What’s wrong with the abnormal cells? Sickled Cell ?

What is anemia?

Anemia - insufficient delivery of oxygen to tissues and organs.

How do red blood cells carry oxygen ? What protein in red blood cells carries oxygen?

What protein in red blood cells carries oxygen? Hemoglobin

Hemoglobin a complex iron-containing protein that carries oxygen and some carbon dioxide throughout the body. It gives blood its red color

Our bone marrow cells produce 100,000,000,000,000 molecules of hemoglobin every second.

What does hemoglobin have to do with sickle cell anemia?

Causes of Anemia abnormal hemoglobin insufficient amount of hemoglobin insufficient amount of red blood cells - genetic factors - dietary deficiency of iron premature destruction of red blood cells

Who has the gene(s) for Sickle Cell Anemia? - approximately 100,000 Americans - most prevalent in persons of African, Hispanic, Mediterranean, and Middle Eastern descent.

Gene for hemoglobin subunit Beta

What is the gene mutation that causes sickle cell anemia? – any change in the base sequence of an organism’s DNA What is the gene mutation that causes sickle cell anemia?

Glutamate

Use the information to figure out the mutation in sickle cell anemia DNA Codon mRNA Amino Acid

Mutation in sickle cell anemia DNA Codon mRNA Amino Glutamic → valine Acid Acid (Glutamate)

Mutation in sickle cell anemia DNA Codon mRNA GAA → GUA Amino Glutamic → valine Acid Acid (Glutamate)

Mutation in sickle cell anemia DNA Codon mRNA GAA → GUA Amino Glutamic → valine Acid Acid (Glutamate) CTT → CAT

Gene Mutations Point mutation – change in one nucleotide

Base Pairing

DNA mRNA DNA mRNA

Deletion of second T in DNA

results from insertion or deletion of a nucleotide Frameshift Mutation results from insertion or deletion of a nucleotide

Mutations Point Mutations (substitution of one nucleotide) Silent Mutation Missense Mutation Nonsense Mutation

The Bubble Boy disease

SCID Severe Combined Immunodeficiency SCID is also know as bubble boy disease

Signs in first year of life: Symptoms of SCID Signs in first year of life: Eight or more ear infections Two or more serious sinus infections Two or more cases of pneumonia Ineffective treatment with antibiotics Infections that require intravenous antibiotic treatment Two or more deep seated infections

Adenosine deaminase- Enzyme that is responsible for the breakdown of an amino group from the adenosine nucleoside. If there is a lack of adenosine deaminase, the deoxyadenosine builds-up and kills white blood cells.

SCID Mutation Alteration in codons which code for the protein/enzyme adenosine deaminase (ADA) Adenosine deaminase deficiency Deficiency of both the B-cell and T-cell forms of immunity

SCID Mutation

Example of a mutation which causes SCID: Codon 140 Deletion of guanime (G) Codon 198 Missense: AG

PKU

What is PKU? Phenylketnonuria Error of metabolism Missing the PAH (phenylalanine hydroxylase) enzyme – this causes the its substrate, the amino acid phenylalanine, to build up in the body

How the PAH enzyme works PAH converts toxic amino acids into non-toxic substances

Symptoms of PKU In infants, symptoms may include: -Slowed development -Inability to crawl, turn over and grasp objects Symptoms are usually recognizable at an early age.

Mutation What codon might be responsible for the shorter protein? Mutant PAH gene single base substitution, G to A. protein is 52 amino acids shorter than normal What codon might be responsible for the shorter protein?

Tay Sachs Disease Extra credit

Can’t make a functional protein Gene Mutation Can’t make a functional protein Genetic (Inherited) Disease

Concept map Add the following terms to your concept map Genetic disease Mutation Inherited Abnormal protein