Microbiology Chapters 7,8, And 9 (T2)

Front 1

What is the Central dogma?

Back 1

the flow of information in the cell

Front 2

Describe the basics of the central dogma

Back 2

the information contained in DNA flows into new DNA after replication, into mRNA after transcription, and the information in mRNA becomes proteins during translation

Front 3

DNA

Back 3

deoxyribonucleic acid, double stranded molecule with the sugar and phosphate groups on the outside and the nitrogeneous bases, adenine, guanine, cytosine, and thymine in between the sides

Front 4

What particular way are the bases always paired?

Back 4

A binds T and G binds C (We say that the bases are complementary)

Front 5

What are antiparallel strands?

Back 5

when the two strands have direction and they run in opposite directions

Front 6

What is the leading strand set to?

Back 6

5' to 3'

Front 7

What is the lagging strand set to?

Back 7

3' to 5'

Front 8

The process of doubling the DNA is called

Back 8

replication, semi-conservative, mean one strand is original and one strand is new.

Front 9

What are the steps in replication regulated by?

Back 9

a number of enzymes

Front 10

What is step 1 of DNA replication?

Back 10

unwinding of the helix is done by helicase. These open and unzip the double stranded molecule

Front 11

What is step 2 of DNA replication?

Back 11

When the strands are separated polymerase comes in to generate a complementary strand "calling" the correct base to pair up with its correspondent complement on the open strand

Front 12

What is step 3 of DNA replication?

Back 12

The strand called leading strand, synthesizes its complementary strand continuously. The lagging strand synthesizes its complement holes. The pieces formed are called Ogazaki fragments

Front 13

What is step 4 of DNA replication?

Back 13

Once the DNA is replicated you have doubled it with perfect precision and is called semi-conservative because the daughter molecule has one old strand and one new strand

Front 14

Transcription

Back 14

the process of making a copy of DNA information into form usuable by the ribosomes

Front 15

Where does transcription occur?

Back 15

cytoplasm

Front 16

What are the 3 stages of transcription?

Back 16

1. initiation
2. elongation
3. termination

Front 17

initiation

Back 17

uses a sigma factor and melts some DNA

Front 18

elongation

Back 18

where sigma factor falls off and bases are added complementing the DNA lagging strand base sequence

Front 19

termination

Back 19

where a terminator is encountered and the mRNA falls off

Front 20

What transcript is produced during transcription is:

Back 20

a single stranded molecule called mRNA

Front 21

What does polymerase do in transcription?

Back 21

it "reads" the bases on the lagging strand of the DNA and makes a complementary strand using almost the same bases.

Front 22

In mRNA the bases are:

Back 22

adenine, guanine, cytosine, and uracil.

Front 23

When an A is encountered in the DNA the complementary base used for the messenger RNA is:

Back 23

U (uracil) not T (thymine)

Front 24

What is the process of transcription in a eukaryotic cell?

Back 24

this transcript(copy) leaves the nucleus through the nuclear pores and goes to the cytoplasm where it interacts with the ribosomes to produce proteins in the process know as translation.

Front 25

Translation

Back 25

the process by which the sequence of bases in the molecule of mRNA is "interpreted" to make it into protein.

Front 26

The transcript is read into groups of three bases. This group is called

Back 26

codon

Front 27

With four bases, how many combinations are possible with the genetic code?

Back 27

64

Front 28

What is the initiation codon?

Back 28

AUG

Front 29

What does the initiation codon do?

Back 29

it starts the process and codes for methionine

Front 30

What are the three stop codons?

Back 30

UAA, UAG, and UGA

Front 31

What do stop codons do?

Back 31

end the process

Front 32

What do the other 60 codons do?

Back 32

they are code for different amino acids

Front 33

The process of translation takes place in what three stages?

Back 33

1. initiation
2. elongation
3. termination

Front 34

What three components does the process require?

Back 34

1. the ribosome with its two subunits and its rRNA make up
2. the mRNA that brings the message of what needs to be made
3. the tRNA that brings to the growing chain the correct amino acid to match the codon being read

Front 35

What does tRNA carry on its "body"?

Back 35

an anticodon and an amino acid

Front 36

What is an Anticodon?

Back 36

three bases that complement the three bases in the mRNA codon

Front 37

What does proper translation depend on?

Back 37

a proper reading frame

Front 38

How can microbes learn to sense the environment for protein production?

Back 38

using signal transduction and quorum sensing strategies

Front 39

What are the controls used for the regulation of proteins production related to?

Back 39

the kinds of enzymes found in living cells

Front 40

What are the three kinds of enzymes that will be regulated using different mechanisms?

Back 40

constitutive enzymes, inducible enzymes, and repressible enzymes

Front 41

Constitutive enzymes

Back 41

enzymes that the cell makes all the time.

Front 42

Inductible enzymes

Back 42

enzymes whose activity depends on the presence of a substance that promotes activity

Front 43

Repressible enzymes

Back 43

enzymes whose production can be stopped by the presence of a repressor

Front 44

In eukaryotic organisms, what are examples of other regulatory mechanisms?

Back 44

*1. tight packaging of the DNA with histones
2. transcription factors
3. splicing of RNA
4. translation controls like mRNA breakdown

Front 45

What are mutations?

Back 45

changes in the sequence of DNA

Front 46

What are spontaneous mutations?

Back 46

mutations that happen in nature (about 1 million)

Front 47

How can mutations be induced?

Back 47

chemicals, UV light, and a variety of other factors

Front 48

Mutations can include?

Back 48

1. substitution
2. deletions
3. insertions

Front 49

substitutions

Back 49

one base in place of the right one (ex. sickle cell anemia)

Front 50

deletions

Back 50

removal of a base

Front 51

insertions

Back 51

addition of a base

Front 52

What do deletions and insertions modify?

Back 52

the reading frame of the transcript, and may or may not be fatal

Front 53

What can substitutions change?

Back 53

the protein and therefore the function, or cause no change at all depending on the codon generated

Front 54

What can DNA be altered by?

Back 54

viruses that incorporate foreign piece of DNA into the cell

Front 55

What are Examples of altered DNA?

Back 55

TMV in plants and AIDS, Ebola and SARS in people

Front 56

How can Mutations be corrected?

Back 56

by proof-reading, excision repair, dark-light repair mechanisms, polymerases editing, etc.

Front 57

*What can Mutations be selected?

Back 57

for either directly (grown on agar and counted) or indirectly (by replica plating on antibiotic-enriched media

Front 58

DNA transfer mechanisms

Back 58

Bacterial cells can modify their DNA sequences by a variety of processes. These processes involve horizontal transfer. We can use these processes to generate products for the use in medical treatments.

Front 59

Bacteria can modify their DNA using:

Back 59

1. Transformation
2. Transduction
3. Conjugation
4. Plasmids
5. Transposons

Front 60

Transformation

Back 60

incorporation of foreign naked DNA into the bacterial genome (about 20 genes)

Front 61

Transduction

Back 61

uses a bacterial virus (phage) as the carrier of foreign DNA and infects the bacterium(it can be lytic or lysogenic) (small fraction of the chromosome)

Front 62

*Conjugation

Back 62

the exchange of genetic material between two bacterial cells that come in physical contact forming a "bridge" for the transfer to occur. It requires a sex pilus and the presence of the F plasmid. This can transfer chromosomal or plasmid DNA.

Front 63

*Plasmids

Back 63

independent, circular forms of DNA in bacterial cells that replicate independent of the chromosome and can confer resistance to antibiotics or the ability to carry out conjugation (diversity of effects)

Front 64

Transposons

Back 64

elements that can "jump" from one location in the genome to another(first reported in maize by Barbara McClintock)

Front 65

What have we been able to do with what we know about DNA replication, transcription, and translation?

Back 65

1. understand cell/ organismal development in higher organisms
2. develop cloning techniques
3. understand and characterize
4. tumor suppressor genes
5. study mutations to better understand breast cancer
6. avoid carcinogens
7. pharmaceuticals: vaccine production, hormones, diagnostic test
8. forensics
9. gene therapy
10. agriculture: modified crops and animals