organelles Flashcards
nucleus structure
surrounded by double membrane called nuclear envelope
nucleus function
-contains most of cells DNA
-materials enter and exit the cell through nuclear pores in the envelope (like mRNA)
what does mRNA instruct
protein synthesis
why does rough endoplasmic reticulum structure appear rough
because of the ribosomes on the surface
what does rough endoplasmic reticulum consists of
connected flat sacs called cisternae
function of rough endoplasmic reticulum
-where some proteins are synthesized
-proteins made by ribosome and inserted into rough ER
-phospholipids (from new cell membranes) are also made
smooth endoplasmic reticulum structure
-no ribosomes so smooth surface and no protein synthesis
-connected mostly by tubes
smooth endoplasmic reticulum function
lipids are made and broken (triglycerides and cholesterol)
-steroid hormones (estrogen and testosterone) are made
what does smooth ER detoxify
-detoxify organic (carbon-based) molecules like ethanol and some drugs and toxins
what does smooth ER store
calcium
where does golgi apparatus lie
between rough ER and cell surface
what does golgi complex consist of
a stack of flattened sacs (or cisternae)
think a stack of pita
functions of the golgi complex
receives, modifies, and ships material (proteins and lipids) to the final destination
-modifies proteins by adding sugars (oligosaccharides) and trimming those sugars
-small vesicles move proteins between organelles and sac of the golgi
where does the golgi complex ship proteins and lipids to
can ship out of cell, to cell membrane, or lysosome back to ER
lysosome structure
-not in the stomach of cell
-very few cells take in food and digest it, they take up building blocks
lysosome function
-break down ingested materials and cellular waste products like old/damaged organelles in ANIMAL cells
-digestive enzyme perform hydrolysis rxns on ingested materials
at what pH does hydrolysis in lysosome occur
about 4.5
what organelles are a part of endomembrane system
-nucleus
-rough ER
-smooth ER
-golgi complex
-lysosome
-vacuole
what is the general function of the endomembrane system
-synthesis of macromolecules
-sorting and shipping macromolecules
-storage
-breakdown of variety of larger substances
peroxisome structure
single membrane-bound vesicles
how does peroxisome break down molecule and why
with oxidation not hydrolysis
-removes electron from fatty acids, organic toxins, alcohol and drugs => makes soluble in water and non toxic
what happens when peroxisome removes H atoms and transfers them to O2
-makes hydrogen peroxide -> toxic to cell
-uses it to detoxify other compounds like alcohol
-catalase converts hydrogen peroxide to water and O2
what is vacuole structure
large version of vesciles
vacuole main function is in
storage
vacuole function in plant cells
perform lysome function and provides pressure to support plant stem and leaf (prevent wilting)
vacuole function om protisst
assist with water balance (too much water will in it will explode) and may be involved in digesting food taken in by phagocytosis
vacuole in animal cells
-used mostly for storage
-assist in killing and destruction of ingested material by phagocytic cells of immune system called a phagosome
vesicles structure
bud and fuse with other membranes
what is the function of vesciles
-move materials (like newly made proteins) between organelles and cell surface
-some store materials until directed to release them outside of the cell
-are involved in the transfer of macromolecules and large substances in and out of cells
mitochondria structure
inner and outer membrane
-have own circular DNA
mitochondria function
site of aerobic respiration
-lots of ATP
-energy comes from ingested food and glucose
chloroplast structure
outer and inner membrane
-have own circular DNA
chlorplast function
-site of photosynthesis
-make ATP and ADP
-use energy from the sun then the ATP helps make glucose
are ribosomes, cytoskeleton, and proteasomes found in eukaryotes or prokaryotes
both
structure of ribosomes
composed of RNA and protein
do eukaryotes and prokaryotes have the same ribosomes
-prokaryotes have different ribosomes than eukaryotes which is why humans can effectively take antibiotics
function of ribosomes
-synthesize protein
-use mRNA strand as template to make polypeptide chain
-perform dehydration synthesis reactions to join amino acids together
-function in the cytosol and on rough ER
cytoskeleton structure
structure determines function and functions come from the different fibers that make up the cytoskeleton
main functions of the cytoskeleton
-structural support (cells ability to stretch, if cant stretch then under stress it will rip)
-movement and endocytosis
-cell division
-intracellular (vesicle) transport
proteasome structure
peptidase enzymes in the core or middle area of the structure
proteasomes function
-degrade/hydrolyze misfolded, damaged, old and unnecessary proteins into small peptides
-hydrolysis reactions take place within proteasome to digest proteins
