Cells 1, 2 & Cell Histology

Question 1

Apoptosis

Answer 1

Normal programmed cell death

Question 2

Necrosis

Answer 2

Cell death occurring due to disease/infection

Question 3

Communication between cells x4

Answer 3

• Endocrine (hormones)
• Paracrine (more local signalling)
• Neuronal (neurotransmitters)
• Contact dependent (signalling, receptors)

Question 4

Plant & animal cells - size

Answer 4

10-100 micrometres

Question 5

Bacteria cells - size

Answer 5

1-10 micrometres

Question 6

Fundamental properties of cells x4

Answer 6

• Act as independent units
• Come from pre-existing cells
• Finite lifetime
• Can change/adapt/respond

Question 7

Euchromatin vs Heterochromatin

Answer 7

Euchromatin = active genetic material, site of transcription
Heterochromatin = inactive genetic material, denser

Question 8

Synthesis in free ribosomes

Answer 8

• Proteins then go either to other organelles, or function in cytoplasm

Question 9

Synthesis in rER

• How occurs
• What happens in rER

Answer 9

• A signal sequence on mRNA signals ribosomes to tether to ER
• Proteins released straight into rER
• Proteins are folded

Question 10

Secretion pathway

Answer 10

rER –> Golgi apparatus –> cell surface

Question 11

Parts of Golgi

Answer 11

• CIS –> reception site
• MEDIAL
• TRANS –> vesicles are released

Question 12

Folding of proteins

Answer 12

• In rER

- If not correctly folded, disposed of

Question 13

Phagocytosis

Answer 13

Endocytosis of larger particles

Question 14

Pinocytosis

Answer 14

Endocytosis of molecules (non-specific)

Question 15

Receptor mediated endocytosis

Answer 15

Specific form of pinocytosis

Question 16

Uptake pathway

Answer 16

Cell surface –> endosomes –> lysosomes

Question 17

Uptake pathway (pH)

Answer 17

• Cell surface –> neutral
• Endosomes –> mildly acidic
  Lysosome –> acidic

Question 18

Lysosomes are acidic as…

Answer 18

Better at degradation

Question 19

Autophagy

Answer 19

When portions of the cell are ‘walled off’ and digested in the lysosome

Question 20

Plasma membrane function x3

Answer 20

• Motility
• Adhesion
• Ion transport

Question 21

ER function

Answer 21

Membrane synthesis

Question 22

Golgi apparatus function

Answer 22

Modification (e.g. adds phosphates) & sorting of secretory proteins into vesicles

Question 23

Lysosome function

Answer 23

Degradation of internalised material

Question 24

Microtubule function x2

Answer 24

• Vesicle tracks that move organelles

- Cell division

Question 25

Microfilament function

Answer 25

Generates contractile force

Question 26

Intermediate filament function

Answer 26

Strength, support

Question 27

Vesicle transport - how - how mediated

Answer 27

Occurs along microtubule 'tracks' | - Mediated by motor proteins

Question 28

Centrosome - function - structure

Answer 28

- Centre for organising microtubules | - 2 centrioles, each = 9x microtubule triplets

Question 29

Advantage of compartmentalisation

Answer 29

Can regulate internal conditions for necessary reactions

Question 30

Clathrin - what - function - advantage

Answer 30

- 'scaffold' coat - helps form & seal vesicle - clathrin coated pit formed, concentrates receptors for endocytosis

Question 31

Endosymbiosis

Answer 31

Non-nucleated cells took up a bacterium --> replicated --> provided ATP --> cell survived by natural selection

Question 32

Mitochondria & DNA - & example

Answer 32

Have their own DNA from MATERNAL lineage | - Defects can cause metabolic disease

Question 33

Light microscopy samples - frozen - +ves - -ves

Answer 33

- Faster | - Not easily preserved, less clear

Question 34

Light microscopy samples - embedded in paraffin wax - +ves - -ves

Answer 34

- Preserved, clearer | - Long process, can damage e.g. proteins

Question 35

Haematoxylin - stains - colour - example

Answer 35

- -ve charged (DNA, RNA) - Purple - e.g. rER

Question 36

Eosin - stains - colour

Answer 36

- Proteins | - Pink

Question 37

Toluidine blue - stains - colour - example

Answer 37

- Nissl susbtance - Blue - e.g. rER

Question 38

PAS - stains - example - PAS +ve?

Answer 38

- Saccharide structures of glycoproteins - e.g. mucin - A cell containing significant glycoproteins

Question 39

Sites of chromatin condensation x3

Answer 39

- Inactive genetic material - Chromosomes of mitosis - Programmed cell death

Question 40

Chromatin condensation in apoptosis

Answer 40

Condensation = more disorganised

Question 41

Plasma membrane & histology

Answer 41

- Not visible in light microscopy | - BUT membrane assoc. structures stain

Question 42

Cilia - contain... - function

Answer 42

- Contain microtubules | - For movement & sensing

Question 43

Microvilli - contain... - function

Answer 43

- Contain actin filaments | - For absorption