Anatomy of cell / Signal Transduction pathways (Harrison) Flashcards
What are the Lysomes?
Lysomes are the Enzymatic degradation of extracelllualr and intracellular macromolecules
What is the nucleus?
DNA package with histones to form chromatin.
RER?
Contains ribosomes for synthesizing proteins.
What is the Golgi?
Site for protein folding, modification and sorting.
What is the SER?
Synthesizes phospholipids, lipoproteins and sterols.
What is the SER?
Synthesizes phospholipids, lipoproteins and sterols.
What is the Mitochondrion?
Synthesizes ATP.
What are Peroxysomes?
Synthesis and degradation of hydrogen peroxide?
What are the purpose of microtubules and microfilaments?
Responsible for cell morphology and the machinery for movement of organelles
What is the hydrophilic head and hydrophobic tail made of?
Hydrophilic head is made of a Phosphate function group and the hydrophobic tail is made of a Glycerol fatty acid chains.
What is an IMP, compared to transmembrane?
An integral, or intrinsic, membrane protein is a type of membrane protein that is permanently attached to the biological membrane. All transmembrane proteins are IMPs, but not all IMPs are transmembrane proteins.
Most integral are transmembrane and have exposed portions on both sides.
Heterochromatin vs Euchromatin
Heterochromatin (packaged tightly) is not actively transcribed into RNA, while euchromatin (loosely) is active transcribed into RNA.
What are Receptor Tyrosine Kinases? Give an example of signal transduction with these
A class of transmembrane proteins that are important for signal transduction.
- ) Inactive tyrosine kinase gets bound by single dimer.
- ) Kinase activity is stimulated.,
- ) Tyrosines are phosphorylated.
- ) Intracellular proteins bind to phosphorylation-tyrosine docking sites.
The fluid mosaic model tells us what about proteins in the cell membrane?
Proteins are constantly changing because of the dynamic bilayer.
3 parts of the nucleus?
Nucleoplasm contains the genetic information, guarded by the Nuclear envelope, with nuclear pores that allow for selective exchange.
Individual genes are present on __?
Only ONE chromosome,
There are 2 homologous chromosomes per cell, so two copies of each gene in a cell.
Chromosome structure?
- Homologous chromosomes
- P arm
- Centromere
- q arm
Total length of human genome in meters + microns, and the average size of a nucleus in microns?
Genome - 2 meters, 2,000,000 microns
Nucleus - 6 microns
Histone charge? How many times does DNA loop? What are histones? What are nucleosomes
DNA wraps are 8 histones twice (histones are positively charged, DNA negatively) forming the nucleosome. Nucleosomes form building blocks of chromatin.
What is the promotor region, exons, introns?
Promotor region - promoter is a sequence of DNA to which proteins bind to initiate transcription of a single RNA transcript from the DNA downstream of the promoter.
Exons - transcribed
Introns - not transcribed
What is at the beginning of the mRNA structure and at the end of it?
Untranslated regions - Start codon and stop codon.
What is splice variation?
RNA splicing resulting in the loss of exons or the inclusion of introns and an altered protein-coding sequence. Also called splice-site mutation.
What are codons? How are they numbered?
3 bases (nucleotides) called triplets that specify amino acids. Ada
Cell communication?
Release of chemical message that is recognized by another cell.
Describe signal transduction using primary messaging, ligand, and secondary messengers?
*message may be directed to certain parts of the cell or even the nucleus to change gene expression via activation of transcription factors*
Describe Protein kinases, what are there targets and where do they target them specifically? What is a Dual specificity protein kinase?
How is specificity achieved?
Modification difference between protein phosphorylation and dephosphorylation?
How is information often relayed? What can this result in?
This often results in massive signal amplification
Describe 3 ways on how pathways may be activated by one or more stimuli?
This often results in massive signal amplification
The relative activation of 1 pathway or another reps on “context”. Name 3 examples of this?
What organizes the relative activation of 1 pathway or another? Describe how they do this?
Adaptor protein + signaling proteins = specific signaling complex
Give a unspecific general example of scaffold protein? Also what is the proper nomenclature for displaying reaction pathways.
Adaptor protein + signaling proteins = specific signaling complex
