BIO Flashcards
1
Q
- entails various modes that allow the genetic material to be transmitted from parents to offspring or progenitors. For cellular entities, reproduction begins with the division of a cell.
- is one of the key characteristics of living organisms, from unicellular prokaryotic cells to complex multicellular eukaryotic animals.
A
Reproduction
2
Q
Multicellular organisms grow and increase in complexity via
A
extensive and repetitive division of cells
3
Q
is one of the major events that take place during the cell cycle, is an active process in
various biological activities such as (A) growth and development, (B) wound healing, and (C)
asexual reproduction.
A
DNA replication
4
Q
DNA replication takes place during the
A
S phase (synthesis phase)
5
Q
DNA replication in human cells occurs at a rate of approximately
A
3 000 nucleotides
per minute.
6
Q
three major models of DNA replication
A
- conservative
- semiconservative
- dispersive
7
Q
- the whole double-stranded DNA molecule serves as the template for duplication to produce an entirely new DNA molecule while fully conserving the original copy
- uses parental DNA as a template but still fully conserves it.
A
conservative model
8
Q
- shows that the DNA strands separate and break down or disperse into fragments for them to serve as templates to synthesize new sequences. Thereafter, these copies reassemble, but with the new and old fragments interspersed in the resulting DNA molecules.
- utilizes fragments of the parental strand as the template but eventually, these
pieces become interspersed in the resulting molecules.
A
dispersive model,
9
Q
- states that each
of the DNA strands will serve as a template to synthesize new DNA molecules. Thus, each of
the products of this mechanism shall consist of an old and a new strand. - produces DNA molecules each consisting of an old and a new strand
A
semiconservative model
10
Q
which is the accepted mechanism of replication
A
semiconservative model
11
Q
The semiconservative model is supported by the findings of
A
Watson and Crick
12
Q
provided solid proof as to the
semiconservative mechanism of DNA replication
A
Matthew Meselson and Franklin Stahl
13
Q
they performed an
experiment that utilized the bacterium
A
Escherichia coli
14
Q
For replication to take place three major groups of molecules are needed
A
DNA template,
deoxyribonucleotides
enzymes and other proteins
15
Q
will be polymerized into a new nucleotide strand
A
deoxyribonucleotides
16
Q
help recognize the template and assemble the subunits.
A
enzymes and other proteins
17
Q
ends of the bubble are called
A
replication forks.
18
Q
Another feature of
replication is its bidirectionality. This means that once the DNA molecule is unwound for
replication, it proceeds in two opposite directions. This property was first demonstrated in
the late 1600s by
A
Maria Schnos and Ross Inman
19
Q
to bind to the
replication origin and unwind a short segment of DNA.
A
initiator proteins
20
Q
- is the enzyme that further breaks the hydrogen bonds between the double-stranded
polynucleotide chains. - unwinds the
DNA helix by breaking the hydrogen bonds between the base pairs. T
A
DNA helicase
21
Q
provide stability to the single-stranded chains
A
single-stranded-binding
proteins (SSBPs)
22
Q
- This protein helps relieve the
supercoiling of the twisted DNA molecule by reducing the strain that builds up in the
replication fork. - helps relieve the tension that builds up ahead of the replication fork.
A
DNA gyrase
23
Q
Humans do not have gyrase, but instead, have the
A
topoisomerase II
24
Q
- synthesizes small nucleotide segments called RNA primers or simply primers.
- These are usually 10–12 nucleotides long that
provides the 3’-OH where the major polymerizing enzyme can initiate synthesis later on.
A
enzyme primase
25
For the strand with the
exposed 3’-OH, replication will occur continuously in the 5’ to 3’ direction.
leading strand
26
synthesizes new DNA strands in both the leading and the lagging strands
DNA polymerase III
27
with an exposed 5’
end, replication must take place in the opposite direction
lagging strand
28
small sequences are called the
Okazaki fragments (named after Reiji Okazaki and his wife Tsuneko Okazaki)
29
is the primary enzyme that catalyzes the elongation of the new nucleotide
chains in both the leading and the lagging strands
DNA polymerase
30
Seals the nicks between the Okazaki fragments through
phosphodiester bond formation
DNA ligase
31
Catalyzes the removal of the RNA primers and replaces
them with DNA nucleotide
DNA polymerase I
32
DNA polymerase I has the ability to correct errors in nucleotide selection in a process that is termed as
proofreading
33
this process is performed after replication because some
errors are found to have escaped initial proofreading
mismatch repair
34
the primary enzymes
that carry out the polymerization in the leading and lagging strands are called
polymerases alpha and delta
35
The copied sequence of the DNA is called a
gene
36
central dogma of molecular biology
dna > replication > transcription > rna > translation > protein > reverse transcription
37
is a collection of processes that allows for the expression of genes in cells. These processes serve as the connection between the genotype and phenotype of organisms.
central dogma of molecular biology
38
- is an intermediate molecule during gene expression. It contains a copy of the information in DNA that must be translated into proteins.
- Serves as the transcript for the
amino acid sequence
Messenger RNA (mRNA)
39
- serve as adaptor molecules
during protein synthesis. Each of them conveys amino acids to the ribosome corresponding
to the information in the mRNA molecule.
- Carries amino acids to the
ribosomes for protein synthesis
Transfer RNAs (tRNA)
40
- alongside some proteins, are structural and functional components of the ribosomes. They help recognize the information in the mRNA so that it can be accurately expressed into polypeptides.
- Structural and functional
component of ribosomes
Ribosomal RNAs (rRNAs)
41
- function during the post-processing of the mRNA after transcription. They are components of spliceosomes, structures in the nucleus that help remove sequences that will not be translated into an amino acid sequence
- Processing of pre-mRNA to
mature mRNA
Small nuclear RNAs (snRNA)
42
- are small RNAs that are essential in the regulation of gene expression. It should be emphasized that, though all of these molecules are products of transcription, only mRNA is translated into a polypeptide.
- Processing of rRNA for
ribosomes
Micro RNAs (miRNA)
43
Messenger RNA
(mRNA) location
Nucleus and cytoplasm
44
Transfer RNA
(tRNA) location
Cytoplasm
45
Ribosomal RNA
(rRNA) location
Cytoplasm
46
Small nuclear RNA
(snRNA) location
Nucleus
47
Small nucleolar RNA
(snoRNA) location
Nucleus
48
the process of synthesizing RNA from DNA, only concerns itself on the genes that are needed by the cell.
Transcription
49
the transcribed sequence is called the
template strand
50
template strand other term
sense and antisense strands
51
transcription requires certain components to successfully produce an mRNA transcript:
- DNA template
- ribonucleotide subunits
- proteins and enzymes that facilitate transcription.
52
This sequence of the DNA involved in RNA synthesis is called the
transcription unit
53
Each transcription unit consists of
- the promoter sequence
- the coding sequence
- the terminator sequence.
54
the enzyme that will catalyze RNA synthesis in the transcription unit is the
RNA polymerase
55
Transcription in prokaryotic cells begins when the RNA polymerase holoenzyme binds to a
promoter region or sequence
56
Nucleotide sequences before and after this site (at a 5’ to 3’ direction) are called the
upstream sequences and downstream sequences
57
TATAAT
Pribnow box
58
is responsible for the synthesis of the mRNA transcript that will, later on, be translated into
proteins.
RNA polymerase II
59
RNA polymerase II has the capacity to move
through the nucleosomes containing the histone proteins with the aid of a protein complex
called
FACT (facilitates chromatin transcription
60
is a sequence of DNA nucleotides that code for a specific protein.
gene
61
is the process that allows the information in the mRNA transcript to be translated into the amino sequence in proteins
Translation
62
The genetic control of enzymatic pathways
was elaborated by the Nobel-prize winning study of
George Beadle and Edward Tatum
63
The mRNA sequence is
read consecutively in three nucleotides called
codons
64
addition of phosphate group
phosphorylation
65
addition of methyl group
methylation
66
addition of sugar group
glycosylation
67
attachment of lipid group
lipidation
68
addition of nitrogen-containing group
nitrosylation
69
the breakdown of proteins into component polypeptides
proteolysis
70
The resulting mRNA molecule undergoes a series of chemical modifications such as
methylation (5’ capping), polyadenylation (addition of poly-A tail), and intron
splicing.
