eukaryotes Flashcards
protoplasm
nucleus and cytoplasm combined
function of cytoplasm
needed for every day chemical tasks
function of nucleus
contains genetic info to produce chemicals for all cell make up
functions of membranes inside the cell
localise enzymes in reaction pathways
-compartmentalise chemicals
largest organelle
nucleus
what is the nucleus surrounded by
double nuclear membrane with pores
nuclear envelope
double nucleur membrane around nucleus that has pores
function of nuclear pores
chemicals pass in and out of nucleus via pores so nucleus can control activity in cytoplasm
2 main substances in nuclear envelope
DNA
RNA
proteins
what happens when cell not actively dividing
DNA bonded to protein to for chromatin which looks like tiny granules
nucleolus
extra dense area of almost only DNA and protein
function of nucleolus
-production of ribosomes
-plays part in growth and division of cell
what surround the mitochondria
an outer and inner membrane
do mit have their own genetic material
oui
cristae
inner membrane of mit folded
fluid matrix
surrounds cristae
function of cristae
gives mit more surface area for respiration
how do scientists think mitochondria and chloroplasts evolved
as symbiotic eubacteria living outside cells
endosymbiotic theory
evolution of eykaryote cells with organelles symbiotic to eukaryotes
where are centrioles found
in a pair near the nucleus
what are centrioles made of
a bundle of nine tubules
function of centrioles
involved in cell division
-when cell divides centrioles pull apart to form spindle of microtubules that are involved in movement of chromosomes
cytoskeleton
dynamic 3d web like structure that fills cytoplasm
whats the cytoskeleton made of
microtubules and microfilaments
what are microfilaments
protein fibres
proteins in microfilaments
related to myosin and actin
-contracile proteins in muscles
what are microtubules made of
globular protein tubulin
vacoules
-not permenant features in animal cells
-many animals make food vacoules around prey
contracile vacoules
important in simple animals that live in fresh water
-allow water content of cytoplasm to be controlled
endoplasmic reticulum
3d network of cavities bounded by membranes
types of cavities in ER
some sac like and some tubular
function of ER
links with other membranes around nucleus and makes up large part of transport system within cell and site of protein transport and synthesis
what are ribosomes made from
ribosomal RNA and protein
large and small subunits
small and large part of 80S ribosomes
40S and 60S
RER
covered with 80S ribosomes
function of ribosomes/RER
make proteins and RER isolates and transports proteins once they are made
exocytosis
when substances leave a cell
features of RER
large surface area for synthesis of proteins and stores and transports them within and out of cell
what is SER involved in
transport and synthesis of steroids and lipids
whats the GA made of
stacks of parrallel flattened membrane pockets called cisternae
how is cisternae formed
by vesicles from ER fusing together
function of GA
-proteins brought to GA in vescicles
-pinched of from RER where theyre made
-vesicles fuse with membrane sacs of GA
-protein enters GA stacks
-
what happens to proteins as they travel in the GA
modified in various ways
lysosomes
digestive enzymes found in GA enclosed in vesicles to form lysosome organelle
features of inner parts of GA
closer to RER
-rich in protein modifying enzymes
features of outer parts of GA
lots of finished protein
receptor binding sites
area#s that need to be outside cell membrane
-oriented by GA so when arriving at membrane inserted correctly
lysosomes
dark spherical bodies in cytoplasm
-mix of digestive enzymes
function of lysosomes
attach to each other or membranes to break down contents in molecules to making them usefull
apoptosis
lysosomes programmed self destruction
