Genes, Traits, & Proteins

Biology 100/101
Lecture 13:
Genes, Traits, & Proteins

Text Readings
in Lewis Review questions "To think about"

Chapter3
Amino Acids, Protein Structure & DNA, pgs 48-53
Chapter 14
Human genome Information, pgs302 & 303
Chapter 15
DNA Structure & Replication pg. 323; 4, 5, 6, & 9 pg. 323; 3

Text Readings in Lewis	Review questions	"To think about"
Chapter3 Amino Acids, Protein Structure & DNA, pgs 48-53 Chapter 14 Human genome Information, pgs302 & 303 Chapter 15 DNA Structure & Replication	pg. 323; 4, 5, 6, & 9	pg. 323; 3

Answers to many of these questions can be found on the "Answers to End-of-Chapter Questions" page at the text website.

For feedback, post possible answers and ideas in the folder "Text 'Review' and 'To Think About' Questions" in the Biology Chat Section of Web Crossing.

Objectives
After studying this material you should be able to:

Draw a diagram, create a concept map, or write a paragraph that explains the relationships among these terms;

semi-conservative
replication chromatids homologous
chromosomes

DNA genes gene loci

alleles nucleotide
base gene expression

proteins traits cell cycle
Use your chromosome models from discussion or lab to illustrate the location of a gene for the production of a particular protein. Illustrate the location of the gene on homologous chromosomes as well as sister chromatids.
Explain in general terms how the structure of the DNA molecule is related to the production of a specific protein, such as the Cystic Fibrosis membrane protein.
Describe the connections among;
- variations in the structure of the DNA molecule of a gene for a particular trait,
- the existence of different alleles for a gene,
- different protein structures produced by different alleles for the same gene,
- and, different expressions of the trait.
Describe the roles of DNA, DNA nucleotides, and enzymes in the semi-conservative replication of DNA.
Use your chromosome models to relate the process of DNA replication to the cell cycle, the formation of sister chromatids, and the replication of alleles.

General Web Resources
Marathon results

What is DNA, Why do we need it, and Where does it come from?

Nucleotide bases - A, G, C, T (Fig. 15.9 & 15.10 in text)

Sugar - Deoxyribose

Phosphate group

Complimentary Base Pairing - A-T & C-G in antiparallel configuration

The Double Helix

DNA & Chromosome Replication

Lewis Text pages 317 - 319
DNA Replication diagram. (from the University of Arizona)
The Collaboration of Proteins During Replication [of DNA]

What is protein, Why do we need it, and Where does it come from??

Protein Molecules and their structure (p. 48-53, text)
- Amino Acids
- Primary Structure (Sequence of Amino Acids)
- Secondary Structures (alpha helices or beta pleated sheets)
- Tertiary Structure (3-D Folding)
- Quaternary Structure (Association of 2 or more polypeptide chains)
Example proteins
- Some hormones like insulin & glucagon;
- O2 carriers such as hemoglobin in red blood cells & myoglobin in muscles
- Antibodies & antigens
- Muscle contraction; Actin, myosin & dystrophin
- Hair structure; keratin
- All enzymes (i.e. alcohol dehydrogenase, DNA polymerase, DNA repair enzyme)

Traits & Gene Expression

What happens when something goes wrong? gene to protein: disease

Cystic Fibrosis: An Example of the Role of Proteins in Gene Expression (Text p. 262, It Can't Be!)

Cystic Fibrosis (SCIENTIFIC AMERICAN, Dec. 1995
Cystic Fibrosis: gene to product
Relationship of the Structure of Proteins to their Functions.
How does heredity influence disease? (Cystic Fibrosis example) (Fig. 138, p. 268 text)

Xeroderma pigmentosum: Another example (Fig. 15.15, p. 322 text)

XP fact sheet
Introduction good site describing all facets of XP
Children of the night describes the everyday life of children living with Xeroderma pigmentosum.
XP Society

Preview: Protein Synthesis (From Access Excelence)

Take me home.

semi-conservative replication	chromatids	homologous chromosomes
DNA	genes	gene loci
alleles	nucleotide base	gene expression
proteins	traits	cell cycle