Flashcards in Eukarya Deck (22)
Cell wall is composed of ___ (___ in fungus, ___ in plants/algae, ___, or ___)
Nucleus contains ___ (___ is loosely packed and easily transcribed while ___ is densely packed with low levels of transcription)
Nucleus is surrounded by a ___ membrane
What is allowed to enter the nucleus?
nucleotides, ATP, DNA/RNA polymerase, transcription factors
What exits the nucleus?
tRNA, mRNA, rRNA
mRNA for ___ PRO stays free in the cytoplasm while mRNA for ___ PRO, ___ PRO, and ___ PRO is directed to the ER
What is the endoplasmic reticulum?
system of phospholipid membrane channels
What makes the rough ER different from the smooth ER?
it is embedded with ribosomes
What are the functions of the rough ER? (In steps)
1. mRNA leaves the nucleus and attaches to the ribosome
2. PRO synthesis begins
3. signal recognition particle (SRP) binds to signal peptide
4. SRP attaches to the receptor, translocator channel opens, polypeptide enters ER
5. signal peptidase removes signal peptide
6. ribosome subunits and mRNA break away
7. PRO folds into final shape
Smooth ER is involved in ___ synthesis
What is the Golgi body?
set of membrane compartments involved in further processing of PRO and their distribution, the PRO are packed in int vesicles and transported
What are lysosomes?
internal vesicles containing hydrolytic enzymes required for degradation of materials brought in by phase/endocytosis
Mitochondria produce most of the ___. They can ___ some PRO while others are ___
List and briefly describe the parts of the mitochondria:
1. outer membrane: many porins make it very permeable
2. inner membrane: 75% PRO and 25% lipid, contains transport PRO, enzymes, cytochromes, and ATPases
3. matrix: contains enzymes from citric acid cycle, DNA and 70s ribosomes
What are the parts of the chloroplast?
outer membrane, inner membrane, thylakoid, stroma
Thylakoids contain ___ and ___ that harvest ___ energy and membrane-bound ___ that use energy to produce ___
Describe the eukaryotic cytoskeleton
complex network of PRO filaments that organize cytoplasm and give cell its shape
What are the types of cytoskeleton?
microtubule, actin filament, intermediate filament
they grow from the centrosome and transport organelles around the cytoplasm, kinesis and dyeing attach to the organelles and "walk" on microtubules to transport
What are centrioles?
organizing centres for microtubule arrays, composed of one complete and two half microtubules (triplets)
What are basal bodies?
centrioles near the cytoplasmic membrane