Virsuses Flashcards

1
Q

What is a virus?

A

viruses are noncelullar microbes.
is a genetic element that can multiply only inside a living cell.
viruses are not alive.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is a virion?

A

structurally intricate extracellular form an encoded genome that allows virus to multiply.
the virion allows the virus to travel from one host cell to another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is capsid?

A

is a protein shell that contains the viral genome.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is a nucleocapsid?

A

the inner structure of nucleic acid plus capsid plus capsid protein in envelope viruses,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is a lytic pathway?

A

the virus redirects the host cell’s metabolism from growth to support virus multiplication and the assembly of new virions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is bacteriophage?

A

Bacterial viruses.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is a capsomers?

A

a number of individual protein molecules which the capsid is composed of.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

do viruses carry metabolic processess?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are the 5 steps of viral replication?

A

1 attachment

  1. penetration of viral nucleic acid
  2. synthesis of new viral nucleci acid and proteins
  3. assembly and packaging of new viruses
  4. cell lysis and release of new virions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is maturation phase?

A

begins as newly synthesized viral genomes become packaged inside their capsids.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what determines host specifity?

A

attachment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is a temperate virus?

A

a virus whose genome can replicate along with that of its host without causing cell death,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is a virulent virus?

A

a virus that lyses, or kills, the host cell after infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are key differences between eukaryotic and bacterial viruses?

A

(1) the entire virion of eukaryotic viruses enters the host cell,
2, eukaryotic cells contain a nucleus, where many (but not all) viruses replicate,
(3) in some eukaryotic cells, membrane-bound “viral factories,” also known as viroplasms, form to increase the rate of virion assembly and protect the process from host defenses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how does the animal virus enter the host cell?

A

entry into a host cell generally occurs by fusion with the cytoplasmic membrane or by endocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

where does viral replication happen in animal cell?

A

nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is the lysogenic cycle?

A
  1. attachment and penetration are identical to virulent viruses.
    2.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what are the outcomes of viral infection?

A

A virulent infection (or lytic infection) results in lysis of the host cell;
in a latent infection, the viral DNA exists in the host’s genome as a provirus
can convert a normal cell into a tumor cell,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

MOLECULAR BIOLOGY AND DNA REPLICATION

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

WHAT IS A GENE?

A

the functional unit of genetic information.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

WHAT IS A GENOME?

A

total complement of genetic elements.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

WHAT IS THE FUNCTION OF THE DNA WHAT DOES IT CARRY?

WHAT IS THE FUNCTION OF RNA WHT DOES IT CARRY?

A

DNA carries the cell’s genetic blueprint .

RNA, produced in transcription, carries a copy of this blueprint.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

WHAT IS A NUCLEOTIDE?

WHAT ARE THE THREE COMPONENTS OF NUCELOTIDES?

A

The monomers of nucleic acids.
has three components: a pentose sugar (either ribose in RNA or deoxyribose in DNA), a nitrogenous base, and a molecule of phosphate,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

IS DNA DOUBLE STRANDED?

A

YES

DNA is double-stranded, the strands being held together by hydrogen bonds between the bases in the two strands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

WHICH THREE CLASSES OF RNA PARTICIPATE IN PROTEIN SYNTHESIS?

A

MESSENGER RNA’s :
are single-stranded molecules that carry the genetic information from DNA to the ribosome.

TRANSFER RNA’s:
help convert the genetic information in the nucleotide sequences of RNA into a defined sequence of amino acids in proteins.

RIBOSOMAL RNA’s:
are important catalytic and structural components of the ribosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

WHAT IS REPLICATION?

A

During replication, the DNA double helix is duplicated. Replication is catalyzed by the enzyme DNA polymerase.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

WHAT IS TRANSCRIPTION?

A

The transfer of genetic information from DNA to RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

WHAT IS TRANSLATION?

A

The formation of a polypeptide using the genetic information transferred to mRNA by DNA is a process that occurs on the ribosome.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

WHERE DOES REPLICATION TAKE PLACE IN EUKARYOTES AND PROKARYOTES?

A

EUKARYOTES: replication and transcription occur in the nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

WHAT IS A CHROMOSOME?

A
main genetic element in prokaryotic cell.
containing all (or most) of the organism’s genes.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

HOW IS A CHROMOSOME DIFFERENT IN EUAKRTOIC CELLS?

A

are composed of two or more chromosomes containing linear DNA.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

WHAT IS A PLASMID?

A

are circular or linear double-stranded DNA molecules that replicate separately from the chromosome and are typically much smaller than chromosomes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

WHAT ARE SOME FUNCTIONS OF PLASMIDS?

A

plasmid genes may encode enzymes for some special metabolism that ensures survival under certain conditions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

WHAT IS A SEMICONSERVATIVE REPLICATION?

A

the two resulting double helices each consist of one new strand and one parental strand.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

WHAT IS A DNA POLYMERASE? what are its functions?

A

Enzymes that catalyze the polymerization of deoxynucleotides
function to repair damaged DNA
ARE REUIRED FOR DNA REPLICATION.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

what is a template strand?

A

DNA strand that is used to make a complementary daughter strand

37
Q

how does DNA replication proceed?

A

DNA replication always proceeds from the 5′ end to the 3′ end,.

38
Q

WHAT ARE THE STEPS IN THE CIRCULAR DNA REPLICATION?

A

1, DNA begins from the origin

39
Q

what is transcription?

A

RNA synthesis off of a DNA template—yields three main forms of RNA: messenger (mRNA), transfer (tRNA), and ribosomal (rRNA)

40
Q

what are the functions of messenger (mRNA), transfer (tRNA), and ribosomal (rRNA)?

A

mRNA encodes genetic information from the genome for the synthesis of proteins and carries this information to the ribosome.

rRNAs play both a structural and a functional role in ribosomes.
tRNAs function as the carriers of amino acids to the ribosome for protein synthesis.

41
Q

what is the three key processes of macromolecules?

A

(1) DNA replication; (2) transcription (RNA synthesis); and (3) translation (protein synthesis).

42
Q

what is translation?

A

mRNA being translated into proteins.

43
Q

what are the three types of proteins?

A

Catalytic proteins, structural proteins, and regulatory proteins.

44
Q

what is the structure of DNA?

A
the backbone of DNA is deoxyribose-phosphate.
The bases in DNA are:
Adenine
Guanine
Cytosine
Thymine
45
Q

what are some of the characterirstics of DNA?

A
double stranded
helical
complementary
hydrogen bonded
antiparallel
46
Q

what is supercoiling?

A

essential in DNA packaging

controlled by enzymes called topoisomerases

47
Q

where is DNA stored in cells?

A

DNA is stored in plasmids or the chromosome.

48
Q

what are the properties of chromosomes?

A

main genetic element

typically the largest genetic element

49
Q

what are the properties of plasmids?

A
extra chromosomal
replicates seperately
smaller than the chromosome
circular
non essential genes
50
Q

describe the process of DNA replication?

A

-semi conservative
-occurs in the 5’ to 3’ direction
begins at the origin of replication
occurs at replication forks
-bidirectional
-mediated by enzymes called DNA polymerases

51
Q

describe the process of DNA repliocation in prokaryotes

A
  • origin binding protein DNAa binds to the origin of replication, opens the DNA
  • helicase unzips the DNA strand unwinds the helix
  • single strand binding protein binds to binds to the single stranded DNA to stop it from binding together again.
52
Q

what are some characteristics of RNA transcription?

A
charcteristics of RNA :
single stranded
similar to DNA except:
uracil is used as a nitrogenous base
sugar is ribose instead of deoxyribose
-complementary to DNA template
53
Q

what are the steps in Transcription?

A

initiation
elongation
termination

54
Q

what is the bacterial ribosome and its functions?

A

the function is to bring mRNA and aminoacyl tRNA.

catalyze the formation of peptide bonds between amino acids and during translation and elongation.

55
Q

what are the three sites in the bacterial ribosome?

A

A site: initial codon recognition site, accepts incomin charged tRNA
P site: hold tRNA bound to the growing peptide chain.
E site: exit site for uncharged tRNA

56
Q

what is the DNA binding protein and its role?

A
THE GENE:
-promoter
-structural gene
-transcriptional terminator
ROLES:
-process of transcription
-regulation of transcription
57
Q

what is the interactions of proteins with nucleic acids?

A

The interaction of proteins and nucleic acid are central to translation, transcription and replication.

58
Q

what are the types of protein and nucleic acid interaction?

A

-specific
-non specific
R amino acid groups interact with nitrogenous bases of nucleic acid.
DNA interactions happen in the major groove.

59
Q

what is the structure of DNA binding protein?

A

-helix-turn-helix
the first helix is recognition helix that interacts specifically with DNA
the second helix:
stabilizing helix stabilizes the first helix.

60
Q

what are the reasons for transcriptional regulation?

A

increase effiecicy of use of cellular resources.
transcription is the first step in information flow.
amount of mRNA generally corelates to the amount of protein present.

61
Q

what are transcription factors?

how do they function?

A

1, DNA binding proteins that control the rate of gene transcription
function:
-bind to promoter regions of DNA
-alter RNA polymerase interactions with promoter regions
-activators: increase rate of transcription
-repressors: decrease rate of transcirption

62
Q

module 10 mutations

63
Q

what is Mutation?

A

is a heritable change in the base sequence of that genome, a change that is passed from the mother cell to daughter cells.

64
Q

what is genotype?

A

the nucleotide sequence of its genome

65
Q

what is phenotype?

A

the observable properties of a mutant.

66
Q

MODULE 11-13

67
Q

WHAT IS DNA SEQUENCING?

A

is the determination of the nucleotide sequence of DNA within a cell.

68
Q

WHAT ARE THE GENOMES OF PROKARYOTES?

A

CHROMOSOMES-
most bacteria and archea have one chromosome.
some bacteria have TWO chromosomes.
Plasmids are found rarely.

69
Q

WHAT ARE THE SIZES OF PROKARYPTIC GENOMES?

A

112kb smallest
16mb largest
3-4 mb for most bacteria

70
Q

WHY ARE PROKARYOTES WITH SMALL GENES NOT FREE LIVING?

A

because they have very few genes to independently produce biomass
exist in endosymbiosis of animals

71
Q

WHAT IS THE MINIMUM NUMBER OF GENES TO BE FREE LIVING?

72
Q

WHY ARE PROKARYOTES WITH LARGE GENOMES FREE LIVING ?

A

they have enough metabolic capacity to produce core componenets of biomass.
they are found in most diverse environments.

73
Q

WHAT ARE THE FUNCTIONS OF GENOMES?

A
DNA replication
transcription
translation
energy generation
signal transduction
74
Q

WHY IS EVOLUTION OF EUKARYOTES MARKED WITH ENDOSYMBIOSIS?

A

PRIMARY ENDOSYMBIOSIS- association with bacteria lead to chloroplats and mitochondria
SECONDARYENDO SYMBIOSIS- assocoaition of other eukaryotes with green or red algea

75
Q

WHAT IS THE GENOME STRUCTURE OF CHLOROPLASTS?

A

STRUCTURE:

100-200 KB IN SIZE 
LINEAR OR CIRCULAR 
MULTIPLE COPIES PER CHLOROPLAST
CONTENT:
6 rRNA COPIES
tRNA genes
chloroplast RNA polymerase
RuBisCO gene
76
Q

WHAT IS THE GENOME STRUCTURE OF MITOCHONDRIA?

A
STRUCTURE:
10-13 KB
CIRCULAR
MAY CONTAIN PLASMIDS
CONTENT:
1 SET OF rRNA genes
t RNA genes
respiratory complext genes
77
Q

WHAT IS THE SIZE AND STRUCTURE OF VIRAL GENOMES?

A
GENOMES OF VIRUSES CAN BE :
DNA 
RNA
SIZE:
DNA (1.75KB TO 2.4 MB)
RNA(1KB TO 50KB 2-40 GENES)
MOST VIRAL GENOMES ARE SMALLER THAN BACTERIA.
78
Q

WHAT TYPE OF BACTERIA VIRUSES ARE THERE?

A
bacteria viruses are DNA viruses class 1, 2 
some RNA viruses class 3 and 4
79
Q

WHAT TYPE OF ARCHEA VIRUS ARE THERE?

A
arechea virus are class 1 and 2 
DNA viruses
80
Q

what type of virus are eukarya?

A

RNA viruses 2 and 4

all classes can be found in animals

81
Q

what is class 4 iv virus? structure? and lifecycle

A
class 4 of virus us poliovirus
structure:
ssRNA +
naked virion
lifecycle:
attachment
penetration in the cytoplasm
synthesis
assembly
release
82
Q

what is class V 5 of virus genome? structure and lifecycle?

A
RHABDOVIRUS
STRUCTURE:
helical symmetry, enveloped
ssRNA- genome
lifecycle:
attachment
penetration
synthesis
assembly
release
83
Q

WHAT IS CLASS 3 VIRUS III? structure and lifecycle?

A

class 3 virus is REOVIRUS
structure:
enveloped virus
dsRNA -,+

84
Q

what is VI class 6 virus? structure and lifecycle?

A

class 6 virus is HIV
structure:
enveloped virus
ssRNA +

85
Q

WHAT CLASS IS CORORNAVIRUS?

A
class 6 virus
ssRNA+
86
Q

WHAT IS VIRIOD AND PERION?

A

Viriods- are infectious RNA found in plants
Piriods- are infectious RNA found in animals
BOTH HAVE NO CAPSID

87
Q

WHAT IS THE STRUCTURE, FUNCTION AND REPLOCATION OF VIRIODS?

A
STRCUTURE:
circular
ssRNA
double stranded
FUNCTION:
infect plants through wounds
replicate in cells
disrupts plant development
REPLICATION:
replicated by host cell RNA polymerase
88
Q

WHAT ARE PIRIONS, STRUCTURE AND FUNCTIONS?

A
STRUCTURE:
proteins translated from host genes
normal and misfolded
FUNCTION:
proteins have normal cell functions
REPLICATION:
replicated by host cells