Lesson 2 Flashcards
What type of microscopy is used to visualize external cell textures?
Scanning Electron Microscopy (SEM).
Which microscopy allows visualization of structures inside cells?
Transmission Electron Microscopy (TEM).
What is a key characteristic of fluorescence microscopy?
It uses fluorescent dyes to visualize specific cellular components.
What are the steps for a gene to be expressed?
DNA is transcribed into pre-mRNA.
Pre-mRNA is processed into mRNA and exits the nucleus.
mRNA is translated into protein.
The protein may require modification to function.
What governs gene expression?
Differential gene transcription (e.g., histone modification).
Selective RNA processing (e.g., alternative splicing).
Selective mRNA translation.
Protein modifications (e.g., phosphorylation, methylation).
What is the function of histone acetyltransferases (HATs)?
They add acetyl groups to histones, making DNA more accessible for transcription.
How does histone methylation affect transcription?
It can either repress or activate transcription, depending on the context.
What is the basic unit of chromatin structure?
Nucleosome.
What is the function of a basal promoter?
It provides a binding site for RNA polymerase II and basal transcription factors, enabling minimal transcription.
What role do enhancers play in transcription?
They bind transcription factors to increase RNA polymerase activity and regulate gene expression.
How can a gene be expressed in different tissues at different times?
By using tissue-specific transcription factors that bind to enhancers in those tissues.
What is the difference between a constitutive and a basal promoter?
Constitutive promoter: Always ‘on.’
Basal promoter: Allows minimal transcription.
What is the purpose of reporter genes?
They indicate when and where specific enhancers or promoters are active.
What method uses GFP to visualize enhancer activity?
Reporter gene assay.
Which transcription factors are required to create insulin-producing beta-like cells?
Ngn3, Pdx1, and Mafa.
What was the key finding of Zhou et al. (2008)?
Exocrine pancreatic cells can be reprogrammed to produce insulin by expressing specific transcription factors.
What causes Type 1 Diabetes (T1D)?
Immune cells attack insulin-producing beta cells in the pancreas.
What happens when the body doesn’t produce enough insulin?
Hyperglycemia can cause blood vessel damage, kidney failure, and other complications.
What is insulin’s main function?
It signals muscle and fat cells to absorb glucose from the blood.
