Structure of prokaryotic DNA?
one supercoiled circular chromosome found in nucleiod
4 major differences between eukaryotes and prokaryotes
- -Eukaryotes are larger
- -Eukaryotes have chromosomes in nucleus
- -eukaryotes have lots of internal membrance
- -eukaryotes have a diverse and dynamic cytoskeleton
Euakryote nucleus is surrounded by?
ribosomal RNA synthesis occurs in?
Where are ribosomes found
cytosol - fluid part of cytoplasm
ribosomes are composed of?
RNA and protein
Rough ER function
Rough ER structure
membrane bound tubes and sacks
function of peroxisomes
function of lysosomes
storage or waste processing
What 3 processes deliver materials to the lysosome
- -receptor-mediated endocytosis
brings fluid into the cell
function of mitochondria
structure of mitochondria
- -2 membranes
- -inner membrane has cristae
solution in cristae of mitochondial inner membrane
membrane bound vesicles called thylakoids
solution outside thylakoids
openings within nuclear envelope
how many membranes does the nuclear envelope have
2 membranes consisting of a lipid bi-layer each
what kind of signal do proteins going to the nucleus have?
17-amino acid long NLS
- -protein enters Rough ER, It's synthesized by ribosomes
- -Protein exits rough ER, Goes ot CIS face of Golgi
- -protein enters Golgi and is processed as it moves to TRANS face
- -protein exits Golgi at trans face and goes to destination
- -proteins going to endomembrance system have a 20-amino acid long ER sequence
- -ER signal sequence binds to signal recognition particle
- -SRP then binds to recepter in ER membrance
how are proteins transferred to and from Golgi?
network of fibers
- -provide structure
- -provide movement
- -transport materials
3 cytoskeletal elements
- -actin filaments
- -intermediate filaments
smalles cytoskeletal elements
actin filaments a.k.a microfilaments
what polymerizes to form actin filament
where are actin filaments found
grouped into long bundles or dense networks, found just inside plasma membrane
function of actin filaments
- -help define shape
- -interact with myosin to cause movement
actin-myosin interaction cause what?
- -cell crawling
- -cytoplasmic streaming
function if intermediate filaments?
- -provide stability
- -provide movement
- -provide structural framework for organelles
large, hallow tubes made of tubulin dimers
where do microtubules originate
Microtubule organization center
microtubule organization center in animals
- -transport vesicles moving throughout cell on microtubule tracks
- -energy dependant
- -requires ATP and Kinesin
What is Kinesin
motor protein that converts chemical energy from ATP to mechanical work
What are flagella
long, hair like projections from cells involved in movement
bacterial flagella are made of?
euakaryote flagella are made of?
cell wall function
gives shape and counters turgor pressure
extracellular matrix function
structural support for cell, helps them stick together
most commin ECM fiber, is flexible
signal tranduction pathway
- -protein binds to receptor at cell surface
- -signal is transduced by G protein
- -G protein changes GDP to GTP and becomes active
- -G protein splits in 2, i part attached to the enzyme
- -enzyme amplifies by catalyzing secondary messengers
activated receptors activate enzymes which activate other enzymes and so on.