Transcript Lazy notes - TeacherWeb

Nucleic Acids & Protein Synthesis
• DNA (_________________________________)
–
contains the information needed to produce
proteins.
•_____________________________ – sequence of
nucleotides in DNA codes for the sequence of amino
acids in protein.
•______________ – a portion of a DNA molecule
that codes for one protein
•_________________________ – the complete set of
genetic instructions in a cell.
1
Structure of DNA
• Two polynucleotide chains
(a) Hydrogen
bonds
P
C
G
Thymine (T)
Adenine (A)
Cytosine (C)
Guanine (G)
P
P
T
P
P
C
G
P
P
G
P
C
P
A
P
• __________________________
between the complementary
base pairs hold the chains
together
• Bases pair specifically:
_________________________
• Forms a double helix
• DNA is wrapped around
histones to form chromosomes
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G
C
A
Nucleotide strand
G
C
T
C
Segment
of DNA
molecule
G
A
(b)
Globular
histone
proteins
Metaphase
chromosome
(c)
Chromatin
2
DNA Replication
•____________________ – process
that creates an exact copy of a
DNA molecule; happens during
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A
G
G
• ____________________________
1) Hydrogen bonds break between
____________________________
2) Double strands unwind and pull
apart
3) New nucleotides pair with
exposed bases (complementary
__________________________)
C
C
G
T
A
Original DNA
molecule
C
G
C
G
A
T
A
C
T
G
A
T
G
C
C
Region of
replication
G
T
T
A
T
A
A
A
C
T
G
A
C
T
T
A
T
G
C
____________________________ enzyme that replicates DNA
T
C
A
T
G
G
G
A
Newly formed
DNA molecules
C
G
A
3
RNA
•RNA – _______________________________________
•Differs from DNA in many ways:
•1) __________________________________ nucleic acid
•2) Nucleotides contain ___________________ instead of
deoxyribose.
•3) Synthesis involves base-pairing like DNA, but uses
________________ in place of Thymine: _____________
4) Different types of RNA have different functions.
___________________________________ - the process of
making RNA from DNA.
4
RNA Molecules
________________________________:
Delivers genetic information from
________________________________
________________________________
Contains information in the form of
______________________________.
Codon – series of _________________
________________________________
That codes for ___________________
________________________________
5
RNA & Translation
•_______________________________ – used to make Ribosomes:
• Provides structure and enzyme activity for protein
synthesis.
1) Attaches to___________ and reads the sequence of codons
2) Forms the peptide bonds between the amino acids after
they are brought to the ribosome by the tRNA.
• _____________________________________________:
•Carries __________________________________ to ribosome.
•Has the complementary _________________ to mRNA codon.
•Translates a codon of mRNA into an amino acid.
•__________________________________ - assembly of an amino
acid chain according to the sequence of codons in the mRNA.
6
Nature of Mutations
• _____________________ – change in genetic information
• Results when DNA nucleotide is:
Changed =
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_____________________________
Code for
glutamic
acid
T
P
Added or Deleted =
T
P
P
A
S
C
P
S
(a)
T
S
S
_____________________________
Code for
valine
P
S
P
• May or may not change the
protein’s structure
Mutation
C
S
(b)
____________________________________ “proof read” and
correct the mutations most of the time.
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