Exam 1 - Lecture 2

Question 1

what name is given to sphere-shaped bacteria?

Answer 1

coccus/cocci

Question 2

what name is given to rod-shaped bacteria?

Answer 2

bacillus/bacilli

Question 3

describe diplococci

Answer 3

pairs of cocci

Question 4

describe streptococci

Answer 4

chains of cocci

Question 5

describe staphylococci

Answer 5

grape-like clusters of cocci

Question 6

describe a tetrad

Answer 6

4 cocci in a square

Question 7

describe sarcina

Answer 7

8 cocci in a cube formation

Question 8

describe streptobacilli

Answer 8

chains of bacilli

Question 9

describe coccobacilli

Answer 9

very short rods

Question 10

describe vibrios

Answer 10

curved rods/crescent shaped

Question 11

describe a spirillum

Answer 11

a short, rigid helix (looks like a curly hair)

Question 12

describe spriochetes

Answer 12

long, flexible helix (long curly hair)

Question 13

what is mycelium?

Answer 13

network of long, multinucleate filaments (network of hyphae)

Question 14

define pleiomorphic

Answer 14

having many forms or shapes

Question 15

order these organisms in order of genome size (smallest to largest)

• viruses
• eukaryotes
• prokaryotes

Answer 15

smallest
- viruses
- prokaryotes
- eukaryotes
largest

Question 16

true or false: small cell size decreases surface-to-volume ratio

Answer 16

false, small cell size increases surface-to-volume ratio

Question 17

which has a bigger surface-to-volume ratio: spheres or rods?

Answer 17

rods

Question 18

what are two things that increase surface-to-volume ratio?

Answer 18

convolutions and microvilli

Question 19

what are the common layers of bacterial cells?

Answer 19

• cytoplasm
• cell envelope
• external structures

Question 20

what are the three components of the bacterial cell envelope?

Answer 20

• plasma membrane
• cell wall
• capsule or slime layer

Question 21

which component of the cell envelope is an absolute requirement for all living things?

Answer 21

the plasma membrane

Question 22

what are the functions of the plasma membrane?

Answer 22

• encompasses the cytoplasm
• selectively permeable barrier
• interaction with external environment
• metabolic processes

Question 23

what is the fluid mosaic model of the plasma membrane?

Answer 23

lipid bilayer with proteins (half lipids, half proteins)

Question 24

what characteristic is defined as having both hydrophobic and hydrophilic ends, like membrane phospholipids?

Answer 24

amphipathic

Question 25

what percent of membrane proteins are peripheral proteins, and what percent are integral proteins?

Answer 25

20-30% peripheral, 70-80% integral

Question 26

which membrane proteins are amphipathic?

Answer 26

integral proteins

Question 27

which are more fluid: saturated or unsaturated lipids?

Answer 27

unsaturated

Question 28

what are the sterol-like proteins that are present in the bacterial membrane?

Answer 28

hopanoids

Question 29

what are common examples of growth factors needed by bacteria?

Answer 29

- amino acids - purines and pyrimidines - vitamins - heme

Question 30

what is passive diffusion?

Answer 30

molecules move from one region of higher concentration to one of lower concentration between the cell's exterior and interior - H2O, CO2, and O2 often use this method

Question 31

what are four transport mechanisms microorganisms use to get most of their nutrients?

Answer 31

- facilitated diffusion - active transport - group translocation (bacteria and archaea only) - endocytosis (eukarya only)

Question 32

what mode of transportation typically involves carrier proteins and is not energy dependent?

Answer 32

facilitated diffusion

Question 33

describe active transport

Answer 33

- energy-dependent process (ATP or proton-motive force) - moves molecules against the concentration gradient

Question 34

what are the three types of active transport?

Answer 34

- primary active transport - secondary active transport - group translocation

Question 35

what do primary active transporters need? what is another name for primary active transporters?

Answer 35

- ATP (energy) - ATP-binding cassette (ABC) transporters (uniporter)

Question 36

what do secondary active transporters use to cotransport substrates (like protons, sodium ions, etc.)?

Answer 36

ion gradients

Question 37

what are the two types of cotransporters?

Answer 37

- symporter (two substances move in the same direction) - antiporter (two substances move in opposite directions)

Question 38

what is group translocation?

Answer 38

energy dependent transport that chemically modifies molecules as it's brought into the cell (i.e., phosphorylation)

Question 39

how do microorganisms take up iron?

Answer 39

they secrete siderophores that complex with the iron and brings the iron into the cell

Question 40

what are the functions of the cell wall?

Answer 40

- maintain the shape of the bacteria - helps protect the cell from osmotic lysis - helps protect from toxic substances - may contribute to pathogenicity

Question 41

which stains purple, which stains pink? - Gram-negative - Gram-positive

Answer 41

- purple: Gram-positive - pink: Gram-negative

Question 42

which has a thicker peptidoglycan layer: Gram-positive or Gram-negative?

Answer 42

Gram-positive

Question 43

which has a thinner periplasmic space: Gram-positive or Gram-negative?

Answer 43

Gram-positive

Question 44

what is the major component of the bacterial cell wall?

Answer 44

peptidoglycan

Question 45

what is the area between the plasma membrane and peptidoglycan called?

Answer 45

the periplasmic space/periplasm

Question 46

describe the structure of peptidoglycan

Answer 46

- alternating NAM and NAG sugars - peptide strands of alternating D- and L- amino acids - NAM has the peptide chain coming off of it

Question 47

what kind of structure do peptidoglycan monomers form?

Answer 47

a helical structure

Question 48

what kind of linkage do the peptidoglycan chains have in E. coli?

Answer 48

direct linkage

Question 49

what kind of linkage do the peptidoglycan chains have in S. aureus?

Answer 49

indirect linkage