Download Chapter 11 DNA and Genes

Chapter 11
DNA and Genes
Section 2
From DNA to Protein
Genes and Proteins
• The sequence of nucleotides in DNA
are a code for building (1) proteins.
• Proteins are important because they
– make up (2)
– a) some structures in organisms.
– b) enzymes that control the rate of all
chemical reactions in organisms
RNA
• RNA is a nucleic
acid that helps
the cell build
proteins.
•
www.biologycorner.com/bio1/DNA.html
• RNA is made up
of a (3) single
strand of
nucleotides.
RNA Structure
• RNA nucleotides differ from DNA
nucleotides in 2 ways
–Ribose sugar instead of
deoxyribose sugar
–(4) Uracil instead of thymine
–So RNA bases are A-U and C-G
Difference Between DNA and RNA
• DNA
–Deoxyribose
sugar
–Thymine
–Double strand
–A-T, C-G
• RNA
–Ribose sugar
–Uracil
–Single strand
–A-U, C-G
5. Three Types of RNA
a. Messenger RNA (m-RNA)
b. Ribosomal RNA (r-RNA)
c. Transfer RNA (t-RNA)
6. Messenger RNA
• Copies DNA’s
instructions for
making proteins
and brings those
instructions from
the nucleus to
the cytoplasm.
•
www.accessexcellence.org/AB/GG/rna.html
7. Ribosomal RNA
• Makes up the ribosome.
The ribosome binds to
mRNA and uses the
instructions to hook together
amino acids into long chains
that will become proteins.
8. Transfer RNA
• Brings amino
acids to the
ribosomes
based on the
RNA code.
•
ghs.gresham.k12.or.us/.../chpt15/chpt15.htm
9. Transcription
• When m-RNA is copied from
DNA, the process is called
transcription.
• It begins in the nucleus.
Steps of Transcription
• DNA molecule must (10) unzip.
• RNA nucleotides form base pairs
with DNA nucleotides. RNA
nucleotides bond together to form
an m-RNA molecule
• m-RNA leaves the nucleus and
enters the cytoplasm.
Science at a Distance
© 1997, 1998, 1999, 2000 Professor John Blamire
Transcription
The Genetic Code
• When m-RNA enters the
cytoplasm, it has instructions for
how to build proteins. These
instructions are written in a
(11) nitrogen base language and
must be translated into a
language that proteins
understand.
Genetic Code
• On m-RNA, a
sequence of 3
nucleotides is called
a (12) codon.
• GCU ACG GAG
CUU CGG AGC
UAG
•.
•
www.answers.com/topic/genetic-code
• Each codon codes for a
specific (13) amino acid
http://www.biology.arizona.edu
All contents copyright © 1996. All rights reserved.
(14) Translation
• Translation is when the
message in the nitrogenous
base sequence of m-RNA is
changed into an amino acid
sequence in proteins.
Proteins
• Proteins are made up of
(15) 20 different amino acids.
• The sequence of the amino
acids determines the function
of the protein.
Role of t-RNA
• Each t- RNA can bond to a
specific amino acid on one
side of the t-RNA molecule.
• The other side of the t-RNA
molecule has 3 nitrogenous
bases called (16) anticodons.
• Anticodons form base pairs
with (17) codons during
translation
Steps of Translation
• The codon
AUG is a start
codon. This
codon is the
first step in
the building of
proteins.
•
staff.jccc.net/.../translation/steps.html
Steps of Translation
• m-RNA attaches to
ribosome
• t-RNA brings an
amino acid to the
ribosome.
• t-RNA anticodons
form base pairs
with m-RNA
codons.
•
© 2006 The Board of Regents of the University of Wisconsin
System.
Steps of Translation
• t-RNA
anticodons form
base pairs with
m-RNA codons.
• Amino acids
form (18) peptide
bonds to one
another and
break away from
t-RNA.
• Amino acids will
continue to bond
together until a
stop codon is
encountered. At
this point, the
amino acid chain
will enter the
cytoplasm for
further
processing.
•
Brooklyn College
City University of New York
Translation
Translation
encyclopedia.quickseek.com/images/MRNA-intera
19) Central Dogma
Central Dogma
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