Lecture 4 Flashcards
What is the cell theory
It is a thoery that states that all organisms consist of cells
What do Eukaryotes include?
It includes plants, protists and fungi
What do Prokaryotes include?
It includes bacteria and arhcae
What’s bigger Prokaryotes or Eukaryotes
Eukaryotes
How do prokaryotes divide
Binary fission, no spindle involved
What is DNA like in Prokaryotes
It is is circular with no proteins, and in the cytoplasm
What is dna like in Eukaryotes?
It is associated with histone(proteins) and formed into chromosomes
What structues are always present in Prokaryotes?
The structures that are are always present are cytoplasm, ribsiomes, plasmids, cell wall and cell surface membrance
What structure are sometimes present in Prokaryotes?
Flagellum, Pili, Infolding cell surface membrance, and flagellum
Why is DNA supercoiled in Prokaryotes
It is tightly fitted so more DNA can be packaged
How do internal photosynthetic membranes develop?
They develop from infoldings of plasma membranes
What do internal photosynthetic membranes?
They contain enzymes and pigement molecules required for reactions to occur
What are organelles
Internal comparments within a cell
What is a Flagella
long filaments that rotate to propel the cell
What are Fimbriae
They are needle like projects that promote attachment to other cells or surfaces
What specialized structures do plant cells have?
Vacuoles, chloroplasts and cell wall
What do Vacuoles do
Digest and recycle macro molecules, storage for water and ions, they aref illed with proteins, they contian pigments in flowers and contain noxious componds to protect leaves and stems from beign eaten
What is the nuclear envelope?
It is a double membrane that surrouns the nucleus
What is the nuclear lamia
Lattice like sheet of fibrous proteins
What is the nucleolus
It is a distinct region where ribosomal RNA is synthesized and ribosome subunits are assembled
What are Ribosomes?
complex molecular machines that manafacture protein
What do ribosomes that are free in cytosol do
They manafacture protein that stay in the cytosol or go to other organelles
What do ribosomes that are attached to endoplasmic reticulum do
manafacture proteins that are meant for other stuff
What is the endoplasmic Reticulum
They are extensive membrane- enclosed factory that is continuous with nuclear envelope
What are part of the ER
rough and smooth ER
What is the difference between Smooth ER and rough ER
The smooth Er contains enzymes that catalyze reactions involving lipids and the rough ER contains ribsomes that are shipped to other orgnaelle, plasma membrnae or secreted out the exterior of the cell
What happens after proteins are manafactured on the RER
they move to the lumen and are folded and processed
What does the golgi apparatus do
The golgi apparatus processes, sorts and ships proteins that are synthesized in the rough ER
What is the Golgi Apparatus formed by?
It is formed by flat membranous sacs called cisternae,
What are the parts of the Cisternae?
The cis which is closest to the nucleus recieves products from the rough ER and the rans part that is connected with the plasma membrane ships the products out to other organelles.
What are lysoenzymes
They are recylcing centers found in animals cells
What is the digestive enzyme inside lysoenzymes called
They are called acid hydrolase
What are peroxisomes
They are the center of the reduction-oxidation( redox reactions)
What are glycoxysomes
they ar eplant peroxisomes that oxidixe fats to form energy storage compounds
What is the mitochonidra
It supplies ATP to cells
what are the two membranes of the mitochondria.
The inner membrane is folded into series of sac like cristae and the outer membrane defines the organelles surface
What does the mitochondira being prone to fusion and fission mean?
It results in either elongated and barnches structures called mitochondiral networks or multiple individual organelles
What is the name of the mitochondrial DNA
mtdna
What are the parts of a chloroplast
They have thylakoids, grana and stroma
What is the inner most membrane
The innermost memrbane are called thylakoids
What are thylakoids arranged in?
They are arranged in stacks called grana
Describe the Endosymbiotic theory
it basically suggest that mitochondria and chloroplast were there own cells and fre e living bacteria but were engulfed by ancestors of eukaryotes and were not destroyed because they devloped an endosymbiotic relationship.
What are the surroundign strucutres
The stroma
What does the nuclear envolope have that helps with nucelar transport
Nuclear pore complexes
How do molecules enter the nucleus
They enter the nucleus through nuclear pores and they contain a 17 amino acids long nuclear localization signal(NLS) which marks proteins for tansport through nulcear pore comples
Describe the the secretory pathway
Proteins enter the rough ER while being snythesized by ribosomes and is proceesed then proteins exit ER inside a cesicle and neters the cis part of the Golgi and after it eneters the Golgi it is further modifid and after it leaves the golgi in a vesicle it goes to the oplasma membrane and then it secreted from the cell
In the pulse chase experiment what si the pulse
It radiolabels cells by exposing cells to modified amino acids for short time
What is the chase:
It is when the modified amino acids have been washed away.
After pulse where are the new synthesized protein
In the rough ER
What is happening during chase
Labeled proteins have left RER and entered the Golgi apparatus.
