dna test Flashcards
1
Q
macromolecule
A
Large biological molecules. Macromolecules: carbohydrates, lipids, proteins, nucleic acids
2
Q
monomer
A
A simple compound whose molecules can join together to form polymers.
3
Q
Polymers
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made of several smaller repeating units (monomers)
4
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condensation
A
DNA nucleotides join together in a condensation reaction: produces water and a covalent bond between the two nucleotides
5
Q
hydrolysis
A
complex molecules are broken down by the water molecules added to form monomers
6
Q
nucleic acids
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long chains of nucleotides to make DNA or RNA, code for proteins
7
Q
nucleotides
A
made of the sugar deoxyribose, a nitrogenous base (which can be either adenine, guanine, cytosine or thymine) and a phosphate group.
8
Q
DNA
A
a double helix molecule made of two antiparallel strands of nucleotides linked by hydrogen bonding. between complementary base pairs
9
Q
nitrogenous base
A
A molecule that contains nitrogen and has the chemical properties of a base. containing (A-T, G-C)
10
Q
Phosphate group
A
The phosphate group of one nucleotide attaches to the sugar of another nucleotide (at the 3’– hydroxyl (-OH) group)
11
Q
Deoxyribose
A
Deoxyribose is a ringed 5-carbon sugar
12
Q
primer
A
A primer is a short nucleic acid sequence that provides a starting point for DNA synthesis. (NOT THE ACTION)
13
Q
primase I
A
RNA primase adds short sequences of RNA to both strands to allow DNA polymerase III to bind and replicate DNA on the lagging strand. (ENZYME)
14
Q
ribose
A
Ribose also called D-ribose, five-carbon sugar found in RNA IN eukaryotic cells
15
Q
complementary bases
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Hydrogen bonds found between bases of the two strands of nucleotides. Adenine forms hydrogen bonds with thymine, guanine with cytosine.
16
Q
Phosphodiester bond
A
group of strong covalent bonds between a phosphate group and two 5-carbon ring carbohydrates in nucleotides
17
Q
Purine
A
Adenine and Guanine
18
Q
pyrimidines
A
Thymine and Cytosine
19
Q
5’ and 3’
A
Each end of DNA molecule has a number. One end is referred to as 5’ (top left phosphate group) and the other end is referred to as 3’ (bottom left of carbon group). The 5’ and 3’ designations refer to the number of carbon atom in a deoxyribose sugar molecule to which a phosphate group bonds.
20
Q
histone
A
histone is a kind of protein, nucleosome has 8
21
Q
nucleosomes
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Nucleosomes help to supercoil the DNA
22
Q
genome
A
the whole of the genetic information of an organism.
23
Q
gene
A
A heritary factor that controls a specific characteristic. It is a portion of the DNA.
24
Q
pseudogene
A
a non-functional sequence of DNA that is homologous to an active gene
25
transposable dna
a segment of DNA that inserts itself into another section within the genome (i.e. 'jumping' genes)
26
Satellite DNA
a portion of the DNA consisting of tandem repeats of non-coding nucleotide sequences that occur in the genome. Tandem repeats are copies of nucleotide sequences that lie adjacent to each other.
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STR's
short tandemly repeated DNA sequences that involve a repetitive unit of 1–6 bp
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Gyrase
Stabilizes DNA helix (ENZYME),
29
single-strand binding proteins
SSB proteins bind to the DNA strands after they have been separated and prevent the strands from re-annealing
30
dna polymerase III
- Free nucleotides align opposite their complementary base partners (A = T ; G = C)
- DNA pol III attaches to the 3’-end of the primer and covalently joins the free nucleotides together in a 5’ → 3’ direction
- As DNA strands are antiparallel, DNA pol III moves in opposite directions on the two strands
- On the leading strand, DNA pol III is moving towards the replication fork and can synthesise continuously
- On the lagging strand, DNA pol III is moving away from the replication fork and synthesises in pieces (Okazaki fragments)
31
DNA polymerase I
DNA pol I removes the RNA primers from the lagging strand and replaces them with DNA nucleotides
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DNA ligase
DNA ligase joins the Okazaki fragments together to form a continuous strand, covalently joining the sugar-phosphate backbones together with a phosphodiester bond
33
uracil
uracil is the nucleotide that is found almost exclusively in RNA.
34
Okazaki fragments
A relatively short fragment of DNA synthesized on the lagging strand during DNA replication.
35
Leading strand
the parent strand of DNA which runs in the 3' to 5' direction toward the fork
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lagging strand
The dna strand that is replicated discontinuously(away from the fork) from the 5′ to the 3′ direction
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prime
lay a foundation for DNA synthesis
38
telomeres
Eend of a chromosome. made of repetitive sequences of non-coding DNA that protect the chromosome from damage. Each time a cell divides, the telomeres become shorter.
39
doublehelix
description of the molecular shape of a double-stranded DNA molecule
40
nucleoside triphosphate
Free nucleotides exist in the cell as nucleoside triphosphates (NTPs)
41
complementary base pairing
the manner in which the nitrogenous bases of the DNA molecules align with each other.
42
antiparallel
two molecules that are side by side but run in opposite directions
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semi-conservative
a new double-stranded DNA molecule is formed:
One strand will be from the original template molecule
One strand will be newly synthesized
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covalent bonds
Covalent bonds occur within each linear strand and strongly bond the bases, sugars, and phosphate groups
45
h-bond
hydrogen bonds hold together the base pairs in the middle
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template
the strand used by DNA polymerase or RNA polymerase to attach complementary bases during DNA replication or RNA transcription,
47
replication bubble
an unwound and open region of DNA where DNA replication occurs.
48
dna sequence
DNA sequencing refers to the process by which the base order of a nucleotide sequence is shown
49
amino acid
a set of 20 different molecules used to build proteins. Proteins consist of one or more chains of amino acids called polypeptides.
50
primary protein structure
unique sequence of amino acids in each polypeptide chain that makes up the protein
51
the central dogma of biology
DNA contains the information needed to make all of our proteins, and that RNA is a messenger that carries this information to the ribosomes
52
transcription
Transcription is the process by which a DNA sequence (gene) is copied into a complementary RNA sequence by RNA polymerase.
53
translation
Translation is the synthesis of polypeptides on ribosomes
54
codon
a sequence of three RNA nucleotides that corresponds with a specific amino acid or stop signal during protein synthesis
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triplet
DNA unit for three nucleotides
56
genetic code
Genetic code is the term we use for the way that the four bases of DNA--the A, C, G, and Ts--are strung together
57
mRNA
a single-stranded RNA molecule that is complementary to one of the DNA strands of a gene. the mRNA is an RNA version of the gene that leaves the cell nucleus and moves to the cytoplasm where proteins are made.
58
prokaryotes
replication occurs in two opposing directions at the same time, and takes place in the cell cytoplasm, prokaryotes only have one type of RNA polymerases,
59
eukaryotes
transcription takes place in the membrane-bounded nucleus, whereas translation takes place outside the nucleus in the cytoplasm. more than one RNA polymerase
60
rna polymerase
an enzyme that is responsible for copying a DNA sequence into an RNA sequence, duyring the process of transcription
61
promoter
"tells" the RNA polymerase where to start the transcription process: transcription is initiated with the binding of RNA polymerase to the promoter site
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anti-sense strand
The antisense strand is the strand that is transcribed into RNA
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sense strand
the segment within double-stranded DNA that carries the translatable code in the 5′ to 3′ direction
64
coding strand
the DNA strand whose base sequence is identical to the base sequence of the RNA transcript produced (although with thymine replaced by uracil). It is this strand which contains codons, while the non-coding strand contains anticodons.
65
initiation
DNA is made accessible to the proteins and enzymes involved in the replication process. There are specific chromosomal locations called origins of replication where replication begins.
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elongation
elongation is the stage when the RNA strand gets longer, thanks to the addition of new nucleotides
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termination
when converging replication forks meet
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terminator
A sequence in DNA that signals termination of transcription to RNA Polymerase
69
pre-mRNA
a pre-mRNA is produced through transcription of a region of DNA from a linear chromosome. This transcript must undergo processing (splicing and addition of 5' cap and poly-A tail) while it is still in the nucleus in order to become a mature mRNA.
70
5'cap
added to the first nucleotide in the transcript during transcription. The cap is a modified guanine (G) nucleotide, and it protects the transcript from being broken down.
71
poly A tail
of adenine nucleotides that is added to a mRNA molecule during RNA processing
72
introns
introns are non-coding regions of an RNA transcript, or the DNA encoding it, that are eliminated by splicing before translation.
73
exons
any part of a gene that will encode a part of the final mature RNA produced by that gene after introns have been removed by RNA splicing
74
rna processing
RNA splicing removes the introns from pre mRNA to produce the final set of instructions for the protein. As DNA is transcribed into RNA it needs to be edited to remove non-coding regions, or introns, shown in green. ... The spliceosome then cuts the RNA to release the loop and join the two exons together.
75
rna splicing
emoves the intervening, non-coding sequences of genes (introns) from pre-mRNA and joins the protein-coding sequences (exons) together in order to enable translation of mRNA into a protein.
76
spliceosomes
assemble on RNA polymerase II transcripts from which they excise RNA sequences called introns and splice together the flanking sequences called exons.
77
snRNA
non-coding RNA molecules. As these molecules have fundamental roles in RNA metabolism, including pre-mRNA splicing and ribosomal RNA processing
78
alternative RNA splicing
process of selecting different combinations of splice sites within a messenger RNA precursor (pre-mRNA) to produce variably spliced mRNAs.
79
gene expression
the process by which the instructions in our DNA are converted into a functional product, such as a protein
80
epigenome
all of the modifications that regulate the activity (expression) of the genes is known as the epigenome
81
transcription factors
proteins involved in the process of converting, or transcribing, DNA into RNA
82
transcription activators
a protein (transcription factor) that increases transcription of a gene or set of genes
83
transcription repressors
blocks the attachment of RNA polymerase to the promoter, thus preventing transcription of the genes into messenger RNA.
84
protein synthesis
the process in which cells make proteins. It occurs in two stages: transcription and translation
85
tRNA
tRNA are responsible for matching amino acids with the appropriate codons in mRNA. Each tRNA molecule has two distinct ends, one of which binds to a specific amino acid, and the other which binds to the corresponding mRNA codon.
86
rRNA
associates with a set of proteins to form ribosomes
87
anticodon
a sequence of three nucleotides on a tRNA molecule that bond to a complementary sequence on an mRNA molecule
88
peptide bonds
ormed between the carboxylic acid group of one amino acid and the amino group of a second amino acid. Nucleic acids (i.e., DNA and RNA) are made up of nucleotide monomers linked via phosphodiester bonds
89
polypeptide chain
refers to many amino acids connected by peptide bonds
90
large ribosome unit
catalyzes the key chemical event in protein synthesis, peptide bond formation.
91
small ribosome unit
in charge of information flow during protein synthesis. It initially finds a messenger RNA strand and, after combining with a large subunit, ensures that each codon in the message is paired with the anticodon in the proper transfer RNA.
92
A/P/E -site(s)
The P-site (for peptidyl) is the second binding site for tRNA in the ribosome. The other two sites are the A-site (aminoacyl), which is the first binding site in the ribosome, and the E-site (exit), the third. During protein translation, the P-site holds the tRNA which is linked to the growing polypeptide chain.
93
mrna binding-site
the ribosome and a tRNA attach to the mRNA. The tRNA is located in the ribosome's first docking site.
94
ATP
Translation of mRNA into a protein requires ribosomes, mRNA, tRNA, exogenous protein factors and energy in the form of ATP and GTP.
95
GTP
GTP is used as an energy source for the binding of a new amino-bound tRNA to the A site of the ribosome. GTP is also used as an energy source for the translocation of the ribosome towards the 3' end of the mRNA.
96
tRNA activating enzymes
Each tRNA molecule binds with a specific amino acid in the cytoplasm in a reaction catalyzed by a tRNA-activating enzyme
Each amino acid is recognized by a specific enzyme (the enzyme may recognise multiple tRNA molecules due to degeneracy)
97
free ribosomes/bound ribosomes
Free and membrane-bound ribosomes produce different proteins. Whereas membrane-bound ribosomes produce proteins that are exported from the cell to be used elsewhere, free ribosomes produce proteins used inside the cell itself.
98
nucleus
DNA is packed tightly in the nucleus of your cells as chromosomes
99
cytoplasm
(RNA) is found mainly in the cytoplasm of the cell although it is usually synthesized in the nucleus.
100
polysomes
A polyribosome (or polysome or ergosome) is a group of ribosomes bound to an mRNA molecule like “beads” on a “thread”. It consists of a complex of an mRNA molecule and two or more ribosomes that act to translate mRNA instructions into polypeptides.
101
translocation
A translocation occurs when a piece of one chromosome breaks off and attaches to another chromosome. This type of rearrangement is described as balanced if no genetic material is gained or lost in the cell. If there is a gain or loss of genetic material, the translocation is described as unbalanced
102
release facotr
a protein that allows for the termination of translation by recognizing the termination codon or stop codon in an mRNA sequence
103
mutation
occurs when a DNA gene is damaged or changed in such a way as to alter the genetic message carried by that gene
104
Base substitutions
are the simplest type of gene-level mutation, and they involve the swapping of one nucleotide for another during DNA replication. For example, during replication, a thymine nucleotide might be inserted in place of a guanine nucleotide.
105
start codon
START codon as it the first codon in the transcribed mRNA that undergoes translation
106
stop codon
a trinucleotide sequence within a messenger RNA (mRNA) molecule that signals a halt to protein synthesis
