Download Introduction to Genetics

Introduction to Genetics
A.
B.
C.
D.
E.
Definition of “Genetics”
Proteins
Nucleic Acids
The Central Dogma of Genetics
Historical Perspective
A. Definition of “Genetics”
Genetics: Understanding how information for
protein structure is transmitted, structured, and
expressed
– Transmission of genetic information during
reproductive processes: Heredity
– Structure of genetic information
– Expression of genetic information
B. Proteins
General properties
– Composed of chains of amino acids
– There are 20 different amino acids, each with
distinctive chemical properties
– A protein molecule may contain several hundred
amino acids
– Each different protein has its own order, or
“sequence,” of amino acids
– The correct sequence of amino acids is essential for
the protein’s function
B. Proteins
Functions
– Enzymes: enzymes are biological catalysts that
control almost every reaction in living systems
– Cellular recognition and communication
– Structural components of living cells
B. Proteins
Levels of protein structure
– Primary structure: amino acid sequence
– Secondary structure: localized folding of a chain into
regions of helix or sheet structure
– Tertiary structure: folding of a single polypeptide
chain into a three-dimensional structure
– Quaternary structure: only in proteins with more than
one polypeptide chain; Folding of more than one
chain together
C. Nucleic Acids
General properties
– Composed of chains of nucleotides
– There are 4 different nucleotides
– A nucleic acid molecule may contain several
thousands or millions of nucleotides
– Each nucleic acid molecule has its own order, or
“sequence,” of nucleotides
– The correct sequence of nucleotides is essential for
the nucleic acid’s function
C. Nucleic Acids
Overall function.
• The sequence of nucleotides in a nucleic acid molecule
serves as a blueprint to encode the correct sequence of
amino acids for a protein. The code for a specific protein
is called a “gene.”
• Deoxyribonucleic acid (DNA): DNA molecules
(chromosomes) serve as the “master blueprint” for all of
the cell’s proteins. The DNA molecules are transmitted to
offspring during reproduction.
• Ribonucleic acid (RNA): RNA molecules serve as
“working copies” of the genes for the proteins that the cell
is making at any given time.
D. Central Dogma of Genetics
DNA replication
Transcription
Translation
E. Historical Perspective
Early ideas
– Preformation vs. Epigenesis
– Dispersive Information vs. Germ Plasm
Mid-1800s – Early 1900s:
– Discovery and re-discovery of transmission genetics
Early 1900s – Mid 1900s:
– Discovery of the structure of the genetic information
Mid 1900s – Early 2000s:
– Mechanisms of genetic expression and regulation
– Development of molecular genetics technology