Golgi apparatus -Lysosomes -Mitochondria -Endoplasmic reticulum

One of the ways smooth endoplasmic reticulum (ER) differs from rough endoplasmic reticulum is that rough ER is covered by

Ribosomes

There are some structures that are common to all prokaryotic cells, and others that are only found in some bacterial species or strains.

Ribosomes Nucleoid Plasma Membrane Cytoplasm

How is simple diffusion different from other types of passive transport?

Simple diffusion does not require a permease.

Which type of active transport protein moves two molecules into the cell at the same time?

Symport

What will happen to a cell that is placed in a solution containing a high concentration of sugar, a molecule that cannot pass across the cell membrane?

The cell will lose its interior water, causing it to shrivel up and possibly die.

Why is no energy required in passive transport?

The concentration gradient drives the movement.

What makes phospholipid membranes good at keeping some molecules out, and allowing others to freely pass?

They have both hydrophilic and hydrophobic regions.

Which transport protein employs transporters that move molecules only in one direction?

Uniport and Symport

How is osmosis different from simple diffusion?

Water movement is driven by the concentration of solutes rather than its own concentration.

Nonspecific permeases

allow a variety of molecules to cross the cytoplasmic membrane.

The structural framework in a cell is the

cytoskeleton

Which of the following molecules would be blocked by a cell membrane? -Dissolved oxygen -Simple alcohols -Water -Ions

ions

A glycoprotein

is a type of peripheral protein above that can be used as a receptor or in enzymatic functions.

What carries instructions for making proteins from the nucleus into the cytoplasm?

mRNA

Where in a cell is ATP made?

mitochondria

Once equilibrium is reached,

molecules move, but there is no net movement in a particular direction.

What structure acts as a selective barrier, regulating the traffic of materials into and out of the cell?

plasma membrane

Where are lipids made in the cell?

smooth endoplasmic reticulum (ER)

Tumbles occur when

the flagella rotate clockwise.

Peritrichous bacteria make a run when

the flagella turn counterclockwise and become bundled.

Integral proteins are mostly involved in

transport function

A positively charged sodium ion -would get stuck in the hydrophobic core of the membrane. -would require the use of integral protein channels to pass through a cell membrane. -freely diffuses directly across the cell membrane.

would require the use of integral protein channels to pass through a cell membrane.