module 1-1 part B

Question 1

the plasma membrane contains lipid and proteins:

Answer 1

lipids form bilayer
proteins are imbedded or associate with lipids

Question 2

lipid
polar ends:
nonpolar ends:

Answer 2

polar: hydrophilic, interact with water
nonpolar: hydrophobic, insoluble to water (fatty acid tails)

Question 3

loosely associated with the membrane and easily removed

Answer 3

peripheral proteins

Question 4

embedded within the membrane and not easily removed

Answer 4

integral proteins

Question 5

separation of cell from its environment
selectively permeable barrier

Answer 5

functions of the plasma membrane

Question 6

granules of organic or inorganic material that are stockpiled by the cell for future use
-some are inclosed by single-layered membrane

Answer 6

inclusion bodies

Question 7

complex structures consisting of protein and RNA

Answer 7

ribosomes

Question 8

site of protein synthesis!

Answer 8

ribosomes

prokaryotic: 70S
eukaryotic: 60S

Question 9

irrregular shaped
location of chromosome
not membrane bound

Answer 9

nucleoid

Question 10

describe the prokaryotic chromosome:

Answer 10

closed circle, double stranded DNA molecule

looped and coiled

Question 11

describe unusual nucleoids:

Answer 11

-some prokaryotes have <1 chromosome
-some have chromosomes that are linear doubled-stranded DNA instead of circular

Question 12

these are small, closed circular DNA molecules that exist and replicate independently of chromsomes

-not required for growth and reproduction
-carry genes for selective advantage (drug resistance)

Answer 12

plasmids

Question 13

provides shape to cell, protects from osmotic lysis, toxic substances

Answer 13

cell wall

Question 14

cell walls of bacteria are divided into two major groups dependings on gram-stain

Answer 14

gram positive: purple and think peptidoglycan

gram negative: pink and 2 portions to cell wall (outer membrane and thin peptidoglycan) also has periplasmic space

Question 15

gap between plasma membrane and cell wall. this is found in:

gap between plasma membrane (aka peptidoglycan) and outer membrane. this is found in:

Answer 15

1. gram +
2. gram -

Question 16

substances that occupy periplasmic space

Answer 16

periplasm

Question 17

found in periplasm of gram - bacteria

functions include:
1. nutrient acquisition
2. electron transport
3. peptidoglycan synthesis
4. modification of toxic compounds

Answer 17

periplasmic enzymes

Question 18

these are secreted by gram positive bacteria

perform the same functions of periplasmic enzymes

Answer 18

exoenzymes

Question 19

important component of both gram - and + bacteria:

polysaccharides formed from these subunits.

what are the two alternating sugars that form the backbone:

Answer 19

peptidoglycan structure

2 sugars:
NAG (N-acetylglucosamine)
NAM (N-acetylmuramic acid)

Question 20

gram positive structure has what that connects the amino acids in the peptide portion

Answer 20

peptide interbridge

Question 21

gram positive cell walls are composed primarily of peptidoglycan. they also contain large amounts of _______. this forms an anchor

Answer 21

teichoic acids

Question 22

polymers of glycerol or ribitol joined by phosphate groups

Answer 22

teichoic acids

Question 23

gram negative cell walls consist of a (thin/thick) peptidoglycan surrounded by an ______ _______

Answer 23

thin
outer membrane

Question 24

the outer membrane in gram negative is composed of:

they do not have:

Answer 24

lipids, lipoorteins, and LPS (lipoolysaccharides)

no teichoic acids

Question 25

these connect outer membrane to the peptidoglycan in gram negative bacteria

Answer 25

braun’s lipoproteins

Question 26

sites of direct contact (possibly true membrane fusions) between plasma membrane and outer membrane) in gram negative bacteria

substances may move directly into cell thru adhesion sites

Answer 26

adhesion sites

Question 27

LPS (lipopolysaccharides) consist of 3 parts:

Answer 27

lipid A
core polysaccharide
O side chain (o antigen)

Question 28

importance of LPS

1. protection from host defense=
2. contributes to negative charge on cell surface=
3. helps stabilize outer membrane structure:
4. can act as an endotoxin=

Answer 28

1. O antigen
2. core polysaccharide
3. lipid A
4. lipid A

Question 29

this is more permable that the plasma membrane due to the presence of porin proteins and transporter proteins

Answer 29

outer membrane in gram negative bacteria