Microbial Genetics Flashcards
1
Q
What does genetics mean?
A
The study of hereditary
2
Q
What does genetics include? (4)
A
- study of genes
- gene replication
- gene products ( proteins, rRNA, tRna)
- genes from one gene expressed to another
3
Q
What does genome mean?
A
sums of the cells genetic material
4
Q
What does the genome consist of?
A
All the chromosomes of a cell & plasmids
5
Q
What does genomics mean?
A
The sequencing and molecular characterization of genomes
6
Q
Does genomics fall under the word genome ? Why?
A
Because genomics are the sequencing of genomes
7
Q
What does genotype mean?
A
Genetic makeup of cell/organism
( sequence of dna )
8
Q
What does phenotype mean?
A
Actual traits due to the expression of the genotype
( the expression of the genes as a trait )
( the trait that we get from this sequence of dna )
9
Q
If you have the gene for green eyes, would you have the genotype or phenotype? Why?
A
Genotype
- you have the literal gene of green eyes in your DNA
10
Q
If you have the ACTUAL ( physical ) green eyes, is it genotype or phenotype? Why?
A
Phenotype
- cause that gene came through and made it your ACTUAL trait ( physically )
11
Q
Most of the time, why do you get that phenotype ( from the example of green eyes )?
A
Because the genes are first transcribed to RNA then translated to proteins
Which then pretty much gives you that trait of having green eyes
12
Q
Is it easy to manipulate bacteria?
A
Yes
13
Q
What are chromosomes?
A
Physical structure that Carries the hereditary information
14
Q
What does chromosomes contain?
A
Nucleic acids ( DNA )
A, T, G, C
15
Q
What’s the shape of a chromosomes ?
A
Double stranded, helical DNA
16
Q
What template does chromosomes help make?
A
A template to make RNA
17
Q
In prokaryotes, they have how many chromosomes, what’s it shape, and may also contain? ( general )
A
One circular Chromosomes
Plasmid
18
Q
In eukaryotes, how many Chromosomes, it’s shape?
A
More than one
Linear chromosomes
19
Q
Does prokaryotes have histones?
A
No
20
Q
Does eukaryotes have histones?
A
Yes
21
Q
What are DNA and RNA made up of?
A
Nucleic acids
22
Q
What are nucleic acids made up of?
A
Nucleotides
23
Q
What is a nucleotides made up of, for DNA ?(3)
A
- nitrogenous base
- deoxyribose (sugar )
- phosphate
24
Q
What is a nucleotide made up of for rna ? (3)
A
- nitrogenous base
- ribose ( sugar )
- phosphate
25
What are the nitrogenous bases for dna ? (4)
A, T, G, C
26
What’s the nitrogenous base for RNA ?
A, U, C, G
27
What’s the dogma( rule) of genetic information?
DNA -> RNA -> PROTEINS
28
What is transcription ?
DNA -> RNA
29
What is translation ?
RNA -> protein
30
Are dna strands complimentary to each other?
Yes
31
What is the backbone of DNA?
Sugar- phosphate
Deoxyribose phosphate
32
What are the pairs for DNA?
Adenine ( A ) & Thymine ( T )
Guanine ( G ) & Cytosine ( C )
33
If you are given one strand of DNA, are you able to find the complementary strand? Why ?
Yes cause of the difference of T and U from dna to RNA
34
If you are asked to explain, what does it mean that DNA is always complimentaryto each other, what would you say ?
They always match because adenine always pairs with thymine
35
Does every strand of dna have a 5 prime and 3 prime end ?
Yes
36
What does the 5 prime end and 3 prime end mean in a dna?( think of the carbon )
The position of the carbon
37
Are we referring to which carbon is exposed to when we say 5 prime end and 3 prime end? Why?
Yes cause it’s the positioning of the carbon ( either 5 carbon or 3 carbon ) attached to sugar
38
What is the rule about 5 prime end ( carbon ) ?
That they are attached to a phosphate bond
39
How can we tell the difference in a picture, between 5 prime end and 3 prime end ?
3 prime end has an OH on the sugar
5 prime end is attached to phosphate
40
What does antiparallel strands mean ?
They are parallel
HOWEVER
they move in opposite directions
41
If one strand is going from 5 prime end to 3 prime end, does that mean the other strand starts as 3 prime end to 5 prime end? Why?
YES!!!
Because they are anti parallel
42
If they ( strands ) weren’t moving in opposite directions ( antiparallel ) would the nitrogenous bases face each other ?
No
43
Is the entire dna replication semi conservative?
Yes
44
What does semi conservative mean in dna replication?
( The entire process of dna replication )
- a parent strand acts as a template for a new daughter strand
- in which results in 2 daughter strands
45
A simple definition of semi conservative ?
- parent strand shows a template to one strand
- then another strand is brand new
46
So to conclude a semi conservative is one strand template from parent and another brand new strand ? And it results in what?
Yes, and results in 2 daughter strands
47
Does NEW dna strand always start with 5 prime end to 3 prime end?
YES!!! ALWAYSSSSS
48
For dna replication what are we mainly trying to do?
- making copies
Using a blueprint, parental, old strand
to make a brand new strand
49
What do we need to replicate dna ? ( big 3 )
Enzymes
- DNA polymerase
- Primase
- helicase
- Ligase
New nucleic tides
- A, T, G, C
New primers
50
What is opening up of dna replication called ( it looks like a zipper opening up, splitting into 2 ) ?
Replication fork
51
What is origin of replication ?
A specific location where dna replication will happen
52
What is the first step of dna replication
- helicase ( enzyme ) will unwind the parental double helix
53
What does the unwinding of the parent double helix create? ( second step )
Replication fork
54
What does the replication fork allows?
Allows for the replication of each strand
55
What is the third step of dna replication ?
Single stranded binding proteins react/ attach to stabilize the single regions
56
What is the 4th step in LEADING STRAND ?
RNA primer is given by the cell
57
What is the 5th step in LEADING strand ?
Dna polymearse III (3) gives out new nucleotides by removing the given RNA primer
58
What is the end result for LEADING strand?
A copy of the parental strand
59
Does the leading strand move continuously?
Yes
60
Does the leading strand start with 3 prime end and moves towards 5 prime end?
Yes
61
Does the leading strand move towards the replication fork?
Yes
62
Can DNA polymerase III (3) start replication?and why?
No because we need RNA primer to help us
63
Can DNA polymerase III (3) add new nucleotides to a pre existing 3 prime end?
YES, ONLY
64
What is the 4th step in LAGGING strand ?
RNA primer is placed AHEAD in order to help connect everything, in small sections
65
What is the 5th step in LAGGING strand ?
The small sections we place the rna primer, they are called OKAZAKI FRAGMENTS
66
What are the small sections called in LAGGING strand?
Okazaki fragments
- helps connects rna primer to other rna primer
67
What is the 6th step in LAGGING strand?
The dna polymerase III (3), can add new nucleotides in those small fragments from connecting one RNA primer to the other RNA primer
68
What’s the 7th step in LAGGING strand?
DNA polymerase I (1) is made when the other rna primer joins
Which removes rna for dna
69
What is the 8th step in LAGGING strand? ( what does it join )
Dna ligase joins everything together
- joins the Okazaki fragments
70
What is the end result from the LAGGING strand?
New daughter strand
71
For the lagging strand, is it moving 5 prime end to 3 prime end?
Yes
72
For the lagging strand, is it moving away from the replication fork?
Yes
73
Is the lagging strand discontinuous?
Yes
74
dna replication is semi conservative and occurs in 3 to 5 direction?
NO
it is semi conservative
HOWEVER
Moves in 5 to 3 direction
75
What is the enzyme that joins Okazaki fragments?
Dna ligase
76
An RNA primer is required to replicate both the leading and lagging strands of DNA ?
Yes!!! Always!!!
77
What is the full name for DNA polymerase?
DNA dependent DNA polymerase
78
What are the big enzymes & names that help DNA replication ? (5 )
- enzyme helicase
- RNA primer
- DNA polymerase
- Okazaki fragments
- DNA ligase
79
Where does dna replication occur in eukaryotes?
Nucleus
80
Where does dna replication occur in prokaryotes ?
Cytoplasm
81
How many replications fork are in eukaryotes? And why?
1 because they are linear
82
How many replication fork for prokaryotes? And why?
2 because it’s circular
83
What is the dogma to genetic information? and is it only cells?
Dna -> rna -> Protein
YES ONLY
84
What does transcription mean?
DNA to RNA
85
What are the 3 types of RNA?
mRNA
tRNA
rRNA
86
What does mRNA mean and function as?
Messenger
- Carries the actual information to make proteins
87
What does tRNA mean and function?
Transfer
- Carries individual amino acids to ribosomes for making new proteins
88
What does rRNA mean and function as?
ribosomal
- ribosomes contain proteins + rRNA
89
What are ribosomes needed for?
Protein synthesis
90
What are the nucleotides of RNA?
A, U, C, G
91
What is the enzyme that we need for transcription ? ( DNA -> RNA )
RNA polymerase
92
What’s the full name of RNA polymerase?
DNA dependent RNA polymerase
93
Why do we call it DNA dependent for RNA polymerase and DNA polymerase?
Because we are using a piece of DNA to make RNA or another DNA
94
What is the starting site for transcription ( DNA -> RNA ) ?
Promoter
95
What does the promoter do for RNA?
Starts matching A with U and C with G
96
When the RNA strand is about to be finished in transcription, what is the endpoint name?
Terminator
97
Once the RNA reaches the Terminotor in transcription, what happenes next?
The cell then decides weather it’s mRNA, tRNA or rRNA
98
Where does transcription occur in eukaryotic cells?
Nucleus
99
Where does transcription occur in prokaryotes?
Cytoplasm
100
What is translation?
RNA -> Proteins
101
What do we need for translation to occur? ( RNA -> Protein ) (6)
- tRNA
- mRNA
- ribosomes
- amino acids
- enzymes
- codons
102
What is the language of mRNA in?
Codons
103
How many letters are in the language for mRNA codons? And what are they?
4
A, U, C, G
104
Does transcription and translation occur in the cytoplasm for prokaryotes?
Yes
105
How many letters in a codon does it take to make 1 set?
3 letters
106
3 nucleotides make up a ?
Codon
107
How many codons can you make in total from only using 3 nucleotides? However we can’t use 3 of them, why?
64
Because 3 of them don’t make any amino acids
It’s 61
108
What are the function of codons?
To code for amino acids
109
What is the codon that Translation starts with?
AUG
110
What are the 3 codons that end translation ?( RNA -> proteins )
UAA
UAG
UGA
111
What is the name of the amino acid that AUG ( the starting of translation )makes?
Methionine
112
Why is UAA, UAG, UGA stop codons for translation?
Because we don’t have any amino acids that use that code
113
How many amino acids do we have in nature?
20
114
How many codons do we have that actually make amino acids ?
61
115
Why do we have 61 condons and not 64 ?
Because 3 of them don’t make any amino acid
116
What does redundant mean for codons?
That more than one codon codes for the same amino acids
117
Why do we have 61 codons for 20 amino acids? ( think of evolution, in case of what happenes )
In case of damage to DNA
- an evolution reprotective methods in cells
- in case of a mutation, the amino acids don’t change so who cares
118
What is a silent mutation?
- change in dna
- change in sequence of rna
However the codon is differenet but for the SAME amino acids
The protein doesn’t change ( stays the same )
119
Does silent mutation give us flexibility during dna replication?
Yes
120
What is degenerate mean in codons?
Even though they(codons) are structurally different after the mutation, they still produce the same amino acids
121
What is the 1st step to translation ( RNA -> Protein )?
Large ribosomal unit and small ribosomal unit of RNA join together
122
What is the 2nd step of translation ( RNA -> Protein )?
- The ribosomal reads the starting codon ( AUG )
- ask the tRNA to bring amino acids so it can match to AUG
- ultimately making methionine
- reads the next condon and tRNA brings amino acids to it as well
123
What’s the first tRNA site called?
P site
124
What’s the 3rd step of translation ( rna -> protein )?
Both amino acids ( starting codon and second condon ) join together and make peptide bond
125
How do we make a peptide bond in translation?
Two amino acids condons join together
126
What’s the 4th step in translation ? ( rna -> to protein )
Then the ribosome moves along and tRNA brings the amino acids and as well for the next codon
127
What’s the 5th step of translation ?
( rna to protein )
The two new amino acids are join together to make peptide bond
128
Now that we are onto the 5th step and have at least 4 amino acids, what is going to happen?
The first amino acid ever read, the starting codon, AUG, is released
129
Where is the first amino acid released from?
E site
130
What is the 6th step of translation? ( rna to protein )
Keeps repeating the same thing from step 2 to 4 until it reaches stop codon
- reading codons
- tRNA brings amino acids
- 2 amino acids make peptide bond
- one is being released after 4 amino acids
131
What is 7th step of translation? ( rna to protein )
We reach a stop codon
- UAA
- UAG
- UGA
132
What is the 8th step in translation?
( rna to protein )
Release all polypeptide to form first structure of protein
133
How many structure are in a protein? ( remember this since translation just took care of the 1st step in making protein )
4
134
Where does translation occur in eukaryotes? ( in general )
Rough endoplasmic reticulum
135
Where does translation occur in prokaryotes ?
Cytoplasm
136
How many amino acids do you make from the sequence below & why?
AUG | CCA | GGA | GUG | UAA
you make 4 amino acids
Why only 4? Because UAA is a stop codon; it doesn’t make amino acids
137
Does bacteria undergo sexual reproduction ?
No
138
Since bacteria doesn’t undergo sexual reproduction, it makes it difficult for what to occur?
Genetic variation
139
What does genetic variation mean?
We have difference in genetics
140
Why or how is genetic variation useful?
So if there is a certain thing that can kill them all, they have that variation that protects them from dying all at once
141
Since bacteria doesn’t undergo sexual reproduction, HOW do they achieve this genetic variation? ( 4 )
- mutations
- transduction
- transformation
- conjugation
142
What is mutation?
A change in the genotype ( dna sequence )
- in which will change the mRNA
BUT
not always a change in the phenotype
143
Why does a mutation not change a phenotype ?
Because we don’t always change the protein
As long as the protein is the same, the phenotype won’t change
144
What is a spontaneous mutation?
- Random, not known cause
- Error from dna replication
145
What is an induced mutation?
Cause by a mutagenic agent ( MUTAGEN )
146
What is the mutagenic agent that causes an induced mutation?
mutagen
147
We have 2 types of mutations that can occur in DNA, what are their names?( the big groups )
- point mutation or Base substitution
- frameshift mutation
148
What’s another name for point mutation?
Base substitution
149
What is a point mutation ( base substitution ) ?
One base is changed
( ONLY ONE NITROGENOUS BASE )
- example like an adenine being different
150
Can point mutations ( base substitutions ) be divided into more groups, and which ones? (3)
Yes
- silent mutation
- missense mutation
- non sense mutation
151
What is a silent mutation ?
- genetic code is degenerate
( changes dna but no change protein )
- but no change occurs in amino acid sequence
152
Does silent mutation affect both genotype and phenotype or only one? And which one?
Only one, the genotype
153
What is a missense mutation ?
- one base changes
- mRNA changes
- amino acid changes
( ONE AMINO ACID CHANGES )
154
Since the missense mutation changes ONE amino acid in the sequence does it change the entire protein?
Yes
(Changes everything & function )
155
What is nonsense mutation ?
Changed the base
Sequence in amino acid changes
Creates 1 of the 3 stop codons
156
So is nonsense mutation making a stop codon ?
Yes
157
To summarize the 3 point mutations ( base substitution )
Silent mutation
- 1 base changes
- no amino acid change
Missense mutation
- 1 base changes
- new/ different amino acid is made
Non sense mutation
- 1 base changes
- makes stop codon & no protein is made
158
What is a frameshift mutation?
Adding or deleting one or more nucleotides
159
When you are adding or removing from the DNA, what does that mean?
That means you’re adding or removing mRNA nucleotides
- which changes the entire reading frame of amino acids
- often creates a stop codon
160
What does mutagens mean?
Physical or chemical factors that cause a change in the DNA ( a mutation )
161
What are the chemicals that can cause a mutation in mutagen? (3)
Alkylating agents
Nitrous acid
Intercalating agents
162
What is the physical method that mutations can undergo for mutagens?
Radiation
163
What is a more in depth explanation of radiation in mutation ?
- ionizing ( gamma rays )
- non ionizing ( UV light )
164
What happens when the UV light hits the dna during radition for mutation to occur?
It causes thymine dimers
165
When thymine dimers come out from the UV light hitting it, what happens next in the DNA? We need to what?
Repair it
166
What type of repair do we do for the dna during radition?
Nucleotide excision repair
