Cell Differentiation & Gene Expression
Test Yourself Q 1: Do you think living things have common genes? Q2: Do you think humans have the same sets of genes? Q3: Do you think different cells from the same organism have the same genes? Q4: Do you think different cells from the same organism have different jobs/functions?
% of DNA Shared The genetic information encoded in living things is similar. Genes coding for: Growth & development Reproduction Metabolism Basic cell functions Living things will retain parts of its original genome key component of evolution
Write the name of the organism in the percentage circle to show shared DNA with humans Try This! chimp mouse 98% Baker’s yeast cow dog Wine grape Zebra-fish platypus chicken roundworm Fruit fly honeybee
Cell differentiation Cell differentiation: differentiation is the process by which a less specialized cell becomes a more specialized cell type. Stem cells can differentiate to become all the different cell types through gene expression Certain genes can be turned ON or OFF at different times Example: early embryonic stem cells differentiate into liver cells or blood cells depending on the specific genes that are expressed
Cell differentiation is due to gene expression Gene expression is the activation of a gene that results in a specific protein specific proteins can dictate a specific cellular function pancreatic cells produce the protein insulin that help in digestion whereas red blood cells have the protein hemoglobin that help in transporting O2 and CO2 Genes can be turned OFF and ON when specific proteins are needed All somatic or body cells in an organism have the same genome- ALL 20,000 genes, but can selectively express the genes needed for it’s specific “job”
Scientists try and “alter” gene expression steps to cure diseases! Gene expression is regulated throughout a cells life in order to control it’s functions For example, you would not want the cells in your eyes to start producing the digestive enzymes that are produced by your cells in your digestive tract Gene expression is regulated at different points “during” and “after” transcription and translation Scientists try and “alter” gene expression steps to cure diseases! http://glencoe.mheducation.com/sites/9834092339/student_view0/chapter16/control_of_gene_expression_in_eukaryotes.html
Gene Regulation Activators increase binding of RNA polymerase to the promoter gene and increases the rate of transcription Repressors bind at or near the promoter and interfere with activity of RNA polymerase to stop transcription
Today’s Activity We will be examining a variety of human cells and exploring the role of proteins in cellular functions We will learn how the type and the amount of proteins produced by a cell are regulated
The Types of Cells Beta cells are located in your pancreas and produce a hormone called insulin. Insulin regulates cellular uptake and metabolism of sugars and fats Red blood cells produce hemoglobin. Hemoglobin is a protein which transports oxygen to every other cell in the body Intestinal lining cells produce enzymes that contribute to steps in digestion Smooth muscle cells are located in your digestive system and contract or relax in waves in order to help move food through the digestive tract
Chromosomes and Genes Expressed We will be using chromosome 2 & 11 from the human genome Each gene shown in the tables represent a segment of DNA on chromosome 2 and chromosome 11 - inactive gene + active gene There are groups of genes which are active in every cell active in 1 type of cell not active in any
Test Yourself Q 1: Do you think living things have common genes? Q2: Do you think humans have the same sets of genes? Q3: Do you think different cells from the same organism have the same genes? Q4: Do you think different cells from the same organism have different jobs/functions?
State test question
State test question