Prokaryotes Cell Structure

What is a thick glycocalyx called?

Capsule

What are the 2 functions of the cell wall?

Maintain its shape and resist turgor pressure.

What are the advantages to having a small cell?

It allows cells to grow faster and multiply rapidly. They can easily meet their nutritional needs to grow.

What is the name of the endotoxin in the cell envelope of the G(-) bacteria?

Lipopolysaccharide

Is a major function of the cell wall to regulate transportation

Nope! False.

What kind of transport uses channel proteins?

Osmosis Facilitated Diffusion

What is a pili?

Short, hollow appendages (like a straw); help cells adhere to other cells and allow for genetic exchange between cells

How does oxygen and carbon dioxide transport across plasma membranes?

Simple diffusion through the phospholipids

Why are G(-) bacteria more resistant to some antibiotics than G(+) bacteria?

Some antibiotics are too large to fit through the channels in porin proteins in the outer membrane. G(+) bacteria don't have an outer membrane, so there is no issue with porins.

Why can't water be easily transported directly across the phospholipid bilayer?

What is Polar (charged), so its repelled by the non polar fatty acid tails of phospholipid molecules.

How do molecules move from a high concentration to a low concentration?

Their own kinetic energy causes them to move and they bump into one another.

Describe the bacterial chromosome

There is only one and they are circular

What are endospores

They are resting structures formed by some bacteria; they allow survival during adverse environmental conditions

What is a flagella

long, hair-like structures; used for motility

What are ribosomes

not membrane- bound ; site of protein synthesis

What is nucleoid?

nuclear region; not surrounded by a membrane

what is a fimbriae?

numerous, short, thin appendages; function in adhesion , not motility.

What kind of transportation involves molecules moving from low concentration to high concentration?

Active Transport

What are 2 major types of transport proteins?

Carrier and channel proteins.

What are the different forms of passive transport?

Diffusion Facilitated Diffusion Osmosis

What kind of environment is bacterium usually in?

Hypotonic

What is an inclusion body?

Stored nutrients such as fat or glycogen deposited in dense crystals or particles

What is the name of the endotoxin in the cell envelope of the G(+) bacteria?

Teichoic Acid

What are the 3 functions of the glycocalyx?

1.protection from drying out 2.helps a cell adhere to a surface where conditions are favorable for growth 3.provides protection against phagocytosis- a slippery glycocalyx makes it difficult for the phagocyte to grab hold of the bacterium

What is the function of peripheral proteins in the plasma membrane?

Act as enzymes (catalyze chemical reactions), part of electron transport chain &/ or photosynthesis, involved in the changes in cells shape that occur during cell division, and serve as receptor sites for viruses.

What kind of transport uses carrier proteins?

Active Transport Facilitated Diffusion

How do most bacteria transport nutrients?

Active transport

How does glucose transport across the plasma membrane?

Active transport

The plasma membrane is said to behave more like fluid. Does this make transport easier or more difficult?

Easier- there is more space between molecules in the plasma membrane.

Teichoic acids are found in the cell walls of ______ cells. Teichoic acids activate the release of chemicals called ____________ from the host which causes host cell damage, septic shock and multi organ failure.

G(+) Cytokines

The outer membrane is found primarily in _____________ cells. It is composed of bilayer of phospholipids and ________________________. When bacteria die they release LPS's that act as ______________, causing fever, shock, and possibly death

G(-) lipopolysaccharides endotoxins

How does the antibiotic penicillin kill bacterial cells?

It interferes with the cell wall synthesis (the cell can no longer withstand turgor pressure and the cell lyses)

What is phagocytosis? Example?

It starts with endocytosis: the plasma mem envelopes the substance to be imported and pinches off to form a vesicle that moves into the cytoplasm; endocytic vesicles can then fuse with enzyme- containing vessicles called lysosomes to digest their contents. It ends with exocytosis; the vesicle containing the digested substance fuses with he plasma membrane and dumps its contents to the outside. WBC with a bacterial cell.

What contributes to fluidity of the membrane?

Kinks in the phospholipid tails create space in the membrane. Shorter tails keep tails from packing.Cholesterol creates space in eukaryotic plasma membranes, but cholesterol is not found in most prokaryotes except Mycoplasma is the exception.

Why is it important to know the differences between prokaryotes and eukaryotes?

Knowing the difference allows us to control disease- causing bacteria without harming our own cells. It allows us to follow the principle of selective toxicity.

A Mycoplasma cell that is in a hypotonic environment is in danger of what?

Lysing and bursting because it doesn't have a cell wall

What group of bacteria lacks a cell wall? How do they keep from lysing?

Mycoplasma- They have solute pumps in their plasma membrane to stop from hypertonic from happening and they have cholesterol in their plasma membrane. However they are still fragile and too much water can cause it to lyse.

The plasma membrane is composed primarily of _________________ molecules.

Phospholipids

What is the name of the channel protein found in the other membrane of G(-) cell envelopes?

Porin

A typical bacterial cell that is in a hypotonic environment is in danger of what?

The cell is not in any danger because the cell wall resists turgor pressure and the cell does not lyse.

Why can't glucose be transported using a channel protein?

The glucose molecule is too large to fit through channel proteins.

What does it mean when the plasma membrane is "semipermeable"?

The plasma membrane regulates what can pass through the membrane; some substances can pass through the membrane and some cannot.

What is the major function of integral proteins in the plasma membrane?

Transport

What is periplasmic flagella (axial filaments)?

bundles of flagella which wrap around the cell body between the cell wall and the other membrane; cause spirochetes to move like a corkscrew through viscous environments.