1) Cell Structure Flashcards
What is resolution ?
ability to distinguish between 2 objects very close together
what is magnification ?
number of times greater that an image is than the actual object
compare the resolution of a light microscope with an electron microscope
light microscope = 200 nm
electron microscope = 0.2 nm
compare the magnification of a light microscope with an electron microscope
light microscope = upto 1500
electron microscope = upto 500,000
compare the radiation used of a light microscope with an electron microscope
light microscope = light rays
electron microscope = beam of electrons
size and function of the cell surface membrane
(7nm)
- controls the movement of substances into and out of the cell
- cell signalling
- cell recognition
- cell to cell adhesion
- protects organelles from damage/pathogens (BARRIER BETWEEN CYTOPLASM & EXTERNAL ENV)
function of the nucleus
- contains DNA
- coding for the synthesis of proteins
structure & function of the rough ER
- covered with ribosomes.
- transport PROTEINS synthesised on the ribosomes.
structure & function of the smooth ER
- no ribosomes.
- synthesises and transports LIPID molecules. (membrane, vesicles formed, cisternae)
function of the golgi body
- synthesises glycoproteins.
- packages proteins for export from the cell.
function of the mitochondria
produces ATP (adenosine triphosphate) by aerobic respiration
location and function of ribosomes
- free in the cytoplasm / attached to the Rough ER.
- site of protein synthesis.
where are 70S ribosomes found ?
Prokaryotes (chloroplasts, mitochondria, bacteria)
where are 80S ribosomes found ?
Eukaryotes
function of lysosomes
(in cytoplasm) digests unwanted materials and worn-out organelles
function of microtubules
(in cytoplasm) involved in the movement of organelles
location of centrioles
- animal cells
- next to the nucleus
- region called centrosome
structure & function of centrioles
- made of protein microtubules
- formation of the spindle during nuclear division
function of chloroplasts
- contain chlorophyll
- site of photosynthesis
function of cell wall
- supports the plant cell and maintains its shape
what is the cell wall made of in plants / fungi / bacteria ?
plants - cellulose
fungi - chitin
bacteria - peptidoglycan
what is the plasmodesmata ?
pores in the cell wall
function of the plasmodesmata
allows movement of materials between cells
function of the vacuole
- holds water
- contains various solutes (sugars, minerals, salts, pigments)
what is the membrane that surrounds the vacuole?
tonoplast
function of the tonoplast
controls exchange of materials between the vacuole and the cytoplasm
give 5 differences between animal and plant cells
- plant cells have cellulose cell walls, animal cells do not.
- plant cells have chloroplasts, animal cells do not.
- plants cells have a large permanent vacuole, animal cells do not.
- plant cells do not have a centrosome but animal cells do.
- carbohydrate storage product in plant cells is starch, whereas in animal cells it’s glycogen
what is the general size of a prokaryotic bacterial cell?
1-5 micrometres diameter
what is the function of the flagellum
locomotion
function of the capsule
additional protection
what is a plasmid
a small circle of DNA
function of pilli
for attachment to other cells or surfaces ; involved in sexual reproduction
difference between DNA in eukaryotes & prokaryotes
–> eukaryotes - it has proteins attached and is linear.
–> prokaryotes - naked and is circular
give 5 differences between Eukaryotic cells & Prokaryotic cells
- eukaryotic are large , prokaryotic are small.
- eukaryotic have a nucleus, prokaryotic do not.
- eukaryotic has linear DNA, prokaryotic has circular DNA.
- eukaryotic cell wall is made of cellulose, prokaryotic is made of peptidoglycan.
eukaryotic has membrane bound organelles, prokaryotic does not. - eukaryotic has 80S ribosomes, prokaryotic has 70S ribosomes.
what does peptidoglycan contain?
peptides/amino acids
list 3 main features of a virus
- non-cellular
- has nucleic acid core (DNA/RNA)
- a capsid made of protein
what is the envelope of viruses made of ?
phospholipids
convert 1 mm into micrometres
1 x 1000 = 1000 micrometres
convert 1 micrometre into nanometres
1 x 1000 = 1000 nanometres
state 3 organelles that have a double membrane
- mitochondria
- chloroplast
- nucleus
how is the structure of the cell surface membrane a fluid mosaic ?
fluid : phospholipid molecules diffuse/ move about
mosaic : protein scattered
