BIO 111 Lecture Notes - Lecture 13: Fetal Hemoglobin, Fetus, Fruit Preserves
Document Summary
Ability of cells to control their level of gene expression. Proteins are produced at certain times and in specific amounts. Constitutive genes are unregulated, have constant levels of expression. Cell types in an organism through cell differentiation. Cells contain the same genome, but express different proteomes (proteins) Gene regulation ensures developing fetus has enough oxygen. Fetal hemoglobin has higher affinity for oxygen compared to adult hemoglobin. Bind to dna, affect transcription of one or more nearby genes. Activators increase rate of transcription repressors inhibit transcription small effector molecules they affe(cid:272)t the a(cid:272)ti(cid:448)ators or the repressors (cid:449)hi(cid:272)h affe(cid:272)ts ho(cid:449) they"re trans(cid:272)ri(cid:271)ed. Binds to transcription factor and causes conformational change. A cluster of genes under transcriptional control of one promoter regulatory region called operator. Transcribed into mrna as polycistronic mrna encodes more than one protein (many) Has info for 3 genes in one bundle. When lactose is present: allolactose is a small effector molecule, binds to respressor and turns it off.
