003 Cellular Homeostasis

Question 1

glucose is a …… molecule and therefore cannot pass through highly hydrophobic plasma membrane

Answer 1

polar membrane

special transporters are required

Question 2

how many glucose transporters are there are what are the main ones

Answer 2

14 glucose transporters 
main ones (GLUT1-4)

Question 3

two types of glycolysis

Answer 3

aerobic (takes place in mitochondria)

anaerobic (converts to lactate)

Question 4

the body relies on ….. to synthesize the glucose from pyruvate and other non carbohydrate and carbohydrate carbon molecules

Answer 4

gluconeogenesis

Question 5

helps newly synthesized proteins ensure they are folded correctly

Answer 5

chaperones and enzymes

Question 6

help to localize and degrade proteins as necessary

Answer 6

translocation machineries, proteasomes and autophagic activities

Question 7

chaperones

Answer 7

HSP 60 and 70

forms irregular aggregates if there is no chaperone

Question 8

translocators

Answer 8

takes up the proteins and brings them to the correct location
The pre proteins are recognized by receptors TOM20 and 22 on mitochondrial surface and are translocated across outer membrane by TOM40 channel

Question 9

transcription factors

Answer 9

trans-acting proteins that regulate transcription of genes across chromosome
have DNA binding domain
can either promote or repress transcription of target genes

Question 10

post translational modifications are crucial to proteins

Answer 10

function, regulation, sub cellular location, interaction with other molecules, degradation

Question 11

4 important post translational protein modifications

Answer 11

acylation
glycation and glycosylation
phosphorylation
ubiquitination

Question 12

acylation

Answer 12

attachment of an acyl group (fatty acids)

Question 13

glycation and glycosylation

Answer 13

non enzymatic attachment of glucose (glycation), or enzymatic attachment of a number and variety of sugars (glycosylation)

Question 14

phosphorylation

Answer 14

attachment of a phosphate group (PO4)3- via an ester bond

Question 15

ubiquitination

Answer 15

attachment of a small protein called ubiquitin

Question 16

intracellular proteolytic control

Answer 16

lysosomal degradation

proteasomal degradation

Question 17

extracellular proteolytic control

Answer 17

proteins are degraded by extracellular proteolytic enzymes as needed
they are often secreted as inactive precursors (zymogens)

Question 18

organelle homeostasis is mostly controlled by

Answer 18

cell membranes

Question 19

autophagy (autophagocytosis)

Answer 19

basic catabolic mechanism that involved cell degradation of dysfunctional cellular component
ensures the synthesis, degradation, and recycling of cellular components

Question 20

mitochondrial matrix is site of

Answer 20

beta oxidation of fatty acids
TCA cycle
urea cycle
storage of Ca2+

Question 21

two ways in which mitochondria maintains its homeostasis

Answer 21

1. fusion

2. fission

Question 22

fusion

Answer 22

helps mitigate stress by mixing the contents of partially damaged mitochondria as a form of complementation
(two sick mitochondria fuse together to form one healthy mitochondria)

Question 23

fission

Answer 23

to create a new mitochondria
the remove the damaged mitochondria
facilitate the apoptosis
(segregation of dysfunctional mitochondria)

Question 24

mitophagy

Answer 24

elimination of damaged mitochondria (use lysosome)