microscopy

Question 1

max resolution and magnifications of
light
tem
sem

Answer 1

light
-200nm
X1400

TEM
0.2nm
X500,000

SEM
10nm
X250,000

Question 2

define fluorescence

Answer 2

absorption + re-absorbtion of light

Question 3

how does a laser scanning confocal microscope work

Answer 3

specimen treated with fluorescent chemical (dye)
move single spot of light across specimen
causes fluorescence from components dyed
light from specimen filtered through pinhole aperture
only light radiated from very close to focal plane is detected

Question 4

nucleus

Answer 4

contains genetic info
controls metabolic activities
nuclear envelope (nuclear pores)

Question 5

nucleolus

Answer 5

produces ribosomes

made of proteins + RNA

Question 6

mitochondria

Answer 6

site of cellular respiration
produce ATP
double membrane 
-inner membrane highly folded to form cristae 
fluid interior called matrix

Question 7

name features f cytoskeleton and their functions

Answer 7

microfilaments
-movement

microtubules
-determine shape

intermediate fibres
-give strength

Question 8

functions of smooth and rough ER

Answer 8

smooth
-storage and production of lipids and carbs

rough
-synthesis and transport of ribosomes

Question 9

ribosomes

Answer 9

no membrane
made of RNA
site of protein synthesis

Question 10

describe the process of protein production

Answer 10

1- proteins synthesised of ribosomes on RER
2- packages into vesicles
3-vesicles move towards Golgi apparatus via cytoskeleton
4-visicles fuse with Golgi apparatus where proteins are structurally modified
5- vesicles carry proteins and fuse with cell membrane to release contents

Question 11

chloroplasts

Answer 11

PS
double membrane
fluid inside= stroma
internal membranes formed flattened sacs= thylakoids
thylakoids stacked together= granum

Question 12

describe prokaryotic cells

Answer 12

unicellular organisms
DNA not contained
no membrane bound organelles
smaller ribosomes
have flagella
cell wall made of peptidoglycan