cc2 - cell structure + organisation Flashcards
eukaryotic cell
cell containing true nucleus + membrane bound organelles
structure of nucleus
surrounded by nuclear envelope - semi permeable + double membraned
nuclear pores - allow substance to enter/exit
dense nucleolus - (made of RNA + proteins) assembles ribosomes
function if nucleus
contains DNA coiled around chromatin into chromosomes
coordinates cellular activity
chromatin
DNA-protein complex in eukaryotic cells
structure of mitochondria
surrounded by double membrane, mitochondrial envelope
folded inner membrane forms cristae (large SA)
fluid matrix contains mitochondrial DNA, respiratory enzymes, lipids + proteins
function of mitochondria
site of aerobic respiration producing ATP
structure of endoplasmic reticulum
series of flattened membrane bound sacs (cisternae) within cytoplasm, continuous w/ nuclear envelope
two types: rough er + smooth er
function if smooth er
lipid synthesis
function of rough er
many ribosomes attached for protein synthesis + transport
structure of ribosomes
made of rRNA and proteins
found free in cytoplasm or associated w/ RER
function of ribosomes
protein synthesis (translation)
- large subunit joins amino acids
- small subunit reads RNA
structure of golgi body
planar stack of membrane bound organelles, flattened sacs
cis face aligns w/ rer
molecules processed in cisternae
vesicles bud of trans face via exocytosis
fuction of golgi body
modifies + packages proteins for export
synthesises glycoproteins
structure + function if lysosomes
fluid filled vesicles surrounded by single membrane, contains enzymes
role in phagocytosis, digest unwanted materials in cytoplasm
structure of centrioles
cylindrical
organised into microtubules in a 9+0 pattern
found in pairs in centrosomes
function of centrioles
migrate to opp poles of cells in prophase
involved in organisation of spindle fibres
structure of chlorplast
disc shaped surrounded by double membrane
thyalkoids - flattened discs stacked to form grana
grana - contain photosystems w/ chlorphyll
intergranal lamellae - tubes attach thylakoids in adjacent grana
stroma - fluid filled matrix
function of a chlorplast
site of photosynthesis
structure of permanent vacuole in plants
surrounded by single membrane - tonoplast
contains cell sap (mineral ion, water, enzymes, soluble pigments)
function of permanent vacuole in plants
controls turgor pressure
water storage
isolates harmful waste producst
maintains ph
plasmodesmata
microscopic channels between plant cell wall that facilitate communication and symplastic transport
prokaryotic cell
type of cell not containing any membrane bound organelles or a true nucleus
structure + function of flagella in prokaryotic cells
long whip like protrusion made of flagellin
rotates to propel organism
sensory organ
how is genetic information stored in prokaryotes
plasmids - small rings of DNA that carry non essential genes, exchanged between bacterial cells via conjugation
loop of DNA - circular DNA stored in nucleoid region of cell
structure + function of pili in prokaryotic cells
hair like microfibres made of pilin that extend through cell wall
enable attachment of bacteria to each other + to other surfaces
structure + function of mesosome
infolds of cell memrbrane
increase SA of cell, aiding cellular respiration
function of capsule in prokaryotic cells
protective slimy layer
helps cell retain moisture + adhere to other surfaces
organelles found in both eukaryotic + prokaryotic cells
cell membrane
cytoplasm with form of cytoskeleton
ribosomes
contrast eukaryotic + prokaryotic cells
prokaryotic:
small, unicellular
no membrane bound organelles
circular DNA, not associated with proteins
70s ribosomes
reproduce by binary fission
peptidoglycan cell wall
eukaryotic:
large, often multicellular
contain membrane bound organelles + true nucleus
linear chromosomes associated with histones
80s ribosomes
reproduce by sexual or asexual reproduction
cellulose (plant), chitin (animal) cell wall
contrast eukaryotic plant + animal cells
plant cell:
cellulose cell wall
large permanent vacuole
contains chlorplasts
no pseudopodia
animal cells:
no cell wall
small temporary vacuoles (vesicles)
no chloroplasts
some may have pseudopodia
light microscope
uses series of lenses to magnify visible light reflecting off a specimem
magnification
number of times bigger an image appears compared to size of specimen
how magnification of image is calculated
size of image
magnification = ————————
size of specimen
cell theory
cell is fundamental unit of all life forms
new cells can be formed from existing cells
cells contain genetic material which can be transferred to daughter cells
virus
non living microorganism that consists of genetic material surrounded by a protein husk
how viruses differ from prokaryotic + eukaryotic cells
virus:
non living
smaller + simpler in structure
genetic material in form of DNA or RNA
can only reproduce within a host cell
no ribosomes
prokaryotic + eukaryotic cells:
living
larger + more complex structure
genetic material in form of DNA
independent cell division, sexual or asexual
contain ribosomes
how are multicellular organisms organised
cells make tissue
tissues make organ
organs make organ system
tissue
group of cell working together to carry out specific function
organ
group of tissues working together to carry out specific function
organ system
group of organs working together to carry out specific function
