Unit 1 Ch 2 - Microbial Cell Structure and Function

Question 1

Archaellum

Answer 1

a long, thin cellular appendage present in many Archaea that rotates and is responsible for swimming motility

Question 2

Basal body

Answer 2

the ‘motor’ portion of the bacterial flagellum, embedded in the cytoplasmic membrane and cell wall

Question 3

Capsule

Answer 3

a polysaccharide or protein outmost layer, usually rather slimy, present on some bacteria

Question 4

Chemotaxis

Answer 4

directed movement of an organism toward (positive chemotaxis) or away from (negative chemotaxis) a chemical gradient

Question 5

Chloroplast

Answer 5

the photosynthetic organelle of phototrophic eukaryotes

Question 6

Cristae

Answer 6

the internal membranes of a mitochondrion

Question 7

Cytoplasmic membrane

Answer 7

the permeability barrier of the cell, separating the cytoplasm from the environment

Question 8

Cytoskeleton

Answer 8

the cellular scaffolding typical of eukaryotic cells in which microtubules, microfilaments and intermediate filaments define the cell’s shape

Question 9

Dipicolinic acid

Answer 9

a substance unique to endospores that confers heat resistance on these structures

Question 10

Endospore

Answer 10

a highly heat-resistant, thick-walled, differentiated structure produced by certain gram-positive Bacteria

Question 11

Flagellum

Answer 11

a long, thin cellular appendage that rotates (in Bacteria) or has a whiplike motion (in Eukarya) that is responsible for swimming motility

Question 12

Gas vesicles

Answer 12

gas-filled cytoplasmic structures bounded by protein and conferring buoyancy on cells

Question 13

Histones

Answer 13

highly basic proteins that compact and wind DNA in the nucleus of eukaryotic

Question 14

Hydrogenosome

Answer 14

an organelle of endosymbiotic origin present in certain microbial eukaryotes that oxidizes pyruvate to H2, CO2 and acetate, and couples this to ATP synthesis

Question 15

Intermediate filament

Answer 15

a filamentous polymer of fibrous keratin proteins, supercoiled into thicker fibers, that functions in maintaining cell shape and the positioning of certain organelles in the eukaryotic cell

Question 16

Lipopolysaccharide (LPS)

Answer 16

a combination of lipid with polysaccharide and protein that forms the major portion of the outer membrane in gram-negative Bacteria

Question 17

Lysosome

Answer 17

an organelle containing digestive enzymes for hydrolysis of proteins, fats and polysaccharides

Question 18

Magnetosome

Answer 18

a particle of magnetite (Fe3O4) enclosed by a nonunit membrane in the cytoplasm of magnetotactic Bacteria

Question 19

Meiosis

Answer 19

the nuclear division that halves the diploid number of chromosomes to the haploid

Question 20

Microfilament

Answer 20

a filamentous polymer of the protein actin that helps maintain the shape of a eukaryotic cell

Question 21

Microtubule

Answer 21

a filamentous polymer of the proteins (alpha)-tubulin and (beta)-tubulin that functions in eukaryotic cell shape and motility

Question 22

Mitochondrion

Answer 22

the respiratory organelle of eukaryotic organisms

Question 23

Mitosis

Answer 23

nuclear division in eukaryotic cells in which chromosomes are replicated and partitioned into two daughter cells during cell division

Question 24

Morphology

Answer 24

the shape of a cell - rod, coccus, spirillum and so on

Question 25

Nucleus

Answer 25

the organelle that contains the eukaryotic cell’s chromosomes

Question 26

Outer membrane

Answer 26

a phospholipid- and polysaccharide-containing unit membrane that lies external to the peptidoglycan layer in cells of gram-negative Bacteria

Question 27

Peptidoglycan

Answer 27

a polysaccharide composed of alternating repeats of N-acetylglucosamine and N-acetylmuramic acid arranged in adjacent layers and cross-linked by short peptides

Question 28

Periplasm

Answer 28

a gel-like region between the outer surface of the cytoplasmic membrane and the inner surface of the lipopolysaccharide layer of gram-negative Bacteria

Question 29

Peritrichous flagellation

Answer 29

having flagella located in many places around the surface of the cell

Question 30

Phototaxis

Answer 30

movement of an organism toward light

Question 31

Pili

Answer 31

thin, filamentous structures that extend from the surface of a cell and depending on type, facilitate cell attachment, genetic exchange or twitching motility

Question 32

Polar flagellation

Answer 32

having flagella emanating from one or both poles of the cell

Question 33

Poly-(beta)-hydroxybutyric (PHB)

Answer 33

a common storage material of prokaryotic cells consisting of a polymer of (beta)hydroxybutyrate or another (beta)-alkanoic acid or mixtures of (beta)-alkanoic acids

Question 34

S-layer

Answer 34

an outermost cell surface layer composed of protein or glycoprotein present on some Bacteria and Archaea

Question 35

Stroma

Answer 35

the lumen of the chloroplast, surrounded by the inner membrane

Question 36

Teichoic acid

Answer 36

a phosphorylated polyalcohol found in the cell wall of some gram-positive Bacteria

Question 37

Thylakoid

Answer 37

a membrane layer containing the photosynthetic pigments in chloroplasts