NUCLEIC ACID PART 1 Flashcards
1
Q
- It is a polymer of nucleotides.
- Responsible for the storage and passage of information needed for the production of proteins
- The source of genetic information in chromosomes, which is then passed from parent to offspring.
- Biological molecules that possess heterocyclic nitrogenous bases as principal components of their structure
A
NUCLEIC ACID
2
Q
Nucleic acids are biological molecules that possess ____ as principal components of their structure
A
HETEROCYCLIC NITROGENOUS BASES
3
Q
contain several million nucleotides
A
DNA
4
Q
contain only a few thousand nucleotides
A
RNA
5
Q
DNA is contained in the ____ of the nucleus
A
CHROMOSOMES
6
Q
humans have how many chromosomes
A
46 chromosomes (23 pairs)
7
Q
- basic unit of heredity
- responsible for synthesis of single protein
A
GENES
8
Q
the portion of the DNA molecule responsible for the synthesis of a single protein
A
GENE
9
Q
The nucleotide monomers that compose DNA and RNA consist of
A
monosaccharide (sugar)
Nitrogenous base
phosphate group
10
Q
In RNA the monosaccharide is the aldopentose
A
D-ribose
11
Q
In DNA the monosaccharide is the aldopentose
A
D-2-deoxyribose
12
Q
PYRIMIDINE BASES
A
Cytosine
Uracil
Thymine
PYCUT
13
Q
naming of pyrimidine
A
counterclockwise
14
Q
PURINE bases
A
Guanine
Adenine
PUGA
15
Q
naming of PURINE bases
A
start sa ring that has 2 nitrogen
16
Q
DNA bases
A
A, G, C, T
17
Q
RNA bases
A
A, G, C, U
18
Q
nucleoside is a ____
A
GLYCOSDIE
19
Q
To name a nucleoside derived from a pyrimidine base, use the suffix
A
-idine
20
Q
For deoxyribonucleosides, add the prefix
A
deoxy-
20
Q
To name a nucleoside derived from a purine base, use the suffix
A
-osine
20
Q
A nucleoside is formed by joining 1’carbon of the monosaccharide in which N atom of PYRIMIDINES
A
N1
20
Q
A nucleoside is formed by joining 1’ carbon of the monosaccharide in which N atom of PURINES
A
N9
20
Q
are formed by adding a phosphate group to the 5′-OH of a nucleoside.
A
NUCLEOTIDE
20
**2 important bonds** formed in a **NUCLEOTIDE**
glycosidic bond (N-type)
phosphodiester bond
20
**Nucleotides** are formed by **adding** a **phosphate group** to the ____ of a nucleoside.
5′-OH
20
**Nucleic acids** are composed of ____
nucleotide
20
**NUCLEOSIDE** contains
Nitrogenous base
Sugar (monosaccharide)
20
**nucleotide** is **synonymous** to
nucleoside phosphate
21
**Nucleic acids** (DNA and RNA) are polymers of nucleotides **joined** by
phosphodiester linkages
21
The ____ and ____ of the bases **distinguish** one polynucleotide from another (primary structure)
identity & order
21
In **DNA**, the ____ **carries** the **genetic information** of the organism
sequence of the bases
21
A **polynucleotide** has one free ____ group at the **3’ end**
OH
21
found on the **backbone** of nucleic acids
phosphodiester linkages
21
A **polynucleotide** has one free ____ group at the **5’ end**
phosphate
21
Serves as genetic material in **most organisms**
DNA
21
contains a **backbone** consisting of **alternating sugar** and **phosphate** groups
POLYNUCLEOTIDE
21
**Double-stranded** helix arrangement
DNA
21
# **DNA**
It is also present in ____ and in the ____ of **plants**.
MITOCHONDRIA
CHLOROPLAST
21
# **DNA**
**Prokaryotic** cells may also contain **nonchromosomal** DNA in the form of ____
PLASMID
21
**Single** stranded
RNA
21
* Serves as genetic material for some **viruses**;
* Carrier of genetic information to the **site of protein synthesis**
RNA
21
**small**, **circular** DNA structures that are found in **prokaryotes**
PLASMID
21
# **DNA**
In **eukaryotic** cells, it is present in **chromosomes** in the ____
NUCLEUS
21
# **DNA**
**Prokaryotic** cells, which **lack nuclei**, have a ____ chromosome
SINGLE
22
The **DNA model** was initially proposed by ____ and ____ in **1953**
WATSON & CRICK
23
**DNA** consists of **two** polynucleotide strands that **wind** into a
RIGHT-HANDED DOUBLE HELIX
24
# **DNA DOUBLE HELIX**
The **sugar-phosphate** groups **lie** on the ____
**OUTSIDE** OF THE HELIX
25
# **DNA DOUBLE HELIX**
The **bases** lie on the
**INSIDE** OF THE HELIX
26
**Hydrogen bonds** present in:
**ADENINE-THYMINE**
2
27
**Hydrogen bonds** present in:
**CYTOSINE-GUANINE**
3
28
The **two strands of DNA** are **arranged** ____ to one another
ANTIPARALLEL
29
# **WATSON'S & CRICK PROPOSED...**
**DNA** was made of 2 long stands of nucleotides **arranged in a specific way** called the
COMPLEMENTARY RULE
30
# **WATSON & CRICK**
in the structure, **Nitrogenous bases** are called
RUNGS OF LADDER
31
# **WATSON & CRICK**
in the structure, **Phosphate & sugar backbone** are called
LEGS OF LADDER
32
spaces between 1 turn
groove
33
diamter of **one turn**
20 A
34
**Length** of one **complete** turn
34 A
35
**Major** / **Large** groove
22 A
36
**Minor** / **Small** groove
12 A
37
* The number of **adenosine** residues **equals** the number of **thymidine** residues** (A = T)**
* The number of **guanosine** residues is **equal** to the number of **cytidine** residues **(G = C)**
* Therefore: **A + G = T + C**
CHARGAFF'S RULE
38
**responsible** for the **formation** of the **unique double helical structure** of **DNA**
FORCES OF ATTRACTION
39
# **FOCES OF ATTRACTION (DNA)**
* The force responsible for the **complementarity** between base pairs
* However, it **does not contribute** significantly to the **stability** of the structure
* **easily denatured, melt easily**
* a **weak type** of force
H BOND
40
# **FOCES OF ATTRACTION (DNA)**
**shield** the **negative charges** of backbone phosphates
METAL CATIONS
41
# **FOCES OF ATTRACTION (DNA)**
* **hydrophobic** interactions
* responsible for the **ring portions** of DNA bases
BASE-STACKING INTERACTIONS
42
# **FOCES OF ATTRACTION (DNA)**
interactions **between** the **stacked adjacent base pairs**
HYDROPHOBIC
43
# **Levels of DNA Structure**
Covalent structure and **nucleotide sequence**
PRIMARY
44
# **Levels of DNA Structure**
Any **regular**, **stable structure** taken up by **some or all of nucleotides** in a nucleic acid
SECONDARY
45
# **Levels of DNA Structure**
**Complex folding** of large chromosomes in the chromatin
TERTIARY
46
# **Levels of DNA Structure**
* The **arrangement** (or order) of **specific nucleotides** along the chain is called the **sequence**.
* The **sequence** is **genetic information**
PRIMARY STRUCTURE
47
the **arrangement** (or order) of **specific nucleotides** along the chain is **called** the ____
SEQUENCE
48
# **Levels of DNA Structure | SECONDARY STRUCTURE**
* **most common** double helical structure
* **right-handed** helix with 10 base pairs per 360°turn of the helix.
* Mostly found in DNA chromosomes
B-DNA
49
# **Levels of DNA Structure | SECONDARY STRUCTURE**
* **temporary**
* produced by **moderately dehydrating B-DNA**, right-handed helix with 11 base pairs per turn and are not perpendicular to the helix axis (but lie 20° to the perpendicular)
A-DNA
50
# **Levels of DNA Structure | SECONDARY STRUCTURE**
**left handed** helix with 12 residues per turn (zigzag look of phosphodiester backbone)
Z-DNA
51
# **Unusual Secondary Structures**
Regions of DNA with **inverted repeats**, such that an inverted, self-complementary sequence in one strand is **repeated** in the **opposite orientation** in the **paired strand**
| (**opposite sides**, magkabilaan)
PALINDROMES
52
# **Unusual Secondary Structures**
forms of **palindromic** DNA
hairpin
cruciform
53
# **Unusual Secondary Structures**
Forms when the **inverted repeat** occurs within **each individual strand** of the DNA
| SAME SIDE
MIRROR REPEAT
54
# **Higher (Tertiary) Structure**
* **Intrinsic property** of DNA tertiary structure
* **Coiling of a coil**
* **Results** when DNA is subject to some form of **structural strain **
* Importance:
To facilitate **compaction** through supercoiling
§ Common - underwinding
Important to enzymes of DNA metabolism that must bring about **strand separation**
§ During DNA replication
SUPERCOILING
55
DNA structure in the form of **double helix**
COIL
56
**further coiling** of DNA upon itself
SUPERCOILING
57
* **right-handed** supercoiling (**under**winding)
* **Fewer** than number of turns
NEGATIVE SUPERCOIL
58
* **left**-handed supercoiling (overwinding)
* **Greater** than number of turns
* During DNA replication
POSITIVE SUPERCOIL
59
DNA is **continuously** ____
INTERTWINED
60
is either **restricted** or **forbidden** altogether
FREE END ROTATION
61
**Two circular strands** are linked ____
ONLY ONCE
62
____ is **impossible**, unless **one of them is broken**
UNTANGLING
63
DNA strands are **unaffected** by **continuous deformation** (conformational changes, protein interactions) as long as **no breaks are introduced**.
DNA TOPOLOGY
64
refers to a DNA segment **constrained** so that the **free rotation of its ends is impossible**
TOPOLOGICAL DOMAIN
65
Maintained only if the DNA is a **closed circle** or if it is bound and stabilized by proteins so that the strands are **not free to rotate** about each other
TOPOLOGICAL DOMAIN
66
* enzymes responsible for **altering** the **superhelicity**/**supercoiling** of the cellular DNA
* important in the process of **replication**
TOPOISOMERASES
67
**cuts one** strand of DNA and **reseals** after
TOP I
68
**cut both** strands of DNA
TOP II
69
* found in **eukaryotes** only
* Formed by **electrostatic attraction** between the negatively charged phosphate group of **DNA** and the positively charged group of **histones**
| DNA + HISTONE =
CHROMATIN
70
DNA is complexed with a number of proteins (**basic proteins**):
HISTONES
71
will **stabilize** histone
ELECTROSTATIC INTERACTION
72
DNA + HISTONE
NUCLEOSOME
73
* the **major class** of proteins associated with DNA which exists in approximately **equal** to **DNA** in the chromatin.
* **Small**, **basic** proteins that **bind to DNA** by noncovalent interactions to form **nucleosomes**
| HELPER PROTEINS
HISTONES
74
**Histones bind to DNA** by noncovalent interactions **to** **form** ____
NUCLEOSOMES
75
**linker** histone
H1
76
In many **eukaryotes** there are **amino acid sequence** variants of **all** the histones **except**
H4
77
**All histones** are ____ **modified** at various stages of cell cycle
POST-TRANSLATIONALLY
78
* **Single**-stranded; most carry out functions as single strands
* Acts as an intermediary by **carrying information encoded in DNA** to specify the amino acid sequence of a functional protein
* Found **both** in the **nucleus** and **cytoplasm**
* Roles
¨ **Storage** and **transmission** of **information**
¨ **Catalysis**
RNA
79
**RNA** is **produced** during
TRANSCRIPTION
80
* **Encode** the amino acid sequence of one or more polypeptides specified by a gene or set of genes
* Once mRNAs reach the ribosomes, the messengers provide the **templates** that specify amino acid sequences in polypeptide chains
| **CONTAINS THE MESSAGE**
MESSENGER RNA
mRNA
81
One mRNA codes for **only one** polypeptide
MONOCISTRONIC
82
One mRNA codes for **2 or more** polypeptide:
POLYCISTRONIC
83
* **Adapter** molecules that act in protein synthesis
* **Read the information encoded** in the mRNA and **transfer the appropriate amino acid** to a growing polypeptide chain during protein synthesis
TRANSFER RNA
tRNA
84
**Components** of ribosomes
RIBOSOMAL RNA
rRNA
