chapter 3 microbiology

Question 1

autotrophs

Answer 1

use carbon dioxide as carbon source

Question 2

heterotrophs

Answer 2

use organic substances like sugars as their source of carbon

Question 3

binary fission

Answer 3

how bacteria reproduce. This results in a logarithmic growth rate

Question 4

phases of the bacterial growth cycle

Answer 4

lag phase, log phase, stationary phase, decline phase

Question 5

lag phase

Answer 5

Bacteria undergo a period of adaptation with vigorous metabolic activity

Question 6

log phase

Answer 6

rapid division which is determined by environmental conditions

Question 7

stationary phase

Answer 7

is reached when nutrient depletion or toxic products cause growth to slow until death rate equals the binary fission rate

Question 8

decline phase

Answer 8

decline of live bacteria

Question 9

What is end product inhibition?

Answer 9

the end product of a pathway inhibits the first enzyme of the same pathway

Question 10

catabolite repression

Answer 10

when catabolites inhibit synthesis

Question 11

what are some extracellular factors that modify bacterial growth?

Answer 11

temperature- mesophiles like 25-40C, thermophiles like 55-80 C, psychophiles like under20C
PH- 7.2-7.4 for optimal growth

Question 12

obligate aerobes

Answer 12

require oxygen to grow because their ATP generating system is dependent on oxygen as the hydrogen acceptor

Question 13

facultative anaerobes

Answer 13

use oxygen to generate energy if oxygen is present. They also can use the fermentation pathway for energy

Question 14

obligate anaerobes

Answer 14

lack superoxide dismutase or catalase so they dont need oxygen to make energy

Question 15

microaerophiles

Answer 15

work best at low oxygen concentration

Question 16

name the 2 bacterial enzymes that oxygen

Answer 16

superoxide dismutase and catalase

Question 17

replication bubble

Answer 17

strand between the replicating forks

Question 18

semiconservative replication

Answer 18

each daughter cell receives a parental strand and a newly synthesized strand

Question 19

polymerase

Answer 19

main enzyme in DNA replication

Question 20

restriction enzymes

Answer 20

cleave double stranded DNA at specific sequences thus deleting foreign nucleotides

Question 21

What is a mutation?

Answer 21

a change in a base sequence of DNA

Question 22

what is base substitution and the 3 types

Answer 22

when the incorrect base is inserted.
missense mutation is when the base substitution results in a different amino acid
nonsense mutation- base substitution results in a premature stop

Question 23

frame shift mutaiton

Answer 23

when one or more base pairs are added or deleted which shifts the reading frame and results in a inactive protein

Question 24

insertion

Answer 24

insertion of additional pieces of DNA or bases and cause profound changes in the reading frame

Question 25

what induces mutations?

Answer 25

chemicals, radiation, or viruses

Question 26

conjugation

Answer 26

mating of bacteria which is controlled by a F plasmid that creates the sex pilus

Question 27

transduction

Answer 27

transferring DNA via a virus

Question 28

generalized transduction

Answer 28

when a bacteriophage has a piece of its old hosts bacterial chromosome

Question 29

specialized transduction

Answer 29

when phage DNA that is integrated into bacterial DNA is excised and carries with it an adjacent part of bacterial DNA

Question 30

transformation

Answer 30

“natural” when a bacterium dies and another picks up some of its DNA

Question 31

transposition

Answer 31

jumps from one to another

Question 32

homologous recombination

Answer 32

2 pieces of DNA with extensive homologous regions pair up and exchange pieces by the processes of breakage and reunion

Question 33

non- homologous recombination

Answer 33

not much homology so they use a lot of enzymes inrecombination process

Question 34

plasmids

Answer 34

extrachromosomal DNA molecules. They are in both gram negative and positive bacteria

Question 35

Transmissible plasmids

Answer 35

transferred by conjugation and contain the sex pilus genes

Question 36

non transmissible plasmids

Answer 36

they dont move but can if there is another plasmid in the same bacteria that is transmissible( they pretty much catch a ride)

Question 37

what are some clinical relevance of plasmids?

Answer 37

antibiotic resistance, resistance to heavy metals, pili which mediate adherence of bacteria to epithelial cells, exotoxins

Question 38

transposons

Answer 38

“jumping genes”, Can code for metabolic or drug resistance enzymes and toxins, Need host to replicate , hide in plasmids,

Question 39

Restriction enzymes

Answer 39

break DNA at a specific nucleotide sequence. This creates a “sticky end” which can be combined with a wanted gene and incorporate it into the DNA of the host.

Question 40

DNA probes

Answer 40

radioactive markers

Question 41

PCR

Answer 41

uses Taq ( watch youtube)

Question 42

multiplex PCR

Answer 42

more than one locus are amplified with multiple primers

Question 43

Why is PCR so widely used?

Answer 43

for miniscule quantities of DNA, rapid clinical diagnostic procedures, amplification of RNA, comparison of different genomes

Question 44

genomics

Answer 44

study of identity of all genes within the chromosomes of a cell

Question 45

proteomics

Answer 45

study of proteins expressed by the genome of either an organism, cell, or tissue type.

Question 46

metabolomics

Answer 46

study of chemical processes involving metabolites of a cell or an organism