Chapter 10

Phenotypes ranging from insignificant to lethal

chemically converting substrates to products

biochemical pathways

The sum of all biochemical reactions occurring in a cell; biochemical reactions are metabolic pathways

1. An abnormal phenotype

2. Or an essential enzyme required to produce a molecule needed for some cellular function is lost

1. Human genetic disorders and metabolism are related

2. Patients with alkaptonuria lacked the enzyme to carry out specific biochemical reactions= inborn errors of metabolism

9, thus we obtain these 9 from our diet

2/3 is converted to tyrosine and 1/3 is recycled into protein construction

a mutation that prevents conversion of Phe into Tyr

*individuals with PKU build up high levels of Phe and its derivatives that can result in mental retardation, neurological disorders, seizures, etc.

1. lipid metabolism

2. nucleic acid metabolism

3. carbohydrate metabolism

an iron-containing protein in RBC's that transports O2 from the lungs to the cells of the body

1. Primary: linear amino acid sequence in polypeptide chain

2. Secondary: 3D configurations that result from interactions between amino acids' NH and CO groups

3. Tertiary: folding of secondary structure back on itself

4. Quaternary: interactions between two or more polypeptide chains

globins

*Each globin contains an iron-containing heme group

2 alpha globins and 2 beta globins

nonfunctional copies of genes whose nucleotide sequence is similar to the functional gene, but mutations prevent their expression

1. Hemoglobin Variants: production of molecules with changes in the amino acid sequence of the globin polypeptides

2. Thalassemias: characterized by imbalances in globin synthesis