Download Nucleic Acids

Biochemical Composition
Evidence of Evolutionary Relationships
How is DNA related to vertebrate evolution?
• How does DNA encode the characteristics of an organism?
• In what different ways can mutations affect an organism?
• How can a simple mutation end up having a major effect on
the phenotype of an organism?
• How do we use biotechnology to further our understanding of
vertebrate evolution?
Levels of Organization
Levels of Genetic Organization
Macromolecules of Evolution
Nucleic acids are the instructions for making proteins, proteins make up traits,
natural selection selects for traits that give organism more chances of surviving
and reproducing.
A. Nucleic Acids - DNA and RNA
1. universal code (blueprints) for making proteins
2. inherited genetic information
Macromolecules of Evolution
Nucleic acids are the instructions for making proteins, proteins make up traits,
natural selection selects for traits that give organism more chances of surviving
and reproducing.
.
B. Proteins - determine physical traits
1. structure - materials for building cells
2. function a. carry substances throughout the body, in & out of
cells
b. trigger muscle movements
c. assist with all chemical reactions
in the body
d. protect the body against disease
Nucleic Acids
A. Building Blocks of Nucleic Acids
1. Nucleotides 
• 3 basic parts:


B. Nucleotides bond together to form
Nucleic Acids
1. a phosphate group of one
nucleotide attaches to the sugar of
another nucleotide (covalent bond)
2. base pairing - bases bond with
complimentary bases (hydrogen
bond)
Nucleic Acids - DNA & RNA
C. Two Basic Kinds of Nucleic Acids:
1. DNA - deoxyribonucleic acid
a. shaped like a twisted ladder (double helix)
b. contains genes - one gene makes one protein
c. is inherited - from preceding generations
(parents/ancestors)
d. nitrogenous bases One
nucleotide
adenine and thymine
guanine and cytosine
e. copies itself - undergoes replication to produce new
DNA strands
Nucleic Acids - DNA & RNA
DNA Replication
(1) A half of the DNA
ladder is a template to
make a copy of the
whole
(2) Occurs before
cell division mitosis or meiosis
Determine the sequence of the developing DNA strand!
Template DNA Strand Sequence:
Complementary DNA Strand Sequence:
G T C T A C T T G
C A G A T G AA C
Nucleic Acids - DNA & RNA
• DNA Replication (continued)
Play The Double Helix Game
2. RNA - ribonucleic acid
a. single strand of nucleotides
b. decodes genes within the DNA to make proteins
c. 3 types: messenger, transfer, ribosomal
d. nitrogenous bases adenine and uracil, guanine and cytosine
IV. Differences Between DNA & RNA
A. Sugars
B. Number
of strands
C. Bases
D. Location
in the
nucleus
1. DNA
deoxyribose
sugar
doublestranded
A-T
G-C
2. RNA
ribose sugar
singlestranded
A-U
G-C
DNA
RNA
in nucleus,
cytoplasm &
ribosome
V. Protein Synthesis
A. The Connection: Nucleic Acids, Proteins & Traits
DNA  RNA  Protein  Trait
V. Protein Synthesis
B. Transcription - the first phase of making a protein
1. a gene is copied
2. a half of the DNA ladder is a template to create mRNA
Determine the sequence of the developing messenger RNA strand!
Template DNA Strand Sequence:
G T C T A C T T G
Messenger RNA Sequence:
C A G A U G AA C
V. Protein Synthesis
C. Translation - the second phase of making a protein
1. mRNA leaves the nucleus and travels to the ribosome
2. tRNA meets mRNA at the ribosome with the
appropriate amino acids (building blocks of proteins)
• a 3-base sequence of mRNA (a codon) codes for a
specific amino acid
• a 3-base sequence of tRNA (an anti-codon) bonds
with a corresponding codon, delivering its amino
acid
3. amino acids attach together (peptide bond) to form a
polypeptide chain
Translation
Glu
Met
Asp
peptide bond
Use the codon chart to determine
the amino acid sequence of the
developing polypeptide chain!
VI. Proteins
A. Building Blocks of Proteins
1. Amino Acids
B. Amino Acids bond together to make
Proteins
1. proteins differ due to the number,
kind, sequence and arrangement of
amino acids
2. amino acids are attached to one
another by peptide bonds to form
polypeptide chains
3. form determines function of a protein
C. Levels of Protein Structure
1. Polypeptide chains spontaneously arrange
themselves into 3-dimensional structures to form
functional proteins
1º - a straight chain
of amino acids
2º - chains bend and
twist
3º - twisted chain
folds even more;
bonds form to hold the
3-dimensional shape
4º - Several polypeptide
chains in the tertiary structure
come together. This is a
functional protein!
VII. Human Genes & Proteins
A. The Human Genome
46 Chromosomes (23 pairs)
approximately 25,000 genes =
approximately 25,000 proteins
1 protein = approx. 500 amino acids
1 amino acid = 3 nucleotides
25,000 proteins x 1500 nucleotides = 37,500,000 nucleotides
If there are approx. 3,000,000,000 DNA base pairs on all 46 chromosomes, then…
How much of our DNA codes for proteins?
What do they call the rest of the DNA that does not code for proteins?