chap 8 Flashcards

1
Q

*genetics

A

study of what genes are,
how they carry information,
how infomation is expressed,
how genes are replicated

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

*gene

A

a segment of DNA encodes a functional product = protein

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

*chromosome

A

containing DNA that physically carries hereditary information; contain the genes

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

*genome

A

every DNA in cell. all the genetic information in the cell

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

plasmid

A

extra piece of chromosomal self-replicating structure in bacterial cells that carries genes; not essential for cell growth

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

*genomics

A

molecular study of genomes

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

*genotype

A

genes of an organism

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

*phenotype

A

expression of the genes

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

horizontal transfer

A

transfer genes from parent cell to daughter cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

DNA structure:

Polymer of nucleotides

A

adenine, thymine, cytosine, guanine

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

DNA structure:

double helix

A

associated with proteins

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

DNA structure:

backbone is

A

deoxyribose-phosphate

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

DNA structure:

  • strands are held together by
  • stands are:
A
  • hydrogen bonds
    between A=T and C=G
  • antiparallel
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

DNA replicates

A

semiconservative

half

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

DNTP=Deoxy Nucleotide Tri Phosphate serves as;

A

DNTP serves as energy source and building blocks for DNA replication

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

DNA is copied by;

A

DNA polymerase = make polymers, cannot start a new strand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q
DNA polymerase (many issues)
copies RNA from DNA template
A
  • 5’ to 3’ direction
  • initiated by RNA primer
  • leading strand is synthesized continuously
  • lagging strand is synthesized discontinuously
  • Okazaki fragments
  • RNA primers are removed and Okazaki fragments joined by a DNA polymerase and DNA ligase(=tie pieces together)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

DNA Ligase

A

= glue bottle = makes covalent bonds to join DNA strands; joins Okazaki fragments and new segments in expression repair

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

DNA Gyrase

A

relaxes supercoiling ahead of the replication fork

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

Helicase

A

“un-zip” unwinds double stranded DNA

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

RNA Primase

A

RNA polymerase that makes RNA primers from a DNA template

Enzyme adds…“un-zip”

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

bacterial DNA replication:

bidirectional

A

Topoisomerase remove supercoils in DNA molecule

flattens, uncoils, keep off making knots

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

bacterial DNA replication:

DNA is methylated = functional maturation

A
  • bacteria methylate Adenine
  • methylation plays ole in variety of processes;
    control of genetic expression,
    initiation of DNA replication
    protection against viral infection
    repair of DNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

DNA replication: Eukaryotes

bacteria start top, goes around

A
similar to bacterial replication
difference:
- use 4 DNA polymerases
- thousands of replication origins
- shorter Okazaki fragments
- plant and animal cells methylate only cytosine bases
25
Q

relationship between Genotype and Phenotype

A
  • Genotype = set of genes in genome. you carry

- Phenotype = physical expression, future, function

26
Q

gene function = protein synthesis

A

2 steps

  • transcription (DNA to mRNA=copy)
  • translation (mRNA to protein=ribosome)
27
Q

Transcription;

A
  • DNA is transcribed to make 3 types of RNA : mRNA, tRNA, rRNA (ribosome RNA)
  • begins when RNA polymerase binds to the Promoter sequence(transcribe only one side)
  • proceeds 5’ to 3’ direction
  • stops when reaches the Terminator sequence
28
Q

Transcription (1, 2, 3)

A
  1. initiation - promoters fit well to RNA polymase. not so fit, then may have lower binding rate.
  2. elongation
  3. termination
29
Q

Transcriptional differences in Eukaryotes

A
  • RNA transcription occurs in the nucleus
  • transcrition also occurs in mitochondria & chloroplasts
  • 3 types of RNA polymerases
  • numerous transcription factors
    mRNA processed before translation:
    + capping
    + polyadenylation
    + splicing
30
Q

Only Eukaryotes have 2 section:

A

Exon =expressed segments

Intron =interrupting segments

31
Q

Translation;

A
  • mRNA is translated in codons (3 nucleotides)
  • translation of mRNA begins at the start codon AUG
  • translation stops at stop codons: UAA, UAG, or UGA
32
Q

Bacteria can transcription & translation at the same time! =

A

= faster!

33
Q

*genetic code

A
  • 64 sense codons on mRNA encode the 20 amino acids

- redundant: not perfect. potential negative

34
Q

tRNA carries the complementary

A

anticodon

35
Q

control of transcription

A

75% of genes are expressed all time

36
Q

Ionizing radiation effect:

A

The formation of free radicals=highly reactive ions

37
Q

Transformation is the transfer of DNA from a donor to a recipient cell

A

As naked DNA in solution

38
Q

Operandi model:

Synthesis of inducible enzyme to occur, the substrate must:

A

Bind to to the repressor

39
Q

Protein synthesis, both eukaryotes and prokaryotes use:

A

Codons to determine polypeptide sequences

40
Q

promoter

A

A site where RNA polymerase binds to DNA

41
Q

terminator

A

A site when RNA polymerase ends binding to DNA=RNA synthesis ends

42
Q

mRNA

A

carries coded information for making specific proteins from DNA to ribosomes.

43
Q

operon:

only in bacteria

A

= a set of operator (O) and promotor (P) sites and the structural genes they control. Regulated by regulatory gene.

44
Q

inducible operons

A
  1. active repressor binds with operator, prevents transcription from operon. 2. when inducer Allolactose binds to repressor protein, inactivated repressor cannot block transcription. production of enzymes needed (and can digest lactose).
45
Q

repressible operons

A
  1. the repressor is inactive, transcription and translation proceed, leads synthesis of tryptophan. 2. when tryptophan (corepressor) bids to the repressor protein, repressor activates and binds with the operator - preventing transcription from the operon.
46
Q

point mutation (base substitution)

A

1 point in the DNA sequence is replaced with a different base.

47
Q

Frameshift mutation

A

insertion or deletion of 1 or more nucleotide pairs.

48
Q

Deletion frame-shift mutations

A

chemical

49
Q

repair of mutations:

photolyases (light repair) :bacteria only

A

photolyases (light repair) :bacteria only

50
Q

repair of mutations:

nucleotide excision repair

A

= all organisms have

51
Q

repair of mutations:

mismatch repair

A

= proof reading mechanism

52
Q

mutagens

A

mutagens increase to -10x10x10x10x10 or -10x10x10per replicated gene.

chemical increase mutation (disinfected procedure) = anti HIV, anti virus.

radiation= ionized(Xray) and nonionized(UV light)

53
Q

Ames test= reverse gene mutation (70’s Bruce Ames)

A

= to creare reversible mutation.
suspected mutagen was added one of two samples of rat liver extract in the culture of histidine-dependent salmonella. Increased numbers of histidine synthesizing revertants, if the test chemical is a mutagen and potential carcinogen (cancer causing substance)

54
Q
  1. silent mutation
A

= genotype changes but phenotype remains the same = no effect on amino acid sequence.

55
Q
  1. missense mutation
A

= base substitution results in change in amino acid = sickle cell anemia.

56
Q
  1. nonsense mutation
A

= base substitution results in a nonsense (stop) codon.

57
Q
  1. insertion
A

The eca tra n

58
Q
  1. deletion
A

Thc atr an

59
Q

operon=

A

set of genes that on bacterial chromosomes that allow them to regulate amount of products made