session 3-cell ultrastructure and organelles

Question 1

what is the limit of resolution for an electron microscope?

Answer 1

-0.002nm

Question 2

what is an endosome, peroxisome and cytosol?

Answer 2

• endosome=membrane bound. assists in transport pathway from plasma membrane to lysosome
• peroxisome=small organelle in cytoplasm which contains catalase and oxidases
• cytosol=aqueous part of cytoplasm

Question 3

in terms of the phospholipid bilayer, what does amphipathic mean?

Answer 3

having both hydrophilic and phobic parts

Question 4

what is the limit of resolution for light microscopes?

Answer 4

-0.2um

Question 5

what is the glycocalyx?

Answer 5

cell ‘coat’ made up of oligosaccharides (a couple of monosaccharides) and polysaccharide side chains on outside of plasma membrane-side chains give cell SPECIFICITY

Question 6

give 3 functions of the plasma membrane (plasmalemma)

Answer 6

• selective permeability
• exo/endocytosis
• signalling
• transport of materials

Question 7

what is the role of the nucleus?

Answer 7

• stored cells DNA
• CO ORDINATES cell activities-metabolism,mitosis, protein synthesis
• contains chromatin

Question 8

what is chromatin?

Answer 8

-unstructured DNA that will organise to form chromosomes in mitosis

Question 9

what is the nuclear envelope attached to?

Answer 9

-a network of tubules (AKA endoplasmic reticulum)

Question 10

what does the nucleolus synthesise?

Answer 10

ribosomes

Question 11

name 3 places the smooth ER is found

Answer 11

liver, mammary glands, ovaries/testes

Question 12

when vesicles bud off from the RER to be moved to the golgi, what face do they attach to?

Answer 12

-cis face of golgi (convex side) then to concave (trans) side

Question 13

what is the function of the golgi?

Answer 13

-modify, package,sort and concentrate proteins

Question 14

what happens to some vesicles?

Answer 14

become lysosomes

Question 15

where are lysosomes generated?

Answer 15

golgi

Question 16

what do you call lysosomes that have digested their contents but contain indigestible remnants?

Answer 16

residual bodies

Question 17

what is produced in peroxisomes?

Answer 17

-H2O2

Question 18

what enzyme uses h2o2 to oxidise things such as phenols, formaldehyde and alcohol?

Answer 18

catalase

Question 19

what are the 2 main substrates of ATP production in the mitochondria?

Answer 19

glucose and fatty acids

Question 20

which 2 places would you find many mitochondria?

Answer 20

• liver

- skeletal muscle cells

Question 21

in terms of mitochondria, what does female lineage mean?

Answer 21

-inheriting all mitochondria from mother

Question 22

name the 3 types of cytoskeleton (maintains or changes cell shape)

Answer 22

-microfilaments, microtubules and intermediate filaments

Question 23

give 3 roles of the cytoskeleton

Answer 23

• supports plasma membrane and organelles
• helps constituents move
• helps muscles contract

Question 24

what is the diameter of microfilaments?

Answer 24

5nm

Question 25

what are microfilaments made up of?

Answer 25

-2 strings of actin twisted together (associated with ATP)

Question 26

what is the diameter of intermediate filaments?

Answer 26

10nm

Question 27

where would you find intermediate filaments?

Answer 27

nerves and some epithelia-form tough network

Question 28

what are microtubules made up of?

Answer 28

-13 alpha and beta subunits form wall of hollow microtubules

Question 29

where are microtubules found?

Answer 29

-near structures that move e.g. nerve fibres, mitotic spindle, cores of cilia and flagella

Question 30

Can mitochondria divide on their own because they have their own genetic info?

Answer 30

Yes

Question 31

What is the role of the nucleolus?

Answer 31

Make rRNA