1Dna
is the set of instruction wherein the organism will grow or smth
sugar is deoxygenated, doesn't have an oxygen at 2’ carbon
-has thymine
2RNA
-5 carbon sugar
-has uracil
3Central Dogma of cell biology
how genetic information is encoded in our DNA read, transcribed, and translated produce proteins
linear process
when 1 cell divide into 2 daughter cells
Semiconservative: each newly synthesized DNA molecule consists of one original strand and one newly synthesized strand
4Semiconservative
each newly synthesized DNA molecule consists of one original strand and one newly synthesized strand
5nucleus
where does central dogma occur
6GENES
Specifies the structure of a single polypeptide or protein chain
• Amino acids à polypeptide à proteins
• Storage of genetic information (DNA)
• In the form of sequences of nitrogenous bases
• Though DNA is present, RNA is the readable form to process the information into proteins
• DNA, RNA, and proteins are informational macromolecules
7informational macromolecules
DNA, RNA, and proteins are called what
8single polypeptide or protein chain
genes Specifies the structure of a ? or ?
9 Pentose sugar (ribose, deoxyribose), Nitrogenous base, Phosphate group
Nucleotides are made up of:
10Chargaff’s Rule
Purine + Pyrimidine
11Purine + Pyrimidine
Chargaff’s Rule
12purines
are larger, with a double-ring structure, and include adenine and guanine.
13pyrimidines
are smaller, with a single-ring structure, and include cytosine, uracil (in RNA), and thymine (in DNA).
145’ to 3’
What is the directionality of DNA?
15B-DNA
• Most common form of dna
• Right-handed
• Anti-helix structure
• 5’ to 3’
• 3’ to 5’
• Major and minor grooves
16expression of specific
traits and qualities
The sequence or order of the bases in a specific
DNA strand is related to the ?
For example, the sequence GTC ATT might be
responsible for curly brown hair, while GTC AAT
might be responsible for straight black hair.
DID YOU KNOW?
17DNA REPLICATION
The process by which a double stranded DNA
molecule is copied to produce two identical DNA
molecules
DNA has junk sequences that need to be cleaned. That's why there is mature rna before it's translated to proteins
18mRNA
is the readable instructions, the most readable molecule of the body for it to be translated
19nucleus during the S-phase of cell division, Semi-conservative
where, when does dna replication occur and is it conservative?
201. Initiation
2. Elongation
3. Termination
steps in dna replication
21Helicase, DNA Primase, DNA Polymerases, Topoisomerase/Gyrase, Ligase
enzymes in DNA REPLICATION
Others:
• dNTPs
• SSBs
• RNA Primer
22helicase
in replication, ? unwinds the DNA -> replication fork
23SSBs
binds to ssDNA to prevent nucleases from
destroying DNA
24wobble theory
The “?” explains why multiple
codons can code for a single amino acid
25Topoisomerase / gyrase
created nicks in the DNA
strands to relive supercoiling
26DNA primase (RNA polymerase)
-> RNA primer at
the initiation site
27DNA Polymerase
incorporates dNTPs:
28DNA polɑ
DNA polymerase incorporates dNTPs:
works with primase to initiate DNA
polymerization
29DNA pol∂
à leading and lagging strand; 5’ -> 3
30Termination of replication
a. in prokaryotes: when two replication forks meet on the
same stretch of DNA
b. In eukaryotes: stochastic, dependent on the location of
replication initiation sites
31in prokaryotes
Termination of replication: when two replication forks meet on the
same stretch of DNA
32in eukaryotes
Termination of replication: stochastic, dependent on the location of
replication initiation sites
33mRNA, tRNA, rRNA
types of RNA
34messenger rna
Produced in the nucleus
• Linear strand that carries a set
of genetic instructions for
synthesizing proteins in the
cytoplasm
• Produced from DNA through
the process of transcription
35Transfer RNA
Produced in the nucleus
• Picks up amino acids floating in
the cytoplasm
• Carries the AA to ribosomes
and positions them correctly as
they are incorporated in a
growing polypeptide chain
36Ribosomal RNA
Together with additional
proteins, rRNA makes up the
structure of ribosomes
• Synthesized in the nucleolus
• Described as an “ancient
molecule” à conserved
through evolution
37DNA TRANSCRIPTION
How is information from DNA copied into a more readable form?
The process by which the information in a
strand of DNA is copied into a new molecule of
messenger RNA. This process is carried out by
RNA polymerase and a number of proteins
called transcription factor.
Steps:
1. Initiation
2. Elongation
3. Termination
381. DNA is unwound like in replication.
2. RNA polymerase would interact with the designated
template strand of DNA through a predetermined
sequence.
a. TATA box
b. Pribnow box
3. RNA polymerase incorporated dNTPs to the growing
stramd à mRNA will be complementary to the
template DNA strand
4. Termination of replication
a. Rho-dependent: protein called Rho-factor is
responsible for disrupting RNA polymerase from
template strand
b. Rho-independent: a loop forms at the end of the RNA
molecule to detach the RNA polymerase
DNA TRANSCRIPTION
39TATA box, Pribnow box
RNA polymerase would interact with the designated
template strand of DNA through a predetermined
sequence.
40Rho-dependent, Rho-independent:
types of Termination of replication in rna transcription
41Rho-dependent
protein called Rho-factor is
responsible for disrupting RNA polymerase from
template strand
42 Rho-factor
Rho-dependent: protein called ? is
responsible for disrupting RNA polymerase from
template strand
43Rho-independent
a loop forms at the end of the RNA
molecule to detach the RNA polymerase
44INITIATION
DNA transcription
1. DNA is unwound like in
replication.
2. RNA polymerase would interact
with the designated template
strand of DNA through a
predetermined sequence.
a. TATA box
b. Pribnow box
45ELONGATION
DNA TRANSCRIPTION
RNA polymerase incorporates dNTPs
to the growing stramd à mRNA will
be complementary to the template
DNA strand
Uracil will replace Thymine
46TERMINATION
DNA TRANSCRIPTION
Termination of replication
a. Rho-dependent: protein called Rho-factor is responsible for disrupting RNA polymerase
from template strand
b. Rho-independent: a loop forms at the end of the RNA molecule to detach the RNA
polymerase
DNA TRANSCRIPTION: TERMINATION
47Prokaryotes
Polycistronic
Translation occurs
simultaneously with
transcription
Little post-transcriptional
modification
48Eukaryotes
Monocistronic
Translation begins after
mRNA is produced,
modified, and exported to
the cytoplasm
Extensively modified after
transcription
49mRNA POST-TRANSCRIPTIONAL MODIFICATIONS
1. Addition of 5’ cap (m7G cap)
2. Poly-adenylation of 3’ end (poly-A tail)
3. Removal of non-coding sequences (introns) through splicing
501. Addition of 5’ cap (m7G cap)
2. Poly-adenylation of 3’ end (poly-A tail)
3. Removal of non-coding sequences (introns) through splicing
mRNA POST-TRANSCRIPTIONAL MODIFICATIONS
515’ CAPPING
Modified guanine (methylated)
attached to the 5’ end of mRNA
transcript
Function:
1. Assist in nuclear transport
2. Prevent degradation by
exonucleases
523’ POLY-ADENYLATION
Serves as the recognition site
for proteins involved in
translation.
Circular structure protects
mRNA from nuclease
degradation.
53mRNA SPLICING
Not all nucleotides within the
pre-mRNA molecule will be used
to encode proteins
• Splicing is catalyzed by a protein-
RNA complex called
spliceosome
• mRNA undergoes “splicing”
• Removal of introns à “junk”
• Maintenance and ligation of
exons
54spliceosome
Splicing is catalyzed by a protein-
RNA complex called
55introns, exons
mRNA undergoes “splicing”
• Removal of ? -> “junk”
• Maintenance and ligation of
?
56mature mRNA
Completion of mRNA post-transcriptional
modifications will result in a ?
transcript ready for translation.
57TRANSLATION
How is transcribed information transformed into proteins?
The process by which proteins are synthesized
using genetic information stored in mRNA. This
process is carried out by ribosomes, tRNA, and
other enzymes.
TRANSLATION
How is transcribed information transformed into proteins?
Steps:
1. Initiation
2. Elongation
3. Termination
58Mature mRNA transcript, Ribosomes, tRNA
in translation: What are needed to start protein synthesis?
59Aminoacyl-tRNA synthetase, Peptidyl transferase
Other important enzymes in translation
60Aminoacyl-tRNA synthetase
“charges” the tRNA with an amino acid
is
responsible for “charging” the tRNA with
its specific amino acid
61Peptidyl transferase
“discharges” amino acid from the tRNA
62Transfer RNA
? brings in specific amino acids (aa)
coded by the mRNA to the ribosomes
• A ? molecule is “charged” when an
amino acid molecule is attached to it
• Aminoacyl-tRNA synthetase is
responsible for “charging” the tRNA with
its specific amino acid
• The anticodon is complementary with an
mRNA codon
Each anticodon is complementary to a
triplet codon in the mRNA transcript
• Each codon encodes for a specific amino
acid
• 61 codons, 21 amino acids
• Start Codon = AUG (Methionine)
• Stop Codons = UAA, UAG, UGA
• “Wobble Theory”
63anticodonA (aminoacyl) site
is complementary with an
mRNA codon
6461, 21, AUG, UAA UAG UGA, wobble theory
? codons, ? amino acids
• Start Codon = ? (Methionine)
• Stop Codons = ?, ?, ?
• “?”
65RIBOSOMES
A (aminoacyl) site
- Where mRNA meets its anticodon
2. P (peptidyl) site
- Where amino acid detaches from its
tRNA and goes with the growing
polypeptide chain
- Start codon attached here
3. E (exit) site
- Where the discharged tRNA leaves
the ribosome
66A (aminoacyl) site
Where mRNA meets its anticodon
67P (peptidyl) site
Where amino acid detaches from its
tRNA and goes with the growing
polypeptide chain
- Start codon attached here
68E (exit) site
Where the discharged tRNA leaves
the ribosome
69PROTEIN SYNTHESIS
mRNA is read in the 5’ to 3’ direction
Growing polypeptide chain has an amino to carboxyl directionality (N-terminus à C-terminus)
705’ to 3’ direction
mRNA is read in what direction
71Polysomes
translation occurs at several points within an mRNA molecule
72CENTRAL DOGMA
says that information flows from DNA to RNA to
protein. In other words, the code in DNA is used to make RNA, and then the code in RNA
is used to make protein. A more complete expression of the Central Dogma in cells has
several components
73dna replication
information flows from DNA to DNA. Each strand of DNA is used as the pattern for building
complementary strands during this ?
74dna transcription
Information flows from DNA to RNA. Genetic code in DNA is used as the pattern for building
complementary RNA molecules. Several kinds of RNA exist in cells: mRNA, tRNA, rRNA, and
other small RNAs (miRNA, siRNA)
75dna translation
Information floes from RNA to protein. Code in mRNA is decoded during translation to determine the amino acid sequence in proteins