Unit 4 Flashcards
1
Q
Transcription
A
DNA —> RNA
2
Q
Translation
A
RNA —> protein (chain of amino acid)
3
Q
Transcription def
A
A complementary sing strand of mRNA is copied from part of the DNA in the nucleus
4
Q
RNA polymerase
A
An enzyme
Unwinds DNA strand
“Reads” one strand of DNA bases and makes the RNA strand
mRNa leaves and DNA strands will coil back up
5
Q
RNA: sugar ribose
A
Instead of deoxyribose
6
Q
RNA: single-stranded
A
Instead of double stranded
7
Q
RNA: contains uracil
A
In place of thymine
8
Q
RNA contains
A
Adenine, cytosine, guanine uracil (not thymine)
9
Q
Comparison of FNA and RNA
A
Sugar: DNA RNA
10
Q
Messenger RNA (mRNA)
A
Carries copies of instructions, for the assembly of amino acids into proteins, from DNA to the ribosome (serve as “messenger”)
11
Q
Three main types of RNA
A
Messenger RNA (mRNA)
Ribosmomal RNA(rRNA)
Transfer RNA “(tRNA)
12
Q
*mRNA editing
A
Cutting and splicing mRNA before it leaves the nucleus
13
Q
*Introns (intruders)
A
“Junk DNA” that doesn’t code for proteins are cut out
14
Q
*Exons
A
“Good DNA” that code for proteins stay and are expressed
Can be spliced together in different sequences to produce different mRNA’s = different proteins
15
Q
Introns are
A
Removed and exons are spliced together
16
Q
Edited mRNA is sent out of
A
Nucleus to ribosome
17
Q
*Ribosomal RNA (rRNA)
A
Makes up the major part of ribosomes, which is where proteins are made
18
Q
*Transfer RNA (tRNA)
A
Transfer (carries) amino acids to ribosomes as specified by codons in the mRNA
19
Q
How the code is read:
A
Every 3 bases on mRNA represents a code for an amino acid = codon
Amino acids are abbreviated most times by using the first 3 letters of the amino acids name
Met = methonine
Leu=leucine
20
Q
tRNA have a order and a sequence also read in
A
3’ to 5’
5’ to 3’
21
Q
Why do we look at sequences of RNA
A
What if there is a mutation in the ribosomes; not going to do a good job making DNA
22
Q
*Translation
A
Translating of a mRNA codons into a protein (amino acid chain)
Takes place on ribosomes in cytoplasm
23
Q
Edited mRNA
A
Attaches to a ribosome
24
Q
Each codon of the mRNA molecule…
A
Moves through the ribosome, the tRNA brings the proper amino acid to the ribosome
25
The anti condor on tRNA
It is complementary to the mRNA codon
26
The amino acids are joined together by
Chemical bonds called peptide bonds to build an amino acid chain called a “polypeptide”
27
*Start codons
Founds at the beginning of a protein
Only one - AUG (methionine)
28
*Stop codons
Found at the end of a protein (end of a polypeptide chain)
29
Three stop codons that do not code
For any amino acid therefore making the process stop
UAA, UAG, UGA
30
The cells uses the vital
DNA “master plan” to prepare RNA “blueprints”
31
The DNA molecules remains within the
Safety of the nucleus, while RNA molecules go to the protein-building sites in the cytoplasm — the ribosomes
32
*Mutation
Changes in the genetic material
(Like mistakes in copying or transcribing)
33
*Chromosomal mutations
Involve changes in the number or structure of chromosomes
Down syndrome
34
*Gene mutation
Mutations that produce changes in a single gene
35
*point mutations
Affects single nucleotide base is replaced with the wrong base (letter)
Ex. Sickle-cell anemia
36
*silent mutations
A base is changed, but the new codon codes for the same Amin acid. Not all mutation are harmful.
Typically it is the third letter in the codon
37
*substitution point mutation
That still codes for an amino acid, just the wrong amino acid
May or may not be harmful
38
Different points of gene regulation
During transcription
Post transcription
During translation
Post translation
39
Regulation of chromatin formation
Euchromatin vs heterochromatin
40
Positive control of the expression of individual genes
Transcription enhancement/inhibition
Increase enhancement
41
Nucleosome
Pulls dna apart and exposes it
42
Acetylation
Histone tails leads to euchromatin formation and makes expression possible
43
Methylation
His tones leads to condensation (heterochromatin formation) the prevents expression
44
Modification
His tones affects gene expression: other post-translation modifications
45
Tails
Acetylation
Methylation
Ubiquination
Sumoylation
Phosphorylation
46
Adding of methyl’s to nitrogenous bases often cytosine:
Tends to favor heterochromatin formation
Long term shutoff of gene expression
47
*genomic imprinting
Methylation passed on
48
*epigenetic inheritance
Changes in inheritance that do not involve the nucleotide sequence
49
Methylation of DNA
Importance to X chromosome inactivation
50
Histone code hypothesis
Specific pattern of methylation and acetylation determines euchromatin heterochromatin patterns and therefore gene expression
51
Exons
Expressed
52
Introns
Junk
53
RNA processing
Cap and tail added
Introns excised and exons spliced together
54
Binding promotes
The stable attachment of RNA polymerase to the promoter
55
Some (TBP) bind to the
TATA box in the promoter
56
Many bind to other
Proteins in the complex, including RNA polymerase
57
Many are regulated
By the other proteins
58
Enhancers
Many short binding sequences
59
Many short binding sequences are grouped
Together at a considerable distance from the promoter
The grouping is termed a DISTAL control element
60
Various transcription factors specifically bind
These regulatory elements and aid in the regulation of transcription
61
Differential expression of genes located in
Euchromatin of different cells varies because of differing amounts of specific transcription factors
62
Totipotent
They can become anything or whatever
63
Pleuripotent
Can turn into a number of things but NOT anything
64
Aldosterone and blood pressure/water balance
The receptor/hormone complex as a activator
65
The central role of the expression of receptors
To the sensitivity of cells to various hormones
66
The same specific transcription factors can
Simultaneously active many genes if the enhancers are similar in each gene
67
Sine transcription factors are in fact…
Repressors
Repression acts in other ways such as by making it more difficult for activator TFs to bind to mediator proteins etc.
However that regulation is still positive
68
Many transcription factors are
Themselves regulated
69
*cell division
The continuity of life is based on the reproduction of cells
70
The ability of organisms to produce more…
Of their own kinds best distinguishes living things from non living matter
71
Diploid
Huh
72
Haploid
Huh
73
Homologs
Chromosome 1 from mom homologous from chromosome 1 from dad
74
*Unicellular organisms
Reproduced the entire organism
75
*Multicellular organisms
Depend on cell division for
Development
Growth
Repair
76
*Cell cycle
The life of a cell from formation to its own division
77
Cell division is an
Integral part of cell cycle
78
Most cell division results in
Frighten cells with identical genetic information, DNA
79
The exception is meiosis
A special type of division that can produce sperm and egg cells
80
*Genome
All the DNA in a cell constitutes the cells
81
A genome can consist of a
Single DNA molecule(common in prokaryotic cells), or a number of DNA molecules (common in eukaryotic cells)
82
*Chromosomes
DNA molecules in a cell are packaged
83
Eukaryotic chromosomes consist of
Chromatin
84
*Chromatin
A complex of DNA and protein that condenses during cell division
Every eukaryotic species has a characteristic number of chromosomes in each cell nucleus
85
*Somatic cells
(Nonreproductive cells) have 2 sets of chromosomes
86
*Gametes
(Reproductive cells: sperm and eggs) have glad as many chromosomes as somatic cells
87
In preparation for cell division
DNA is replicated and the chromosomes condense
Each duplicate chromosome has 2 sister chromatids which separate during cell division
88
*sister chromatids
joined copes of the original chromosome
89
*Centromere
The narrow “waist” of the duplicated chromosome, where the 2 chromotids are most closely attached
90
Mitosis
Uhr division of the genetic material in the nucleus
91
Cytokinesis
The division of the cytoplasm
92
Eukaryotic cell division consists of
Mitosis and cytokinesis
93
Meiosis
Gametes are produced by a variation of cell division
94
Meiosis yields no identical daughter cells that have only
One set of chromosomes, half as many as the parent cell
95
In 1882, the German anatomist
Walther Flemming developed dyes to observe chromosomes during mitosis and cytokinesis
96
Cell cycle consists of
Mitotic (M) phase
Interphase
97
Mitotic m phase
Mitosis and cytokinesis
98
Interphase
Cell growth ans copying of chromosomes in preparation for cell division
99
Interphase (about 90% of the cell cycle) can be divided into sub phases
G1 phase (first gap)
S phase (synthesis)
G2 phase (second gap)
100
The cell browns during all three phases, but
Chromosomes are duplicated only during the S phase
101
Name of the phases
Interphase, prophase, prometaphase, metaphase, anaphase, telophase, cytokinesis
102
*mitotic spindle
A structure made of microtubules that controls chromosome movement during mitosis
103
Centrosome
Assembly of spindle microtubules
The microtubule organizing center
104
Aster
A redial array of short microtubules
Extends from each centrosome
105
The centrosome replicated during interphase forming
2 centrosome that migrate to opposite ends of the cell during prophase and prometaphase
106
The spindle includes the
Centrosomes, the spindle microtubules, and the asters
107
Kinetochores
Are protein complexes associated with centromeres
108
Metaphase plate
At metaphase, the chromosomes are all lines up
An imaginary structure at the midway point between the spindels two poles
109
During prometaphase
Some spindle microtubules attach to the kinetochores of chromosomes and begin to move the chromosomes
110
*Binary fission
Prokaryotes reproduce by a types of cell division
111
In binary fission
The chromosome replicates (origin of replication) and two daughter chromosomes actively move apart
112
The plasma membrane pinches inwards
Dividing the cell into two
113
The frequency of cell division
Varies with the type of cell
114
These differences result from
Regulation at the molecular lebel
115
Cancer cells manage to escape the usual
Controls on the cell cycle
116
The cell cycle appears to be
Driven by specific chemical signals present in the cytoplasm
117
Some evidence for this hypothesis comes form experiments in which
Cultured mammalian cells at the different phases of the cell cycle were fused to form a single cell with two nuclei
118
The sequential events of the cell cycle are
directed by a distinct cell cycle control system
119
Cell cycle control system is regulated by
Both internal and external controls
120
Checkpoints
Where the cell cycle stops until a go-ahead signal is received
121
If a cell receives a
122
Diff gene and alleles
Genes unit of heredity passed from parents offspring
Genes that show variation
123
Locus
Specific, fixed position of a chromosome where a particular gene is located
124
Meiosis I
Is preceded by interphase, when the chromosomes are duplicated to form sister chromatids
125
The sister chromatids
Are genetically identical and are joined at the centroemere
126
The single centromere
127
Synapsis
Homologous chromosomes loosely pair up, aligned gene by gene
128
Prophase I
Typically occupies more than 90% of the time
Chromosomes begin to condense
129
Crossing over
Nonsister chromatids exchange DNA segments
130
Each pair of chromosomes
Forms a tetrad, a group of 4 chromotids
131
Each tetrad usually has
On or more chiasmata
132
Chiasmata
X-shaped regions where crossing over occurred
133
Characters
Varieties with distinct heritable features
134
Traits
Character variants
135
Truebreeding
Plants that produce offspring of the same variety when they self pollinate
136
Hybridization
Mated two contrasting true breeding varieties
137
P generation
True breeding parents
138
F1 Generation
Hybrid offspring of the P generation
139
F2 Generation
F1 individuals self pollinate or cross pollinate with other F1 hybrids
