Mutations altering a protein's amino acid sequence can result in...
Phenotypes ranging from insignificant to lethal
Enzymes facilitate biochemical reactions by
chemically converting substrates to products
In cells, enzymatic reactions are interconnected to form chains of reactions called...
biochemical pathways
What is metabolism
The sum of all biochemical reactions occurring in a cell; biochemical reactions are metabolic pathways
Substrate of the blocked reaction may accumulate to toxic levels resulting in...
1. An abnormal phenotype2. Or an essential enzyme required to produce a molecule needed for some cellular function is lost
In early 20th century, Sir Archibald Garrod proposed that....
1. Human genetic disorders and metabolism are related2. Patients with alkaptonuria lacked the enzyme to carry out specific biochemical reactions= inborn errors of metabolism
Humans cannot synthesize____ essential amino acids, including phenylalanine
9, thus we obtain these 9 from our diet
Where does the phynylalanine that we consume go?
2/3 is converted to tyrosine and 1/3 is recycled into protein construction
Phenylketonuria results from...
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.
Disorders stem from genes that affect...
1. lipid metabolism2. nucleic acid metabolism3. carbohydrate metabolism
Hemoglobin is...
an iron-containing protein in RBC's that transports O2 from the lungs to the cells of the body
*a protein's amino acid sequence determines its 3D structure and function4 levels of protein structure:
1. Primary: linear amino acid sequence in polypeptide chain2. Secondary: 3D configurations that result from interactions between amino acids' NH and CO groups3. Tertiary: folding of secondary structure back on itself4. Quaternary: interactions between two or more polypeptide chains
Hemoglobin is composed of four protein molecules called...
globins*Each globin contains an iron-containing heme group
Each adult hemoglobin molecule is made of...
2 alpha globins and 2 beta globins
pseudogenes
nonfunctional copies of genes whose nucleotide sequence is similar to the functional gene, but mutations prevent their expression
Genetic disorders of HbA fall into 2 categories:
1. Hemoglobin Variants: production of molecules with changes in the amino acid sequence of the globin polypeptides2. Thalassemias: characterized by imbalances in globin synthesis