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...
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 phenotype
2. 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 related
2. 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 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
*a protein's amino acid sequence determines its 3D structure and function
4 levels of protein structure:
linear amino acid sequence in polypeptide chain
3D configurations that result from interactions between amino acids' NH and CO groups
: folding of secondary structure back on itself
interactions between two or more polypeptide chains
Hemoglobin is composed of four protein molecules called...
*Each globin contains an iron-containing
Each adult hemoglobin molecule is made of...
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
Genetic disorders of HbA fall into 2 categories:
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
From Proteins to Phenotype