Cell ultrastructure Flashcards Preview

Tissues of the body > Cell ultrastructure > Flashcards

Flashcards in Cell ultrastructure Deck (22):
0

Define limit of resolution

The minimum distance at which two objects can be distinguished

1

What is the relationship between resolution and wavelength

-Indirectly proportional -> the lower the wavelength the higher the resolution

2

Why do electron microscopes have a higher resolution then light microscopes and which kind has the highest?

-EMs have a shorter wavelength as they use electrons whose wavelength depends on the accelerating voltage used
-Transmission EM have a higher resolution then Scanning EM as they have a shorter wavelength

3

Why do prokaryotes not exhibit compartmentalisation?

-They have an external membrane but no internal membranes, i.e. all the biochemical processes occur in the same compartment

4

What is the structure and function of cell membranes?

-Phospholipid bilayer with free mobile proteins as well as proteins anchored to the cytoskeleton
-Contains cholesterol
-Is amphipathic (hydrophillic and hydrophobic)
-Impermeable selective barrier
-adherence and recognition
-signal transduction
-has a glycocalyx for biochemical specificity

5

In what cells is the nucleus not present?

-RBCs
-Stratum Corneum
-Lens fibre cells

6

How is heterochromatin packaged?

-selenoids

7

How is euchromatin packaged?

-Nucleosomes

8

What is the function of the nucleolus?

-RNA synthesis and ribosomal assembly

9

What are the functions of the cytoskeleton?

-Cell morphology and movement (within the cell)
-Structural support
-To enable locomotion (Cilia)

10

Describe microfilaments of cytoskeleton and give an example of where they are found

-actin fibres twisted together
-contractile
-dymanic (assemble/deassemble)
-intestinal microvilli

11

Describe intermediate filaments of the cytoskeleton and give an example of where they are found

-Non-dynamic
-Supporting meshwork in cytoplasm
-nerve, neuroglia and keratin

12

Describe microtubules of cytoskeleton and give an example of where they are found

-Polymers of tubulin
-Hollow
-Motile
-Mitotic spindle/cilia

13

What is the function of the sER in the liver and mammory glands?

-Lipid synthesis

14

What is the function of the sER in the ovarys, testes and adrenal glands?

-Steroidogenesis

15

Name some hydrolytic enzymes found in lysosomes?

-Protease
-Nuclease
-Lipase

16

What are residual bodies?

-Lysosomes which have digested cellular contents but contain undigestible remnants

17

Why are lysosomes not broken down by the hydrolytic enzymes they contain?

-Lysosome membrane is heavily glycosylated for protection

18

Why does the golgi exhibit polarity?

-To cause proteins in vesicles to migrate from the convex face to the concave face of the golgi

19

Which two organelles are self-replicating and which contains its own genome?

-Peroxisome - doesn't have genome
-mitochondria - has genome

20

Where are there high amounts of peroxisome and why?

-Kidney tubules and parenchymal cells of liver for detoxification

21

Of what lineage is mitochondria?

-maternal