cell structure Flashcards
what is the difference between prokaryotes and eukaryotes?
> prokaryotes have no nucleus and membrane bound organelles _ eukaryotes do.
prokaryotes are significantly smaller in size compared to eukaryotes
describe the structure and function of the nucleus
> surrounded by nuclear envelope - nuclear pores allow mRNA out
connected to endoplasmic reticulum (ER)
contains genetic info and controls the centre of the cell
produces mRNA protein synthesis
describe the structure and function of mitochondria
> has double membrane
where cellular respiration occurs and ATP is generated
describe structure and function of lysosomes
> membrane sac of hydrolytic enzymes
acidic envt for its enzymes for digestion
its a digestive organelle - hydrolysis of macromolecules
describe the structure and function of ribosomes
> two subunits made of rRNA and proteins
either free in cytosol or attached to ER
protein synthesis
describe structure and function of endoplasmic reticulum (ER)
> two types: rough and smooth
membrane synthesis and metabolic processes
describe structure and function of golgi apparatus and vesicles
> stacks of flat membrane sacs
synthesis, modification and secreting of cell products
describe the structure and function of cell surface membrane
> made of lipids and proteins
controls the passages of substances in and out of the cell
list the seven components of the structure of a chloroplast
inner membrane
outer membrane
inter membrane space
stroma lamellae
thylakoid
granum
stroma
what is the thylakoid and what’s it for?
> flattened fluid-filled sacs/discs
the thylakoid allows substances in and out of the chloroplast
these thylakoids stack up to form structures known as grana
thylakoid membranes have a pigment on their outer surface called chlorophyll which absorbs light during photosynthesis
what are grana connected by?
grana are connected by membraneous channels called stroma lamellae which ensure the stacks of thylakoids are connected but distanced from each other.
what is the fluid found in the inner membrane of chloroplasts called? where else can it be found?
stroma - the space outside the thylakoid space is also called the stroma.
what is found floating in the stroma?
DNA
ribosomes
strach granules
proteins
what’s the structure and function of the membranes of a chloroplast
> inner membrane - forms a border to the stroma, it regulates the passage of materials in and out the chloroplast - fatty acids and lipids are synthesised.
> outer membrane - its a semi porous membrane and is permeable to small molecules and ions which diffuse easily (not permeable to larger proteins).
> inter membrane space - a thin space between the inner and outer membrane.
what is the function of the pili?
reproduction of prokaryotic cells, attach to other bacterial cells
