Central Dogma: Molecular Basis of Heredity -- DNA, RNA, & Proteins Flashcards
(91 cards)
1
Q
What are the 3 basic component of a nucleotide?
A
- Nitrogenous bases
- Pentose sugar
- Phosphate group
2
Q
Under the nitrogenous bases, what are the compontents?
A
Nitrogenous bases
- Purine bases: Adenine & Guanine
- Pyrimidine bases: Thymine & Cystosine (in RNA: Uracil instead of Thymine)
3
Q
Under the pentose sugar, what are the compontents?
A
DNA: Deoxyribose
RNA: Ribose
4
Q
Pentose sugar + Nitrogen base
A
Nucleoside
5
Q
Phosphate group + Pentose sugar + Nitrogen base
A
Nucleotide
6
Q
Who demonstrated how the 3 nucleotide components are physically assembled to form DNA?
A
Watson & Crick
7
Q
It is a model of DNA where it is like a twisted ladder with chemical bonds as its rungs
A
Double Helix model
Discovered by Watson & Crick
8
Q
Nucleotides are joined to form a __________
A
polynucleotide chain
9
Q
- Covalent bond that links adjacent nucleotides
- 5’-phosphate group of the new nucleotide is linked to the free 3’-OH group of the existing nucleotide
A
Phosphodiester bond
10
Q
Enumerate the nitrogenous base pairing
A
- Adenine and Thymine
- Guanine and Cytosine
- In RNA: Adenine and Uracil
11
Q
How many hydrigen bonds are there for the following:
- A – T pair has ____ hydrogen bonds
- G – C pair has ____ hydrogen bonds
A
- A – T pair has two hydrogen bonds
- G – C pair has three hydrogen bonds
12
Q
In a DNA duplex, the ____ end of one strand is opposite the ____ end of the other
Have opposite orientations = antiparallel
A
5’ end to 3’ end
13
Q
These are important for the attachment of DNA Binding Proteins involved in replication and transcription
A
Major and minor grooves
14
Q
It is important in duplicating the DNA so that there will be sister chromatids at anaphase stage and at the end of cytokinesis, each daughter cell would have the genetic material.
A
Replication
15
Q
True or False
**DNA replication **is described as Semiconservative
A
False
16
Q
What are the major steps in DNA Replication?
A
- Unwinding of the double stranded DNA
- DNA synthesis
- Rewinding of the double helix
17
Q
It unwinds the two DNA
strands at the replication fork
A
Helicase
18
Q
It stabilizes the DNA as it forms so it will not anneal to reform the double helix
A
Single-strand DNA binding proteins (SSB)
19
Q
It releases the tension (positive supercoils) ahead of the replication fork caused by the unwinding of the DNA helix
A
DNA Gyrase
20
Q
Replication
- Unwinding of parental strands through Helicase protein binding creating a ______
A
replication fork
21
Q
Replication
What step of replication is this?
Stabilizing the ssDNA through the single-strand DNA binding proteins (SSB) at the replication fork
A
2nd step
22
Q
Replication
What step of replication is this?
Primase binding at the replication fork to synthesize short RNA primer, needed at the start of DNA synthesis, since it provides the 3’-OH group, to which new nucleotides are added
A
3rd step
23
Q
Replication
In the 4th step of replication, ________ binding at the DNA template which adds DNA nucleotide at the RNA primer
A
DNA polymerase
24
Q
Replication
In the fifth step of replication, ________ in a 5’ to 3’ direction to both Parental DNA template
A
adding of nucleotides by DNA polymerase
25
# Replication
In the sixth step of replication, the other strand produced short fragments aka ________, known as
Okazaki fragments (discontinuous synthesis)
26
In the seventh step of replication, ________ proofreads the newly synthesized DNA and replacing incorrect bases
DNA polymerase
27
In the eighth step of replication, ________ rewinds the DNA double helix and ________ seals the sugar phosphate
Annealing helicase; Ligase
28
What is the summary of the DNA Replication process?
1. **Helicase unwind** the parental double helix
2. **SSB **stabilies the ssDNA
3. Primase binding at the replication fork to s**ynthesize short RNA primer**
4. DNA polymerase binding at the DNA template ------> adds DNA nucleotide at the RNA primer
5. The leading strand is synthesized continuously in the **5 ------> 3 direction** by the **DNA polymerase**
6. The lagging strand produced **Okazaki fragments**
7. DNA polymerase **proofreads** and **corrects** the newly synthesized DNA
8. **Anneling healicase** rewinds the DNA & **Ligase** seals the sugar phosphate
29
It is the process by which an **RNA sequence is formed from a DNA template**
Transcription
30
What are the major steps of Transcription?
1. Initiation
2. Elongation
3. Termination
31
What are the two complementary DNA strands in transcription?
- Template strand
- Coding strand
32
Between the two complementary DNA strands in transcription, what has these characteristics:
- is used for **RNA synthesis** and is
- aka the **antisense strand**
Template Strand
33
Between the two complementary DNA strands in transcription, what has these characteristics:
- Has the same sequence as the RNA produced, with exception of **U replacing T**
- Non-template strand
- Aka: **sense strand**
Coding strand
34
Type of RNA produced by the transcription process
Messenger RNA (mRNA)
35
In the 1st step of transcription, one of the RNA polymerase enzymes (**RNA polymerase II** for mRNA) ________ to a **promoter site** on the DNA
binds
36
In the 2nd step of transcription, ________ pulls a portion of the DNA strands **apart** from each other, **exposing unattached DNA bases**
RNA Pol
37
In the 3rd step of transcription, one of the two DNA strands provides the template for the ________
- **Antisense strand:** template DNA strand
- **Sense strand**: other DNA strand that doesn’t serve as template
sequence of mRNA nucleotides
38
In the 4th step of transcription, the RNA sequence is synthesized **only** in _______
5’ to 3’ direction
- **RNA Pol** moves in 3’ to 5’ direction along the DNA template strand while assembling mRNA strand from 5’ to 3’
39
In the 5th step of transcription, transcription continues until a group of bases called ____________ is reached
termination sequence
40
In the 6th step of transcription, **DNA strands** and **RNA Pol** **separate** from the transcribed _________
single mRNA strand (primary transcript)
41
What is the summary of the DNA Transcription process?
1. RNA polymerase binds to a **promotor site**
2. RNA Pol pulls DNA strand apart, exposing unattached DNA bases
3. One DNA strands provides the template for the sequence of mRNA nucleotides
4. RNA sequence is synthesized only in **5’ to 3’ direction**
5. Transcription continues until it reaches the **termination sequence**
6. DNA strands and RNA Pol separate from the transcribed single mRNA strand
42
This are modifications that occur in a primary mRNA molecule before it leaves the nucleus
Post-transcription Modifications
43
# True or False
RNA products of transcription **are not necessarily functional RNAs**
True
44
What are the processes under the post-transcription modifications?
- Splicing
- Capping
- Polyadenylation
45
In the post-transcription modifications, this is when introns in the precursor mRNA are **excised**, and the exons are ________ together to **form a shorter mature mRNA**
Splicing
46
In the post-transcription modifications, this is where the 5’ end of RNA is ________ by the **addition of a methylated guanine nucleotide**
Capping
47
In the post transcription modification process, the **capping** is done through the addition of ________
methylated guanine nucleotide
48
In the post-transcription modifications, it is the process wherein the **3’ end acquires a poly(A) tail** that contains approx. 200 adenine residues
Polyadenylation
49
It is the process in which **mRNA provides a template** for the synthesis of a protein.
Translation
50
What are the major steps in Translation?
1. Initiation
2. Elongation
3. Termination
51
In the translation process what are the 3 important types of RNA?
1. Messenger RNA (mRNA)
2. Ribosomal RNA (rRNA)
3. Transfer rna (tRNA)
52
In the translation phase, it is the RNA that **carries code** for prootein synthesis
Messenger RNA (mRNA)
53
In the translation phase, it is the RNA that is a **component of ribosome** (structural support and catalytic activity)
Ribosomal RNA (rRNA)
54
In the translation phase, it is the **adaptor molecule** that provides physical and **informational link between mRNA and the polypeptide being synthesized**
Transfer RNA (tRNA)
55
In the translation phase, it is the **site** of **protein synthesis**
Ribosomes
56
What are the two subunits of Ribosomes?
1. Small subunit
2. Large subunit
57
Between the two subunits of ribosomes, which is the **decoding site** and **mediates the interaction between mRNA and tRNA**?
Small subunit
58
Between the two subunits of ribosomes, which is the **active site** and **catalyzes peptide bond formation**?
Large subunit
59
In the 1st step of Translation, the **ribosome** finds the ____________ on the mRNA sequence
initiation site
60
In the 1st step of Translation, what codon represents the **initiation site**?
AUG codon (start codon)
- it codes for Methionine
61
In the 2nd step of Translation, the ________ binds the tRNA to its surface so that base pairing can occur between ________ and _______
ribosome; tRNA and mRNA
62
In the 3rd step of Translation, the ribosome moves along the mRNA, codon by codon, in the ________ direction
5’ to 3’ direction
63
In the 4th step of Translation, as each codon is processed, an ________ is translated by the interaction of mRNA and tRNA
amino acid
64
In the 5th step of Translation, the ribosome provides an enzyme that **catalyzes** the ________ between adjacent amino acids, resulting in a **growing polypeptide** – catalyzed by enzyme peptidyl transferase
covalent peptide bonds
65
In the 5th step of Translation, the ribosome provides an enzyme that **catalyzes** the covalent peptide bonds between adjacent amino acids, resulting in a **growing polypeptide** which is catalyzed by the enzyme __________
peptidyl transferase
66
In the 6th step of Translation, **termination of translation** occurs when the ribosome arrives at a ________ on the mRNA sequence
stop codon
- UAA
- UAG
- UGA
67
In the 7th step of Translation, upon completion of synthesis, the **mRNA**, **ribosome** and **polypeptide** ________ from one another
separate
68
In the 8th step of Translation, The ________ is **released** into the cytoplasm
polypeptide
69
What is the summary of the DNA Translation process?
1. Ribosome finds the **initiation site** (AUG)
2. Ribosome binds to tRNA to its base ---> **base paring** occurs betw. tRNA & mRNA
3. Ribosome moves along the mRNA in the **5’ to 3’ direction**
4. **Amino acids** are translated by the interaction of mRNA and tRNA
5. The ribosome provides an enzyme that catalyzes the covalent peptide bonds ----> growing polypeptide (catalyzed by peptidyl transferase)
6. Ribosome arrives at a **stop codon** ---> **Termination of translation**
7. **mRNA**, **ribosome** and **polypeptide** **separate** from one another
8. Polypeptide is released into the cytoplasm
70
Type of modifications that occur in **newly synthesized polypeptides** to become **functional proteins**
Post-translation Modifications
71
72
Identify the protein by its structure
It is a type of protein that is a **linear** sequence of amino acids
Primary
73
Identify the protein by its structure
It is a type of protein that is a local **folded proteins** that occur inside a polypeptide due to atom interactions
- alpha-helix
- beta-pleated sheets
Secondary
74
Identify the protein by its structure
It is a type of protein that is a **three-dimensional framework** of the polypeptide, due to interactions between the R groups of the A sequence of the protein - Hydrophobic interactions
- H bonds (non-covalent bonds)
- sulfur bridges
Tertiary
75
Identify the protein by its structure
It is a type of protein that is an association of two or more polypeptides into a **multi-subunit complex**; assembly of individual polypeptides into a larger functional cluster (contains more than one subunit - hemoglobin)
Quaternary
76
Identify the protein by its composition
It is a type of protein that contains a series of **amino acids only**
Simple protein
77
Identify the protein by its composition
It is a type of protein that contains amino acid residues plus prosthetic groups
Conjugated protein
78
Give the corresponding amino acid for the protein
Nucleoproteins
Nucleic acids
79
Give the corresponding amino acid for the protein
Lipoprotein
Lipids
80
Give the corresponding amino acid for the protein
Glycoproteins
Carbohydrates
81
Give the corresponding amino acid for the protein
Phosphoproteins
Phosphate groups
82
Give the corresponding amino acid for the protein
Hemoproteins
Heme
83
Give the corresponding amino acid for the protein
Metalloproteins
Iron or Zinc
84
Identify the protein by its function
It is a type of protein that catalyzes **covalent bond breakage or formation** and speeds up chemical reactions
Enzyme (catalytic)
85
Identify the protein by its function
It is a type of protein that provide **mechanical support** to cells and tissues
Structural
86
Identify the protein by its function
It is a type of protein that **store** amino acids or ions
Storage
87
Identify the protein by its function
It is a type of protein that serves as **antibodies** that protect the body from antigens and serves as **coagulation factors**
Protective
88
Identify the protein by its function
It is a type of protein that bind to DNA to **switch the gene on or off**
Regulatory
89
Identify the protein by its function
It is a type of protein that carry **extracellular signals from cell to cell**
Nerve impulse transmission (Hormones)
90
Identify the protein by its function
It is a type of protein that generate movement (actin, myosin)
Movement (contractile)
91
Identify the protein by its function
It is a type of protein that **carry** small molecules or ions
Transport
