module 9 cell growth

Question 1

how do bacterial cells divide?

Answer 1

Bacterial cells divide by binary fission

Question 2

during division what new elements are being created?

Answer 2

peptidoglycan and cytoskeleton elements

Question 3

what are the key proteins involved in bacterial binary fission?

Answer 3

proteins are called Fts proteins.

Question 4

what is the role of FtsZ protein in binary fission?

Answer 4

plays a crucial role in binary fission. FtsZ is related to tubulin, the important cell-division protein in eukaryotes

Question 5

how is the divisome made?

Answer 5

division apparatus called the divisome ( place where cell division takes place)

formation begins with the formation of FtsZ in a ring around the center of the cell.
After the ring is formed other FTsZ proteins are attached to the ring FtsA and Zip A.

Question 6

what do FtsA and ZipA do?

Answer 6

ZipA is an anchor that connects the FtsZ ring to the cytoplasmic membrane and stabilizes it.

FtsA both recruits FtsZ and other divisome proteins and helps connect the ring to the cytoplasmic membrane

Question 7

what other elements are made in the divisome beside the cell replication?

Answer 7

divisome also contains Fts proteins needed for peptidoglycan synthesis

Question 8

Why does DNA replication has to happen before cell division?

Answer 8

DNA replication must coexist with cell division and must be regulated.

Question 9

what are the proteins that regulate chromosome replication and cell division?

Answer 9

Fts proteins are the proteins important for these processes.

Question 10

What happens in the early G1 and S phase?

Answer 10

• DNAa-ATP binds to the origin of replication.
• DNAa-ATP opens the double helix.
• the replisome begins replicating the chromosome.

Question 11

what happens in the S phase?

Answer 11

• chromosome replication.
• replication occurs bidirectionally.
• it begins at Ori C and finsihes at terminus.

Question 12

what determines cell morphology?

Answer 12

the cytoskeleton.

Question 13

what is the default bacteria shape?

Answer 13

sphere

Question 14

what is the divisome and what does it do?

Answer 14

a bunch of proteins that forms the septum and dividing prokaryotic cells

Question 15

what are the components of the divisome?

Answer 15

FTS proteins:
Fts Z
Fts A
Fts I
Fts A
Zip A

Question 16

what is Mre B protein? where is it located? what does it do?

Answer 16

a cytoskeletal protein in bacteria and Archea
it is located at cytoplasmic membrane
recruits other proteins for cell wall biosynthesis.

Question 17

what are the functions of elongasome components?

Answer 17

• Mre B -protein anchor
• Rod Z-protein anchor
• Rod A

Question 18

how does elongasome help rod shaped bacteria?

Answer 18

the divisome makes new peptidoglycan

Question 19

what is a vibrio shape bacteria ? what proteins are requied for this shape?

Answer 19

vibrio shape bacteria are the simplest of spiral shaped bacteria.
proteins required are MreB and crescentin like proteins

Question 20

what is the process of peptidoglycan biosynthesis?

Answer 20

• small openings are created in cell wall autolysisns
• lipid carrier called bactoprenol carries peptidoglycan units across the cytoplasmic membrne.
• new peptidoglycan is added to the existing cell wall by transglycolysis and transpeptidases.

Question 21

what is a biofilm? what are its properties?

Answer 21

colonies of bacteria attached to a surface.

• cells have heterogenous metabolic and morphological sites.
• matrix prevents the diffiusin of molecules.
• it is a highly social environment
• common mode of growth.

Question 22

what are the stages of biofilm development?

Answer 22

• attachment
• colonization
• development
• active dispersal

Question 23

what signals control biofilm development?

Answer 23

-Intracellular signals
cyclic-di-GMP
cAMP
-extracellular signals
autoinducer levels

Question 24

what are antibiotics? what do they do?

Answer 24

are antimicrobials naturally produced by bacteria

• kill or inhibit microbial growth
• target important molecular processes

Question 25

what major bacterial cellular processes are targeted by antibiotics?

Answer 25

-cytoplasmic membrane
-cell wall
-chromosomes
-RNA polymerase
-DNA gyrase
-

Question 26

what is persistance in bacteria? why are these bacteria not affected?

Answer 26

-bacteria tht are not affected by antibiotics
-they are not affected because most antibiotics work on negatively growing cells
-

Question 27

MODULE 10

Question 28

WHAT IS MUTATION?

Answer 28

heritable change in the nucleotide base of organisms.

Question 29

what is wild type genome and mutant?

Answer 29

wild type is a genome isolated from nature.

mutant is an alteration in the nucleotide base from the wild type.

Question 30

describe genotype vs phenotype?

Answer 30

genotype- the sequence of nucleotides in a genome

phenotype- observable trait

Question 31

what are ways mutations happen?

Answer 31

happens in two ways:
spontaneous mutations:
-occurs without external intervention
-mistakes during DNA replication
induced mutation 
-caused environmentally
-cause from being exposed to natural radiation and chemicals