Chapter 3

Question 1

What is glycocalyx

Answer 1

a slimy substance that adheres to the outside of the cell wall

Question 2

What are the other two names for the same structure

Answer 2

capsule-thick layer

slime layer- thin layer

Question 3

Name three possible functions of glycocalyx

Answer 3

1. protect the cell from dehydration when the environment dries up.
2. allows the bacteria to attach to tissue, which can then be invaded.
3. protection against phagocytosis by white blood cells increasing the survival of the cell in the human body

Question 4

What are the functions of the cell wall

Answer 4

1. Its rigid structure maintains cell shape.
2. Provides protection from the environment.
3. also provides protection from osmotic pressure.

Question 5

How do some antibiotics and lysozyme work on the cell wall

Answer 5

Bacteria produce enzymes to reseal breaks in the peptidoglycan cell wall that occurs during normal growth and division. Penicillin binds to enzymes, inactivating the enzymes
Lysozyme is an enzyme found in tears it digests peptidoglycan

Question 6

Describe the structure of peptidoglycan

Answer 6

Is composed of two major subunits: alternating glycan molecules plus tetrapeptide chains

Question 7

Glycan molecules

Answer 7

a simple sugar connected to an amino acid, there are two types: NAG, NAM

Question 8

Gram Positive

Answer 8

a thick homogenous sheath of peptidoglycan ranging from 20-80nm and forms about 90% of the cell wall it also contains techoic acid

Question 9

Gram Negative

Answer 9

more complex than gram positive, contains two layers: periplasm space and outer membrane

Question 10

Periplasm space

Answer 10

region between the cell membrane and the outermembrane, composed of a layer of periplasm and peptidoglycan

Question 11

Outer membrane

Answer 11

consists of bilayer structure: one layer is composed of phospholipids and other macromolecules, the outer layer is made of Lipopolysaccharide forms outer sheath of membrane

Question 12

Porin proteins

Answer 12

allow specific molecules to pass and will shut off when the cell is threatened

Question 13

Where is techoic acid found

Answer 13

gram positive cell wall which is a complex molecule that contains amino acids

Question 14

Where is the outer membrane found and what does it do

Answer 14

in the gram negative cell wall and it acts as a barrier

Question 15

Name the molecules that are found on the outer cell membrane

Answer 15

composed of phospholipid bilayer with proteins embedded in the bilayer

Question 16

Integral proteins

Answer 16

Mainly involved in transport

Question 17

Carrier protein

Answer 17

bind to specific substances and transport them across the cell membrane

Question 18

Channel protein

Answer 18

opening which allows small, water soluble substances to go across the membrane

Question 19

Function of cell membrane

Answer 19

serves as barrier to molecules using selectively permeable and enzymes embedded within the cell membrane help with anabolic chemical reactions including synthesis of the cell wall and appendages and catabolic pathway such as electron transport chain

Question 20

Describe how mycoplasma has adapted without cell wall

Answer 20

it pumps ions (Na) out of the cell to keep turgor pressure equal inside and outside the cell…prevents lysis from occurring, cell membranes are strengthened by adding cholesterol, usually found in some eukaryotic cells

Question 21

What is a flagella

Answer 21

long, thin, rigid hair-like appendages composed of protein

Question 22

What does flagella do

Answer 22

it rotates 360* at nearly 2000rpm it causes the cell itself to slowly spin in the opposite direction it provides a way for bacteria to locomote

Question 23

Composition of flagella

Answer 23

filament, hook, two rings

Question 24

Filament

Answer 24

the long tube-like structure

Question 25

Hook

Answer 25

the filament is inserted into hook

Question 26

Two rings

Answer 26

hook inserted here, provides the anchor for the filament and the hook has one ring is attached to the cell membrane and the other ring is attached to the cell wall

Question 27

Can bacteria have more than one flagella

Answer 27

yes bacteria can have one or more these can be arranged in many different ways

Question 28

monotrichous

Answer 28

single flagellum at one end of the cell

Question 29

amphitrichous

Answer 29

single flagellum at each end

Question 30

lophotrichous

Answer 30

a tuft of many flagella at one end

Question 31

peritrichous

Answer 31

flagella located on many sides of the bacterial cell

Question 32

In what bacteria are flagella found

Answer 32

in all spirilla, half of the bacilli, and a few coccus

Question 33

Fimbriae

Answer 33

short but numerous tubes composed of protein, have a tendency to stick to surfaces and to others

Question 34

Function of fimbriae

Answer 34

adhere to epithelial cells, allowing the cells to invade the tissues

Question 35

Pilus

Answer 35

long, less numerous hollow, tubular structures, found in gram negative bacteria and some gram positive bacteria, long pilus tube links the cytoplasm of one bacteria with the cytoplasm of another bacteria of the same species

Question 36

functions of pilus

Answer 36

are used to exchange small amounts of circular DNA called plasmids between cells in a process called conjugation

Question 37

where is fimbriae found

Answer 37

in E. coli it invades the intestine by clinging to epithelial cells lining the intestines

Question 38

where is pilus found

Answer 38

in gram negative and some gram positive bacteria

Question 39

How many chromosomes do bacteria have

Answer 39

a single, double stranded, circular piece of DNA

Question 40

How many genes are found in a bacteria

Answer 40

3000 to 4000 genes

Question 41

How many genes are found in a human cell

Answer 41

25000 to 32000

Question 42

What are plasmids

Answer 42

very small circular pieces of DNA that are not essential for bacterial growth and cell maintenance

Question 43

where are plasmids found

Answer 43

they are free floating and are not attached to the cell membrane they can however incorporate themselves into a bacterial chromosome on occasion

Question 44

plasmid function

Answer 44

can provide information that can be helpful to survival, but not essential: resistance to drugs, production of toxins, and production of enzymes

Question 45

70S ribosomes

Answer 45

the only true organelle found within a prokaryotic cell, 15,000 are found in the protoplasm of the cell

Question 46

Macromolecule composition

Answer 46

ribosomal RNA-60% and proteins- 40%

Question 47

Are prokaryotic cells and eukaryotic cells the same

Answer 47

no prokaryotic cells have 30s subunit, 50s subunit=70s and eukaryotic has 40s subunit, 60s subunit=80s

Question 48

70s ribosome function

Answer 48

are used for protein synthesis

Question 49

cytoplasmic inclusions

Answer 49

are small, membrane bound structures that will contain various substances they contain energy rich organic substances-- produced in times of plenty and used when the environment is low in energy sources and contains gases used in buoyancy and floatation

Question 50

Granules

Answer 50

areas within a cell that contains inorganic crystals, but are not membrane bound

Question 51

granules function

Answer 51

stores important resources that are essential elements(sulfur, phosphorous) in building macromoleculs

Question 52

Who produces endospores

Answer 52

only some gram-positive rods will produce, Bacillus and Clostridium

Question 53

When are endospores produced

Answer 53

when conditions become unfavorable for further bacterial growth and the survival of the bacteria is in question

Question 54

What is an endospore

Answer 54

is a small, protected, dormant bacteria that will germinate under favorable growth conditions into a new bacterial cell. It cannot divide or degrade compounds for energy or synthesize cell components until it has germinated into a new bacterial cell. It is genetically identical to the cell that produced it

Question 55

Spore coat

Answer 55

this outer layer provides a nearly impervious barrier to many chemicals

Question 56

cortex

Answer 56

this middle layer contains many calcium salts and dipicolinic acid this layer keeps the core very dry it prevents water from reaching core

Question 57

core

Answer 57

this is the innermost layer contains the bacterial chromosome