Eukaryotic Cells Flashcards
Centromere
The center of a chromosome
Nucleus
Contains genome surrounded by nuclear envelope. Within replication splicing and transcription occurs
Telomeres
The ends of chromosomes, which have repeats
Telomerase
Maintains the the telomeres during dna replication
Locus
Location of a chromosome
What affects the expression of genes on a chromosome
Depends on the promoter region and the enchanter elements. Also the location or locus plays a part
Heterochromatin
Area of the chromosome where it is incredible dense. It’s usually not active and the genes are inaccessible
Euchromatin
Not as densely packed areas compared to heterochromatin
Nucleolus
Region of the nucleus with no membrane departing it from the nucleus so it is a ribosome factory
Nuclear envelope
Has two lipid bilayers. The outer membrane is contiguous with ER lumen. It has nuclear pores which allow molecules smaller than 60kda in
Nuclear localization sequence
Larger protons have a specific AA sequence that allow it to get into the nucleus. For example proteins made in the ribosomes of the cytoplasm
How does RNA leave the nucleus?
Via a specific transport system with a localization sequence
What are amino actor tRNA syntheses for?
For AA to attach to their respective tRNAs within the cytoplasm
Why is the inner membrane important for within the mitochondria?
It’s the site if the ETC, ATP synthase, and it’s the site of the proton gradient. It’s also impermeable
Outer membrane of mitochondria?
Smooth and allows for passage of small molecules
What kind if DNA does mitochondria have?
Single circular DNA much like prokaryote DNA
maternal inheritance is
Means mitochondria is inherited from the mother
Where are the proteins that encode for the ETC located
They’re located in the mitochondria also mitochondria DNA encodes for those proteins
Why is the rough ER rough
Because of the large amount of ribosomes on the surface it’s important for protein synthesis and the lets proteins go to the secretory pathway
Smooth ER
No protein synthesis but contains proteins for steroid hormones and degradation of environmental toxins
Where do all proteins get translated
On the rough ER
What are localization signals for
For proteins that are going to the mitochondria nucleus or peroxisome
What is the function of the Golgi apparatus
Modification of proteins made in RER sorting and sending proteins to the correct destinations
synthesizing macromolecules like polysaccharide
What is the direction of flow in the Golgi
ER – C I S – medial – trans. They leave the transport vesicles from the trans
Lysosomes function
Responsible for the degradation of biological macromolecules by hydrolysis
Made in the RER are modified by the golgi released from the trans
Phagocytosis
Degradation of large particles
Macrophages
Made by the immune system to engulf bacteria and viruses
Peroxisome
Produce peroxides
Produce hydrogen peroxide as a byproduct
Necessary for lipid breakdown which are fats
Are important for the liver for detox
