Transcript biochemical composition presentation

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,
and traits that are best fit for the environment are passed on.
Nucleic Acids - DNA and RNA
• universal code (blueprints) for making proteins
• inherited genetic information
Macromolecules of Evolution
Nucleic acids are the instructions for making proteins, proteins make up traits,
and traits that are best fit for the environment are passed on.
Proteins - determine physical traits
• structure - materials for building cells
• 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
Nucleotides are the building blocks of nucleic acids.
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Nucleic Acids
Nucleotides bond together to form nucleic acids
• a phosphate group of one nucleotide attaches to the
sugar of another nucleotide (covalent bond)
• bases bond with complimentary bases (hydrogen bond)
DNA - deoxyribonucleic acid
• shaped like a twisted ladder (double helix)
• contains genes - one gene makes one protein
• is inherited - from preceding generations (parents
ancestors)
• nitrogenous bases - adenine and thymine; guanine and
cytosine
• copies itself to produce
new DNA strands
DNA Replication
• A half of the DNA ladder is a template to make a copy of
the whole
• Occurs before cell division
– mitosis or meiosis
DNA Replication
Determine the sequence of the developing DNA strand!
Template DNA Strand Sequence:
G T C T A C T T G
Complementary DNA Strand Sequence:
C A G A T G AA C
2. RNA - ribonucleic acid
• single strand of nucleotides
• decodes genes within the DNA to make proteins
• nitrogenous bases –
adenine and uracil
guanine and cytosine
2. RNA - ribonucleic acid
• 3 types: messenger, transfer, ribosomal
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
in nucleus,
cytoplasm &
ribosome
Protein Synthesis
Protein Synthesis
DNA  RNA  Protein  Trait
Transcription
• a gene is copied
• a half of the DNA ladder is a template to create mRNA
Transcription
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
Translation
• mRNA leaves the nucleus and travels to the ribosome
Translation
• tRNA meets mRNA at the ribosome with the appropriate
amino acids (building blocks of proteins)
• amino acids attach together (peptide bond) to form a
polypeptide chain
Translation
• 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
Translation
Glu
Met
Asp
peptide bond
Use the codon chart to determine
the amino acid sequence of the
developing polypeptide chain!
Proteins
• Amino acids bond together to make
proteins.
• Proteins differ due to the number, kind,
sequence and arrangement of amino
acids.
• Amino acids are attached to one another
by peptide bonds to form polypeptide
chains.
• Form determines function of a protein.
Levels of Protein Structure
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!
Human Genes & Proteins
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?