Lecture 2

Question 1

Bacteria

Answer 1

Gram pos: stained violet in gram reaction, thick multilayered peptidoglycan, teichoic acid often present, periplasmic space and outer membrane absent, virtually no lipopolysaccharide (lps) low lipid/lipoprotein content flagellar 2 ring basal body structure, produce exotoxins, resist physical disruption and drying, cell wall disruption by lysosomes common, inhibited by basic dye, susceptible to ionic detergents

Gram neg: can be decolourised to accept counter stain (safranin) and stained red. Thin peptidoglycan layer, no teichoic acid, periplasmic space and outer membrane present, high lipopolysaccharide and lipid/lipoprotein content (due to outer membrane) 4 ring basal body flagellar structure, produce endotoxin, low resistance to physical disruption low disruption from cell wall lysosomes, low resistance to drying/low inhibition by basic dyes, unsusceptible to anion detergents

Pathogenic activity associated w/periplasmic space

Cytoplasmic membrane encloses nucleus

Question 2

Organelles

Answer 2

Lipid bilayer membrane bound compartments containing specialised environments for biochem reactionse.g. diff salt or pH level to improve efficiency of reaction

Nuclear membrane: contains/organised genome and RNA synthetic machinery

ER - protein synthesis, folding & secretion

Lysosomes- degradation/recycling of unwanted/worn out components

Golgi - modify/package/deliver proteins

Mitochondria/ chloroplasts - self contained energy production

Question 3

Nucleus terms

Answer 3

Euchromatin aka open chromatin - not tightly packed
Heterochromatin - tight packed chromatin
Cytosol- aqueous part of cytoplasm
Lamina - double membrane

Question 4

Endoplasmic reticulum

Answer 4

Smooth: fatty acid and lipid synthesis for cell membrane

Rough: protein synthesis/modification

Abnormal ER and consequent protein tracking cause craniofacial abnormalities - facial structure mutation

Question 5

Golgi apparatus

Answer 5

Protein modification - glycosylation

Question 6

Peroxisome

Answer 6

Fatty acid oxidation using hydrogen peroxide.

adrenoleukodystrophy is an X linked
Recessive peroxisomal disorder affecting white matter in the brain and adrenal cortex

ALDP functions as a transporter of VLCFA from the cytosol into the peroxisome. A deficiency in ALDP blocks this transport, which results in impaired degradation of VLCFA and a subsequent build-up of VLCFA in cells, tissues and organs.

Question 7

Endocytosis

Answer 7

Endosomes transport macromolecules into the cell, lysosomes digest waste as endosomes from external or autophagy from internal.
Bacteria are engulfed by phagocytosis into a phagosome to a lysosome

Question 8

Lysosome disease Tay Sachs

Answer 8

Defect in lysosomes ability to destroy a lipid leading to build up of fats in cell resulting in cell death