Cell structure and organisation Flashcards
membranous structures in cytoplasm known as
internal cell membranes
organelle
specialised structure with a specific function inside a cell
eukaryotic cells having organelles means
-harmful chemicals concentrated in one area
-large SA for attachment of enzymes
-transport system inside the cell
size of animal cell
10-30 µm
size of plant cell
10-100µm
mitochondria size
1-10µm
how many membranes in mitochondria
2
inner and outer membrane fold inwards to form
cristae
cristae function
increase SA for attachment of respiration enzymes
matrix
solution of many compounds(proteins, lipids) and enzymes
DNA in mitochondria
small circle of DNA, allows replication and coding for proteins and RNA
mitochondria ribosomes
70s, used for protein synthesis
mitochondria function
produce ATP in aerobic respiration in either matrix or inner membrane
high SA:V ratio due to being cylinder= reduces diffusion distance
endoplasmic reticulum
extensive system of parallel double membrane forming flattened sacs with cisternae
connected with nuclear envelope so allows transport
cisternae
interconnected, fluid filled spaces between flattened sacs
rough er
ribosomes outside and transports proteins made there
rough er function
present in protein synthetic cells, eg. amylase makers
smooth er
no ribosomes
smooth er function
synthesis and transport of lipids and steroids
cells with large quantities of carbs, proteins and fats have
an extensive ER
ribosome sizes in eukaryotic vs prokaryotic
70s in prokaryotic
80s in eukaryotic- single or attached to membranes on RER
ribosome structure
1 large, 1 small subunit assembled in the nucleolus from RNA and protein
where are ribosomes found
free in cytoplasm or bound to er
ribosome function
protein synthesis: site of translation, mRNA and tRNA are used to assemble pp chain
golgi apparatus structure
compact version of er
series of dynamic flattened sacs which package proteins for secretion
dynamic flattened sacs of golgi
pp vesicles pinch from RER and fuse with the membranes
golgi apparatus secretion
at the other end of the GA, vesicles are pinched off and carry proteins to fuse with membranes, secreting proteins
golgi apparatus function
-producing secretory enzymes and carbs
-transport and store lipids
producing glycoprotein
-forming lysosomes
lysosome function
small, single celled temporary vacuoles that isolate potentially harmful digestive enzymes
they are released when the cell needs to recycle organelles or digest material
centrioles structure
in all animal cells outside the nucleus
2 rings of microtubules= hollow perpendicular cylinders, known as centrosome
centriole function
organise the microtubules that make the spindle fibres in cell division
chloroplasts
highly concentrated in the palisade mesophyll cells bellow upper surface of plant
aid with photosynthesis
chloroplast structure
double membrane- chloroplast envelope
stroma- fluid filled with some starch and liquid
thylakoids- flattened sacs stacked in pieces called grana, contains
pigments
70s ribosomes+circular DNA
vacuoles in plants
plants- large consisting of fluid filled, single membrane sac
—-> contains cell sap
supports soft plant tissue
cell sap content
vitamins
minerals
amino acids
glucose
pigments
vacuoles in animals
small temporary vesicles formed during phagocytosis
nucleus size
10-20µm
nucleus structure
spherical, contains DNA and protein
double membrane= nuclear envelope
nucleoplasm- contains chromatin
nucleolus- 1+ spherical bodies
DNA+ protein
chromosomes
chromatin
coils of DNA bound to protein which condense to form chrosomes
nuclear envelope adaptation
pores allow large molecules like mRNA and ribosomes to enter
nucleolus function
site of formation of rRNA
what organelles are only in plants
**chloroplasts
**plasmodesmata
tonoplast
**cell wall
**large permanent vacuole
plants and animal cells both have
-cell surface membrane
-membrane bound nucleus
-nucleolus
-chromatin
-mitochondria
-RER and SER
-ribosomes
-golgi body
what organelles are only in animal
lysosome
centriole
1 protein production: DNA uncoils and is used to make
mRNA
2 protein production: what allows mRNA to escape the nucleus
nuclear pore
3 protein production: what is created to help ribosome synthesis
rRNA
4 protein production: —- attaches to ribosomes to help create protein
mRNA
5 protein production: rough endoplasmic reticulum…
packages proteins into vesicles
6 protein production: what further packages proteins by….
Golgi apparatus packages by modification
7 protein production: vesicle is transported towards
cell membrane
8 protein production: vesicle leaves the cell, also known as
exocytosis
9 protein production: what provides atp
mitochondria
prokaryotes have no nucleus or internal membranes so have no
membrane bound organelles
prokaryotes are
unicellular and acellular
eukaryote
organism containing cells with membrane bound organelles with DNA in the nucleus
site of aerobic respiration in prokaryotes
plasma membrane
prokaryote size vs eukaryotes
pro- 1-10 micrometers
eu- 10-100 micrometers
prokaryote ribosomes vs eukaryotes
pro- 70s free in cytoplasm
eu- 80s free or attached to er
mesosomes and function
infoldings of the plasma membrane that increase the sa, used for respiration
capsule prokaryotic
protective outer layer against phagocytosis
plasmids prokaryotic
small circular DNA with genes for antibiotic resistance
viruses are…
non living and acellular
very small
use a host cell to reproduce
use DNA/RNA for replication
viruses are obligate parasites, this is because
they dont have the metabolic capabilities to create their own energy or dna so have to use a host
virus structure
core of nucleic acid surrounded by a protein coat and SOME have an outer lipoprotein envelope, e.g., HIV
virus diseases in humans, plants, birds and others
human: flu, chickenpox, cold, ebola
plants: cauliflower mosaic virus
birds: bird flu
others: cowpox, swine flu
comparisons between eukaryotes, prokaryotes and viruses can be seen on
electron micrograph images
cell theory: 3 points
all living organisms are multicellular
cell is the basic unit of life(structure, organisation and function)
cells can only arise from pre-existing cells
differentiation
development of a cell into a specific type
